Introduction to Drilling

Post on 23-Apr-2017

251 views 3 download

Transcript of Introduction to Drilling

Drilling and CompletionsDrilling and Completions

Spectrum ofSpectrum ofD&C activityD&C activity

DRILLING & COMPLETIONSBASICS

Main Components of a Drilling Rig

All drilling rigs have the following basic systems

•Hoisting•Rotating•Circulating & Solids Control•Power•Blowout Prevention

Hoisting System

Used for raising and lowering the drilling assembly, and for running casing, completion equipment and other tools in and out of the hole.

Rotating SystemA hexagonal or square pipe is

connected to the topmost joint of the drill string. The rotary table and kelly drive bushing impart

rotation to the drill string while allowing it to be moved up or

down.

As an alternative to the kelly and rotary table, most modern rigs employ a Top Drive system for rotating the drill string. A powerful electric or hydraulic motor is suspended from the traveling block.

Circulating SystemDuring drilling, fluid is continuously pumped down the drill string, through the bit, and up the annular space between the hole and the drill string. Its main purpose is to bring up the cuttings, cool the bit, maintain hole stability, and prevent formation fluids from entering the wellbore.

Circulating System & Solids Control

Types of Drilling Fluids

Non-dispersedDispersed

Calcium treatedSaltwater based

Low solidsPolymer

Water-based PneumaticOil-based

Diesel basedMineral Oil based

Synthetic:EstersEthersOlefins

Dry air/gasMistFoam

Aerated mud

Selection of the type of drilling fluid systems for a well is based on:PERFORMANCE, ECONOMICS, and ENVIRONMENTAL CONSIDERATIONSMore than one system may be used in the same well.

Diesel Electric

Power SystemMost modern rigs are electric. Generally, large diesel engines are the primary source of power. Electric power generated by the engines is first converted from AC to DC in the SCR unit. DC motors supply power to the drawworks, rotary, and pumps. AC power is still used for auxiliary equipment.

Drill String & BitHole is made by turning a bit connected to the bottom of the drill string and applying weight at the same time.

The bit is turned either entirely by drill pipe rotation from surface or with the help of a downhole motor which rotates when drilling fluid is pumped through it.

Drill pipe

Drill collars

Measurementtools

Downholemotor

BottomHole

Assembly

Bit

Bit Types

Roller Cone

Fixed Cutter

Steel tooth

DiamondNatural & Synthetic

DiamondPDC

Tungsten Carbide Insert

Well ControlPrimary control of wellbore pressures is maintained by ensuring that the hydrostatic pressure of the drilling fluid in the well is always slightly higher than the highest formation pressure exposed to the open wellbore. Primary control is lost if a kick is taken due to imbalance of pressures.

RIG TYPES

Inland Barge

Semisubmersible

Land

Jackup

Drillship

Types ofDrilling Rigs

Land RigPlatform

Jack-upSemi-Submersible

Drill ShipT.L.P.

Offshore Drilling Rigs SUBMERSIBLE (35 – 50 world wide)

INLAND BARGES (POSTED) - Very Shallow Water (up to 20 –22ft) SUBMERSIBLE RIG / BARGE - Shallow Water (up to 70 – 100ft)

PLATFORM Intermediate Water (Petronius US GOM=

1800ft+)

JACK-UP Shallow to Intermediate Water(+/-400 worldwide) (20 – 400ft, very few 300ft)

SEMI-SUBMERSIBLE Intermediate – Deep Water(+/– 180 world wide) (300 – 7500+ft)

DRILL SHIP Intermediate – Deep Water(+/- 50 world wide) (200 – 10,000ft)

SHALLOW-WATER BARGE RIG

PLATFORM RIG

JACK-UP RIG

Derrick cantileveredover stern of hull.

Well conductor

SEMI-SUBMERSIBLE RIG

“Ocean America” (on tow)

Year Rated Water Deck Mud BOPBuilt Depth (ft) Load (tons) Capacity (bbls) (Mpsi)

5th 97+ 5000-10000 6000+ 6000+ 15

4th 86+ 2000-5000 4000-5000 4000+ 15

3rd 81-85 1200-2500 2500-3500 2000-3000 15

2nd 73-80 600-1500 1500-2500 1500-2500 10

1st pre-73 600 <1500 <2000 10

Semi-Submersible Generations

Transocean “Discoverer 534” and “Discoverer Enterprise”

Transocean’s “Deepwater Discovery”

(+800ft long)

DRILLSHIPS

1. COST

Approximate Rig Rates (September ‘02)

Jack-Up (GoM) $30 K /day

2nd / 3rd Generation Semi (<2,000 ft) $40 – 70 K / day

Enhanced 3rd Generation Semi (4,500ft WD) $100-130 K / day

DP Semi’s & Drill Ships $150-180 K / day

DP Dual Activity Drill Ships $200 K / day

WELL CONSTRUCTION & EVALUATION

Well Construction and Well Types

By Objective

• Exploration•P&A or keeper

• Delineation•Size of

reservoir• Appraisal

•Reservoir characteristics

• Development•Reservoir

drainage• Injection

•Pressure maintenance

0 ft Rig Datum - RKB

Mud Wt (ppg)

Dep

th (f

eet)

PP FG

Mud Wt (ppg)

Dep

th (f

eet)

PP FG

Primary Cementing Process

3 Displacing Cement 4 Job completed2 Pumping Cement

BottomPlug

TopPlug

CementHead

1 Hole conditioning

FloatShoe

FloatCollar

AnnulusOutlet

Full-bore plug cementing Full-bore plug cementing The Conventional jobThe Conventional job

Directional Drilling - Why?• On Land:

– Surface constraint due to land owner, natural event, etc.

– Relief well in blowout situation

– Horizontal

• Offshore:– Save Cost on Platform– Relief well in blowout situation– Horizontal– Extended Reach– Multi-Lateral

Angle Build with Motors

• Bent Sub w/ Straight Motor

• Single Bend Steerable

• Double Bend Steerable

MWD vs Near Bit Sensor

Evaluation MethodsMud

Logging and LWD/MWD

Electric logging

Coring

Drill Stem Testing (DST)

• Shale– High Gamma Ray– +/- 1 ohmm

Resistivity– Density Porosity <

Neutron Porosity• Sand

– Low Gamma Ray– High Resistivity– Density Porosity =

Neutron Porosity

Evaluation MethodsElectric logs showingoil-bearing sand

Basic CompletionEquipment Terminology

Tubing hanger

Tubing spool

Surface ControlledSubsurface SafetyValve (SCSSV)

Gas lift valves

Production casing

Production packer

No Go NippleRe-entry guide

Blast jointSeal bore extension

Seal assembly

Production tubing

Flow coupling

Landing Nipple

Circulating sleeve

Completion Types

1. Open-Hole Completions

2. Cased-Hole Completion Types

• single zone completion• single tubing w/ multiple

selectives• dual tubing strings• dual tubing strings w/

sand control

3. Monobore Completions

4. Sand Control• gravel packs• frac packs

4. Horizontal Wells• open hole, slotted liner, cased

5. Multi-Laterals• TAML Levels

6. Intelligent Well Systems

7. Artificial Lift Systems• beam (rod) pump• gas lift• electric submersible pumps

(ESP)• progressive cavity pumps

(PCP)• jet pump• plunger lift

Hydraulic Fracturing

Damaged Area

Damaged Area

Borehole

Gravel Pack

Horizontal Wells

A “horizontal well” or high angle well describes a well drilled at an angle greater than 70º relative to vertical.• Can connect natural fractures in carbonates.• Prevent water/gas coning by reducing pressure draw

down.• Improves sweep efficiency through infill drilling,

horizontal injection for waterflood or EOR.• Can enhance property value by increasing recovery in

tight gas reservoirs or thin sands or low permeability reservoirs.

• Location constraints limiting numerous wells.

Horizontal Open-Hole Gravel Pack

PackerSand

Control Screen

Sized gravel

Casing Shoe

Unconsolidated Sandstone Reservoir

Underlying Water

Horizontal Well Cased-Hole

Reservoir Characteristics that favor this completion• Vertical permeability

greater than 50% horizontal permeability

• No inter-bed barriers or sealing laminations

• Some sand production or plan to gravel pack

• Confined surface and reservoir access

• Fracture treatments

Drivers of Multilateral Technology

• Cost reduction• Slot conservation• Increased reserves• Accelerated reserves• Delineation of the reservoir

Intelligent Well Systems (IWS)

An Intelligent Well System is defined by ChevronTexacoto include at least one downhole flow control valve, onedownhole sensor, and two distinct intervals.

Provides real-time reservoir management:• Downhole data sensing, acquisition, and transmission

of temperature, pressure, density, flow, etc.

• Remote control of flow and well operations

Beam Pump (sucker-rod pump)

Mechanics• Utilizes a reciprocating rod to

move a downhole pump.• Downhole pump consists of

“traveling” and “standing” valves, which utilize check valves to trap and mechanically lift a column of fluid.

Characteristics• Comprised ± 80% of all artificial

lift.• Predominantly land use.• Handles gas and solids fairly well.• Best for low-volume producers (5

to 5,000 BFPD)

Gas LiftMechanics• Best mimics “natural” flow. Utilizes

pressurized gas injection downhole to lighten the hydrostatic “head” of a column of fluid, allowing reservoir pressure to lift the fluid column to surface.

• Uses downhole valves to regulate the amount and depth of gas injection

• Continuous or intermittent lift.

Characteristics• Used wherever a gas source is

available.• Second most common lift system (Most

common offshore lift system).• Good handling of solids.• Wide range of production rates

Electric Submersible Pump (ESP)

Mechanics• Utilizes a downhole electric motor to

drive a downhole centrifugal pump.• Uses surface electrical transformers

and variable frequency speed drives to deliver consistent power.

Characteristics• Requires electrical power supply.• Highest lift efficiency of all lift

systems. Becoming more common as an offshore lift system.

• Poor handling of solids and fair handling of gas.

• Wide range of production rates (200 to 30,000 BFPD)

• Lifespans anywhere from 1 to 7 years depending on environment and horsepower/power quality.

Potential Environmental Emissions

Ozone Depleting Halocarbons

Flaring

Waste to Shore

Muds & Cuttings Produced Water

Power Generation Emissions

Mark Webster

Environmental Team LeaderGoM Deepwater Production BU

Aspects and Impacts

Aspects Impacts

> Discharge of muds & cuttings

> Air emissions from diesel engines

> Disposal of wastes on shore

> Decline in quality of GoM waters

> Degradation of air quality

> Adding to landfills; potential groundwater contamination

A 24,000’ Well Generates A 24,000’ Well Generates 3430.27bbls of Waste3430.27bbls of Waste

Conductor Hole Conductor Casing26 “ in 2 days 20” @ 700’459.68 bbls

Surface Hole Surface Casing17.5 “ in 15 days 13 3/8 @ 2000’595.00 bbls

intermediate Hole Intermediate Casing12 1/4” in 25 days 9 5/8” @ 13000’1603.54 bblsProduction Hole Production Casing8 1/2” in 60 days 7 5/8” at 24000772.05 bblsAssuming gauge hole, does not take into accounta number of factors, such as porosity or washout.

Disposal and Treatment Options

• TREATMENT– S/S– Thermal– Presses/ Washes– Ultrasonic

Technology– Dryers– Separation

techniques

• DISPOSAL?????– Discharge– Injection– Evaporation– Burial– Landfarming– Landspreading

Drilling Waste Concerns• Offshore

– Oil– Toxicity

• Onshore– Salinity– Oil– Heavy Metals

WELL PLANNING:A MULTI-DISCIPLINARY

APPROACH

Geophysical Data

Gravity, seismic, and petrophysical log data are combined to make 3D Earth Models

Anticlinal Trap

rock

Seal

Oil

Water

Types of Petroleum ReservoirsSalt Trap

Salt Dome

Cap Rock?

POROSITYSedimentary rock has pores (small openings)

PERMEABILITYConnected pores allow fluid to flow

PORE PRESSURENormal, abnormal or subnormal pore fluid pressure

ROCK STRESSForce imposed to the rock

BALANCEMud weight must balance pore pressure and rock stress

WELL PLAN BASICS

HIVE – well planning

• HIVE’s in 12 locations• 16 HIVE’s across BP• HIVE’s regularly used for well

planning.• Valhall OOC - 1st BP onshore

operations centre

Decision Space: Temis 3D + EarthVisionAndrew Field with

EarthVision top reservoir surface and Temis 3D Pressure slices at Eocene Limestone horizons

A17 Well planning with targets identified from subsurface reservoir and EarthVision models

Top Reservoir

Rev H: A17

A09 : comparable trajectory to Rev H A17

Comparison of Andrew A09 to Planned Rev H (A17) Trajectory

VIEW NORTH

Wellpath Rev H

Top Reservoir

Andrew Platform

VIEW SOUTH

23”

16”

12 1/4”

Hole Sections Rev H (A17) Trajectory

Grouped drilling NPT

Grouped drilling NPT

23/32”

Grouped drilling NPT

VIEW NORTH

Base Miocene Sand

Lower Eocene

Grouped drilling NPT associated

with Base Miocene and

Lower Eocene Limestone

Rev H: A17

Andrew Field No Drilling Surprises (NDS) Project:Wells with Geological Surfaces and Drilling NPT

A09 : comparable trajectory to Rev H A17

VIEW NORTH

Base Miocene Sand

Lower Eocene

12 1/4”

A09

NDS Lower 12 ¼”section :

Hole Cleaning, Tight Hole, Stuck Pipe, Gas in Limestones, Mudstones washing out.

Andrew NDS : Lower 12 ¼” Section

Drilling Cost Estimation

• Deterministic - Single figure

• Probabilistic - Considers risk and uncertainty using probabilities (objective, empirical, subjective) - Decision Trees, Monte Carlo - Cost estimates are given with associated probabilities, usually P10, P50 and P90

Both methods require base case estimation by hole intervalsPlot of Cost vs. Days – for tracking actual vs. estimated costCost per Foot of offset wells for benchmarking and cost estimating

C o u n t r y : P r o j e c t :

D e l i v e r a b l e : C V P S t a g e :

C o s t E s t i m a t e :

B e s t i n C l a s s P e r f o r m a n c e :

#S a n c t i o n A m o u n t : S a n c t i o n % i l e :

P r o m i s e ( P 1 0 - P 9 0 ) :

B e s t i n C l a s s P e r f o r m a n c e :

R i g r a t e 0 . 6 1P r o j e c t S c o p e A s s u m p t i o n s : D r i l l i n g l e a r n i n g r a t e - 0 . 5 9

o S t u c k p i p e f r e q u e n c y 0 . 5 3o L o s t c i r c u l a t i o n f r e q . 0 . 4 9o W a i t i n g o n w e a t h e r 0 . 4 1

1 2 - 1 / 4 " h o l e R O P - 0 . 2 9K e y R i s k A s s u m p t i o n s : 8 - 1 / 2 " h o l e R O P - 0 . 2 1

o A v g . s t u c k p i p e d u r a t i o n 0 . 1 8o 1 7 - 1 / 2 " R O P - 0 . 1 5o C o m p l e t i o n l e a r n i n g r a t e - 0 . 1 3o

M M ( ± )

m i l l i o nM e a n C o s t : $ 3 8 1

P r o j e c t D e t a i l s

I n p u t D a t a

M u l t i - w e l l e s t i m a t e w i t h l e a r n i n g . I n i t i a l p e r f o r m a n c e b a s e d o n f o u r p r e v i o u s E & A w e l l s . P l a t e a u p e r f o r m a n c e b a s e d o n m u l t i p l e o f T e c h n i c a l L i m i t .

O r s i n o P h a s e 2 D e v e l o p m e n t

D e f i n e1 2 o i l p r o d u c e r s + 2 w a t e r i n j e c t o r s

A v e r a g e o f t o p 1 0 % o f a l l I l l y r i a p l a t f o r m w e l l s , 1 9 9 7 - 2 0 0 0 , 2 0 0 1 R u s h m o r e d a t a .

T i m e & C o s t S u m m a r y

2 5 %$ 4 7 6$ 2 9 0

P 5 0m i l l i o n$ 3 7 9

M M -

W e l l s t e a m i n p l a c e 3 m t h s b e f o r e s p u dM a j o r N P T r i s k s a r e p o s t - m i t i g a t i o nF i r s t w e l l s p u d d e d i n 2 n d Q t r

d a y s (1 2 6 5 P 2 7

K e y P e r f o r m a n c e I n d i c a t o r s P 5 0 P 9 0

)

4 65 44 8D a y s / 1 0 K

2 23 62 7D a y s / C o m p l e t i o n

R i g r a t e s p e r 2 0 0 1 a c t i v i t y l e v e l s

1 4 w e l l s ( 1 2 p r o d . + 2 i n j . )2 g e o l . S i d e t r a c k s , 1 r e s p u d" E x p l o r e r " c l a s s d r i l l i n g r i g

I l l y r i a

D r i l l i n g U n c e r t a i n t y S t a t e m e n t - S u m m a r y

A s s u m p t i o n s & R i s k s

B e s t i n C l a s sP 1 0

4 4

2 1

- 1 - 0 . 5 0 0 . 5 1

Frequency Chart

Cer t aint y is 79. 74% f r om 1, 200. 83 t o 1, 480. 69 days

. 000

. 006

. 013

. 019

. 026

0

64

128

192

256

1, 000. 00 1, 175. 00 1, 350. 00 1, 525. 00 1, 700. 00

10, 000 Tri al s 30 Outl i ers

Forecast: Total Days

Frequency Chart

Cer t aint y is 80. 09% f r om 290. 00 t o 476. 67 m illion dollar s

. 000

. 008

. 015

. 023

. 030

0

75. 5

151

226. 5

302

150. 00 275. 00 400. 00 525. 00 650. 00

10, 000 Tri al s 10 Outl i ers

Forecast: Total Cost

B i C

PUSHING THE ENVELOPE….

Build:Drilling PerformanceExtending the drilling envelope

0

5,0 00

1 0,0 00

1 5,0 00

2 0,0 00

2 5,0 00

3 0,0 000 5 ,00 0 10 ,0 0 0 15 ,00 0 20 ,0 0 0 25 ,00 0 30 ,0 0 0 35 ,0 0 0 4 0 ,0 0 0

E quiva lent De pa rtu re ( ft )

TV

D B

RT

(ft

)

0

1,0 00

2,0 00

3,0 00

4,0 00

5,0 00

6,0 00

7,0 00

8,0 00

9,0 00

0 1,0 00 2 ,00 0 3,0 00 4 ,0 0 0 5 ,00 0 6,0 00 7 ,00 0 8,0 00 9 ,00 0 10 ,00 0 1 1,0 00 12 ,00 0

E qu iv ale nt D ep arture (m )T

VD

BR

T (m

)

Am be rjac k Am e th ystAm he rs tia And re wAs pen B ruc eCh ir ag C olom biaFoina ve n Go odw ynHa rding Liuhu aM ag nus M a rnoc kM ille r M ilne P o in tNia ku k N orth E ve res tP ed ern ale s P om pa noRe d M a ngo S c hieha llio nS ha h De niz S ta rnm ee rThun der H or se Tyn eUla /Gyda V a lh allW ytc h Fa rm Y ac he ngTiubula r B ells M a d Do g De e p

bp d rillin g envelop e

T ubula r Be lls

M a d Do g De epT hun der H orse

Total Depth

PompanoPompano MarsMars UrsaUrsaEmpireEmpire

State Bldg.State Bldg.DianaDiana

HooverHoover Na KikaNa KikaHornHornMtnMtnHolsteinHolstein AtlantisAtlantis

MadMadDogDog

ThunderThunderHorseHorse

Note: Conceptual illustration only

10,000’

15,000’

20,000’

25,000’

30,000’

1,000’

2,000’

3,000’

4,000’

5,000’

6,000’

7,000’

8,000’

BP Steps Out in GoM Deepwater

ROV Launch

Control cabin, launch arm, tether system, and ROV on rig deck

ROV and tether system being launched

Typical ROV

Thrusters

Buoyancy

DRILL-SUPPORT

ROV SYSTEMS