SEAL-N-PEELMaximum fluid-loss protection

with easy cleanup in sand-control completions

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Fluid losses during and after sand-control completions can severely jeopardize a well’s productivity. Oncefluid invades the formation, remedialtreatments cannot only inflate costsdramatically, but lead to a host ofadditional problems, not the leastof which is the risk of formation damage. Even with the additionalcosts and risks, it is extremely diffi-cult, if not impossible, to completelyrid a formation of the ill effects ofinvading fluid.

The SEAL-N-PEEL pill is a uniquelyengineered fluid-loss control system,designed specifically as a contingencyfor frac-pack, gravel-pack or stand-alone completions. It provides superbsupplemental fluid-loss control whenmechanical fluid-loss-control deviceseither fail or are unavailable. TheSEAL-N-PEEL pill deposits an impen -etrable, thin, filter cake against theinside surface of the screen assembly.When the well is ready to go on pro-duction, the cake simply peels away,using production pressure and flowas the lift-off mechanism.

There’s no invasion into the for -mation or gravel pack. No damagefrom remedial cleanup measures.No impediment to downhole comple-tion hardware. And no resistance toproduction initiation.

A safety net for your gravel-pack completionsUntil now, there weren’t many optionsfor controlling fluid loss in sand-controlcompletions, and quite often, theyhad negative consequences. Popularmechanical controls, such as spring-loaded flapper valves, have beenknown to fail and are sometimesunavailable or incompatible withthe completion scheme.

The only other option was to pumpminimal-solids or solids-free fluid-loss-control pills. Sized-salt pills andthose containing some solids are usu-ally of the “all-in-one-sack” variety,which eliminates the ability to cus-tomize particle-size distribution.Such a non-specific approach tobridging raises the risks of particlesinvading the gravel-pack mediumor the formation.

On the other hand, solids-free pillscannot be fully effective withoutsome invasion into the gravel-packand formation matrix. They also haveto be pumped in large volumes tocontrol losses effectively.

Regardless of the pill type used, onceits job is done, it must be removedwith acid, oxidizers or enzymes.All too often, pumping an externalbreaker is corrosive to screens andother downhole components. Thereis also the threat of leak-off and serious formation damage.

One SEAL-N-PEEL pill protects your completion, the formationand your production

� A P P L I C A T I O N S

Wells where sand-control completionsare being used. All types of gravel-packscreens from wire wrapped throughpremium designs can be sealed.

� P R O B L E M S

Clear brine completion fluid lossesduring and after sand- control com -pletions can severely jeopardize awell’s productivity.

� S O L U T I O N S

SEAL-N-PEEL* technology is auniquely engineered fluid-losscontrol system, designed specificallyas a contin gency for frac-pack, gravel-pack or standalone screen comple-tions, by sealing the internal faceof the sand-control screen.

� E C O N O M I C S

This pill controls loss of expensivebrines during completion operationsand readily releases during produc-tion, eliminating the need forremedial treatments.

� E N V I R O N M E N T A L

Controlling losses downhole not onlyprevents formation damage, but alsoreduces well-control risks and subse-quent potential spills. By controllinglosses, the amount of producedstartup water is also reduced.

Features • Supplements or replaces

mechanical fluid-loss-control devices

• Particles sized specificallyfor each screen

• Specially engineered additivereduces adhesive and cohesivetendencies

• Contains minimal solids

Benefits• Minimally invasive pill

• Easily peels from the screen

• Requires no remedial washes

• Non-damaging to the formation

High-pressure test device evaluates SEAL-N-PEEL to 5,000 psi (345 bar).

The SEAL-N-PEEL approach

The flapper valve has failed. Withoutthe backup protection of a SEAL-N-PEEL

pill, fluid invades the formation. Lossescould vary from tens of barrels to hundreds of barrels per hour. All fluid lost is either produced back orremains in the formation. Brine production offsets/ limits hydrocarbon production and ultimate recovery.

When it is time to commence produc-tion, there is no need to intervene witha mechanical or chemical treatment.Natural hydrocarbon production easily removes theSEAL-N-PEEL barrier from the face of the production screen.

Despite fluid-loss-control-device fail-ure, the SEAL-N-PEEL fluid is placedinside the sand-control screen. The pillseals the inside face of the screen and generates animpenetrable barrier to prevent further loss of fluid to the formation. Once established, the barrier can remain stablefor extended periods of time at downhole conditions.

With a SEAL-N-PEEL pill, the calciumcarbonate particles are specially sizedfor each application. This promotesthe immediate deposition of a thin,tough filter cake on the inside surfaceof the gravel-pack screen. Once inplace, the cake becomes an impene-trable shield that effectively reducesfluid invasion into the formation.

When it’s time to produce thewell, the releasing agent withinSEAL-N-PEEL fluid will have reducedthe cohesive and adhesive forcesthat bind the filter cake togetherand to the screen surface, respectively,allowing it to be completely removedwith very little differential pressure.In fact, production from the wellremoves the filter cake entirely.

The evolution of the newstandard in fluid-loss controlTo understand why SEAL-N-PEEL

technology works so well, it’s helpfulto see how it evolved in the labora-tory and how it has succeeded in thefield. Each component is the result ofa painstaking development and test-ing program that has resulted in a superior product.

M-I SWACO* has developed bridg- ing agent guidelines for all types ofcompletion screens from premium toexpandables to wire wrapped. Theseguidelines have been incorporatedinto the M-I SWACO OPTIBRIDGE* software program. The sealing

capability is evaluated under down-hole conditions on the expected filtermedia. Additional laboratory test-ing is undertaken to confirm the laboratory formulation effectiveness.

We look at the rheological stabilityof the pill to make certain it willremain intact during sometimeslengthy stays in the wellbore envi -ronment. We look at its damagepotential and how it should be placedinside the screen to optimize sealingcapacity and facilitate easy removal.

What grows out of this comprehen-sive investigation is a non-damagingpill that provides a highly effectiveseal, that remains stable for severaldays at bottomhole conditions, andwill easily be removed when thewell produces.

A proven track record of more than 10 yearsSEAL-N-PEEL technology has been usedsuccessfully to seal a wide variety ofscreens for more than 10 years. It hasbeen applied in prepacked, wire-wrapped, shrouded metal-wrappedpremium and expandable screens.Densities have varied from 8.3 to18.5 lb/gal (1 to 2.2 SG) and tem -perature from 70° to 400° F (21°to 204° C). Filter-cake lift-off pres -sure has been recorded as low as2 psi (0.1 bar) which has saved operators millions of dollars in chemical/ mechanical filter-cake

cleanup intervention. In some appli-cations, SEAL-N-PEEL technology hasreplaced the mechanical formationisolation valve and has sealed theinside of screens for over 30 dayswhile simultaneous operationswere conducted.

Depleted reservoirs: ExtendingSEAL-N-PEEL technologyWith the recent need to re-enter andwork over depleted, formerly high-pressure, deepwater reservoirs,M-I SWACO has developed a high-pressure flat-screen tester thatenables design engineers to testthe SEAL-N-PEEL system at higherpressures before it is applied in thefield. This simulation can apply upto 5,000 psi (345 bar) on the screencoupon to prevalidate the seal inhigh-overbalance conditions. Thishas been particularly helpful in estab-lishing burst and collapse pressuresof downhole completion screens.The SEAL-N-PEEL system is used bymany screen suppliers to establishthese parameters. It has also enabledM-I SWACO to expand the SEAL-N-PEEL

technology to depleted reservoirswith ultra-low formation pressures.

To learn for yourself how SEAL-N-PEEL

is performing for our customersworldwide, contact your localM-I SWACO representative.

SEAL-N-PEEL success stories• A well in the Gulf of Mexico that

encountered 160-bbl/hr losses after

the mechanical flapper failed to close,

used a 12.9-lb/gal (1.5-kg/L) calcium-

bromide-base SEAL-N-PEEL pill. It effec-

tively sealed the 125-micron premium

screen. The pill remained stable over

eight days while the upper completion

and production tubing were run. The

well was put on production without

a remedial treatment and a –1 skin

was determined.

• Another Gulf of Mexico well encoun-

tered losses of 150-bbl/hr while attempt-

ing to set the production packer. A

15.7-lb/gal (1.9-kg/L) zinc-brine-base

SEAL-N-PEEL pill was used to seal the

8-gauge wire-wrapped screen while

re-running the production packer. This

pill had been designed for four days of

stability at a bottomhole temperature

of 216° F (102° C). The well started up

at the expected production rate with

a calculated skin of –2. No remedial

treatments were required.

• A series of five gas wells offshore

Trinidad required SEAL-N-PEEL treat-

ments to limit uncontrolled losses dur-

ing production-tubing-replacement

operations. These wells used 110-micron

premium screens. The SEAL-N-PEEL sys-

tem was designed to maintain a stable

seal at 135° F (57° C) for 18 days. In all

cases, losses were controlled to permit

the recompletion operations, and the

wells were restarted without impairment

or remedial treatments.

©2009 M-I L.L.C. All rights reserved. *Mark of M-I L.L.C.

CBR.1909.0901.R1 (E) 2.5M Litho in U.S.A.

This information is supplied solely for informational purposes and M-I SWACO makes noguarantees or warranties, either expressed or implied, with respect to the accuracy and useof this data. All product warranties and guarantees shall be governed by the Standard Termsof Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.

P.O. Box 42842Houston, Texas 77242-2842

Tel: 281·561·1300Fax: 281·561·1441

www.miswaco.comE-mail: questions@miswaco.com

Technology Centers:

HOUSTON, TEXASTel: 281·561·1300 · Fax: 281·561·1441

ABERDEEN, SCOTLANDTel: 44·1224·334634 · Fax: 44·1224·334650

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