R. A. PATTERSON ASSOCIATES · 2018-08-02 · This Manual defines a blowout prevention strategy for...

i R. A. PATTERSON & ASSOCIATES

.M.El'-IOR.ANDTJM Date: November 9, 1992

TO: Manabu Tagamori-DOWALD

SUBJECT: BOP Manual draft - Suggested reviewers REVISED

A REVISED listing of suggested reviewers for the draft BOP Manual, is as follows:

Bill Rickard

Paul Stroud

Louis E. Capuano, Jr.

Allan Frazier

Jerry Hamblin

Pete Wygle

Bill Teplow

Bill Craddick

Gary Hoggatt

Dunn, James C.

Gene Anderson

Robert Wagner

1

PGV Consultant

PGV Consultant

ThermaSource, Inc. P. 0. Box 1236 Santa Rosa, CA 95402

Tecton Geoligic P.O. Box 1349 Healdsburg CA 95448

UNOCAL Geothermal Division P. 0. Box 6854 Santa Rosa, CA 95406

California DOG 1000 South Hill Rd. Ventura CA 93003-4458

1518 Excelsior Oakland CA 94602

Barnwell Industries 2828 Paa St. Ste 2085 Honolulu HI 96818

TRUE Geothermal Drilling P. 0. Box 2360 Casper WY 82602

Sandia National Laboratories P. 0. Box 5800, Division 6252 Albuquerque NM 87185

Nabors Loffland Drilling Co. P. 0. Box 418 Bakersfield CA 93302

PARKER Drilling Co. 8 East Third St. Tulsa OK 74103

Richard Thomas

Bowen E. Roberts

Geothermal Officer California DOG 801 K Street - MS 22 Sacramento CA 95814-3530

ARCO Oil & Gas 4550 California Ave. Bakersfield CA 93309

We have not included any Hawaii State or County officials, as many of these will likely see the draft anyway. A possible draft cover letter is attached.

If there are any questions about the above list, or if we can provide more information on possible reviewers, please call.

2

DEPARTMENT 0~ LAND AND NATt..JR.A..!_. RESOURCES

DRAFT TRANSMITTAL LETTER

(DATE)

Mr. __________________ __

Dear

As a result of recommendations made in the "Independent Technical

Investigation of the Puna Geothermal Venture Unplanned Steam Release",

of June 12-13, 1991, the Department of Land and Natural Resources,

State of Hawaii, contracted for a preparation of the Hawaii Geothermal

Blowout Prevention Manual.

This document is intended to provide clear guidance that both

regulatory agencies and geothermal development organizations can use

for plans and procedures regarding blowout prevention in their Hawaii

drilling activities. The enclosed draft of the Manual is designed to

improve operational and safety procedures for ALL geothermal drilling

activities in the State.

A draft copy of this Manual is enclosed for your information,

review, and comment; we would appreciate your review and comments on

the draft so that the final Manual will reflect the experiences and

thoughts of the industry and other regulatory agencies.

In order to maintain our production schedule, we would appreciate

your forwarding comments to us by ____ (date) ____ . Your comments, and

others that we may receive, will be considered in the preparation of

the final document.

Your help to the State of Hawaii in this review is appreciated;

we hope to manage the Hawaii geothermal resources so that the best

possible development practices are followed at all times.

Sincerely,

DRAFT

HAWAII GEOTHERMAL BLOWOUT PREVENTION MANUAL

DRAFT

I. INTRODUCTION

. The prevention of an uncontrolled well flow, commonly known as a "blowout", is .£' )IL.f..:~( •iM P.off.::(>'\d!~ fr\ 1mportant consideratioii for geothermal oper:-ators, drilling crews, state and county,.,

:I"'vl ... s~-r w•h1 h.:(~ ~o~e""- ~ cc..<.ts.e o'r ct regulators, and the general public. ~eotner1mal well blowouts qpe' noe'-a!!seeiateeJ-~

3 a-t d ~ rt)ef no I -exi Sf; significant number of fatalities, Ror is t.here a practical. danger of fire, as in petroleum

drilling. However, blowout incidents may have af'~~X~t on surface and subsurface

environments, cause resource waste, and develop unfavorable public perceptions of

geothermal activity. These concerns ~t:>rovide powerful incentives to operators and

regulators to minimize the risks of a blowout.

This Manual has been developed to promote safety and good resource

management by discussing and describing blowout prevention as it can best be

practiced in Hawaii.

intended to supplement State and County regulations, especially those pertaining

directly to drilling permits and operations~ ...blowout prevention pradice~, espeeie:l1y -when modifications are Pequir ed due to

clrattges il"' erillil"' 9 een e=itiott~

This first edition of the Blowout Prevention .. Manual is a likely candidate for

revision as more drilling experience and information is gathered in the exploration and

development of Hawaii's geothermal resources.

1 Department of Land and Natural Resources (DLNR) Title 13, Subtitle 7. Water and Land Development; Chapter 183.

BOPINTROOUCTION/RAP/October 13, 1992 1-1

DRAFT

I I . SCOPE

The material in this Manual has been extracted from ~ key information

sources in order to present a complete and accurate review of the practices of

geothermal well control in Hawaii. In developing this Manual, a careful review of ---r"'-e K E ~ "'Z

:!ec-k\tefWial drilling to date in the Kilauea East Rift Zone (KERZ) was conducted.~ is where

nearly all Hawaii geothermal drilling has taken place, and is where most experts believe

the geothermal resource~ "Yill be developed. . /1,4~a,l J.dc~/ irtf••i1b1fy cf 1hAi· e.-dt q~ .:\ <.ur 1qUL1 fr-r.~( ~-"le~{ ar'l!!lf -fh"'"'"'"""'" &:tf'tee eaeh prospesti¥-e -geotl-rerFRa.l.-ar ea ~ HI-I~• ~e world has pro'V'en

to have its own characteristics in terms of drilling conditions, resource chemistry,

geology, e ., e ral · 1 · y 1 · 'q '. While fent<ll ri .. il4 .. ·d.,.e1 dP eJCtiJ. ~e .... qe~~# welt f:t

c..t~;1.ttll.t-i~ -tiris" may be true in detail, \:he1 e a.rli same similaritili&, and va.111ablQ le~~o1 13 te be

-learAed, From geutl1e1mal dsvelop111ellt activities Llla'e-arelocated in or nearby, active

volcanic areas. Thus, it has been helpful to briefly review well control techniques and

experiences from other similar volcanic areas around the world.Some of the information

gathered may have an influence on ~tttq,wa#---sit.uatiefrr----·jiF flr...~,;;.,t A,; 1/;,~i· ... Jl-· " ;/. In order to review the experiences in Hawaii and in other geothermal areas

where active volcanism is prevalent, a great number of specific publications and

selected references wer~ consulted. These are listed in Appendix C, References. In i~~~~ addition, much of the ~and many recommendations contained in this Manual

came from the accumulated experience of others who were consulted on various

elements of the items presented. A partial list of those consulted is also contained in

Appendix C.

This Manual defines a blowout prevention strategy for geothermal drilling in the

State of Hawaii. The essential components of this strategy are:

~f> Improved risk analysis and well planning. · L. 1 a ~ft>GI'if'~

II 2) Sound selection of blowout prevention stacks and~ equipment.

3) Rigorous use of drilling monitoring procedures.

4) Expertise in kick control and blowout prevention equipment utllization.

5) Excellence in supervision and training of drilling personnel.

BOPSCOPE/RAP/August 24, 1992 I I- 1

DRAFT

III. GEOTHERMAL DRILLING RISKS IN HAWAII

THE VOLCANIC DOMAIN

The State of Hawaii consists of a chain of volcanic islands. Each island is a

composite of several volcanic eruptive centers builtr"'rfy a succession of basaltic lava

flows, first as submarine deposits and subsequently as volcanic lands (or subaerial. "'llv.zN i>4SC4I~<-l~ Pf~s &-. o.. s-c (.Ao&Ao\.c. cP £..t.-, .-..1-....1 l.:t'(e..--sc-~dff~

deposits.) · · t::r~ ~ ....... .£ c.,.,.,*-' l(,·""-'Z ~ -roG(!....'' t"' ~b-e~ t.o),f1'\ l'<2'>~e.r u~..,h. o "'-•sk"- ~~~He ..sl.l:bs'l::ui~aeet reek §eoH!etry of hard, sry.talljnQ fleu roelts, interbeeiaed1 with lesser y"IH/1.<,. ck.P/•f• -t1M-~'€ ..a~;~eunts o~ hif§Jhll'. variable roelt GQbd.a\~ flow sequences ~

.. .,..e e "1 ~+- 1~k<A 1 ._ ~,,.,..,...,..,...~fl:a¥C!.-J;~m-Tl!~fC'ID·~~ in extensive outcrops and 'lA..lithology logs from ~

~water well drilling. \.D.-Btrnc,essful exploitation of the large an~aiuable

..,_grol.lnd l•later rQiOOl.lrce that S'l:l_!?OrtS sotb ?iripulture and utba11 <~eueJep~QRta ~ I J(f'f rr~ete rece,f > (/ re -

v'V\.e c~ks F~vf-a~"""¥ ~ec~~ Yef~-e4 2-rc..~rttef..n~ ~ • ....J.

1 T~e H!ere re~n-t:tr reC2,9'¢zea g~thcrff\al r~e:1.1J;s~ is leeateci in Hll:lefi smeilet

fJli"" roe t..A.h~!. F"n-t.41f lfi(;4-A<;; (..l)J?,c'-1 t~~re ,Jyf>f I e>Ct~d' · · · with active or recent volcanism. The

VI•~~~ p~;,., b,-41.... a,r-e~ ~ qeotfur-~ 11<e I•P.fHPif' ~~racliVe at eaY o~rlie the volcanic rift zones which are, or recently were, deep

conduits for magma transport away from the volcanic .eruptive center. Hawaiian acJute

geothermal drilling to date has been confined to therKilauea East Rift Zone (KERZ).

--wh±drts an active ma~nna tl:ansperlin§J and lava er upling slt uctl:lie. In the KERZ, ~ {tqoo•ra~ kiQ!..v) -httSf?n+ . . ...... .

magma ~ ·woces~es prov1t1.e very high subsu~ace temperatures,-r~t::~. -~ .• ~b--f'~~L .t} laf<~ k1""x... o~ MR~'" ~(fl..-e,kc.,,.,_e~ ··

~· Bet.h meteor:i:s water (g:roYRd. t•~V and sea water mtr1:1d:e into the KEt<:.

geothermal resource zones, :prov.idlli19(ari:~al:HiriAant:::tiUi(fs\:( pliiC · /J r...ov-;;.w ~ ~;;;;;..:. :P fk../.,';.1~ Z"vf~ d,,.~~s crf w ~·

Geothermal drilling in Hawaiian rift zones involves distinctive risks.

drilling experience, combined with extensive studies by the Hawaii Volcano Observatory

(HVO) of KERZ rift zone function, structure and_ dyna,mic processes.~~ - ---~-- . IS V?&t.) p~c;td·£.e~ to

reasonable initial identification of hazards and risks;c This an:a.~:ys~ CR.n be used to -e>'< r---~ -.£.-<: ~ kVJ.-:l I.e~ e

refine geothermal drilling programs and procedures to minirmz~ upsets and blowouts .

..ftu. Yl.fk<, ~f

KERZ DRILLING TO DATE

The most valuable subsurface information for this Blowout Prevention Manual

comes from 11 deep geothermal wells and three exploratory slimholes drilled in the

KERZ between 1975 and 1991. Rotary drilling rigs' appropriate to the drilling

objectives' were used on the vte~"thermal wells. Common drilling fluids used in this

BOPRISKS/WLD/October 13, 1992 III-1

~ rotary drilling are mud, water, aerated fluids and air. ~'Well depths range between

.f't-. ~4s (?'-eet bela-V q.-..d ~",..~) 1,670"' to 12,5001\. T.t'l'e l>perators tot the well drilling included four private resource

companies and one public sector research unit.

demonsb

subsequent

electrical generation

As of 1992, nine wells had penetrated prospective high

temperature rocks and s~ven of these were flow tested or manifested high temperature

fluids. Two of t:f1':f:S:'~ells incurred casing contained blowouts in 1991 upon

encounterin hi h ressured geothermal fluids at S~tas~~e'jff* \';lila~ ~ ~ r~:,tft<4."Cg J.s~over7 ~/i,#wP-1/, c,_1 re-k.i ;.....,,.,"J- tft1(,, f"~ ~la--...f.e. ct.

'$+tv/ ~-;1Y'•Ii-- e.l~IY·c-""' c,.QIIn'-.t,;;-. f'M .. /- beku...... 1'1~1-..1 1 c;qo . _) - L:..,. qeo-#t.er'JM<t-( r'eSoufct evcot{l.44tt~1

Three deep scientific observation holes (SOH) were drilledTaS continuously cored fl. b,a~ ~:o~w.- A6()~ t'\'\1• ~

exploratory slimholes to 5,500'-6,80tY".-dep-ths m the H~O 1991 mtervaJ.. These SOH s

helped to prove that favorable high temperatures pr~vail ov~r a te:u _mile interval {'.J.i,r~~ c-1,./y~ Pt-1' ,,fv./~

along the KERZ. These holes did not encountert-Signifi.cant blowout risks; however,

special blowout prevention equipment ia !h l!ilaele and must be considered for future

use of the slimhole technology in Hawai.:i.ttu:.,:.l""'a

SUBSURFACE CONDITIONS IN PROSPECTIVE AREAS

High temperatures, commonly in the 600-700°F range, are characteristic of~ \It> leo""' ~CA {1)1

production zones in · oc ~ctive ntt zones. The prospective

geothermal reservoir occurs in the roof rock above the deeper magma conduits. The

well completion targets are loci of permeable, highly conductive fault and fracture

zones' which are gene;:-ally e_nclosed by extensive secondary mineralization. Magma

transport downrift ·ana it:$ planar injeCtion upward into the roof rock :<a.It~ the primary

heat sources for the geothermal resource.

The primary hazard of geothermal drilling in the volcanically active KERZ

is the currently unpredictable distribution of fault planes and major fractures. ~ . r ~·/., • -fk .... s ae:?.~j

v.JaJk 0 -t ~t regional geologic structures f}fer sealed by secondary mineralization_,~ -aet as ~l~L+ ~~cl-e cAA.h ~ c~; t-~geothermal fluidS',.ee;ndu#:s: aUl an fractures, particularly as they extend upward

into cooler ground water regions~·::~~ < :: :·· :~·-·:··: " ·: ~:~::· .,. .. ~,·::··: ·: ". ·: ·::~ ca

present pressures in the range of 500 to 750 si above normal hydrostatic pressure.,

Unexpected entry into '.~·::·: : · (u;ft Ill\ ~ (?f'efJ4I~et f_, /{- j'f~ t7t-d .;i-a.e.fu~

BOPRISKS/WLD/October 13, 1992 f I I I -2

---fl'Uilr can cause substantial upsets to all well control procedures.

A si~n:ificant hazat d :is Pl: e~en'eed in the Rear surface volcanic rocks (subaerial

-deposits) of t.he rift BOI):fi• Primary features such as lava tubes, irregular layers of

ash and rubble, and g~ fractacing conse~ueet to laua.-fl:.,w aem19 contribute. ,;)J.t.it."'- <-a"'- -oe;~ ... 1r-~:>te- ......,.; 11-\ Lo .s Q [ Jr:u . ...., fL. R. ir"A,&...ft..n-...

to very high vertical permeability1 Yo nuids anc1 to low rock strengths. Thes.e;(Eeatures ,?,.,,..,,._., diminish down ward, but appear to present ~a~;ards iB the deptl:t ran9e of l!1500' te . ~ k f.-- •V'I _.f.- #......., I~ ~ Zooo f!.;. &3s.

···:···_"'i'_··:··::··::······:····_t·· f f ~ e'!3K~ •) ~ .'i~~d. ?(,,;>- +:. •. d !-,.~ {' 1 h 5d?.(f4~~~ffl?r"'- /l4#\K An mportan eatu;!:'e o cross rift tenSJ.OnaJ. stress _partie arly operates m the c-... .. ~ ir'l cr~s- fltt e....._~,.m~ $~~~· 111~, s-.....-.~ 7 I iJ,...,, e7,F -f1.u< ~p . n:oc:..¥;,.ccn.p ld ....;.,ftt S';~S~1c..:.h.., shallow. volcamcs ~nd. rqof ~ock dll~ to .th~ sea ward sll~g or t.he southeast flanlt of., ··I '(l!l~l~ "'' IIVl."lh d.•.l<:< .... •'\1:':'.~·•~'> ~ ~"'"u• 1/1Ke \•\tf''-<l<..n'\l d(-cJ 0.>\ At>UA:Jc<,.f· -, .. U9.b_:,..j. l. •.• t the _KER~. 'F~ -~~ie.ttf.til stre~~ ~ ~ ·:abttfidarit' heat s\iipPl}t'lii(>~Qltea t~e, """'-

. . . . ..... ?P ........ ~~l~ ~??YJ; .. ... --...,.. P pecti e ractunng for the -llitr\1sl&i\s; eott lea" d·~~f' dO . ··=:..;;.;.;~ :cr_ei:lt'~• res . v f .

geothermal reservoir. d~.t-:6~ hrlhijf' contribtite~~-~hese-~~ low roc~ strengths in the shai16wjl'leM"-~ttr£aee volcanics, ~~s\tf-9'i=~• ~~ma~efimil ~ ~ (oUtte. e"+eiaif'~ a sound ea~~-anchor for eompl-etioft-of.-the wellheai! wit:h-~

blowout prevention $'qtiipmehti

~;~h7rftiaa::fi'ki.~~t;:~i;i-'de'~~~~;-: ... · · ~~r . ~~n.ter-a~Lirrtitless (~ ·· :..;.,~-- · · ···· ····· ······· M.. :;;_~ C'kA-l~-~~- g~k ~ GetJ~ Y"eieri-v~i.;~ u

~~ij~~,li~~;~~F;i~"'~M-~~~~;~ f~arrifol·~m.rv'6iri l.,jjb{y""tlfrisiigp:·{~···~4~~ei.t·tli'•~q&'i!ke..."" fty'dros~tfc!.;~;~e~·fre~at:~ti~'to''P~~e.fu fr:ctti~e-rift zones,· but these can be

escalated to higher fluid pressures in the temperature conditions prevailing. The

~hMl:ow-f:i:i$.h jlri~Ls~Url.~L9l:"()\irid:~~~~~J:)Odyj~ regions; shown to prevail as deep as 2,500'

in the Puna geothermal field, may prove to be a generiu condition, but not one that can

be expected at every proposed well location.

SUMMARY

The KERZ geothermal drilling experiences prove two significant hazards that

must be addressed in a blowout prevention strategy for every proposed well:

1. Significant fault and fracture planes ~f can be sealed conduits fo'r • ell~~ b.

overpressured geothermal fluid$. These features ITU.ghtrprove ·'to e


~predictable or detectable by drilling precursors. Blowout

prevention planning, equipments and procedures must be taken as a

critical requirement, ready for immediate and proficient use.

2. Weak and broken near surface volcanic rocks.

--a. reliable casing anchor: must be abtain&d before the fundament:sl-of

--orowout prevention ey complete shut off is safely workah~

~ veco'7Vlt-.h.;._ e; .{ ht.cf c..~-~ ~s ~ pr"Q..Curs<H' -f-o <D ~ t.·,,..W,

~ ve.(L~(c.e' ca-s··~ -c.."'-rl., w~•~l\. ~~ ~a~W J- c_,qk,

c~~ l-<2k c:[hv.-4- t:> ..f, b C~ ouJ- ~~ .


IV_ GEOTHERMAL WELL PLANNING

DRAFT

INTRODUCTION

The proven higher costs and uncertainties in Hawaiian geothermal drilling

operations are sound reasons to make an extraordinary investment in well planning.

Detailed planning is a must for each c;nd every type of well because of the paucity of (€l<Af-lilelJ

subsurface information and thersmall base of drilling experience to date. Blowout

prevention is an integral element of geothermal well planning.

WELL PLANNING OBJECTIVES

Safety The concept of safety must be carefully applied for all workers and

activit."s on the wellsite, and for the public. A blowout

prevention strategy is a crucial part of any successful practice of safety in geothermal

drilling; it is a necessity in Hawaii.

Well Function Geothermal wells, if beneficial development is to be attained, must

convey and control very large quantities of fluid and energy, hopefully for the

greater part of the 30-year life that is expected in electric power systems. The HGP-A

discovery_ well demonstrated a reasonable performance in the production mode-£"~ I'\ g) -4- \ 'tf1o. ~; Jaut no othm; wall has atte:ifted either the proda~ or injeet:iOk.

Reasonable Cost Hawaiian geothermal wells are in the very costly category;

perhaps $2,500,000 per well is a representative minimal cost (1992$) if no significant

problems impact a good drilling plan. Competent planning might cost only 1 or 2% ~ ~ ~.f -1tv2. (!1'\/9\" 41. ~ CD?-}. ~ {: ~ ...v6 l(.

High quality well planning will assure a greater degree of safety and improved

well functions. Proper well planning will allow the Operator to be more confident in

responding to the upset conditions that can't be avoided and actual dtillirig

performance can be better assessed for continued improvements in future Hawaiian

geothermal wells.

DRILLING TARGETS AND WELL TYPES

BOPPLANXING/WLD/October 13, 1992 IV-1

Geothermal drilling targets in the volcanic realm of Hawaii can be organized into

three simple classifications:

and fractvres ~oids). Targets that can win drilling funds, but which present

a high risk exposure, are classified as exploratory by the Operator and

participants.

Reservorr targets - to develop the resource, are generally qualified by high

ffe.,-c;..-"Ce.() ~ temperatures, indicated fault planes and fracture. systems or by nearby well

production data. The probability of penetrating both high temperatures and

fluid producing permeability intervals is high. Hawaiian geothermal reservoirs

are of the hydrothermal type (~Aii'- predominate type now in :\4\i)~~~i;iiiCI.$

utilization.)

Supplemental targets - to conduct research on the resource, are comprised of

scientific and/or observational objectives which can contribute to a better

understanding of a geothermal resource and its enclosing subsurface

environment.

At the present level of knowledge in Hawaiian rift zones, no class of geothermal

drilling target can be confidently identified with lower blowout risks. Off-rift

geothermal drilling targets may offer the perception of lower drilling risks, however,

no such drilling has been undertaken as of 1992.

Geothermal wells can be categorized as to function and several additional

features. The common types of wells include the following:

Exploration well. Any well drilled to evaluate a prospective geothermal resource

target, usually at some significant distance from an established or proven

geothermal reservoir. Hard and proximal subsurface data are not likely to be

available for a blowout prevention plan; diligent drilling monitoring procedures

(see Section VII) and casing plan flexibility are essential to blowout risk

reduction in exploration wells.

Production well. Any well designed to exploit the energy and fluids of a

BOPPLANl!ING/IlLD/October 13, 1992 IV- 2

geothermal reservoir for beneficial use or demonstration purpose. Blowout

prevention plans for production wells can be better specified to more

confidently known subsurface conditions.

Injection well. Any well designed to return the geothermal effluent to the

reservoir or other deep disposal zones. Injection wells will have blowout

prevention requirements similar to nearby production wells.

~Deep versus shallow wells. These are terms of convenience in their general

I usage; however, regulations may impose a legal definition on them. A historical

point of interest in the KERZ should be noted; several early geothermal

exploration holes, drilled safely with cable tools, encountered near boiling waters

I I i

at very shallow depths next to recent lava flow fissures and vents. Depth seems

to have no correlation with blowout risk in Hawaii's geothermal drilling to date.

However, it should be evident that relatively shallow blowouts in the porous

surface lava rocks and large fissures, broadly prevailing in Ha waii,could be

particularly difficult to kill.

Vertical versus deviated wells. It appears that Hawaiian geothermal wellfields

will be extensively developed with deviated wellbores. Blowout prevention

requirements are not altered in any type of geothermal well by the vertical or

deviated course of its wellbore.

· (p h lf ir~Cike.s 11" v-r.- B~ ;"v~e~ ~limhole. F type of geothermal fell U; identified by its small diameter

1 borehole,~~ compared to the ~ b4r/t diameter range commonly I / used world wide in the geothermal industry. The slimhole technology, presently

. I I , surging in evaluation and use in the petroleum industry, has a distinct blowout LJ 1 risk and prevention requirement. The technology has been safely introduced

I in the KERZ when HNEI accomplished three continuous boreholes between 5500

! and 6000 foot total depths in its Scientific Observation Hole Program (1989-91).

l_giscussion of the blowout prevention in slimholes is presented in Section XII.

THE DRILLING PLAN

Every geothermal well proposed for funding and permitting will require a

drilling plan. Regardless of the geothermal well type, the drilling plan is the specific

technical document that should reflect the best thinking on how the well can be safely

BOPPL&~!NG/RLD/October 13, 1992 IV-3

constructed and it!=' .c:unction obtained at reasonable c-- -:;t. Safety is considered on a

broad front in a ca:?efully prepared drilling plan. ComrTionly the deliberate actions to

optimize safety in geothermal drilling will be specified or reflected in four distinct

sections of the drilling plan, as follows:

l. Casing and cement. The intended function of the proposed well will be

a factor in casing design and cementing procedures selected. However,

the best available subsurface data sets on geology, hydrology 1 pressure

and temperature profiles, formation failure thresholds (fracture gradient),

together with the wellsite elevation, comprise the basis for increased

safety in drilling and quality of construction. The subsurface conditions

and wellsite elevation are unique to each intended wellbore; the proposed

casing and cement plan must reflect a reasonable response to these

conditions. KERZ drilling experience reveals several special concerns for

blowout prevention.

~0- ;nd-. a. A preference to cement the surface casing (commonly ~

diameter) below the lctwe~~-aq-tri:£er--contsin±n~-pot.ab±e-water ~p~~

can be acknowledged. Where the ground water table is within

600-800 feet below the surface, an approximate 1,000-foot length of

surface casing would meet this objective. Where the ground water

table is much deeper 1 it could be cliffi.cult to obtain a good cement

sheath on surface casing set at, say 1 1 700 feet/ because of the

presence of lost circulation zones and incompetent rock in which

to cement the ~~ii.i~sn~o.~n:P:~~4e,pee.)~li99~~$i~P.:~t.:~t~~:A~t~et~~

()~t~:::::a:Jq\l@ty:::c~~m~ti~:~s~;.~~;p;~qti~:~J-~ll.e>:rt:et::l~fist;h.i::of:~u:r:face

(i$.fi.Hj:; --into--eomp~ent- -t"'C'k,--e~en- -if--ehe--p1."'0CedttJ:&e-~

ee~~-~he-bo~-~into~rotl~a~~

b. Independent of the quality of cement sheath obtained on surface

casing 1 the possibilities of fractures/ other permeable paths to the

surface and low formation fracture gradients exist in the near

surface volcanic rocks penetrated by the surface casing. This

points to a serious risk in using a complete shut off (CSO) blowout

prevention system on the surface casing while drilling to the

intermediate casing depth. A CSO could force unexpected hot and

possibly pressured formation fluids to an external blowout (outside

BOPPLANKING/WLD/October 13, 1992 IV-4

the surface casing and cellar). External venting of this type can

posa•more•·eomplex··and·p:r~riliu$·kur·op:erations; arid aJ.® M-mg

an--±n'l"!'nediat-e--threateri the drilling rig's ground support.

Accordingly, a diverting capacity and large diameter flow line from

the wellhead to a distant disposal point is to be considered. This

approach would contain such~~ncontrolled flow inside the surface

casing and afford a safer kill procedure confined to the wellbore.

1? ~/e-·.:,"'"' c. Intermediate casing (commonly 1~ diameter) may be set at

depths between 1,000-2,500 feet below the surface casing shoe if no

unexpected geothermal fluids or anomalies are encountered. The

intermediate casing shoe depth should optimally be below the major

ground water body. !fshbUld also be k>eloijj extensive fracturing that

may reach up to the ground water table, frequent occurrence of lost

circulation zone~~ and less competent volcanic tock:elastie-zones:

Because the intermediate casing becomes the anchor ¢aslli9 for the

complete BOP equipment stack required to drill to total depth, it is Y"t- i"'dl.

critical that the cement sheath in the open hole (17 Y diameter)

annulus be of the highest possible quality. The findings in the 17

Jt.-.nth -? Y drilled hole should be carefully studied. Any adverse downhole

conditions can be mitigated by cementing the bottom portion of the

intermediate casing as a liner in the open hole interval (lapped

several hundred feet into the bottom of surface casing). The upper

portion can be run and cemented as a tie back string inside the

surface casing. Each of the two cement jobs required should be of

enhanced quality, should offset the external natural hazards and

should optimize the anchor for the complete BOP equipment stack

with its multiple CSO capacity over a full range of drilling fluids.

2. Drilling fluids. The subsurface conditions encountered within the KERZ

are prompting the use of many drilling fluids ranging from moderate to

low density muds, water, aerated muds and water, to foam, and air.

Additionally, the ability to switch drilling fluids promptly is being

recognized as a cost effective advantage in greater well control. This

pradti(tifi ea-pe.eit:y demands the use of BOP equipment compatible a

BOPPLAKNIHG/WLD/October 16, 1992 ~J (.di[,~,~-5

broad range of drilling fluid options in a single wellbore. The diversity

and flexibility of drilling fluid utilization in Hawaii is encouraging, not

only because all fl\ii<}~ t:hey-can be controlled by available BOP equipment,

but because this approach should lead directly to advanced safety

margins, reduced drilling times and lower costs. Drilling fluids and

geothermal well control are further discussed in Section VII.

rillin. . . his )~f~~~ . all . d . h h 3. D g Momtonng. T ~L lS usu y mtegrate m t oroug

drilling plans at many points. It is, however, quite important and

deserves more recognition as an effective method to reduce blowout risks.

A detailed consideration of drilling monitoring procedures is presented in

Section VII.

4. Blowout Prevention. Drilling plans may contain minimal specific

discussion of blowout prevention; a graphic sketch of the proposed BOP

equipment stack may be the lone obvious recognition of the subject.

However, a competent drilling plan will reflect, in its detailed provisions,

an Operator's blowout prevention strategy. The implementation of risk

reduction will be evident in the casing, cementing and drilling fluid aniA 1-1"4•" i.,~

provisions, in the drilling monitoring j...procedures and finally in the BOP

stack and its supplemental equipment. The drilling plan should reveal the

Operator's awareness that a blowout can happen, and reflect the drilling

supervisor's responsible determination that it has been given the least

possible chance to occur in the proposed well. Blowout prevention is every

Operator's final responsibility; it is achieved first in the thinking and

actions of all drillsite personnel through training, J.5Y. :tl'j_~ practice of

sound procedures, and by the use of reliable, proper equipment.

30?PLfulNING/~LD/Octaber 13, 1992 IV-6

DRAFT

V_ BLOWOUT PREVENTION STACKS AND EQUIPMENT

INTRODUCTION

Hawaii's geothermal drilling industry, still in a formative stage, has gained

sufficient experience and information to provide reasonable guidance to the

identification of more reliable and safer blowout prevention stacks and equipment. The

blowout prevention stack on the wellhead, when all other well control procedures have

failed, must function reliably \J:Qb.ta~:~ a complete closure or effective control of

unexpected fluid flows from the wellbore. Blowout prevention stacks and related

equipment are not simple systems; they rely on integrated mechanical, hydraulic and

electrical processes to operate. Both redundancy and sophistication exist; however, the !.le>..o.,..+rfel) .a"'h.,...

risks of human error in criticaP'utilization have not been eliminated. Blowout

prevention systems require careful selection, maintenance, and repetitive training

of drilling crews to attain the reliability and safety which are essential in the final

defense against an actual blowout.

BOP DEFINITIONS AND FUNCTIONS

1. Definitions

• The term blowout prevention equipment (BOP) here means the entire array

of equipment installed at the well to control kicks and prevent blowouts. It includes

the BOP stack, its activating system, kill and choke lines and manifolds, kelly cocks,

safety valves and all auxiliary equipment and monitoring devices. (see Glossary in

Appendix D for these terms).

• The BOP stack, as used here, is that combination of preventers, spools,

valves, and other equipment attached to the wellhead while drilling.

• A diverter stack is a BOP stack that includes an annular preventer, with a

vent line beneath. A valve is installed in the vent line so that the valve is open

whenever the annular preventer is closed, thus avoiding a complete shut off (CSO),

and diverting the flow of fluids away from the rig and personnel.

A full BOP stack is an array of preventers, spools, valves, and other equipment

attached to the wellhead such that complete shut off (CSO) is possible under all

BOPSTACKS&EQUIP/HEW/WLD/October 13, 1992 V-1

conditions.

2. Functions

The main function of the BOP equipment is to safely control the flow of fluids

at the surface, either by diversion or by complete shut off. The equipment must be

adequate to handle a range of fluid types, pressures, and temperatures, and to

accommodate different drilling situations such as active drilling and trippin~11 or out

of the hole. The requirements of the BOP stack are to:

a. Close the top of the wellbore to prevent the release of fluids, or, to safely

divert the fluids away from the rig and personnel.

b. Allow safe, controlled release of shut in, pressured fluids through the choke

lines and manifold.

c. Allow pumping of fluids (usually mud or water) into the wellbore through kill

lines.

d. Allow vertical movement of the drill pipe without release of fluids.

Selection of BOP stacks and equipment should be made jointly by an experienced

geothermal drilling engineer and drilling supervisor. It is preferable to employ a

supervisor that is experienced in Hawaii geothermal drilling experiences and

conditions.

THE BOP ANCHOR

Complete shut off capability with a BOP stack requires the existence of a BOP

anchor. Three key factors are required for a sound BOP anchor:

1. A mechanically sound, continuous steel casing of reasonable length, which

probably will be 1000 feet or more, attached to·the BOP stack.

2. A continuous and solid cement sheath in the annulus between the casing and

the rock wall of the wellbore.

3. An impermeable rock interval around the wellbore and cement sheath. The

entire section of rock need not be impermeable,but priority is given to placing

and cementing the casing shoe in a thick interval of competent a;ng iifti:p~romeab'le ;--low-per-mea-bm'ey rock.

BOPSTACKS&EQUIP/HEW/WLO/October 13, 1992 V-2

IMPACTS OF SUBSURFACE RISKS

Hawaii geothermal drilling has inherent risks due to the unpredictability of

subsurface conditions. Recognizing the risks and being prepared for all possible

conditions is the best form of blowout prevention. Subsurface conditions that may pose

the risk of a well blowout are listed below:

1. The almost certain inability to obtain a sound BOP anchor with surface casing

in the weak, often broken,11and vertically permeable near surface volcanic rocks. As

• (.t a w ttl l<1C.k occ.a('' discussed in Section III,Vthese shallow rocks will not allow a CSO at the wellhead

without posing a significant risk of creating :ain\~$.x~rf1a~ly':v6,ritie~ '}/elF¢asin9 hlp¥fout; (For discussion of externally vented blowouts, see Section IX.)

2. The unexpected entry while drilling into a major fault and fracture conduit.,

which is charged with overpressured geothermal fluids. Termination and control of

such events requires the certainty of a wellhead CSO with a full capacity BOP stack. i

The risk factors cited above reveal the importance of knowing when a BOP

anchor and consequent CSO capacity nee~to;--be-*','e. available to PH~:Ye:~t~~

a blowout. If they are not available, diversion of uncontrolled flows is judged to be

the more prudent response. On these fundamental considerations, two basic BOP stacks

are recommended for Hawaii geothermal wells which are drilled with rotary rigs for

exploration, production or injection purposes.

BOP STACK RECOMMENDATIONS

1. Diverter Stack (Figure 1-Appendix B)

A diverter consisting of an annular preventer and a vent line should be 40 ~"c:. .. e.$'

installed on the surface casing. In Hawaii, this casing is typically J.E". in diameter

and is cemented in the ~ depth range. /' ~oo- t 1\00 .PI!Iet

1 In the KERZ, sudden geothermal fluid flows, which subsequently registered 500 to 700 psi shut-in wellhead pressures, were encountered at depths shallower than expected; in one case as shallow as 1,400 feet.

BOPSTACKS&EQUIP/HEW/WLD/October 13, 1992 V-3

Incompetent near surface

volcanic rock and the high risk of cementing failure will not provide an

adequate BOP anchor. CSO is not intended with this equipment; diversion of

fluids is deliberate to avoid creating externally vented blowouts, and for

personnel and rig safety.

2. Full BOP Stack (Figure 2)

A full BOP stack should be installed on the intermediate casing. In Hawaii, this v'"3 ~~ ioc.heo; zeoo -1,5"= r.;.,.t

casing is typically ~ in diameter, and is cemented in theY~

depth range. This deeper casing, cement sheath, and host rock serves as a BOP

anchor. The selection and arrangement of this stack allows for the use of a full

range of drilling fluids (mud, water, aerated fluid, foam, air) and should be a

geothermal industry premium stack that is capable of confident, immediate CSO

over the range of temperatures and pressures anticipated. If a sufficient BOP

anchor is not obtained, this stack also has diverter capacity because of the flow

"T"/vent line, or banjo box/blooie line, included in the stack.

ADDITIONAL RECOMMENDATIONS

1. Diverter stack. The diverter stack should have the following

characteristics:

a. A mm1mum pressure rating of 2,000 psi for all components.

b . . 1' d. te f ,.,.,..; rz ,~ ... ~e~ . Mm1mum vent me 1ame r o , ~

c. A full opening valve on the vent line that opens automatically

when the annular preventer is closed; OR a 150 psi rupture

disk and a normally open valve.

d. The vent line directed through a muffler.

e. H2s abatement capability connected to the vent line.

2. Full BOP Stack. The Full BOP Stack should have the following

characteristics:

a. A minimum pressure rating of 3,000 psi for all components.

BOPSTACKS&EQUIP/HEW/WLD/October 13, 1992

A pressure rating of 5,000 psi is recommended when indicated

by the risk analysis of the well. For temperatt.ir"e impaCtS on

V-4

b.

c.

d.

~:::~u=:~~::~~~fct~illi~~~~~nd ;f~~ ad~~:::~ine. The pressure ratings for the kill and choke lines the same

as the stack.

A 11 preventers should have high temperature rated ram

rubbers and packing units.

BOP EQUIPMENT RECOMMENDATIONS

-z.- ~f\Ch 1. Kill Line. r kill line from pumps to spool. Two full opening valves and

one check valve at the spool. Fittings for an auxiliary pump connection;

pressure rating for the kill line the same as the stack. The kill line is not

to be used as a fill up line.

4- 1~Ck

2. Choke Line and Choke Manifold. f" choke line and manifold; pressure

rating the same as the stack. Two full opening gate valves next to the

spool; one of these valves remotely operated.

3. Actuating system. The actuating system should have an accumulator

that can perform all of the following after its power is shut off:

a. Close and open one ram preventer.

b. Close the annular preventer on the smallest drill pipe used.

c. Open a hydraulic Y:alv~eiffie on the choke line, if used.

5o f-ee+ The actuating system is to be located at least ~ from the well, with two

control stations - one at the drillers station on the rig and one at the

actuating system location.

4. Other equipment. During drilling the following miscellaneous BOP

equipment is to be provided:

a. Upper and lower kelly cocks and a standpipe valve.

b. A full opening safety valve, to fit any pipe in the hole. Kept

on the rig floor.

c. An internal preventer, kept on the rig floor, with fittings to

adapt it to the safety valve.

d. Accurate pressure gauges on the stand pipe, choke manifold,

e. A 11 flow lines and valves rated for high temperature service.

BOPSTACKS&EQUlP/HEW/WLD/October 13, 1992 \/-5

DR..AFT

VI. EQUIPMENT TESTING AND INSPECTION

In general, a visual inspection and an initial pressure test should be made on

all BOP equipment when it is installed, before drilling out any casing plugs. The BOP

stack (preventers and spools, choke and kill lines, all valves and kelly cocks) should

be tested in the direction of blowout flow. In addition to the initial pressure and

operational test at time of installation, periodic operating tests should be made.

Pressure tests should subject the BOP stack to a minimum of 125% of the

maximum predicted surface pressure. If the casing is tested at the same time then the

test should not be more than 80% of minimum internal yield of the casing at the shoe.

If a test plug is used, the full working pressure of the BOP stack can be tested; a

casing test would be made separately. Testing of the actuating system should include

tests to determine that:

1) The accumulator is fully charged to its rated working pressure;

2) The level of fluid is at the prescribed level for that particular unit;

3) Every valve is in good operating condition;

4) The unit itself is located properly with respect to the well;

5) The capacity of the accumulator is adequate to perform all necessary

functions including any kick control functions such as hydraulic valves

that are using the same unit for energy;

6) The accumulator pumps function properly;

7) The power supply to the accumulator pump motor will not be interrupted

during normal operations;

8) There is an adequate independent backup system that is ready to operate

properly; and Gof-t.ot.+ 9) The control manifold is at least ~ from the well and a remote panel is

located at the driller's station.

10) All control valves are operating easily and properly, have unobstructed

access and easily identifiable controls.

The sequence of events to test the BOP stack and all other valves depends on

the stack configuration, but it is important that all equipment is tested, including the

annular preventer, pipe rams, CSO rams, upper and lower kelly cocks, safety valves,

BOPTEST!NG\HEW\WLD\October 13, 1992 VI-1

internal preventers, standpipe valve, kill line, choke manifold and choke control valve,

pressure gauges, and any other items that are installed as part of the BOP equipment.

In addition to the initial testing of BOP equipment when it is first installed,

there should be frequent BOP testing and drills. The closing system should be

checked on each trip in or out of the hole and BOP drills should be held at least once

a week for each crew. It is most important that every member of the crew be familiar

with all aspects of the operation of the BOP equipment, along with all of the

accessories and monitoring devices that aid in detection of a kick. The main purpose

of drills is to train the crew to detect a kick and close the well in quickly. BOP drills

should cover all situations, while drilling, tripping, and with the drill string out of the

hole.

BOPTESTIHG\REW\WLD\October 13, 1992 VI-2

VII. DRILLING MONITORING PROCEDURES

INTRODUCTION

Operators commonly provide for some level of monitoring in the drilling of most

geothermal wells. All types of monitoring procedures will incur additional costs, which

may limit the selection of specific procedures. However, most Operators determine the

specific procedures in the context of what is known and not known about the

subsurface environment to be penetra~ed by the wellbore. This discussion of

monitoring will use the broad sense of the term, including mud logging.

Monitoring procedures may be defined as an array of continuous sensing actions

which attempt to accurately indicate subsurface conditions as the drill bit is advancing

through the:@~ formation.

MONITORING RATIONALE

Geothermal wells, drilled within the prospective, active volcanic rill zones of

Hawaii, merit carefully planned and integrated monitoring procedures. This view is

supported by two primary concerns. First, the subsurface geology, hydrology,

temperatures and pressures in the rock roof above the deep magma conduits, which

create the rift zon~are only partially known. Only 14 deep geothermal bores (11 wells

and three scientific observation holes) have provided hard, factual subsurface data

as of mid-1992. Secondly, two geothermal wells have demonstrated that fault or

fracture conduits, charged with high pressure, high temperature fluids can ef{t~nd ~~~-\- C(W'I \V\~

upward to relatively shallow depths from a deeper subsurface domain ')n: >600VF

temperatures. These near vertical and planar conduits present both blowout risks and

significant geothermal energy production potential. This recent finding, proven by

drilling, has major implications. Geothermal drilling requires the evaluation and more

effective utilization of monitoring procedures as a supplemental strategy for blowout

prevention.

VITAL SECTORS

Monitoring focuses on three vital sectors during the drilling of a geothermal

BOPMONITORING/WLD/October 13, 1992 VII-1

well:

1. Drilling penetration rate and drill bit performance measurements. The

penetration rate, commonly measured anq recorded in feet per hour, ~<crp~f'l"'g, "'-.l>•<e~o\e

indicates the mechanical progress of~ in the host rock. Weight

on bit, rotational speed and torque are additional measurements that are

made to better understand the variations of the drilling penetration rate.

2. Drilling fluid circulation in the wellbore which clears the new made hole

of drilled rock debris, cools and lubricates the rotating ~bi.~~~ ,drilling assembly)i:f)Ji:id.!~:<:I~W~ri9T~~~¥iS· Importantly, the density and

hydrostatic pressure gradient of the drilling fluid are commonly used to

control the formation fluids and pressures encountered.

3. Physical conditions and resource potential of the newly penetrated rock

formation. The array of information gathered in this sector is commonly

presented in a continuous "mud log" graphic record over the entire

interval drilled.

The information products from the sectors discussed above have important

potential applications. Possible immediate improvements might be indicated in drilling

procedures, drilling fluid properties or casing plan in the well itself. Enhancements

in well design, drilling program and/or cost ~tmcan be determined for future

wells. ~...--....+..frlli\. .. the information products of mon~to~ing procedures, with careful -... "'r'""'V•""-'-If'f JI'I•K~ "-:'. i"'.vor~411l#-" ccmtnbuf-i611\

integration and evaluation, can r~ to an Operator's strategy of blowout

prevention.

OPTIMIZING BLOWOUT PREVENTION

Any effective reduction in blowout risks is primarily contingent upon accurate

interpretation of monitoring data and ultimately depends on the decisions made, based

on this data. This must be achieved by the Operator. Having made the risk analysis,

written the drilling plan and obtained the funding for the well, the Operator's

geologist and drilling engineer presumably would be the most qualified persons to

establish the method by which the selected monitoring procedures would be used to

BOPMOMITORI~G/WLD/Octaber 13, r992 VII-2

contribute to a blowout prevention plan. In prospective Hawaiian rift zones, the

prudent Operator, making careful use of monitoring information, can better identify

the potential for hot and overpressured fault and fracture conduits, and can better

prepare for penetration of such conduits and reduce impacts of kicks and lost

circulation. Alternatively, a decision on whether or not to set casing can be made,

particularly if a long open hole section is exposed above the interval of concern.

Critical data that may reveal the degree and/or immediacy of a blowout risk are

probably first observed by key personnel of the drilling and mud logging contractors.

Exercising personal control of drill bit performance in making hole, drillers are the

first to sense change at the bottom of the wellbore. Additionally, drillers must have

an accurate, real time knowledge of the drilling fluid upflow in the annulus between

drill pipe and the wall of the open hole. Gain or loss departures from 100% of the

drilling fluid pumped down the drill pipe and through the bit orifices are critical

indicators that, alone or with other corroborating information, signal a disruption of

a normal drilling mode.

The mud logger and a supporting multiple sensor system continuously survey

the changing rock features, formation fluids and temperature variations reflected in

the returning drilling fluid. This work is both time critical and time short because it

focuses evaluation on the narrow window of freshly exposed hole behind the

continuously advancing drill bit. Accordingly, good quality, competitive mud logging

has become a highly automated, computer assisted service with an impressive

reliability. The mud logger is the first to evaluate the formation gas and liquid

entries, via the returning drilling fluid, that may signal the penetration of high

temperature, high pressure conditions.

Operators of Hawaiian geothermal drilling projects need to assure that a high

level of cooperation in comprehending the norm and the upset hole conditions are

mutually practiced by their contracted drillers and mud loggers. The Operator's

drilling engineer and geologist should establish and maintain active communications

with these key specialists throughout the drilling process. It is essential that drillers

and mud loggers have reliable, instantly available electrical communication between

their work stations if monitoring procedures are to more effectively contribute to the

reduction of blowout risks. These simple procedures are intended to eliminate a

BOPMONITORING/iiLD/October 13, 1992 VI I- 3

common problem: too often a key piece of new information is received, but is not

properly read, understood or communicated. Operators must lead their drillers and

loggers to consistent cooperation in monitoring procedures as an important protection

against the loss of well control. O'l'lersi.~ht-:i:n-~1-hadequateroespbnS$$ to new

well monitoring information must be e1i'fTti1otstedmiriimiZ.ed in Hawaiian geothermal

drilling.

DRILLING FLUIDS AND GEOTHERMAL WELL CONTROL

All authoritative publications on blowout prevention (which to date exclusively

address oil and gas drilling) stress the role of drilling fluids in minimizing, if not

precluding, entries of normal or high pressured formation fluids into the wellbore

during the active drilling process. This is achieved by circulating a weighted mud or

salt water drilling fluid which creates an excess or overbalance of internal hydrostatic

pressure on every square inch of the open wellbore. The normal hydrostatic pressure

gradient for the formation fluids in Hawaii rift zones should approximate 433 psi per

1,000 feet of vertical depth for fresh water and 442 psi per 1,000 feet for salt water.

This range of pressure gradients may prevail over much of the KERZ in the deep

geothermal zones because several geothermal wells were drilled through 2,500 foot

intervals of hot (760°F) prospective rock interval by circulating fresh water as a

wholly satisfactory drilling fluid. Well control was maintained confidently in these

operations and subsequently these fresh water drilled intervals yielded proven

geothermal fluids during flow tests following well completion. It should be noted that

the greater cooling capacity of water, as compared with mud drilling fluids, played a

positive role in these achievements.

Cooling by the circulation of drilling fluid is an inherent physical process in

geothermal well drilling. Where accelerated or optimized, the cooling process itself can

be recognized as a well control function. The efficient cooling of circulating drilling

fluids particularly will require an adequate surface cooling facility in the loop. Mud

cooling towers which allow the hot returning mud to fall in a baffle system against a

cool air draft are a standard equipment option for geothermal drilling. It is important

that mud cooling towers be adequate for the heat load anticipated and that they be

carefully maintained and monitored during use to assure that cooling is being

effectively accomplished. Additionally, geothermal well control in Hawaiian rift zones

BOPMONifORI!G/WLD/October 13, 1992 VII -4

requires ready access to an ample supply of cool water for wellbore circulation as a

well control option.

I< 6fZZ J(,[l,~g Both the specific ~experience and the practice of world wide geothermal

drilling demonstrate the disinclination tO:' dtillor~ with heavily weighted muds

or saline solutions as a preferred means of well control. This relates to the

expectation of finding fractures in the prospective hot zones which have much higher

permeability and production potential than a bulk rock interval of some uniform

primary (commonly lower) permeability. Fractures present the immediate risk of lost

circulation and a possible well kick , particularly when overpressured fracture fluids

are released. The perceived benefits of significantly weighted drilling fluids

(significant overbalance) usually is lost immediately in geothermal wells which

successfully penetrate fractures. The loss of drilling fluid from the wellbore anmti~

into formation fractures is accelerated in direct proportion to the overbalance ue to

tf:itcii:tSSively~ weighted~ ri\Uq~;-n~4lead. If, as indicated to date, blowout risks

in Hawaiian r:ift zones are predominantly fracture controlled and fracture specific, it

does not appear that excess weighting of drilling fluids will be a common means of

blowout risk reduction.

MONITORING INDICES FOR BLOWOUT PREVENTION

Monitoring procedures, taken as an aid to blowout risk reduction in Hawaiian

geothermal drilling, can be focused on a group of fi.ve categories, as discussed below.

The sequence of the categories is believed to be in order of importance when they are

examined with the assumption that the sudden encounter of high pressured geothermal

fluids in fractures constitutes the primary blowout hazard in these volcanic r:ift zones.

A. DRILLING WITH MUD OR WATER CIRCULATION

1. Bottom hole temperature variation. The blowout hazards in Hawaiian

rift zones have a strong correlation with high subsurface

temperatures. A working impression that 600°F and higher

temperatures were present below 4,000-foot depths under the

Kapoho-State geothermal leaseholds, and at greater depths upr:ift

in KERZ, may have prevailed before the KS-7 and 8 blowout events.

BOPMON!TOR!NG/WLD/October 13, 1992 VII-5

These wells respectively vented 500°F fluids from below 1,400 feet

and 620°F from below 3,476 feet in uncontrolled flows at the

wellheads. Bottom hole temperatures (BHT) cannot be measured in

the active drilling process because of the cooling induced by the

drilling fluid circulating around the rotating bit.

Alternatively, the exit temperature of the drilling fluid vented at

the wellhead annulus is continuously recorded. The sharper

excursions of increasing temperature with depth are the features

of interest in the automated plot of exit temperature. The mud

logger can immediately read such temperature increases in the

context of the complete temperature profile (surface to current

depth) and detect possible correlations with events on other ·fo-1

indices. A supplemental temperature,iiepth record is frequently

obtained by measuring with maximum reading thermometers inside

the drill pipe at a stop immediately above the drill bit for some

consistent time interval (say 20 minutes) at some regular frequency 1-~"1-

the Operator finds appropriate. This independent survey does not

obtain equilibrated BHTs; however, it provides a more discriminate

reference for the exit temperature plot. With respect to blowout risk

reduction, neither the existing BHT value or any specific high

temperature value has primary importance. Rather, it is sharply

rising temperatures, coincident with other dynamic events observed

in an integrated monitoring procedure, that ate'tOea!'l be taken as

a caution or evidence that a blowout threshold is being approached.

2. Drilling penetration rate. Variations in drilling rate commonly

reflect rock conditions encountered by the drill bit, provided such

factors such as weight on bit, rotational speed and torque are

uniform or their coincident variations are understood. Increases

in drilling rate (a drilling break) can indicate a porous and

permeable interval containing formation fluids; fractured rock can

cause sudden erratic perturbations in all these mechanical drilling

indices. Major fractures in the KERZ can allow the drilling assembly

to free fall into open voids. The consequences of such a fracture

BOPMON:~ORING/~D/October :3, :992 VII-6

~·dl encounter are frequently immediate. Competent drillers llquickly

determine the status of their drilling fluid return flow ~~1~praising the situation and appropriate response, if required. Increases in

drilling rates coincident with the penetration of high pressure

zones are described in some blowout prevention treatises on the

conclusion that bits drill faster in underbalanced mud weights

approaching high pressured zones. It needs to be determined if

KERZ drilling experience, past or future, suggests any basis for

reading drilling rate variations as an indicator of penetration of

high pressures. One prudent option in drilling fractured, high

temperature intervals, especially with initial formation fluid entries

identified in the return drilling fluid, is to deliberately reduce

penetration rate or briefly hold in a full circulation mode to confirm

drilling fluid system status and to observe more of the impact of

the formation fluids encountered.

3. Drilling fluid circulation. Accurate knowledge of the drilling fluid

condition, particularly its weight in pounds per gallon, and its

Je_g-ree o.f functioning in the wellbore, are critical to drilling with effective

well control. Any departure (gain or loss) from a 100\ return of

the pumped circulating volume, delivered through the drill pipe to

the drill bit, needs to be promptly evaluated as to magnitude and

meaning. Continuous measurement and recording of the drilling

fluid gain, loss, or 100\ return is made in specific tanks (mud pits)

included in the fluid circulation loop. Either gain or loss of drilling

fluid must be taken as a warning o£" increasing blowout risk. A gain

is a reliable indicator of formation fluid entry into the wellbore

(kick). If well flow is indicated or suspected following a gain,

drilling should be halted, the kelly pulled above the rotary table,

the mud pump shut down and the exit flow line visually examined

for possible flow. If the well is flowing in these circumstances, the

anri'Ul#;ciri:H--pi~-ram preventer should be closed to identify

pressure buildups on both annulus and drill pipe. These pressures,

when stable, would identify the increases in mud weight and

wellbore hydrostatic pressure necessary to terminate the formation

BCPMONITCR:NG/IG/Cct~ber :3, :992 VII-7

4.

fluid inflow. An evaluation of the option of circulating cool water

in the wellbore should be made if the kick is associated with a

temperature increase.

Partial or complete loss of drilling fluid returns is the more common

problem consequent to fracture penetration. Complete loss of

circulation, followed by a falling fluid level in the wellbore annulus

is a most likely trigger for a blowout event. Drilling must be

halted, the drilling string pulled up (only to the first drill pipe

tool joint) and the preventer closed until the situation is evaluated

and a response determined.

Formation fluid entry. All geotherm.al fl.W;d beari;ng. zones, both high vb~ j det~ri f~d v'Y ~"'ill btt

and normallx pressured, will first~~ penetration ~ ~~{~ ) <Ab\e'(Wtt-

~ ·~ charge of gases into the drilling fluid ~ in the

annulus. Mud logging systems will automatically measure and

record carbon dioxide, hydrogen sulfide, methane and ethanol in

parts per million on a log scale whenever the drilling fluid is being

circulated. Although this information has a time lag compared to

the immediacy of a drilling break, it is the most positive specific

indicator that geothermal fluids have been encountered. Gas:..::cut drillili9' flUid' returris~T~~~ ct:tt:~ coupled with temperature

increases, are a clear warning that a high pressure zone of

considerable flow potential may be at hand. With additional

penetration, geothermal formation liquid fractions may cause

detectable salinity increases in the return drilling fluid. Salinity a~ . -

determinations are notrautomated monitoring procedure, but are

optionally performed by the mud logger in evaluating fluid entry

events.

5. Secondary mineralization. Geothermal fluid bearing faults, fractures

and zones are predominantly enclosed in a sheath or seal of

secondary minerals. Secondary minerals are continuously identified

and recorded in geothermal mud logging with the intent of

discerning, in correlation with the wellbore temperature profile, the

most prospective intervals for fluid production. Logic would

BOPMONITORING/W~~/October l3, l992 VII-8

SUMMARY

suggest that the larger hot fluid conduits, which present both

significant production potential and blowout risk, would likely have

a thicker sheath of secondary minerals. The extent to which this

prevails in the Hawaiian rift zones and to which it may be a

particular precursor to high pressured geothermal fluids in

fractures is not well known. Natural variations in the secondary

mineralization process, consequent to a new fracture opening for

geothermal fluid conduction, may be extreme; any secondary mineral -~o.fl\etllllil

sheath could presage a V"fluid filled fracture or a fracture that is

completely sealed by mineralization., particularly in the active

faulting and fracturing of the KERZ. Whatever may be the present

view of this apparent index, it appears to merit careful evaluation

within the concept of integrated monitoring as a logical part of

blowout prevention strategy.

An optimal use of monitored drilling information in a blowout prevention strategy

requires the informed participation and responses of competent drillers and mud

loggers. A logical assignment of primary responsibility for the categories discussed

above would be:

Driller

drilling penetration rate

drilling fluid circulation

Logger

temperature variations

secondary:: mme~auzatlli* fbi"mat.ion: 'flUid': ~htrw

Computer based graphic data presentations are increasingly used at the driller's

stations to quickly provide both present status and cumulative record on the drilling

and fluid circulation processes. Both caution and alarm thresholds can be set on the

incoming real time information streams to alert drillers and supervisors to upset

conditions. Such systems offer an advantage to the blowout prevention objectives

necessary to Hawaiian geothermal drilling, provided that competence in their use is

created by diligent training.

3CPMON:~cR:NG/m/Cc:ober :3, :992 VII-9

The mud logging services contracted to most of the geothermal drilling

operations in the KERZ have been state of the art quality at the time of every

execution. Very substantial improvements in reliable automation have been made since

the rnid-1980s. In summary, Operators have adequate monitoring procedures at hand

to reduce blowout risks. The driller's main focus is on immediate deviations from the

controlled drilling process, and the mud logger's main focus is on subsurface physical

consequences of borehole advancement. Blowouts are commonly preceded by multiple

warning signs of increasing risks. The Operator's drilling engineers and geologists,

with the close cooperation of drillers and mud loggers, can more accurately recognize

such risks and more quickly act to control or reduce them with the drilling monitoring

procedures discussed here.

A final comment should be made on drilling fluid monitoring requirements while

tripping the drilling string. Frequently in geothermal well drilling with mud and

water, the hydrostatic pressure of the fluid has only a moderate overbalance on the

formation fluids. This is further reduced with the cessation of circulation immediately

before pulling the drill string, as for a new bit. In hot, prospective rock zones, the

large diameter drilling assembly moving uphole can swab, or pull formation fluids into

the borehole, by further reducing the hydrostatic pressure below the bit. The

greatest danger of swabbing occurs when pulling the first few stands of drill pipe

(drilling assembly just pulling off bottom). At this point, a careful confirmation of the

drilling fluid fillup volume, r~quired to hold the fluid level at the wellhead, is

essential. If the well ~~Y'~olume is less than the volume of drill pipe pulled,

swabbing should be inferred, the bit returned to the bottom and the hole recirculated

to clear the formation fluids from the well. In summary, swabbing is a mechanism that

can and has caused blowouts. A slower pulling of the initial stands and the fillup

check are the defensive procedures to use.

B. DRILLING WITH AIR, AERATED LIQUIDS OR FOAM

These drilling fluids are utilized in the underbalanced drilling option which is

often employed in geothermal drilling, particularly in known vapor dominated

reservoirs. Air or aerated liqUids Tdrilling I signified by substantial additional

equipment and service requirements, (air compressors, rotating head, banjo box, blooie

line, drilling muffler and H2s abatement backup) has been employed on a geothermal

BOPHOKITORING/~n/October ~3, l9S2 VII-10

exploration well in the KERZ. Expectedly, air and aerated fluids drilling will be used

and further evaluated in the Hawaii environment. Air drilling eases the driller's

concern with circulated fluid controls on formation fluids; the formation fluids, with

relatively unrestrained entry to the annulus, are transported to the surface and

through the drilling muffler for chemical and noise abatement before release to the

atmosphere. The mud logger's interpretation of rock and mineral cuttings is degraded

somewhat by the much reduced rddk particle size p~~«-th~pt'dd"(lced:: py air

drilling-1naO.~. Otherwise the drilling monitoring procedure discussed above will apply

for the same objective of blowout risk reduction.

BOPMON!TORiNG/W~D/October :3, 1992 VII-11

DRAFT VIII. KICK CONTROL

INTRODUCTION

In drilling terms, a 'kick' is often the first indication at the wellhead that there

are problems with control of formation pressure. A kick is defined as the entry of

formation fluids (water, steam, or gasses) into the well, which occurs because the

hydrostatic pressure exerted by the drilling fluids column has fallen below the

pressure of the formation fluids. If prompt action is not taken to control the kick and

to correct the pressure under balance, a blowout may follow. Some of the main causes

of these pressure imbalances are:

1. Insufficient drilling mud weight.

2. Failure to properly fill the hole with fluids during trips.

3. Swabbing when pulling pipe. If the drill string is pulled from the hole too

rapidly, the pressure may be reduced, allowing formation fluids into the

bore.

4. Lost circulation.

KICK IDENTIFICATION

There are a number of warning signs that indicate that a kick is occurring or

that it may soon occur. Some of these signs, which may not be present in all situations,

are:

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

An increase in the returning drilling fluids flow rate, while pumping at

a constant rate.

An increase in mud pit volume.

A continuing flow of fluids from the welf when the pumps are shut down.

Hole fill up on trips is less than the calculated amount.

A pump pressure change and a pump stroke increase while drilling.

An increase in drill string weight.

A drilling break. (A sudden increase in penetration rate)

Gas cut mud or reduced mud weight at the flow line.

Lost circulation.

A rapid increase in flow line temperature.

Each of the above warning signs individually does not positively identify a kick.

BOPKICKS/WLD/HEW/Auqust 2C, 1992 VIII-1

However, they do warn of a potential for a kick. Every driller and derrick man should

be expert in recognizing these indicators and all crew members should be trained to

take action. In geothermal drilling, in addition to being alert to the above warning

signs, it is of prime importance to: 1) monitor drilling fluid temperatures in and out

while drilling; 2) maintain a frequent and close analysis of the formation cuttings for

a change in mineralization; and 3) exert caution when drilling through formations

where lost circulation zones are expected. Difficulties or abnormal conditions with any

of these indications or procedures can also indicate of a potential kick.

SHUT IN PROCEDURES

The severity of a kick depends on the volume and pressure of the formation

fluid that is allowed to enter the hole. For this reason, it is desirable to shut the well

in as quickly as possible. When one or more warning signs of a kick are observed,

procedures should be started to shut in the well. If there is doubt as to whether a

kick is occurring, shut in the well and check the pressures and other indicators.

Specific shut in procedures when one or more kick warning signs are observed

1. WHILE DRILLING

a. Pick up kelly until a tool joint is above the table.

b. Shut down the mud pumps.

c. Close the annular preventer.

d. Notify the company supervisor.

e. Record the drill pipe and annular pressure build up.

2. WHILE TRIPPING


b. Install the full opening safety valve.

c. Close the safety valve; close the annular preventer.


e. Make up the kelly; open the safety' valve.

f. Record the drill pipe and annular pressure build up.

3. WHILE OUT OF THE HOLE

a. Close the well in immediately.

b. Record the pressure build up.

c:; J ~otiflf: theJ co mP: aii:Y:: ~u P~rviSCi~;

BO?KICKS/WL~/EEW/August 2C, lS92 VIII-2

4. WHILE USING A DIVERTER


b. Shut down the mud pumps.

c. Open the diverter line valves.

d. Close the annular pre venter.

e. Start pumping at a fast rate.


KICK KILL PROCEDURES

Several proven kick killing methods have been developed over the years, based

on the concept of constant bottom hole pressure. Two of the most common methods are

know as the "drillers" method and the "wait and weight" method. Rig personnel should

be familiar with, and trained in, these procedures.

Selection of the method to be used in a particular kick situation should be made

by an experienced, qualified drilling supervisor. The actual method used will depend

on knowledgeable considerations of surface pressure, type of influx, the time required

to execute the procedure, complexity of the procedure, down hole stresses that may

be present or introduced, and available equipment.

All of the above are suggested procedures, to be modified by a knowledgeable

drilling supervisor to suit the particular conditions existing at the time of the kick.

30?K:i~KS/W:::/F.Et:/Augu.s: 2C I : m VIII-3

_. .t·. _,,I

DRAFT

IX- BLOWOUT CLASSIFICATION

INTRODUCTION

Any uncontrolled flow of steam, brine or other well fluids constitutes a blow out.

A discharge of these fluids at the surface is usually taken as the basic identifier of a

blowout. However, surface discharge, if it occurs, is only the symptom or consequence

of the fundamental upset condition that results in a blowout.

In the context of Hawaii geothermal activities, a broader, yet more precise,

definition of a blowout can be stated as a "loss of control of the natural pressures and

fluids encountered in the drilling of a geothermal well."

There are several types of geothermal well blowouts, varying in their severity and

in the techniques needed to control them. The impacts on surface and subsurface

environments, resource waste, and public perceptions of these incidents demand that

Operators and regulators minimize the risks of blowouts. The types of blowouts that may

be experienced in Hawaii include the following:

A. SURFACE BLOWOUTS

1. Casing Contained. An uncontrolled flow of steam or other fluids through ..lk4

the casing and wellhead will result inrescape of fluids to the atmosphere. This

may result in unabated gas emissions and noise disruptive to the surrounding

community and the surface environment surrounding the well. This type of

blowout may cause minor to major damage to the wellhead, BOP equipment

stack, or drilling rig. Response to the blowout will depend on the specific

situation. Efforts will focus on wellhead repairs, control of fluid discharge,

and access to the area for specific procedures. The availability of drilling

fluid supplies (including water), and the condition of the drilling string and

casing will be key elements in an effective operation to regain well control.

2. Externally Vented.

• Moderate case - low-to-moderate fluid venting outside the casing

or the cellar; the drilling rig, wellhead and BOP are generally

BOPTYPES/WLD/July 14, 1992/REV October 13, 1992 IX-1

undamaged and operable. May or may not be disturbing to surrounding

community. Responses may include grouting at the leak to terminate

surface flow.

• Worst Case - venting volume and/or velocity leads to rig collapse

and/or cratering around or near the wellhead. Response will probably

require a relief well if the hole doesn't bridge or collapse on its own,

thus terminating the flow.

B. UNDERGROUND BLOWOUTS

Although this class of blowout lacks any surface display, the event could escalate

into a surface blowout if not recognized and resolved at an early time .

.1_ High pressure fluid upflows, in the open hole, from a deep zone to a

shallower permeable zone (lower temperature reservoir or groundwater). Such

events may range from serious degradation or destruction of the open hole,

to minor resource loss and conservation problems. Response is generally to

subdue the flow with water, weighted muds, or cement plugs as required.

Additional casing/liner probably will be required, or the well may be plugged

with cement for redrill or suspension.

~ High pressure fluid upflows, in the open hole, from a deep zone to an

escape by hydraulic fracturing at the deepest casing shoe, where the

formation (pressure) gradient is exceeded by higher fluid pressure from the

deep zone. Response as above in 1.

BOPTYPES/WLD/July 14, 1992/REV October 13, 1992 IX-2

DRAFT

X- SUPERVISION AND TRAINING

INTRODUCTION

The major cause of most blowouts is human error; either none of the crew or the

Operator's advisors recognizes an existing well control problem, or steps to control the

situation are not performed soon enough. Most blowouts are fully preventable by

properly trained drilling personnel. Thus, proper training of the crew is as important

to successful well control as is the proper selection and use of blowout prevention

equipment, as discussed in the preceding sections. The Hawaii conditions for

geothermal drilling require that every Operator recognize its prime responsibilities

to provide supervision and training that is several levels above the industry average.

Hawaii's geothermal drilling industry is still in a formative stage. Because there

is no pool of operators and drilling personnel thoroughly familiar with all potential

problems in Hawaii's geothermal resource areas, there is a need for operators and

drilling contractors to pay extraordinary attention to all elements of training for their

crews. There must be a proper balance between practical, on-the-job-training,

operational drills, and formal study for a wide range of individual experience levels.

In a few cases, drilling and monitoring crews will have worked together closely m

other geothermal areas, some of which may exhibit well control challenges similar to

Hawaii's. In other instances, crews will be made up of a mixture of individuals that

have not worked as a team before, and may have a larger percentage of new workers,

especially at lower skill levels in the drilling and production jobs.

An additional consideration in the Hawaii case is the known occurrences of

relatively high levels of H2s gas in the geothermal resource. Proper well planning and

equipment selection can mitigate many of the hazards of H2s drilling in the well control

sense, but it is necessary that all drilling crews have a clear understanding of the

dangers and rules that accompany drilling in known H2s zones.

SUPERVISORY EXPERIENCE

Although complete training for specific crews that will drill in Hawaii's

geothermal zones is of primary importance, the art of well control is not learned from

classroom training alone. Therefore, experienced supervisory personnel are vital to the

BOPTRAINING/RAP/October 13, 1992 X-1

process of training the drilling crews, as well as in lending their experiences to the

ongoing supervision of the drilling. Drilling plans submitted should discuss the levels

of experience of the drilling crews, supervisors, consultants and managers, with

comment on the methods to be taken to ensure that such experienced persons will be

directly involved while drilling activities are underway in Hawaii.

DRILLING TEAM TRAINING AND DRILLS

The training of drilling teams, including supervisory, management and operating

personnel, in well control and blowout protection can be discussed in three basic

levels. Level one:training through formal courses that are infrequently offered by

industry and regulatory organizations, often at a regional or national level; level two:

the training that an Operator conducts on a more or less formal, or classroom, basis

with its drilling supervisors, drilling crews, and others who directly support its Hawaii

drilling operations; level three: Operators must have a program of drills that ensure

all personnel actually have 'hands-on' experience with the installed blowout prevention

equipment.

A number of organizations conduct training and certification in well control,

mainly directed toward the petroleum drilling industry. However, recent classes in the

specifics of geothermal well control have been held by a cooperative effort of the

Geothermal Resources Council and the National Geothermal Association, with funding

in part by the Federal Department of Energy. This course has been approved by the

Federal Minerals Management Service for training and certification in well control

subjects, and is recommended for supervisory and other drilling personnel, as an

indication of the level of specific well control training and experiences of these

personnel assigned to Hawaii drilling tasks. There are no plans to hold these formal

courses often, and most certainly not in concert w-1th specific drilling schedules of

individual projects. Therefore, each Operator and drilling contractor will need to

supplement the experiences of their supervisory personnel with direct team training

pointed toward developing an integrated effort for Hawaiian projects.

Operators should outline the formal (classroom) training proposed for drilling

personnel, with specific references to 'kick' recognition and blowout prevention,

including monitoring systems, equipment, and drilling procedures. A number of study

guides and references are available for these purposes; publications to be used should

be listed in drilling plans so that they can be reviewed by regulatory review

personnel. A list of specific references is not included in this Manual because these

30PTRAlNlNG(m(October 13, 1992 X-2

publications may become obsolete by newer editions. Appendix C, References, contains

documents and sources used in preparing this Manual, and should be consulted for

suitability to each drilling plan.

In addition to classroom training and periodic updates as drill crews may shift

or the drilling may enter new phases, blowout prevention drills should be conducted

on a regular (but unannounced) basis to provide further training, and to keep crews

focussed on the possibilities of well kicks, and blowouts. Crews should be familiar with

the equipment in use, and be able to properly and safely shut in the well before a

control problem becomes dangerous to personnel or the well itself. These drills should

be directed at well control and proper blowout prevention procedures in three basic

situations - when drilling ahead, when 'tripping out' of the well, and when the drill

pipe is out of the wellbore.

Other blowout prevention and general safety training - both informal and on

the-job situations, should be outlined in the drilling plan. Subjects covered should

include new employee orientation, visitor briefings and general safety training. Formal

training sessions, regular review training and blowout prevention drills held should

be noted in the daily reports of the drilling operation.

BOPTRAINING/RAP/October 13, 1992 X-3

DRAFT

X I. POST COMPLETION BLOWOUT PREVENTION

It is important to realize that blowout risks are not restricted to the initial

drilling and completion of a geothermal well. At a much lower incidence rate, blowouts

can occur at producing wells and at shut-in idle wells. Wellhead equipment should be

recognized as vulnerable to natural surface conditions and vandalism. The capacity,

integrity, and security of geothermal wellhead equipment are all the responsibility of

a production engineering expertise which is not within the scope of this Blowout

Prevention Manual.

Two areas of subsurface risks to casing string integrity in existing Hawaiian

geothermal wells should be noted. The corrosion potential of wellbore fluids, in both

the production and shut-in (static) modes should be identified. Baseline chemistry and

casing evaluation procedures should be established shortly after well completion. The

objectives here are to assure and prolong casing integrity, and to preclude any

blowout consequent to a casing failure due to corrosion. Wells that have been tested

or have produced high temperature fluids, and then are shut-in for periods of time,

particularly require regular and accurate monitoring of casing conditions. Temperature

decreases imposed by the active Hawaiian ground water regime can accelerate H2s corrosion in shallow casing strings in idle wells. Finally, the tt~w-n-risk of casing

failure in rift zone eruptions and earthquakes e't'~{sha11o~i"faUlt movernerits;'gf¢uhd. di:Sfuptio!i or'tptati9h.~lf$fllir~~l), should be recognized.~-the--by-wo~d-of·eoneel 1"1-t:o

W"e1lbo1 e!!.

Blowout prevention requirements durins remedial work, redrills, recompletions

and abandonments, in all geothermal wells, must be e-valuated and provided for by the

same process of consideration required in every new geothermal well drilling permit

proposal.

80P'CS!CCMPLE7:0N/ILD/August 13, 1992 Xl-1

DRAFT

X I I - BLOWOUT PREVENTION IN SLIMHOLES

INTRODUCTION

Deep drilling with slimhole (approximately 4-6 inch bit diameters) technology and

equipment has achieved major advances in the mining industry in the last several

decades. However, the mining drilling environment does not present pressure control

problems comparable to those encountered in petroleum and geothermal drilling. For

this reason, well control practices in slimholes were poorly understood until recently.

This hindered an expanding use of th~ technology. However, the technical and

economic advantages of slimholes have recently registered with several petroleum

companies; Amoco Production Company has particularly investigated the requirements

' of well control and blowout prevention in slimhole drilling. 1

KEY ATTRIBUTES

Much smaller volumes of drilling fluids are circulated in slimholes. Kicks of any

volume are of more consequence, and immediate detection of fluid entry, or lost

circulation, is critical. Quantitative electromagnetic flow meters are used to measure

drilling fluid entry and exit volumes at the wellhead. These flow meters are reliable

and accurate, measuring gains of one barrel or less as compared to pit gains of 15

barrels or more as frequent kick events in the standard drilling mode. Unfortunately,

the much greater size of this type of meter required for standard diameter wellbores

make them cost prohibitive. Another feature of importance is the high annular

pressure loss (AP L) incurred by drilling fluid circulation in slim holes. The higher

rotary speeds (RPM) used in slimholes also adds, wit!T the APL, a substantial increase

(overbalance) above the hydrostatic pressure of the drilling fluid on the borehole

while actively drilling or coring. This physical phenomena relates to the very smal~

annuli between drill tubulars and the rock wall. The high APL can be used

advantageously to effect a dynamic kill and control of formation fluid entry below

2,500-foot depths in slimhole by accelerating the pumping rate to maximum levels in

Well Control Methods and Practices in Small-Diameter Wellbores; D. J. Bode, et al Amoco Production Co., October 1989. (Available from the Society of Petroleum Engineers, P. 0. Box 833836, Richardson, Texas 75083-3836; Telephone 214-669-3377.)

BOPSOH/WLD/Ju1y 13, 1992 X I I -1

circulating out the intruding fluids. In summary, blow out prevention in slim holes

requires special training, precision flowmeters, real time data presentation and

dynamic kill proficiency. It is likely that additional slimhole drilling will be considered

in Hawaii geothermal exploration and development; Operators should carefully evaluate

the Amoco paper referenced when developing plans for these boreholes.

BCPSOH/WLD/Ju1y 13, 1992 X I I -2

• I


APPENDIX A

MANUAL- REVIEW AND REVISIONS

DRAFT

APPENDIX A-

MANUAL REVIEW AND REVISION

Geothermal drilling experience in Hawaii, as of mid 1992, has been quite limited.

Only 14 deep geothermal boreholes had been drilled, and these were located on only

one prospective feature, the KERZ. Reasonable increases in geothermal drilling in the

KERZ, and perhaps other areas, can be anticipated. New operational and regulatory

experiences should accumulate in the next few years.

This Blowout Prevention Manual can best be accepted as a first edition. Ideally,

it should serve as a working reference for operators and regulators in a cooperative

approach to the achievement of blowout risk reduction.

It is recommended that this Manual be reviewed and revised within 5 years of

its date of issue by DLNR. Such a time interval seems ample for the collection of new

operating information and for a reasonable application of the blowout prevention

procedures recommended in the Manual. Frequent and informed discussion of blowout

prevention procedures between operators and regulators could prove to be one of the

most important consequences of the use of this Manual.

DLNR authorities might consider a workshop process as an appropriate element

of the review process. Both Hawaiian geothermal operators, and those working

elsewhere in similar volcanic domains, could join DLNR in a thorough evaluation of

blowout prevention in geothermal drilling. Such an invitational workshop might best

be conducted 6 to 8 months before the first revision of this Manual.

BOPREVISIONS-APPEND A/ILD/August 12 1992 1


APPENDIX 8

ILLUSTRATIONS

'

HAWAII GEOTHERMAL DIVERTER STACK

Fi9ure I.

A 2M ANNULAR PREVENTER

FLOW TEE or BANJO BOX

API ARRANGEMENT SA

2000 PSI

5

HAWAII GEOTHERMAL FULL BOP STACK

FiQure 2.

ROTATING HEAD

I G l When usinQ air

-installed on top of ANNULAR PREVENTER

RAM PREVENTER

RAM PREVENTER

KILL 2"

API ARRANGEMENT RSRS RRA

MIN. 3000 PSI

A ANNULAR PREVENTER

VENT/BLOOIE 12''

BLIND RAM ..

Remotely operated .. V.ALVE

CHOKE 4"

PIPE RAM

DRAFT

FI<3LJRE 3

In Hawaii, where wellhead temperatures in excess of 600°F may occur, Operators

must consider the pressure derating of steel due to elevated temperatures when

selecting wellhead equipment. The table below, from the American Petr-oleum Institute

(API) Specification 6A, provides the recommended working temperatures for steel at

high temperatures; this table goes only to 650°F.

In addition to the steel in wellhead equipment, the temperatures found in

Hawaii far exceed the temperature ratings of elastomers found in most BOP equipment.

Operators often use all steel rams in ram type preventers for a more effective seal.

The API recognizes temperature ratings of elastomers up to 250°F, but some

manufacturers can now produce elastomers that are rated to 420°F.

BOPFIGURE 3 HEW/October 14, 1992 APPENDIX B, FIG 3 -1

RECOMMENDED WORKING PRESSURES AT ELEVATED TEMPERATURES

E.1 Pressure-Temperature Derating. The maxi~um working oressure ratings given in this section are apoiicable to steei parts of the wellhead she11 or pressure containing structure, such as bodies, bonnets, covers, end flanges, metallic ring gaskets, welding ends, bolts, and nuts for metal temperatures between 20F and 650F (-29 and 343°C). These ratings do not aoply to any non-metal~ic resilient seaiing materials or plastic sealing materials, as covered in Par. 1.4.4.

Maximum Working

Pressure, psi (Bar)

TABLE E.1 PRESSURE-TEMPERATURE RATINGS OF STEEL PARTS

(See Par. 1.2.4) (1 BAR : 100 kPa)

(See Fa-ewa-d fa- Explanati:m ri Units)

Temperature, F CO-c)

0

(-29 to 121) 300 (149) 350 ( 177) 400 (204)

2000 ( 138. 0) 1955 ( 134 . 8) 1905 (131.4) 1860 (128.2) 3000 (2D7. D) 2930 (202.0) 2880 ( 197. 2) 2785 (192.0)

5ooo* (345. D) 4980 (336. 5) 4765 (323.5) 4645 (320.3)

~net apply to 500l psi 6BX conn«tD!s

Maximum Working

Pressure, psi (Bar)

TABLE E.1-Continued PRESSURE-TEMPERATURE RATINGS OF STEEL PARTS

(See Par. 1.2.4) (1 BAR: 100 kPa)

Temperature, F ~-C)

500 (260) 550 (288) 600 (316) 650 (343)

1735 (119.6) 1635 ( 113. 7) 1540 (106.2) 1430 (93.6) 2605 (179.6) 2455 (169.3) 2310 ( 159. 3) 2145 (147.9)

4340 (299.2) 4090 (232. 0) 3850 (285.5) 3575 (246. 5)

450 (232)

1810 (124.8) 2715 (187.2)

4525 (312 .D)

BOPFIGURE 3 HEW/October 14, 1992 APPEND I X B, FIG 3 -2


APPENDIX C

REFERENCES

AUTHOR: TITLE: API RECOMMENDED PRACTICES FOR SAFE DRILLING OF WELLS CONTAIN

PUBLISHER: API PUB_DATE: 1974

EDITION: PAGES:

ISBN: NOTES: API Amer. Petroleum Inst. RP 49

AUTHOR: TITLE: API RECOMMENDED PRACTICES FOR SAFE DRILLING OF WELLS CONTAIN


EDITION: PAGES:

ISBN: NOTES: API Amer. Petroleum Inst. RP" 49

AUTHOR: TITLE:

PUBLISHER: AN APPLICANT GUIDE TO STATE PERMITS AND APPROVALS FOR LAND DPED/CZM

PUB_DATE: EDITION:

PAGES: 22 ISBN:

1986

NOTES: AND WATER USE AND DEVELOPMENT

AUTHOR: TITLE: BLOWOUT PREVENTION EQUIPMENT SYSTEMS FOR DRILLING WELLS


EDITION: 2nd PAGES:

ISBN: NOTES: API-Amer. Petroleum Inst. RP 53

AUTHOR: TITLE: REGULATIONS AND RULES OF PRACTICE & PROCEDURE-GEOTHERMAL

PUBLISHER: Nevada PUB_DATE: 0

EDITION: PAGES:

ISBN: NOTES:

AUTHOR: TITLE: CAILIFORBNIA ADMINISTRATIVE CODE-Title 14, NATURAL RESOURCES

PUBLISHER: CA State PUB_DATE: 0

EDITION: PAGES:

ISBN: NOTES: chap.4, Sub-Chap. 4- State Wide Geothermal Re

AUTHOR: TITLE:

PUBLISHER: PUB_DATE:

EDITION:

RULES FOR GEOTHERMAL AND CABLE SYSTEM DEVELOPMENT PLANNING DLNR-DOWAL

1989

PAGES: 22 ISBN:

NOTES:

AUTHOR: TITLE:


EDITION: PAGES:

ISBN: NOTES:

AUTHOR: TITLE:


EDITION: PAGES:

ISBN: NOTES:

CHAPTER 185

PLANNING FOR DRILLING IN H2S ZONES PET EX

1978

44 0-88698-129-8

Golns.w.c. BLOWOUT PREVENTION Gulf Publ

0

214

PRACTICAL DRILLING TECHNOLOGY - VOL 1

AUTHOR: HALLMARK+ TITLE: OIL AND GAS BLOWOUT PREVENTION IN CALIFORNIA

PUBLISHER: CA DOG PUB_DATE: 1978

EDITION: Second PAGES: 65

ISBN: NOTES: Manual #M07

AUTHOR: Hills, A.+ TITLE: OVERVIEW OF STATUS, DEVELOPMENT APPROACH AND FINANCIAL FEASI

PUBLISHER: DBED PUB_DATE: 1988

EDITION: PAGES: 52

ISBN: NOTES:

AUTHOR: R.Thomas+ TITLE: INDEPENDEN"' ~~TECHNICAL INVESTIGATION 01:-·~GV UNPLANNED STEAM R

PUBLISHER: PUB_DATE: 1991

EDITION: PAGES: 22+

ISBN: NOTES:

AUTHOR: Rowley, J. TITLE: GEOTHERMAL STANDARDS .. A DECADE OF LEADERSHIP CONTINUES

PUBLISHER: GRC PUB_DATE: 1991

EDITION: Decemb PAGES: 4

ISBN: NOTES: Article, GRC Bulletin

AUTHOR: Sumida, G. TITLE: ALTERNATIVE APPROACHES TO THE LEGAL, INSTITUTIONAL AND FIN-

PUBLISHER: DPED PUB_DATE: 1986

EDITION: PAGES: 17

ISBN: NOTES: ANCIAL ASPECTS OF DEVELOPING AN INTER-ISLAND


APPENDIX D

GLOSSARY

Al?FEN'D I X D

GLOSS.AR.Y

A

accumulator n: 1. a vessel or tank that receives and temporarily stores a liquid used in a continuous process in a gas plant. 2. on a drilling rig, the storage device for nitrogen-pressurized hydraulic fluid, which is used in closing the blowout preventers.

annular blowout preventer n: a large valve, usually installed above the ram preventers, that forms a seal in the annular space between the pipe or 'k$llfj and wellbore or, if no pipe is present, on the wellbore itself. Compared to a ram blowout preventer.

API abbr: American Petroleum Institute

B

BHP abbr: bottom hole pressure.

BHT abbr: bottom hole temperature. ~ v;;d<

blowout n; A blowout is an uncontrolled flow of formation fluids or gas rom a well bore into the atmosphere or into lower pressure subsurface zones. A occurs when formation pressure exceeds the pressure applied by the column of drilling fluid) -:::L"P q \!(; cl<.. ~ '5 "" o.t- c. ~ -lv o t \e oP , j -1- ~ H \""e Hd ~ · • "' a. t=- ( et.D ooc .... .+ .

BOP equipment n: The entire array of equipment installed at the well to detect and control kicks and prevent blowouts. It includes the BOP stack, its actuating system, kill and choke lines, kelly cocks, safety valves and all other auxiliary equipment and monitoring devices.

bottom hole temperature n: The temperature of the fluids at the bottom of the hole. While drilling, these temperatures may be measured by minimum reading temperature devices, which only record temperatures above a .designed minimum, and may not provide an accurate bottom hole temperature. Bottom hole temperature readings should be recorded after a period of fluids circulation at a particular depth, in order to stabilize the reading.

blowout preventer n: the equipment installed at the wellhead to prevent atn:ontrolthe escape ofU .. J jpressure -~~'Jl~-~Heither in the annular space between the casing and drill pipe or in an open hole (i.e., hole with no drill pipe) during drilling and completion operations. The blowout preventer is located beneath the rig at the

1 Rotary Dri 11 ing BLOWOUT PREVENTION Unit I I I, Lesson 3; Petroleum Extension Service, The University of Texas at Austin, Austin Texas, in cooperation with the International Association of Drilling Contractors, Houston Texas. 1980; 97 pages.

BOPGLOSSARY/RAP/Auqust 14, 1992 1

surface See annular blowout preventer and ram blowout preventer.

BOP abbr: blowout preventer

BOP stack n: The array of preventers, spools, valves and all other equipment attached to the well head while drilling.

borehole n: the wellbore; the hole made by drilling or boring.

~k c

cap rock n~ 1. ridatl'ii:el:Y''impermeable rock overlying a geothermal reservoir that tends to preven~migration of formation fluids out of the reservoir.

casing n: steel pipe placed in a geothermal well as drilling pY09E'eBSeet advances. to prevent the wall of the hole from cavi.r}.g during drilli.ng,'[J.O.~:pro~':potable wat$t toni$~ and to provide a means of extracting steam or hot water if the well is productive.

cellar n: a pit in the ground to provide additional height between the rig floor and the wellhead, ·)m'a to accommodate the installation of blowout preventers, rathole, mousehole, and so forth. It also collects drainage water and other fluids for subsequent disposal.

cementing n: the application of a liquid slurry of cement and water to various points inside or outside the casing.

conductor pipe n: 1. a short string of large-diameter casing used to keep the top of the wellbore open and to provide a means of conveying the up-flowing drilling fluid from the wellbore to the mud pit. 2. a boot.

CSO abbr: complete shut off (of a geothermal well)

D

diverter n: a system used to control well blowouts~x-tll•lrL,..:1i~naril.litigL:at relatively shallow depths by directing the flow away from the rig. The diverter is part of the BOP Stack that includes an annular preventer with a vent line beneath. A valve on the vent line is installed so that it is opened whenever the 4ii••'~••-a:ririUlar preventer is closed.

drill collar n: a heavy, thick-walled tube, usually steel, used between the drill pipe and the bit in the drill stem to provide a pendulous effect to the drill stem.

drilling fluid n: a circulating fluid, one function of which is to force cuttings out of the wellbore and to the surface. While a mixture of clay, water, and other chemical additives is the most common drilling fluid, wells can also be drilled using air, gas, or water as the drilling fluid. Also called circulating fluid. See mud.

drillin s ool n: . 1 •• 1" a s acer m~tu?ljjiiilU)I~:.th*-' wellhead 9 P llitJII!!I_ i!!L 4&-, .. t .. M,;... P A4!4.. ..... ........ . equipment. It provides room between various wellhead devices (as the blowout preventers) so that devices in the drill stem (as a tool joint) can be suspended in it.

drill pipe n: the heavy seamless tubing used to rotate the bit and circulate the drilling


fluid. Joints of pipe are coupled together by means of tool joints.

drill string n: the column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and bit. Often, the term is loosely applied to include both drill pipe and drill collars. Compare drill stem.

E

electric well log n: a record of certain electrical characteristics of formations traversed by the her~ dt1lt'bit, made to identify the formations, determine the nature and amount of fluids they contain, and estimate their depth. Also called an electric log or electric survey.

F

flange n: a projecting rim or edge (as on pipe fittings and opening in pumps and vessels), usually drilled with holes to allow bolting to other flanged fittings.

formation pressure n: the force exerted by fluids in a formation, recorded in the hole at the level of the formation with the well shut in. Also called reservoir pressure or shut-in bottom-hole pressure. See reservoir pressure.

J

joint n: a single length of drill pipe or of drill collar, casing, or tubing, that has threaded connections at both ends. Several joints, screwed together, constitute a stand of pipe.

K

kelly n: the heavy steel member, four-or six-sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill pipe to turn the drill stem as the rotary table turns. It has a bored passageway that permits fluid to be circulated into the drill stem and up the annulus, or vice versa.

kelly cock n: a valve installed between the swivel and the kelly. When a high-pressure backflow begins inside the drill stem, the valve is closed to keep pressure off the swivel and rotary hose. See kelly.

kick n: an entry of water, gas, or other formation-fluid into the wellbore. It occurs because the 1~ressure exerted by the column of drilling fluid is not great enough to overcome the pressure exerted by the fluids in the formation drilled. If prompt actiDn is not taken to control the kick or kill the well, a blowout will occur.

kill linen: a high pressure line that connects the mud pump and the well and through which heavy drilling fluid can be pumped into the well to control a threatened blowout.

L

L.C. abbr: lost circulation

log n: a systematic recording of data, as from the driller's log, mud log, electrical well log, or radioactivity log. Many different logs are run in wells to obtain various characteristics of downhole formations. v: to record data.

BOPGLOSSARY/RAP/August 14, 1992 3

lost circulation n: the loss of quantities of whole mud to a formation, usually in cavernous, fissured, or c:earseb-:lillilUY permeable beds, evidenced by the complete or partial failure of the mud to return to the surface as it is being circulated in the hole. Lost circulation can lead to a Xllilf/ W~li~ if 'riot eohttb1l.Jid~ ea~lei~'bj"if'blo wout. 'LOSt dtthi!aftiljdt.A.Cdy~:riatie«t$-aftd;-i:ft-geft'M"M,--red\:!ce the efficiency of the drilling operation. It is also called lost returns.

M

manifold n: an accessory system of piping to a main p1pmg system (or another conductor) that serves to divide a flow into several parts, to combine several flows into one, or to reroute a flow to any one of several possible destinations.

mud n: the liquid circulated through the wellbore during rotary drilling and workover operations. In addition to its function of bringing cuttings to the surface, drilling mud cools and lubricates the bit and drill stem, protects against blowouts by holding back subsurface pressures;~-~~revent loss of fluids to the formation. Although it was originally a suspension of earth solids (especially clays) in water, the mud used in modern drilling operations is a more complex, three-phase mixture of liquids, reactive solids, and inert solids. The liquid phase may be fresh water, and may contain one or more conditioners. See drilling fluid.

mud logging n: the recording of information derived from examination and analysis of formation cuttings S.U.jadid]ii~th4!l•tM'IIsa, ..... ,....,mud:~~-d .circulated out of the hole. A portion of the muci is diverted through a gas-detecting device. Cuttings brought up by the mud are examined to detect potential geothermal production intervals. Mud logging is often carried out in a portable laboratory set up _,e.~the well. .

mud pits n pl: a series of open tanks, usually made of steel plates, through which the drilling mud is cycled to allow sand and sediments to settle out. Additives are mixed with the mud in the pits, and the fluid is temporarily stored there before being pumped back into the well. Modern rotary drilling rigs are generally provided with three or more pits, usually fabricated steel tanks fitted with built-in piping, valves, and mud agitators. Mud pits are also called shaker pits, settling pits, and suction pits, depending on their main purpose. Also called mud tanks.

mud weight n: a measure of the density of a drilling fluid expressed as pounds p~r gallon (ppg), pounds per cubic foot (lb/ft3), or kilograms per cubic meter (kg/mJ). Mud weight is directly related to the amount of pressure the column of drilling mud exerts at the bottom of the hole.

p

permeability n: 1. a measure of the ease with which fluids can flow through a porous rock. 2. the fluid conductivity of a porous medium. 3. the ability of a fluid to flow within the interconnected network of a porous medium.

pipe ram n: a sealing component for a blowout preventer that closes the annular space between the pipe and the blowout preventer or wellhead. See and blowout preventer.

pit-level indicator n: one of a series of devices that continuously monitors the level of the drilling mud in the mud pits. The indicator usually consists of float devices in the mud pits that sense the mud level and transmit data to a recording and alarm


device (called pit-volume recorder) mounted near the driller's position on the rig float". If the mud level drops too low or rises too high, the alarm sounds to warn the driller that action may be necessary to control lost circulation or to prevent a blowout.

pounds per gallon n: a measure of the density of a fluid (as drilling mud).

ppg abbr: pounds per gallon.

pressure n: the force that a fluid (liquid or gas) exerts when it is in some way confined within a vessel, pipe, hole in the ground, and so forth, such as that exerted against the inner wall of a tank or that exerted on the bottom of the wellbore by drilling mud. Pressure is often expressed in terms of force per unit of area, as pounds per square inch (psi).

R

ram n: the closing and sealing component on a blowout preventer. One of three types - blind, pipe, or shear - may be installed in several preventers mounted in a stack on top of the wellbore. Blind rams, when closed, form a seal on a hole that has no drill pipe in it; pipe rams, when closed, seal around the pipe; shear rams cut through drill pipe and then form a seal.

ram blowout preventer n: a blowout preventer that uses rams to seal off pressure on a d~i'P'fhch:HaYop~;lhole ... .._. .. .,.,......_._._, __ ..,_., It is also called a ram pre venter. See blowout preventer and ram.

reservoir pressure n: the pressure in a reservoir under normal conditions.

s

stack n: a vertical pile of blowout-prevention equipment. Also called preventer stack. See blowout preventer. v: to allow a geothermal well to flow to the atmosphere, usually without mufflers or abatement.

surface pipe n: the first string of casing (after the conductor pipe) that is set in a well, varying in length from a few hundred to several thousand feet. Compare conductor pipe.

T

trip n: the operation of hoisting the drill stem from_and returning it to the wellbore. v: shortened form of make a trip.

w

wellbore n: a borehole; the hole drilled by the bit. A wellbore may have casing in it or may be open (Le., uncased), or a portion of it may be cased and a portion of it may be open. Also called borehole or hole.

wellhead n: the equipment installed at the surface of the wellbore. A wellhead includes such equipment as the casinghead and tubing head. adj: pertaining to the wellhead (as wellhead pressure).

BOPGLOSSARY/RAP/August 14, 1992 5

DRAFT

APPENDIX D

GLOSSARY

A

accumulator n: 1. on a drilling rig, the storage device for nitrogen-pressurized hydraulic fluid, which is used in closing the blowout preventers.

annular blowout preventer n: a large valve, usually installed above the ram preventers, that forms a seal in the annular space between the pipe ~ifn:~~Y:i::and wellbore or, if no pipe is present, on the wellbore itself.

API ahhr: American Petroleum Institute

B

BHP ahhr: bottom hole pressure.

BHT ahhr: bottom hole temperature.

blowout n; A blowout is an uncontrolled flow of formation fluids or gas from a well bore into the atmosphere or into lower pressure subsurface zones. A blowout occurs when formation pressure exceeds the pressure applied by the column of drilling fluid.l

BOP equipment n: The entire array of equipment installed at the well to detect and control kicks and prevent blowouts. It includes the BOP stack, its actuating system, kill and choke lines, kelly cocks, safety valves and all other auxiliary equipment and monitoring devices.

bottom hole temperature n: The temperature of the fluids at the bottom of the hole. While drilling, these temperatures may be measured by minimum reading temperature devices, which only record temperatures above a designed minimum, and may not provide an accurate bottom hole temperature. Bottom hole temperature readings should be recorded after a period of fluids circulation at a particular depth, in order to stabilize the reading.

blowout preventer n: the equipment installed at the wellhead to prevent ~n¢P~i*-Pf:the escape of ~:li.!11pressure ~mfi~P.~\~N~~f:neither in the annular space between the casing and drill pipe or in an open hole (i.e., hole with no drill pipe) during drilling and completion operations. The blowout preventer is located beneath the rig at the surface See annular blowout preventer and ram blowout preventer.

1 Rotary Dri 11 ing BLOWOUT PREVENTION Unit I I I, Lesson 3; Petroleum Extension Service, The University of Texas at Austin, Austin Texas, in cooperation with the International Association of Drilling Contractors, Houston Texas. 1980; 97 pages.

BOPGLOSSARY/RAP/August 14, 1992 Appendix D-1

BOP abbr: blowout preventer

BOP stack n: The array of preventers/ spools1 valves and all other equipment attached to the well head while drilling.

borehole n: the wellbore; the hole made by drilling or boring.

c

casing n. steel pipe1 cemented in the wellbore to protect it against external fluids and rock conditions1 and to facilitate the reliable and safe production of geothermal fluids from the well.

cap rock n: 1. !t,~~~V~tlimpermeable rock overlying a geothermal reservoir that tends to prevent migration of formation fluids out of the reservoir.

cellar n: a pit in the ground to provide additional height between the rig floor and the wellheadnn~*-~ to accommodate the installation of blowout preventers/ rathole/ mousehole1 and so forth. It also collects drainage water and other fluids for subsequent disposal.

cementing n: the application of a liquid slurry of cement and water to various points inside or outside the casing.

~~p~:~m;:~:~:~g::~~~@!!q~lt~!i~4i!!qqij~m~~t!a~~::~~P9~~~!~$.1!~4iitP~~*~~ ~ :~~r::~~ljljti.ii,«f.~

conductor-pipe n: 1. a short string of large-diameter casing used to keep the top of the wellbore open and to provide a means of conveying the up-flowing drilling fluid from the wellbore to the mud pit. 2. a boot.

CSO abbr: complete shut off.~a-g~hertnai-welij

D

diverter n: a system used to control well blowouts efteet::~:nte!oed-;#ll!,i~mlf::4.~g;gat relatively shallow depths by directing the flow away from the rig. The diverter is part of the BOP stack that includes an annular preventer with a vent line beneath. A valve on the vent line is installed so that it is opened whenever the di:verler~ij.,~ preventer is closed.

drill collar n: a heavy 1 thick-walled tube1 usually steel1 used between the drill pipe and the bit in the drill stem to provide a pendulous effect to the drill stem.

BOPGLOSSARY/RAP/AUCJUSt 14, 1992 Appendix D-2

drilling fluid n: a circulating fluid, one function of which is to force cuttings out of the wellbore and to the surface. While a mixture of clay, water, and other chemical additives is the most common drilling fluid, wells can also be drilled using air, gas, or water as the drilling fluid. Also called circulating fluid. See mud.

drilling spool n: aft--accessory-~ti--as-a spacer in--i!~4T~#F~D#D!.~H:wellhead equipment. It provides room between various wellhead devices (as the blowout preventers) so that devices in the drill stem (as a tool joint) can be suspended in it.

drill pipe n: the heavy seamless tubing used to rotate the bit and circulate the drilling fluid. Joints of pipe are coupled together by means of tool joints.

drill string n: the column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and bit. Often, the term is loosely applied to include both drill pipe and drill collars. Compare drill stem.

F

:Bange n: a projecting rim or edge (as on pipe fittings and opening in pumps and vessels}, usually drilled with holes to allow bolting to other flanged fittings.

formation pressure n: the force exerted by fluids in a formation, recorded in the hole at the level of the formation with the well shut in. Also called reservoir pressure or shut-in bottom-hole pressure. See reservoir pressure.

J

jai.nt n: a single length of drill pipe or of drill collar, casing, or tubing, that has threaded connections at both ends. Several joints, screwed together, constitute a stand of pipe.

K

kelly n: the heavy steel member, four-or six-sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill pipe to turn the drill stem as the rotary table turns. It has a bored passageway that permits fluid to be circulated into the drill stem and up the annulus, or vice versa.

kelly cock n: a valve installed between the swivel and the kelly. When a high-pressure backflow begins inside the drill stem, the valve is closed to keep pressure off the swivel and rotary hose. See kelly.

kick n: an entry of water, gas, or other formation fluid into the wellbore. It occurs because the 'ijj~~C,l~~ipressure exerted by the column of drilling fluid is not great enough to overcome the pressure exerted by the fluids in the formation drilled. If prompt action is not taken to control the kick or kill the well, a blowout will occur.

kill linen: a high pressure line that connects the mud pump and the well and through which heavy drilling fluid can be pumped into the well to control a threatened blowout.

L

L.C. abbr: lost circulation

BOPGLOSSARY/RAP/l119ust 14, 1992 Appendix D-3

log n: a systematic recording of data, as from the driller's log, mud log, electrical well log, or radioactivity log. Many different logs are run in wells to obtain various characteristics of downhole formations. v: to record data.

lost circulat:iDn n: the loss of quantities of ~if:~4~J~:t\ii.i~~m*'l-whele-ml1d to a formation, usually in cavernous, fissured, or eoarsel:y-'~9,ffifit\Permeable beds, evidenced by the complete or partial failure of the fliddiito return to the surface as it is being circulated · th h 1 L st · ul ... ~- ····~········d··· to ,..;z:;.;.,..;:::::···,...:a.w"''''"'"'"'"'ia.'''' .. , .. ~.,.;.;;.n.;;.;a='" ....... ",,...,.:;Ji"1',.. m e o e. o Cl.I'C ai..UJn can ea a ~'"Jiol:;:::1h~aq.::a::b~.n.<::CO~~Ji11ft'. :;::c.ati:::.a..~::w.

~!iblowou~~;;~:~~~:ts:~~~~~·~·~ift~ener1li~~·re~·th~eiener·:.o£ ehe-drilling--operatiorr.--R-i:s--also-ea:H.ed-lost:-retttrns:

M

manifold n: an accessory system of piping to a main p1pmg system (or another conductor) that serves to divide a flow into several parts, to combine several flows into one, or to reroute a flow to any one of several pnssi.hle destinations.

mud n: the liquid circulated through the wellbore during rotary drilling and workover operations. In addition to its function of bringing cuttings to the surface, drilling mud cools and lubricates the bit and drill stem, protects against blowouts by holding back subsurface pressureS.;':inClF-to-prevent loss of fluids to the formation. Although it was originally a suspensiDn.of'.earth solids (especially clays) in water, the mud used in modern drilling operations is a more complex, three-phase mixture of liquids, reactive solids, and inert solids. The liquid phase may be fresh water, and may contain one or more conditioners. See drilling fluid.

mud logging n: the recording of information derived from examination and analysis of formation cuttings ~iiij~~:~~~j)made--by-the--mt-a~~~lP~H¥A1iP!9.~f-Ji~),ll~~ circulated out of the hole. A portion of the mud is diverted through a gas-detecting device. Cuttings brought up by the mud are examined to detect potential geothermal production intervals. Mud logging is often carried out in a portable laboratory set up ~~ti~:jat-the well.

mud pits n pl: a series of open tanks, usually made of steel plates, through which the drilling mud is cycled to allow sand and sediments to settle out. Additives are mixed with the mud in the pits, and the fluid is temporarily stored there before being pumped back into the well. Modern rotary drilling rigs are generally provided with three or more pits, usually fabricated steel tanks fitted with built-in piping, valves, and mud agitators. Mud pits are also called shaker pits, settling pits, and suction pits, depending on their main purpose. Also called mud tanks.

mud weight n: a measure of the density of a drilling fluid expressed as pounds per gallon (ppg), pounds per cubic foot (lb/ft3), or kilograms per cubic meter (kg/m3). Mud weight is directly related to the amount of pressure the column of drilling mud exerts at the bottom of the hole.

p

permeability n: 1. a measure of the ease with which fluids can flow through a porous rock. 2. the fluid conductivity of a porous medium. 3. the ability of a fluid to flow within the interconnected per-e-network of a porous medium.

pipe ram n: a sealing component for a blowout preventer that closes the annular space between the pipe and the blowout preventer or wellhead. See and blowout preventer.

BOPGLOSSARY/RAP/August 14, 1992 Appendix D-4

pit-level indicator n: one of a series of devices that continuously monitors the level of the drilling mud in the mud pits. The indicator usually consists of float devices in the mud pits that sense the mud level and transmit data to a recording and alarm device (called pit-volume recorder) mounted near the driller's position on the rig floor. If the mud level drops too low or rises too high, the alarm sounds to warn the driller that action may be necessary to control lost circulation or to prevent a blowout.

pounds per gallon n: a measure of the density of a fluid (as drilling mud).

ppg abbr: pounds per gallon.

pressure n: the force that a fluid (liquid or gas) exerts when it is in some way confined within a vessel, pipe, hole in the ground, and so forth, such as that exerted against the inner wall of a tank or that exerted on the bottom of the wellbore by drilling mud. Pressure is often expressed in terms of force per unit of area, as pounds per square inch (psi).

R

ram n: the closing and sealing component on a blowout preventer. One of three types - blind, pipe, or shear - may be installed in several preventers mounted in a stack on top of the wellbore. Blind rams, when closed, form a seal on a hole that has no drill pipe in it; pipe rams, when closed, seal around the pipe; shear rams cut through drill pipe and then form a seal.

ram blowout preventer n: a blowout preventer that uses rams to seal off pressure on a 4.~i.P:'~~l¢, .. ~j:j~i.)i*"~j:».:::~n~;;hole--that:-is-"With-or-wi.t:hout-pipe. It is also called a ram preventer. See blowout preventer and ram.

reservoir pressure n: the pressure in a reservoir under normal conditions.

s

sl:aek-n~a-ve~"'lrile-c£-Nowout--prevention-equi-pment.--~eal:led-~-staek-: See-blowout-preventer-:-~-to--Mlow-e;~hennal weil-to-Bow-to~1!1t~:here1~:r witho11~-lfttlftlers--or-~

surface ~~-pipe n: the first string of ~:jj!i.P#Uea!Sin9-(after the conductor-pipe) that is set in a well, varying in length from a few hundred to several thousand feet. eom:pM"e'-eoftdlietor-pipe:

T

trip n: the operation of hoisting the drill stem from and returning it to the wellbore. v: shortened form of make a trip.

w

wellbore n: a borehole; the hole drilled by the bit. A wellbore may have casing in it or may be open (i.e., uncased), or a portion of it may be cased and a portion of it may be open. Also called borehole or hole.

BOPGLOSSARY/RAP/Auqust 14, 1992 Appendix D-5

wellhead n: the equipment installed at the surface of the wellbore. A wellhead includes such equipment as the casinghead and tubing head. adj: pertaining to the wellhead (as wellhead pressure).

BOPGLOSSARY/RAP/A119ust 14, 1992 Appendix D-6

R- A- PATTERSON & ASSOCIATES

~at~ September 25 1 1992

TO: Jonathan Flores/ Bill D'Olierr Herb Wheeler

SUBJECT: DRAFT BOP MANUAL

The enclosed material is a "redline/strikeout" revision to the draft BOP Manual. It has been marked with a ~t:r±keotlt to show DOWALD recommended deletions and with a redTirie indication to show additions. Minor typos, where noted, have been corrected without marking. Sections without DOWALD notations are not included.

Please review the documents for changes and agreement with the DOWALD comments. If any of the comments or markings are not clear 1 please call me. All of these marked changes can be made with one command on the word processor/ after any further changes are made following your review.

As discussed with .Jon Flores on 9/23, DOWALD's intention is to send copies to the at least some of the list of reviewers that we provided. After this round of review/comment, we would then produce the final version.

enclosure

LNRMEM 16/RAP

September 23,1992

TO: M. Tagomori and G. Akita

FROM: Jonathan Florez

SUBJECT: Progress of Hawaii Blowout Prevention Manual and Geothermal Drilling Guide

On September 23, 1992, I met with Ralph Patterson of Patterson & Associates to review and discuss DOWALD's edit requests for the first draft of the Hawaii Blowout Prevention Manual. Mr.Patterson agreed that the edit requests were valid, and he will now produce a copy showing the DLNR deletions and additions, which will be sent to Bill D'Olier and Herbert Wheeler (the principal authors of the manual), and DOWALD early next week for further review. Mr. Patterson will have clean corrected draft copies available for the suggested list of geothermal consultant/contractors in middle to late October, 1992.

Included in the attached packet are:

1) R. A. Patterson's August - September invoice

2) R. A. Patterson's Activity Report

3) DLNR mark-up copy of the Hawaii Blowout Prevention Manual

4) R. A. Patterson's Draft copy of the Table of Contents for the Hawaii Geothermal Drilling Guide

R. A. PATTERSON & ASSOCIATES

MEr:--10RAND'UM Date: September 22, 1992


SUBJECT: Activity report - Contract RCUH #4361021

SUMMARY - 16 AUGUST - 15 SEPTEMBER

During the period of this report, activities consisted of:

-Shifting attention to completion of the review draft of the Drilling Guide. A copy if the revised Table of Contents for this document is enclosed.

- Forwarding of a suggested listing of reviewers for the BOP Manual draft.

- We have scheduled a visit to Hawaii by Messrs. D'Olier and Wheeler for a review meeting and discussion on OCTOBER 20, 1992. (Reservations were made to take advantage of the low air fares available in June)

PROBLEMS ENCOUNTERED

No specific problems have been encountered, either in the availability of resource information, or in the scheduling of the work.

enclosures

DLKR PROGRESS 07/RAP September 22, 1992

1

HAWAII GEOTHERMAL DRILLING GUIDE

DRAFT

TABLE OF CONTENTS (Revised: 4 September 1992/WLD)

I. INTRODUCTION WLD/RAP

A. Objectives of the Guide • Describe key concerns and issues of drilling as critical first

task to develop Hawaii's geothermal assets. • State the purpose: to assist developers, regulators and public

as a supplement to State geothermal drilling regulations. • Compare geothermal potential to Hawaii's ground water

resource; water well drilling has provided an incalculable pub lie benefit.

• Promote safe and least obtrusive drilling practices to contribute to optimal use of Hawaii's geothermal resources.

B. Geothermal historical summary

II. SCOPE

• Hawaii's knowledge of volcanic activity, culminating in King's realization of its energy potential through his inquiries to Thomas Edison regarding volcano's use for electricity.

• Hawaii Thermal Power Company's first holes in the KERZ -early 1960's.

• HGP-A project of UH/State/County; 1976 discovery well; >7 years of production of electricity (82-90); purchase of drill rig and early exploration by local firm - GEDCO.

• Recent drilling on Hawaii State leases ('80-'92); 30 MW plant built and tested for power delivery to HELCO - 1992.

RAP

A. Key Information Sources • KERZ drilling to date - > 14 wells/SOH; multiple operators. • Geothermal industry literature; selected industry experiences. • Drilling contractors, qualified in the geothermal sector.

B. Brief on contents and organization of the Guide • Guide's relationship to Chap 183 - DLNR Regulations for

Geothermal Drilling; indicate expected revision to these Regs.

Ill. PERMITTING HAWAII GEOTHERMAL WELLS RAP

A. Introduction B. Approval Process c. State and County Permits

DRILLING GUIDE CONTENTS/September 23, 1992 1

IV. GENERAL REQUIREMENTS FOR DRILLING OPERATORS ALL

A. Strong Operator needed; in experience, commitment and financing. B. Highest quality professionals needed to manage, supervise and execute drilling plans and operations. C. Careful selection of drilling contractor: quality of supervision, crews, equipment and geothermal drilling experience; costs a secondary element. D. Capacity to identify and manage difficult logistics/support services from distant sources.

V. GEOTHERMAL DRILLING ENVIRONMENT WLD

A. Active volcanism: basis of the geothermal resource. • Rift's magma transport function and subsurface heat. • Rift zone summary of geology (lava flow sequence and dikes),

hydrology, structure, seismicity, etc. • Vertical/directional drilling not difficult, but costly.

B. Subsurface conditions and hazards • High temperature ranges; consequent high fluid pressures. • Large torsional faults/fractures; entry and blowout risks. • Weak, near surface volcanics; shallow cementing problems;

possible lava tubes/consequences, ground disruptions. • H2s gas in the geothermal zones: safety requirements for the

crews, mitigation for the public. C. Drillsite Selection Criteria

• Elevated drillsites to offset surface lava flow risks. • Multiple wellhead pads - better defended from lava flows,

total land use considerations. • Occasional proximity to residential areas will raise visibility

and awareness of emissions and noise mitigation requirements. D. Summary

• Probable wellfield scene; clustered wellheads to reduce roads and powerline/piping grid.

• Optimal use of every well, of directional drilling and recompletion options to minimize total well count.

VI. GEOTHERMAL WELL PLANNING HEW/WLD

A. Introduction and Well Planning Objectives

B. Drilling targets and well types

C. Casing design and cementing; surface, intermediate, production casing

D. Drilling fluid options/uses; broad range and switching capacity

E. Drilling monitoring and blowout prevention

F. Well completion requirements; production, injection service, liners, hang-down strings, wellhead equipment grades

G. Safety issues, precautions, crew training


VII. THE DRILLING PROGRAM HEW/RAP

A. Criteria/content for the written document - as attachment to drilling permit application given to DLNR. (study/compare PGV KS-9 & True KA3-1 documents) ·

B. Explain drilling program as 1. Product of a creditable well planning process. 2. The mutually accepted understanding, between Operator and DLNR, of the well construction process. 3. The baseline reference from which all required changes, in actual drilling conditions encountered, will be derived.

VI I I. WELL FLOW TESTING WLD

A. Rational for testing following well completion - safety issues

B. Water injection with wellbore temperature surveys for permeability identity.

C. Thermal recovery and wellbore heat up by bleed flow

D. Vertical venting, full flow to clean fluids for safer, continuous long flow test interval

E. Long flow mode; identify production capacity and parameters; sample all fluid components; mitigate all H2s emissions

F. Step rate flow for well deliverability plot and plant design input

G. Well shut in and pressures build up

IX. SLIMHOLE DRILLING OPTION WLD

A. Summary of SOH program in KERZ; attributes in Hawaii

B. Cite the potential of this technology for exploration, development step out wells, monitoring, and scientific objectives

C. Caution re: blowout risks; cite available special BOP equipment, procedures and skills required.

x. DRILLING DOCUMENTATION AND REPORTING ALL

A. Daily tour reports and special entries thereon

B. Well drilling history and well completion reports

C. Other documents, if appropriate

D. Operator - Regulator interface during drilling operations (Guide needs to point to necessity of good Operator-Regulator communications on drilling upsets and changes that will occur. Precise verbal communications, brief meetings on specific issues/problems, are invaluable tools when hole conditions force departures from the Drilling Plan.)


R- A- PATTERSON & ASSOCIATES

Date: August 24, 1992


SUBJECT: Activity report - Contract RCUH #4361021

SUMMARY - 16 JULY - 15 AUGUST

During the period, activities consisted of:

-Completion of the draft of the review draft of the BOP Manual, two copies of which are enclosed.

- We will present a suggested listing of reviewers for this draft under separate cover.

- We wi 11 be seeking cooperation to have the BOP Manual review completed by the first of October, and have scheduled a visit to Hawaii by Messrs. D'Olier and Wheeler for a review meeting and discussion on OCTOBER 20, 1992. (Reservations were made to take advantage of the low air fares available in June)

PROBLEMS ENCOUNTERED

No specific problems have been encountered, either in the availability of resource information, or in the scheduling of the work.

enclosures

DLHR PROGRESS 06/RAP August 24, 1992

1

HAWAI ~-~EOTHERMAL BLOWOUT PREVENTl6N MANUAL DRAFT

TABLE OF CONTENTS

(Revised: May 29, 1992/RAP)

__ I, INTRODUCTION AND SUMMARY

A. OBJECTIVES (a Statement of Purposes- with same sample concepts)

1 . B 1 owout Prevention as it can be best practiced in Hawaii, for safe drilling/ completion of all wells required in exploration & development.

2. One document to guide both operators and State regulators to determine, approve and use Blowout Prevention requirements appropriate to each dr i 11 i ng propos a 1 . Manu a 1 is intended to supplement regulations and to promote the use of an informed flexibility in Blowout Prevention practice, especially when modifications are required by drilling condition changes.

B. SCOPE (of Manual's contents)

1. Key information sources 2. KERZ Drilling to date 3. GT dri 11 ing in other

volcanic domains 4. Specific publications and

selected references C. Geothermal well types

1. Exploration 2. Production 3. Injection 4. SOH's 5. Vertical/deviated bores 6. Etc.

D. Organization of Manual Successful blowout prevention is a matrix of

1. Risk analyses 2. Procedures 3. Equipment

E. Hawaii situation Limited drilling experiences (14 KERZ wells to date) NOTE: Manual should became a basic working tool to all parties at interest. Expected1y, a large, we11 infonned group wi 11 contribute to a revision within five years.

F. Permitting Hawaii Geotherma 1 We 11 s 1. DLNR Admin. Rules, Chap 183 2. Other State permits 3. County permits

G. Resource Management and Safety

H. KERZ Drilling Experience

__ I 1 __ • GEOLOGY AND DRILLING RISK ANALYSIS A. SLITlllary

1. KERZ drilling to date 2. Prospective GT areas

a. High Temp (500-900F) b. Rift structure c. Rift functions d. Rock geometry e. Hydrology

Note: Ccmbination of high terrps. and large fracture conduits present risk of sudden meet i ng of overpressured high temperature fluids in the rift zones. We 11 s KS-7 and -8 proved the existence of this hazard and demonstrated penetration risk. Note: these are major f 1 u i d production zones, too.

B. Precursor signals 1 . Mud and bot tan temp.

increase 2. Mineral alterations 3. Entrained gasses/fluids 4. Impacts on mud or fluids 5. Changes in drilling and

casing programs Note: Operators and regulators must have an awareness/detailed knowJed9e of subsurface hazards in vo Jeanie rift zone; operator's proposa 1, and DLNR approva 1 of drilling/casing and blowout prevention plans always face two tests- pre-drilling and while drillin9.

_I _I 1_. WELL PLANN I NG AND DES I GN

A. Classification Of Reser-voir-s 1. High Temp. 2. Low Temp. 3. High Pressure 4. Low Press. 5. Hot Dry 6. Vapor Daninated 7. Water Dominated

B. Classification Of Wells

1. Exploratory ~lls 2. Production Wells 3. Injection Wells 4. Shallow Wells 5. Deep Wells 6. Slim Hole Wells

C. The Drilling Plan 1. Site Selection 2. Cellar -

a. Depth b. Construction

3. Personnel Training and Experience

D. Emergency Planning

C. Experience and Training 1. Drilling Supervision

a. Operator b. Drilling Contractor c. State and County

Agencies 2. Crew Training and

Instruction a T r a i n i n g

materials/subjects

~

~

b. Scheduling c. Testing and retraining

EQUIPMENT SELECTION

A. Selection of Rig/Drilling 1. PLfllJ Sizes 2. Circulation System 3. F 1 u i d Coo 1 i ng 4. Fluid Storage 5. Cooling Water Supply

B. Valves

c. Piping

D. lnstrunentation and Alarms

BOP EQUIPMENT

A. RAM Preventers 1. Single Gate 2. Double Gate 3. Annular 4. Rotating Head

B. Actuating System C. Control Stations

1. Back-up System D. Slab Gates E. Banjo Box F. BOP Stack Configurations

1. Kill and Choke Lines

Equip.

2

Internal Preventers 3. Safety Valves 4. Kelly Locks 5. Choke Manifold 6. Blooie Line 7. Muffler

G. Diverters H. Fluid Monitoring and Alarms I. Drill Pipe Floats

VI. EQUIPMENT TESTING AND INSPECTION

A. Testing and I nspect ion by State Authority

B. Periodic Testing of Closing System C. Periodic Crew Training and BOP

Drills

~ CASING PROGRAM

A. Conductor B. Surface Casing C. Protection Casing D. Cementing

VI I I. DRILLING PROCEDURES

A. Drilling fluid monitoring-first line of defense

B. Drilling penetration rate-fracture indicator

Alarms

c. D. E. F.

1. Bit weight 2. Torque

Drilling with Mud or Water Drilling with Air Drilling with Mud/Air, Foam, Misc.

Drilling Fluid Monitoring and

G. Formation and Lithology Monitoring H. Crew BOP Drills I. Changes in Dri 11 ing and casing

procedures due to changes in hole conditions

~ KICK CONTROL PROCEDURES

A. Training of Crews B. Kicks

1. While Drilling 2. While Tripping out of hole

C. Procedures involving H2S D. Notification of Authorities

LOGGING AND REPORTS

A. Mud Logging - On Site Geologist B. Reporting

1. Drilling Contractor

2. Operator 3. Regulatory authorities

~ POST DRILLING BLOW OUT PREVENTION A. Wellhead Equipment Specifications B. Inspection and Testing C. Flow Lines and Surface Equipment D. Corrosion and Erosion Centro 1 -

Inspection and Monitoring.

APPENDICES

- Procedures for Manual Updates

- Illustrations

- References

- Glossary of BOP terms

3

R- A- PATTER~N & ASSOCIAT~ 1274 Kika Street Kailua, Hawaii 96734-4521 (808) 262-5651 (808) 262-5350 (FAX)

March 18, 1992

Mr. Manabu Tagomori Department of Land & Natural Resources Division of Water and Land Development P. 0. Box 373 Honolulu, HI 96809

Dear Mr. Tagomori;

As a result of our productive meeting yesterday, we have revised the proposed tasks and changed the attached Scope of Work For a DLNR Technical Services Contract, which was enclosed in our March 16, 1992 letter. The purpose of the contract which covers these tasks will be to provide

1) a Hawaii Blowout Prevention Manual, to include both operating procedures and equipment specifications, and 2) a Hawaii Geothermal Drilling Guide, including standards as they can be defined at this time.

We estimate that Tasks 1-3 of the work can be completed within five months (22 weeks) after the signing of the RCUH contract. We have estimated that 8 weeks will be required, after distribution by DLNR, for review of the drafts and the receipt of comments; revising the draft documents and final production (Tasks 4 and 5) is expected to take 3-4 weeks after comments are received.

Presentations to the DLNR staff and TAC can be completed in 4-6 days, including preparations of visuals, etc., and presentation, and will depend on schedules of these groups. Thus, the entire project is estimated to be finished in eight and one-half months (35 weeks).

Sincerely,

'\i?~ enclosure

SCOPE OF WORK FOR

A DLNR TECHNICAL SERVICES CONTRACT

REVISED

March 18, 1992

R. A. Patterson & Associates {RPA) proposes the following tasks to carry out the objectives requested by Department of Land & Natural Resources (DLNR) letter, dated February 27, 1992. Tasks will includi the conduct of research and analysis and then development, review, and production of two manuals for use in Hawaii geothermal drilling activities:

1) a Ha'W'aii B10'W'c:n . .1t Pr~"V~ti~ ~""U.a.1, and

2) a Ha'W'aii Geoth~Ln1161.1 Dr:i.11:i.:n.g Gu..::ide:

Task 1. Gather and review existing data, blowout prevention specifications and procedures, and drilling rules, standards, and procedures for Hawaii and other governmental and regulatory jurisdictions, with emphasis on geothermal areas with identified geophysical characteristics similar to Hawaii.

Gather existing data on geothermal drilling results problems to date in the Kilauea East Rift Zone (KERZ}, particular attention to the blowouts that occurred at the Geothermal Venture wells, KS-7 and KS-8.

Provide regular, informal progress reports to DLNR.

and with Puna

DELIVERABLES - Reference 1 isting of sources and data gathered. ESTIMATED HOURS - 180

Task 2. Draft proposed Hawaii Blowout Prevention Manual for geothermal drilling activities, using the attached draft Table of Contents as a guide.

Provide suggested list of reviewers for DLNR approval.

Present draft Manual to DLNR for review and discussion.

DELIVERABLES Two complete copies of draft Hawaii Blowout Prevention Manual. ESTIMATED HOURS - 96

1

Task 3. Draft proposed Hawaii Geothermal Drilling Guide, using and revising as necessary, the attached draft Table of Contents, and incorporating specific standards as they can be defined at this time.

Provide suggested list of reviewers for DLNR approval.

Present to DLHR for review and discussion.

DELlVERABLES Two complete copies of draft Hawaii Geothermal Drilling Guide. ESTIMATED HOURS - 96

Task 4 .. Revise Hawaii Blowout Prevention Manual and Geothermal Drilling Guide, based on comments of DLHR and other reviewers.

DELIVERABLES .- Revised documents (three Manual - one unbound for reproduction, copies). ESTIMATED HOURS -

Task 5.

copies of each and two bound

104

Present final Hawaii Blow-Out Prevention Manual and Drilling Guide to DLHR.

Develop materials (visual aids, handouts, etc.} and make presentations to DLNR staff and to the 'l'AC (2 presentations)

DELIVERABLES - Presentation materials. ESTIMATED HOURS -

Attachment - Draft Tables of Contents for Manuals

DLHRSOW.DOC-3/18/92/RAP

2

72

DRAFT HAWAII GEOTHERMAL DRILLING GUIDE

TABLE OF CONTENTS

- Introduction/Summary o Permit Process o Safety and Resource Management o KERZ Drilllng Experience/Wells Drilled

- Geothermal Well Types o Exploration, Production, Injection,. Monitoring,

Water Supply, ScienUUc Observation - Hawall Conditions

o Risks o Problem Areas

-General Requirements- Hawaii Drilling o Planning - Field/Wells o Safety o Operator Competence/Experience o Drilling Procedures o Monitoring and Reporting

- Well Testing o Safety o Equipment o Procedures o Reports

- Industry Oversight Organizations o Geothermal Drilling Organization - GDO o American Society of Testing & Materials - ASTM o Others

nn 1\ t.'T

DRAFT HAWAII BLOWOUT PREVENTION MANUAL

TABLE OF CONTENTS

- Introductio~ and Summary o Permit Process o Safety and Resource Management o KERZ Drilling Experience

- Planning and Design -Experience and Training - Equipment Selection

· o Cooling Water Supply o Valves o Piping o Instrumen taU on and Alarms

- Drilling Procedures o Supervision o Monitoring o Temperatures o Pressures

- Casing Program - Logging and Reports

APPENDICES • Manual Updates - Procedures • Graphics

SCOPE OF WORK FOR

A DLNR TECHNICAL SERVICES CONTRACT

SUMMARY - ESTIMATED TASK HOURS

TASK RAP HEW WLD 1 72 36 72

2 48 32 16

3 52 28 16

4 52 28 24

5 .!Q_ l.L 8 TOTAL 264 148 136

COSTS

TOTAL PROFESSIONAL HOURS (ESTIMATE)

TOTAL PROFESSIONAL FEES (EST-INCLUDES OVERHEAD)

HAWAII GET (4%) ..

SUBTOTAL, REVISED

TOTAL 180

96

96

104

TL 548

548

$54,800

$2,192

$56,992

It is our estimate that some travel will be required during the data gathering and presentation phases, and perhaps for hearings, etc. Travel costs wi 11 be treated as a reimbursable expense. An estimate of the travel required is presented below:

TRAVEL (ESTIMATE) Three RT SAC-HNL- $1,500, 14 days lodging @ $75/day, 12 days rental car@ $35/day, and 14 x$40/day meals and mise expenses. 3 RT HNL-AUCK - $1350, 12 days 1 edging at $7 5/day, 4 days rental car @ $30/day, 12 days meals and mise @ $40/day. 2 RT HNL-HILO - $200, 3 days rental car @ $30/day, 6 night's lodging @ $ 80/day, and 6 x$30/day meals and misc ... $7,330

TOTAL, REVISED $64,322

DLKRSOK.DOC-3/18/92/RAP

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