Swellable Well Construction Systems

Meeting the ChallengesEffective well construction requires wellbore isolation technologythat is versatile, reliable and cost effective.Swellable elastomers provide a broad spectrum of technical andcommercial solutions that can be easily customized to meet thechallenges of even the toughest wells.Isolation performance is complicated by a diverse scope of constructionproblems, from the most common wells to complex wellbore designs inextreme environments. Issues range from short-term stimulation concerns tolong-term microannulus isolation. Differences in wellbore fluids and downholetemperatures affect swelling and compatibility to make planning difficult.Weatherford’s swellable well construction products and servicesare engineered to meet the challenges of well construction by using a portfolio ofindustry-leading tool designs and elastomer formulas. We incorporate oil swell,water swell or the industry’s only customizable, dual-fluid activated swellablehybrid elastomer technology in our range of tools to meet these challenges.Without the Micro-Seal systemWith the Micro-Seal systemWeatherford’s Micro-Seal swellable system prevents microannular fluid and pressure migration.2 © 2010-2011 Weatherford. All rights reserved.

Addressing microannular issuesSwellable Well Construction SystemsWeatherford’s swellable Micro-Seal isolation systems (MSIS)are an innovative solution for preventing microannular fluid andpressure migration.The approach is based on swellable isolation seal units thatare distributed along the cemented tubulars and provide a series ofresponse points, or resistors, that ensure fluid or pressure migration ismet and stopped wherever it enters the microannulus. The seals canalso be economically deployed as a system using proven mechanicalcementing products.Total annular isolationThe objective of the MSIS is to create at least one point in the well withtotal annular isolation. When the Micro-Seal isolation unit is used withmechanical cementing products, the MSIS provides maximum standoffto achieve the most efficient displacement of mud and the most effectiveplacement of the cement.The swellable MSIS units are designed to swell into microannular spacesthat may form after the cement is in place, as well as against the OD of thecasing on which it was deployed. The combination of these tools results ina system that provides multiple locations in the annulus, each with the bestpossible chance of achieving isolation.This unique, innovative system improves wellbore quality with an economic,simple solution. Expensive workovers and remedial cementing operationsare reduced. Strategic positioning of multiple products across the expectedproblem areas prevents buildup of annular casing pressure, thus eliminatingthe need to bleed off at the wellhead.The hybrid elastomers used inthese swellable seals are anultraslow, swell-rate formulation,designed specifically formicroannulus isolation.They have been designedso that they do not react withfluids in the well when the pipeis run or with the mix water in thecement as it is curing.Micro-Seal isolation units arestandalone, slip-on devices.© 2010-2011 Weatherford. All rights reserved. 3

Swellable Micro-Seal isolation systemWeatherford’s swellable elastomer Micro-Seal isolation unitis the heart of the MSIS system.The Micro-Seal unit is deployed as a standalone, slip-on device.Multiple units are recommended to ensure proper placement toachieve the required results.The units can float on the casing or be secured with set screws.When deployed with the appropriate industry-leading mechanicalcementing product, the MSIS provides the best possible chance forwellbore isolation. The system includes:▪▪MSIS-B—a slip-on device with bows designed for optimal casingstandoff in appropriate cased-hole and openhole wellbore sections▪▪MSIS-R—a slip-on device with rigid blades (either axial or biased)designed to optimize mud displacement in vertical, inclined andhorizontal wells▪▪MSIS-S—a sub designed for optimal casing standoff in wells withultratight clearances and underreamed openhole sectionsThe unique swell cage of the Micro-Sealunit provides extra strength while the endrings provide elastomer protection whenrunning into the wellbore.4 © 2010-2011 Weatherford. All rights reserved.

Swellable Well Construction SystemsMicroannular applicationsOur swellable MSIS units provide new levels of cost-effective performanceand flexibility in a wide scope of well construction applications, including:▪▪Any well with a risk of microannular migration▪▪In wet gas or liquefied petroleum gas (LPG) storage and injection wells▪▪For fracturing or pressurized well applications▪▪Where perforating damages the cement sheath▪▪In steam or other thermal stimulation processes▪▪In multiple casing-string applications▪▪Wells drilled through shallow gas formations▪▪Wells to be stimulated by steam or other thermal processes andexperience wide variances in temperature and/or pressure▪▪Any well location where there is a history of wellhead pressure buildupMSIS-BMSIS-RAs part of the Micro-Seal system, these proprietary tools are justa couple of the unique designs that Weatherford has engineeredfor wellbore isolation and centralization during well construction.© 2010-2011 Weatherford. All rights reserved. 5

Enhancing annular isolationWeatherford’s annular swellable packers (ASPs) offer the reliabilityand cost benefits of conventional swellable packers with the advantagesof customized swelling performance and proprietary design features.All swellable packers offer cost-effective, one-trip,self-setting isolation with no moving mechanicalcomponents. However, Weatherford’s hybridelastomers provide a new dimension of performance.Activation in oil, water and wet gas—and thecapability to fine-tune swelling rates and elastomercompatibility—results in significant advantages forplanning, reliability and efficiency.Antiextrusion systemThe antiextrusion end assemblyimproves the differential pressurecapability of the Nemisis packer.A patented antiextrusion system—featured in ourNemisis ® swellable packers—can maintain higherdifferential pressure across the tool in overgaugeholes, as well as enhance the thermal stability ofthe pressure seal in well applications that couldexperience downhole temperature changes, suchas water injection, frac and acid stimulation.BeforeswellingShorter slimmer elementsAfterswellingThese antiextrusion attributes also result in muchshorter and slimmer packers that are ideal for tightholes, short-radius wellbores, and in horizontalwellbores that require multipacker isolation systemsfor zonal isolation and stimulation. The shorter andslimmer elements aid in deployment efficiency andminimize excessive drag, while running throughwell intervals with high-angle doglegs.A close-up view shows the Nemisis swellable packer’santiextrusion ends, deployed by swelling element.The Genisis ® swellable packer provideseasy deployment and ultimately reduceswell construction costs.6 © 2010-2011 Weatherford. All rights reserved.

Swellable Well Construction SystemsSwellable packer family productsWeatherford’s family of swellable packers are a one-trip, self-setting isolationsystem for openhole or cased-hole applications that enhance well constructionapplications with a full scope of packer configurations and options, including:▪▪Genisis ® ASP—a standard performance, cost-effective packer bonded to pipe▪▪Nemisis ® ASP—also bonded to pipe, the shorter, slimmer elements are idealfor restricted and high-radius well geometries. It offers higher performancethan the Genisis series packers▪▪Morphisis ® ASP—a proprietary slip-on technology for installation of swellablepacker systems onto standard non-upset API tubulars▪▪Genisis FT ASP—with features for spliceless cable feedthrough for remotemonitoring and control in smart completionsAnnular swellable packer applicationsWeatherford’s annular packer elastomers and proprietary-design featuresprovide the flexibility to address a wide range of isolation applications incased-hole and openhole wellbores, including:▪▪Interzonal isolation▪▪Reservoir compartmentalization and wellbore segmentation▪▪Gas and water coning management▪▪Isolation of fluid contacts▪▪Straddle isolation systems (shales, fractures, water)▪▪Isolation in stimulation treatments▪▪Plugging and abandonment▪▪Isolation of build sections from horizontal pay zones▪▪Casing-shoe integrity and sustainedcasing-pressure isolation▪▪Isolation at lateral junctionsor milled windows▪▪Wells drilled through shallow gas formationsGenisis FT annulus swellable packer0.43 × 0.43 in.(11 × 11 mm)1/4 in.bare tube0.47 × 0.71 in.(12 × 18 mm)Possible cable configuration forGenisis FT annulus swellable packeris shown.The Morphisis annulus swellablepacker slips on casing and is securedwith stop collars or set screws.© 2010-2011 Weatherford. All rights reserved. 7

Swellables Product Application GuideMicroannulus isolationCement assuranceCentralization in standardcasing-hole combinationsCentralization where high-axialloading is anticipatedCentralization (high-doglegseverity, inclined, horizontal wells)Ultratight tolerance-clearancecasing stringCentralization underreamedhole sectionsCentralization undergaugedhole sectionsMSIUStandalone unitMSIS-B 1MSIS-R 2MSIS-S 3Morphisis ® ASPGenisis ® ASPNemisis ® ASPGenisis FT ASPUnit with built-incentralization featureUnit with built-incentralization featureUnit built intospecialized centralizer18-in. low-pressureslip-on unit(500 psi/3.4 MPa)Industry standardbonded to pipe packerBonded to pipeHP packerBonded to pipepacker with cablefeed-through ability1Well inclinations 55°3Ultraclose tolerance applications, underreamed hole sections= first choice; = second choice8 © 2010-2011 Weatherford. All rights reserved.

Swellable Well Construction SystemsCentralization (horizontal wells andextended-reach drilling, wheredrag-force minimization required)Interzonal isolationReservoir compartmentalizationGas/water coning managementIsolation of fluid/gas liner andcasing contactsIsolation in stimulation and/orfrac jobsInflow control device, expandablesand screen and standalonescreen isolationPlug-and-abandon operationsIsolating buildup sections;heel drawdown managementPoint anomaly isolation (straddles)Secondary seal barrier casingshoe integrity; sustained casingleaksIsolation at lateral junctions;milled windowsIntelligent well construction© 2010-2011 Weatherford. All rights reserved. 9

Enhancing hybrid elastomersWeatherford’s exclusive hybrid elastomers provide the industry’sonly swellable elastomers that respond to oil, water, wet gas andmultiphase environments.The capability to ensure swelling with onlyone elastomer—regardless of the wellborefluids—is a significant advantage comparedto conventional swellables that are limitedto single-fluid activation.Engineered elastomerOur swellable elastomers are engineered sothat swelling occurs predictably and only inresponse to specific well conditions, well fluidsand temperature conditions. This flexibilitygreatly enhances planning and performance.These elastomers are formulated to meetspecific swelling objectives and wellborecompatibility issues as well dynamics changeover time. These robust elastomers provide aunique capacity to enhance well constructionperformance, reduce expenses and ensurereliable isolation over the life of the well.Volume Change (%) (%)Volume Change (%) (%)Swell Profile – Tap Water at 176ºF (80ºC)350 Swell Profile – Tap Water at 176ºF (80ºC)350300300250250200200150150Elastomer type100Elastomer Oil type100Oil Water50Water Hybrid50Hybrid000 10 20 30 40 500 10 20 30 40 50Time (days)Time (days)Swell Profile – Clairsol Base Oil at 176ºF (80ºC)350 Swell Profile – Clairsol Base Oil at 176ºF (80ºC)350300300250250200200150150Elastomer type100Elastomer Oil type100Oil Water50Water Hybrid50Hybrid000 10 20 30 40 500 10 20 30 40 50Time (days)Time (days)The hybrid elastomer (green line) swells in oil or water.Oil SwellableHybridWater SwellableOil Swellable Hybrid Water Swellable• Diffusion-absorption process• Swell time and volumegoverned by temperature andhydrocarbon composition• Will swell in condensate andwet gas• Swell speed customizableSwell rate is faster at highertemperatures and in lighterhydrocarbons.• Hybrid elastomer capable ofswelling in either hydrocarbon,water-based solutions, and/orwet gas• Swell speed customizablefor each activation fluid(independent swell control)• Element is single piece ofrubber (not sections)Combination• Swell time and volumegoverned by temperatureand water salinity• Will swell in water vapor• Swell speed customizable• Super absorbent polymer (SAP)used as means of swellingSwell rate is faster at highertemperatures and lowersalinities.Weatherford’s swellable elastomers are a breakthrough technology that yield many benefitsand are formulated to meet your specific operational environment and objectives.10 © 2010-2011 Weatherford. All rights reserved.

Swellable Well Construction SystemsCustomized, swellable, wellbore isolationWeatherford provides worldwide service and support from more than 900 locations inapproximately 100 countries. To find out more about our swellable wellbore isolation technologies,contact an authorized Weatherford representative or visit weatherford.com/micro-seal.weatherford.com© 2010-2011 Weatherford. All rights reserved. 7387.02Weatherford products and services are subject to the Company’s standard terms and conditions, available on request or at weatherford.com. For more information contact an authorized Weatherford representative. Unless notedotherwise, trademarks and service marks herein are the property of Weatherford and may be registered in the United States and/or other countries. Weatherford products named herein may be protected by one or more U.S. and/or foreign patents. For more information, contact patents@weatherford.com. Specifications are subject to change without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth inthe applicable contract between Weatherford and the client.