FLOTHRUThis water-base filter cake wont come between you and your oil

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TECHNOLOGY

FLOTHRU: Another SMART RDF Technology from M-I SWACOAt M-I SWACO*, we realize the importance of intelligent control in drilling

and completion operations. Our technologies give you the means to take a

smarter approach to production, which in the end, allows not only higher pro-

duction, but greater control over your costs. SMART RDF* Technology gives you

the best tools on the market to put you in control of downhole operations.

FLOTHRU* is the latest addition to the M-I SWACO suite of SMART RDF

Technologies fluid systems that address formation-damage and productivity-

impairment concerns. These technologies, which include both reservoir drill-

in fluids and breaker systems, put more finesse into drilling and cleaning up

reservoir drill-in fluids by giving the engineer more control over what occurs

downhole. FLOTHRU offers a dramatic improvement over the more conven-

tional approach of pumping aggressive, and potentially damaging chemicals.

M-I SWACO will continue to develop intelligent solutions for coping with

formation damage and productivity impairment and will add those systems

to the SMART RDF suite.

The FLOTHRU system creates a filter cake with channels that open the way to higher production

A P P L I C A T I O N SOpen-hole gravel packs, expandablescreens, stand-alone completions or anyopen-hole application where chemicalbreakers are normally applied, includ-ing oil- or condensate-production wells.

P R O B L E M SOnce the gravel pack is complete orthe screen expanded, the filter cake istrapped between the formation andthe completion assembly, making itdifficult to access with a chemicalbreaker. In the case of stand-alonecompletions, premature breakthroughor other complications sometimesprevents the breaker from fullycontacting the filter cake.

S O L U T I O N SThe FLOTHRU systems oil-permeablefilter cake requires lower flow-initiationpressures, permitting oil to readilypass through.

E C O N O M I C SThe FLOTHRU system eliminates thetime and costs associated with chemi-cal breakers and permits higher earlyhydrocarbon production rates thatoften offset water production.

E N V I R O N M E N T A LThe FLOTHRU systems water-baseformulation minimizes environ-mental concerns, and its flexibilityallows it to be engineered with compo-nents that meet most environmentalcriteria worldwide.

During an open-hole completion wherethe filter cake is confined, as in open-hole gravel packs or expandable-screencompletions, the cake must remainintact to prevent losses and prematurescreenout. Once the completion opera-tion has finished, however, the filter cakeis usually removed with a chemicalbreaker to aid well productivity andavoid pieces of the cake plugging thescreen during production.

The catch is that it can be difficult toaccess the confined filter cake with achemical breaker. The cake can fail pre-maturely during breaker application,causing the breaker to bypass, or fail tocontact, portions of the cake. This resultsin inadequate filter-cake dissolution.

One way to address this problem isto include a chemical breaker duringthe gravel-packing operation, but thatapproach can be problematic. If thechemical breaker is too aggressiveand/or applied too early, prematurefilter-cake breakthrough can occur andprevent the well from being completelygravel-packed.

The FLOTHRU system offers a solu-tion that eliminates the need for achemical breaker.

How the FLOTHRUsystem worksThe FLOTHRU system is a water-baseReservoir Drill-In Fluid (RDF) designedwith enhanced flowback capabilitiesthat eliminate the need for a chemicalcleanup treatment, while providinghigher return permeability and lowerflow-initiation pressures. The primaryapplication for a FLOTHRU system is inopen-hole completions where the filtercake is trapped between the formationand the completion assembly. In open-hole completions where the filter cakeis not confined, the FLOTHRU system stillprovides a major benefit: lower flow-initiation pressures at comparablereturn-permeability values.

In the FLOTHRU system, a proprietaryhydrophobic-carbonate componentcombines with a hydrophobic starchto control fluid loss. These materials

Features Higher return permeability

through Open-Hole GravelPacks (OHGP)

Lower flow-initiation pressuresfor OHGP and stand-alonecompletions

Higher tolerance to drilled-solids contamination

Channels for steady oil flow

No chemical breakers needed

Benefits Increases production rates,

from heel to toe

Removes cleanup risk/cost

Cuts completion time and costs

Allows oil to preferentiallyproduce

Eliminates remedial completion operations

create organophilic (oil-preferential)channels through the FLOTHRU filter cake.Their filter-cake-building characteristicsprovide a low-permeability barrier towater and prevent high infiltration.These same organophilic channelsavoid the cohesive nature of conven-tional water-base RDF filter cakes andprovide increased transmissibilityof hydrocarbons, eliminating theneed for chemical breakers.

The SMART way to protect the reservoirThe FLOTHRU system is one of theSMART RDF Technologies fromM-I SWACO and utilizes a combinationof conventional and advanced RDFdesign concepts to minimizeformation damage:

Custom particle-size distribution to bridge formation pores

Appropriate salts for densityor inhibition

Effective and appropriateshale inhibitors

Minimal solids

Low-Shear-Rate Viscosity (LSRV)for hole cleaning and suspension

Hydrophobic componentsthat enhance productivity

An organophilic filter cake that pro-motes low flow-initiation pressures

Building a more productive filter cake.Like other SMART RDF systems, theFLOTHRU system contains the smallestpossible amount of bridging solids that

will still protect the reservoir, maxi-mize the efficiency of solids-controlequipment and minimize the impair-ment of gravel-pack completions.

The system relies on a combinationof conventional bridging agents andTHRUCARB hydrophobic carbonate.The conventional bridging agents pro-vide protection for a wide range offormation pore sizes. The THRUCARBproduct is a very fine, treated calciumcarbonate that maximizes the numberof organophilic channels while avoid-ing fine gravel-pack and completion-screen plugging.

THRUCARB is supplemented withconventional calcium carbonateselected with M-I SWACO OPTIBRIDGE*

software to determine the optimumparticle-size distribution of the bridg-ing agent helping to create an externalfilter cake and avoiding deep invasionof potentially damaging solids.

Formation-damage testing, per-formed on FLOTHRU samples, hasconsistently shown higher return per-meabilities and lower flow-initiationpressures in gravel-pack completionsthan conventional RDFs. The organo-philic components aid the oil in flowingthrough the filter cake. For stand-alonecompletions, comparable return valueshave been seen with substantially lowerflow-initiation pressures using FLOTHRU.

Maintaining the downholeenvironment. Monovalent salts,

Return Permeability and Flow-Initiation PressureAll 40/60 Gravel Packs withNo Chemical Cleanup100% Return permeability

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Conventional RDF FLOTHRU psi

Clean fluidsFLOTHRU formulations

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Return Permeability and Flow-Initiation PressureClean Fluids, No Chemical Cleanup100% Return permeability

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Description Water-base monovalent salts

Organophilic cake components Carbonate very fine Starch

Biopolymer viscosifier

Properly sized bridging agents

The FLOTHRU filter cake resists water invasion to the formation while allowing hydrocarbons to flow at low flow-initiation pressures.

Inside wellbore

Hydrocarbons

Hydrocarbons flowing through the filter cake

FLOTHRU filter cake

THRUCARB

Associations of THRUTROL starch

THRUTROL starch

Formation sand where filtrate has displaced back the hydrocarbons

Hydrocarbons

such as NaCl, KCl, NaBr and sodiumor potassium formate, provide a widedensity range, 8.33 to 12.5 lb/gal (1 to1.5 SG), to minimize overbalance onthe formation. In addition, formula-tions can utilize calcium chloride brineto a density of 10.8 lb/gal (1.3 SG).

The low-solids system withsuperior drilling characteristicsThe rheological properties of aFLOTHRU system are created witha variety of biopolymers, includingFLO-VIS* PLUS and FLO-VIS NT. The rheo-logical profile of a FLOTHRU systemexhibits an elevated low-shear-raterheology while maintaining minimalhigh-shear-rate rheology in particu-lar, minimal plastic viscosity. This typeof rheological profile has consistentlydemonstrated low pump pressures,rate-of-penetration enhancement andexcellent hole-cleaning capabilities.

To engineer a highly inhibitive sys-tem, the chemistry of the FLOTHRUsystem can be adjusted with saltsor hydration suppressants such asKLA-STOP* or KLA-GARD*. These mate-rials utilize cation exchange to sup-press clay hydration. They are alsocompatible and work together withthe systems polymers, a viscosifierand a fluid-loss-control agent to

impede the absorption of water byshales and/or formation clays.

Due to the low solids and the poly-meric nature, FLOTHRU systems gen-erally have a very low coefficient offriction typically 0.2 to 0.25. Thisassists in rotary and oriented drillingoperations. Lubricants have beenfound to further decrease the coeffi-cient of friction in FLOTHRU systemsto about 0.15.

As easy to use as it is effectiveThe FLOTHRU system is designedwith a minimal number of products,all of which provide a great degreeof flexibility.

Rheology. A premium-grade biopoly-mer is the primary viscosifier for allFLOTHRU systems. It provides minimalplastic viscosity and exceptionallyhigh LSRV. Depending on the makeupbrine, salt concentration and desiredLSRV, biopolymer viscosifier concen-trations of 0.75 to 1.5 lb/bbl are used.

Biopolymer can be added whiledrilling to maintain the LSRV. Duringdrilling, the systems elevated LSRValleviates drilling, hole-cleaning andwellbore-stability concerns.

Inhibition. Controlling shale hydrationwith FLOTHRU systems is a major keyto successful projects. Many timeswhile drilling reservoir zones, clays maybe encountered within the productive

Product Functions and Descriptions Product Function Description

FLO-VIS* PLUS, FLO-VIS NT Rheological properties, Biopolymerespecially LSRV

THRUTROL* Fluid-loss control Organophilic starchGreencide 25 Bactericide Glutaraldehyde

Caustic Soda, KOH, MgO Alkalinity pH control

SAFE-CARB* 2, 10, 20,40 Bridging agent, Properly sized calcium carbonatefluid-loss control

NaCl, KCl, Formates, etc. Density, inhibition Salts

THRUCARB* Bridging, fluid-loss control Organophilic calcium carbonateKLA-GARD*, KLA-STOP*, Shale inhibitors Cationic, amphoteric materialsKLA-CURE*

Typical FormulationsProduct Concentration

FLO-VIS* PLUS 1 1.5 lb/bbl

Freshwater 0.9 bbl

KCl 10.8 lb/bbl

NaCl 32.3 lb/bbl

THRUTROL 10 lb/bbl

THRUCARB 6 lb/bbl

Greencide 25 0.25 lb/bbl

SAFE-CARB* (blend) 24 lb/bbl

MgO 0.5 lb/bbl

Properties Value

PV, cP 15 20

YP, lb/100 ft2 25 35

10 s Gel, lb/100 ft2 10 12

10 m Gel, lb/100 ft2 13 18

LSRV, KcP >30

API Fluid Loss

sand or as interbedded shales, as aresult of directional changes, faultingor other geological phenomena.

Maintaining a clean FLOTHRU sys-tem reduces the potential of damag-ing the formation or completion andincreases the flowback potential.Cleaner FLOTHRU systems also drillfaster and encounter fewer drillingand fluid-maintenance problems.

General. The systems non-damagingcharacteristics are the result of opti-mized bridging, minimized filtrationand organophilic nature.

Engineered to protect the environmentA FLOTHRU system can be engineeredto meet most environmental regula-tions worldwide. While the precise

toxicity of FLOTHRU systems dependson the formulation and local environ-mental criteria, the basic components FLO-VIS PLUS or FLO-VIS NT, THRUCARB,THRUTROL and calcium carbonate are considered environmentallyacceptable worldwide.

Predictions surpassed: More oil faster than offsetsIn the field, FLOTHRU has delivered pro-duction results higher than predicted.

In one offshore application, the system drilled 1,004 ft (306 m) of 618-in. horizontal hole trouble-freeand was gravel-packed using a highrate water-packing technique with no problems. Despite a higher-than-desired drilled-solids content, the well came online with net production

25% higher than expected due to filtercakes low flow-initiation pressure.The oil production stayed at thishigher rate for a longer period of time than existing offset wells.

In another well, the system wasused to drill 920 ft (280.4 m) of pay-zone and, again after gravel packing,net oil production was higher thanthe operator anticipated, with oilproduction up to 100% greaterthan expectations.

FLOTHRU is now routinely usedin that field for open-hole gravel-pack-completed oil producers. Onhorizontal wells, the productionof the 10 to 14 API gravity oilexceeds expectations.

In a Gulf of Mexico application, acalcium-chloride-base FLOTHRU systemwas used to drill 555 ft (169 m) of a6-in. horizontal section without anyproblems. The open hole was gravel-packed with 20/40 gravel. During thegravel-packing operations, there wereminimal losses indicating an effectiveand efficient filter cake was formedwhile drilling.

The well was put on productionwithout any post completion cleanup.Initial production of 20 to 25 APIgravity oil suggests up to 65% greaterthan expectations.

Increase your production todayTo find out more about how theFLOTHRU system is helping operatorsworldwide increase production ofoil instead of water, contact your localM-I SWACO representative.

OPTIBRIDGE software generates a target line that defines the ideal blend of locally pro-duced bridging materials that would best fit the targeted formation characteristics.Available anywhere in the world, the OPTIBRIDGE service is an ideal tool for formulatinga non-damaging reservoir drill-in fluid. It also can be used to design fracture-sealingand lost-circulation treatments, and to formulate kill and perforation-sealing pills forworkover and completion operations.

FLOTHRU: Another SMART RDF Technology from M-I SWACOAt M-I SWACO, we realize the impor-tance of intelligent control in drillingand completion operations. Our tech-nologies give you the means to take asmarter approach to production, whichin the end, allows not only higher pro-duction, but greater control over yourcosts. Smart RDF Technology gives youthe best tools on the market to put youin control of downhole operations.

FLOTHRU is the latest addition tothe M-I SWACO suite of SMART RDFTechnologies fluid systems thataddress formation-damage andproductivity-impairment concerns.These technologies, which include bothreservoir drill-in fluids and breakersystems, put more finesse into drillingand cleaning up reservoir drill-in fluidsby giving the engineer more controlover what occurs downhole. FLOTHRUoffers a dramatic improvement overthe more conventional approach ofpumping aggressive, and potentiallydamaging, chemicals.

The first step toward a more consid-ered approach to reservoir protectionand production enhancement camewith the introduction of the FAZEPRO*system. The industrys only reversible,invert-emulsion reservoir drill-in fluid,the FAZEPRO system has demonstratedits ability to contend with a variety

of conditions across the globe. Whenapplied to injector wells, the systemallows direct injection just after cleanup,with injection rates more than twicethose achievable with conventional oil-base muds. In production well applica-tion, FAZEPRO wells routinely produce1.5 to 4 times more than offset wells.

SMART RDF Technology also includesbreaker systems that are used in appli-cations requiring a chemical treatment toprevent completion impairment. Breakerssuch as FAZEBREAK*, BREAKDOWN* andBREAKFREE* are designed as integral com-ponents in the drilling and open-holecompletion of wells. The chemistry ofthese systems was selected to provide agentle yet thorough destruction of thefilter cakes. They can be placed duringcompletion operations and avoid theneed for intervention equipment likecoiled tubing.

FAZEBREAK is a delayed-breakersystem designed to disperse FAZEPROfilter cakes on oil-production wells. Theproprietary chelant chemistry providesa slow reversal of the filter cake, providingmore operational time before the filtercake is compromised. FAZEBREAK can beadded during the gravel-pack operationwithout losing filter-cake integrity.

BREAKDOWN employs patentedenzyme/chelant chemistry to provide aslow uniform break to FLOPRO* NT filtercakes. This gentle chemical treatmentprovides a slow uniform destruction ofthe water-base filter cake. The systemattacks specific chemistries in the filtercake, but does not negatively react withformation solids, formation fluids orwellbore tubulars.

BREAKFREE is an enzyme-base systemused to disperse FLOPRO NT filter cakes.The subtle BREAKFREE system removesthe starch component of the filter cake,allowing the bridging agents to disperseinto individual particles. This allowsthem to produce through the completionor settle out of the way, avoidingcompletion impairment.

M-I SWACO will continue to developintelligent solutions for coping withformation damage and productivityimpairment issues and will add thosesystems to the SMART RDF suite.

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

Tel: 2815611300Fax: 2815611441

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

Technology Centers:

HOUSTON, TEXASTel: 2815611300 Fax: 2815611441

ABERDEEN, SCOTLANDTel: 441224334634 Fax: 441224334650

STAVANGER, NORWAYTel: 4751577300 Fax: 4751570605

2005 M-I L.L.C. All rights reserved. *Mark of M-I L.L.C.FBR.0615.0601.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.