58 Oileld ReviewTesting Oileld Technologies forWellsite OperationsMichele ArenaStephen DyerRosharon, Texas, USALarry J. BernardAllen HarrisonWalter LuckettThomas ReblerSundaram SrinivasanSugar Land, TexasBrett BorlandRick WattsConocoPhillipsHouston, TexasBill LessoHouston, TexasTommy M. WarrenTesco CorporationHouston, TexasFor help in preparation of this article, thanks to Claire Bullen,Luanda, Angola; Robert Edmondson, Joe Fuentes and TeresaGarza, Cameron, Texas; and John Hobbins, Randy LeBlanc,Thomas Querin and Don Shapiro, Sugar Land, Texas.EcoScope, FIV (Formation Isolation Valve), InterACT,PowerDrive, StethoScope and TeleScope are marksof Schlumberger. Casing Drilling is a mark ofTesco Corporation.At full-scale test facilities, new drilling, logging and completion technologies can betested under actual wellsite conditions in a controlled and condential environment,before they are utilized in the eld. The industry is now taking the ultimate step inquality assurance by providing full-scale system integration tests and testing whiledrilling. The knowledge gained by this rigorous assessment helps create tools thatperform as designed, even under the most demanding conditions.Demandforresourcesisdrivingourindustrytoseekoilandgasinincreasinglydifficultlocations.Operatorswantnewcapabilitiesindownholetools,butdonotwanttoriskfailureofanewtoolinahigh-costwellbore.Predeployment testing has become a critical stepin the introduction of new tools.Identificationofproblemswithanewtechnologyisbestwhendoneearlyinthedevelopmentprocess,becausesolutionstendtobemoreexpensivewhenimplementedlater.Earlytestingisthereforecrucialandformsanintegralpartofproductdevelopment,fromconception to design to deployment in the eld.Testsshouldexaminegeneralusability,applic-ability, measurement accuracy and repeatability,productsafety,manufacturability,anddeliveryconguration and logistics.Service companies are interested in testing atoolunderconditionsthatareascloseaspossible to those likely to be experienced in theeld,butwithoutthelogisticalandexternaloperationalconstraintsofthefield.Inacontrolledenvironment,atestcanbefocused,concise and complete. As a result, unanticipatedusage scenarios and measurement issues, as wellas hardware reliability, can be thoroughly investi-gatedandworkedthroughonsiteduringthetestingphase.Havingtheabilitytoaddressproblems when they are rst encountered greatlyimproves the development process.Oilandgascompanies,ontheotherhand,want to minimize the nancial risk resulting froma tool malfunction or failure. In a test facility, theycan explore tool functionality or system interfaceissuesinacontrolledandwell-characterizedenvironmentwithouttheconstraintsofrig-timecostsorsafetyproblems.Someofthelatestadvances in drilling technology, including drillingwith casing in high-angle wells, can be evaluatedin settings that mimic the actual well conditions.Equallyimportantforboththeoperatorandtheserviceprovideristheneedtocomparetestsonnewtoolswithpreviouslyproventechnologiesperformedundersimilarconditions.Theinterpretationresultsofthecomparison are more accurate and reliable whentest conditions can be controlled and monitoredunder identical operating conditions, rather thantryingtoextrapolatebetweendifferenteldsorwell conditions.Variouskindsandlevelsoftestingareperformedatanumberofcentersaroundtheworld.1Thisarticlediscussesqualificationtesting, which ranges from components to systemintegration,andcollaborativeexperimentsbetweenoilandgascompaniesandserviceproviders.Ofparticularinterestarethenaltests and performance measurements made justprior to eld deployment or before a customizedcomplexproductcongurationisdeployedinacommercialwell.TheSchlumbergerCameronTexas Facility (CTF) is designed to accommodatesuch advanced tests.1. Schlumberger test centers include, among others, theAbingdon Technology Center, England; BeijingGeoscience Center, China; Cameron Texas Facility,Texas; Gatwick Technology Center, England; IntegratedProductivity & Conveyance Center, Singapore; OsloTechnology Center, Norway; Princeton TechnologyCenter, New Jersey; Schlumberger Conveyance andDelivery Center, Sugar Land, Texas; SchlumbergerEuropean Learning Center, Melun, France; SchlumbergerKabushiki Kaisha, Fuchinobe, Sagamihara, Kanagawa,Japan; Schlumberger Reservoir Completions TechnologyCenter, Rosharon, Texas; Schlumberger Reservoir FluidsCenter, Edmonton, Canada; Schlumberger RiboudProduct Center, Clamart, France; SchlumbergerStonehouse Technology Center, Gloucestershire,England; and Sugar Land Technology Center, Texas.For additional information on other test facilities: Lang K:Oileld Testing Centers: Nurseries for New Ideas,Petroleum Technology Transfer Council Newsletter 9,no. 4 (2003): 69.Winter 2005/2006 59From Components to SystemIntegration TestingReliabilityisakeyfactorinthesuccessandprotabilityofanywellsiteproduct.Althoughanynewequipmentortoolmaybeawonderfulinnovation,itisdestinedtofailifitcannotwithstandtheharshenvironmentofdownholeoperations or drilling. Good engineering coupledwithrigorousperformanceandenvironmentaltesting is an effective means to success.2Forexample,eachcomponentofaloggingtool is tested for a wide variety of factors such asthe operating environment, deployment methodsandmeasurementdynamicrange.Environ-mentalconditionsintheoileld,bothupholeanddownhole,arequantiedforextremesoftemperature,pressure,shock,vibrationanddifficultloggingconditions.Deploymentandcontingencymethodstestedincludewireline,slickline and coiled tubing. Real-time interactionandcontrolthrougheachdeploymentmethodarealsotested.Theabsoluteandrelativeaccuracy of the measurement dynamic range andits repeatability are tested in different mud typesand lithologies.WithinSchlumberger,therigorousproductdevelopment process begins when the feasibilityof a project is rst examined. Based on the toolsplanned operational environment, a requirementand specication document details the expecteduse and life of the product and the conditions itwillbesubjectedtooveritslifetime.Thisdocumentprovidesthebasisforaplanthatspecifiestheteststobeperformedatthecomponent,subassembly,assemblyandsystemlevelstoverifythattheproductsdesignmeetsqualityandreliabilityrequirements.Thenallevel of tests is system integration testing (SIT),whenmultipletoolsandpiecesofequipmentfrom Schlumberger and third-party suppliers aretested in actual wellsite operating conditions.Alsoduringtheprojectfeasibilityphase,thephysicsofthemeasurementsareveriedinthelaboratory, in external test facilities or downhole.Oncetheprojectisshowntobetechnicallyfeasibleandtohavesufcientbusinessjusti-cation to warrant further investment, the productmoves on to the development phase, in which testsare performed every step of the way (below).Duringthedevelopmentphase,component-level testing starts at the earliest possible stage.At this point, test costs are the lowest, yet designimprovementsatthisstageyieldthemosteffective results. During component testing, testmachinesandlaboratoryconditionsproducestressesonindividualcomponentssimilarto,orinexcessof,whatcanoccurinanactualwell.60 Oileld Review>Stages of testingfrom components to system integrationduring the development phase of tools or equipment.Component setup for high-temperature test Vibration test of subassemblyHigh-pressure, high-temperature test vessel for system testing Compression test of a tool assemblyWinter 2005/2006 61Thetestconditionstypicallyrangefromlowtemperatureduringtransportationandstorageto very high temperature at the bottom of a wellandalsoincludeshock,vibration,lowandhighpressure, bending, corrosion and erosion.Subassemblytestingbeginswhentheindividual components are qualied and multiplecomponentsareassembledandcombined.Vericationsofperformanceandreliabilityareperformed.Thisisaccomplishedinamannersimilartocomponent-leveltestingbutrequireslarger test machines. Each engineering center hascustomizedtestmachinescorrespondingtothetype of subassemblies developed at that center.The next stage is subsystem or assembly-leveltesting, when a downhole tool is built to a pointwhere it can stand alone and provide one or morefunctions at a wellsite. Subsystem testing may bechallengingbecauseofequipmentsizeandusuallyrequiresspecialfacilities.Surfacetestsincludemudowthroughandaroundthetool,pressure,shock,vibrationandrotationofcomplete downhole tool sections.Insystem-leveltestingorprecommercialevaluation,measurementsareverifiedforaccuracyandrepeatability,especiallywithrespecttovariationsthatoccurduringthemanufacturingprocess.Manyofthesetestparameterscanbeexaminedundercontrolledconditions,forexample,bydrillingthroughhardenedwellcement (left).Severalquestionsareaddressedatthisstageoftesting.Doestheproductiontoolperformaccordingtothespecificationsoftheengineeringprototype? Doallthetoolsperforminaconsistent manner?Arethereunanticipatedtool-to-toolproduction variations? What is the sensitivity of aspecictoolparametertotheoverallmeasure-ment performance?Finally,intheSITphase,multipletoolcombinationsaretested.Forinstance,theSITmayinvolvelongwell-completionassemblies;thesestringsmaycomefromdifferentcentersandsuppliers.Vericationofsysteminterop-erabilityandperformanceiscrucialandisvirtuallyimpossibletodeterminewithoutassembling and testing the entire system at a testfacility that provides a complete dress rehearsal.In the past, rig qualication was performed on anoperators rig. Today, test facilities equipped withdrillingrigsareavailabletoperformthesamefunctionwithouttheconstraintsofcostlyrigtime and safety issues.About Test FacilitiesSchlumbergeroffersseveralfacilitiesforsystemintegrationtesting,eachwithdifferentcapabilities.Beginningwiththersttestwellin1956,thefourtestwellsattheSchlumbergerReservoir Completions (SRC) Technology CenterinRosharon,Texas,havebeenusedfordevel-opmentandtestingofperforatingguns,wirelineloggingtools,tubing-conveyedperforatingequipment and, more recently, drillstem test andcoiledtubingequipment.ThefacilityalsohasasmallartificiallakethathasbeenusedbyWesternGecotoconducttestswithmarineseismic sources.TheSchlumbergerEuropeanLearningCenter(SELC)inMelun,France,providescasedhole,openhole,downholeandsurfacewelltestingprimarily for wireline and some well services. Wellsat the Sugar Land Technology Center are used forcustomeracceptancetestingofwirelineandcertainlogging- andmeasurements-while-drilling(LWDandMWD,respectively)tools.TheGenesisDrillingTestFacilityisafull-sizedrillingrigthatcanduplicatemanyconditionsthatoccuratthewellsiteincasedverticalboreholes.Therignotonly is an excellent facility for performing drillingtests, but also serves as a training facility.2. At Schlumberger, quality and safety assurance arebased on industry standards such as the InternationalOrganization for Standardization (ISO) 9001certicationfor engineering and manufacturing, Det Norske Veritas(DNV) certication, International Air TransportAssociation (IATA) qualication for transportation of>Genesis Drilling Test Facility. Genesis is a 142-ft [43.3-m] cantilever-type,skiddable land-drilling rig with 1,250,000-lbf [5,560-kN] derrick capacity. Inservice at the Sugar Land Technology Center since 1988, Genesis is used toreproduce downhole eld conditions for various types of tests. Mud ow,pressure, shock, vibration and rotation of downhole tools can be performedunder controlled conditions, either by drilling through cement or by using ashock-inducing device, also known as cam sub.explosives and batteries, third-party safety audits,American Petroleum Institute (API) recommendedpractices for industry standards in hardware tests,NACE International and American Society of MechanicalEngineers standards for completion equipment, andrigorous quality control both on site and off site.TheSchlumbergerCameronTexasFacility(CTF)hasafull-capabilitydrillingrigforperformingdrilling,boreholemeasurementandsystemintegrationtests.TheCTF,whichencompassesseveralhundredacres,becameoperational in 2004 (below left). The CTF drillingrigprovidesboreholeswithmorethan6,000 ft[1,829 m]ofhorizontalreach.Theformationspenetrated by CTF wells have a wide diversity ofporosities,permeabilitiesandmineralogies.Drilling,LWD,MWDandwirelinetoolsmayberunincarbonateandsandstonelithologies.Becausethesitecoverssuchalargearea,manydifferentboreholetrajectoriescanbedrilledtopenetrate the various formations.AsaSchlumbergerfacility,CTFservesasacondential test bed for the latest downhole andupholetechnologies.Thehigh-bandwidthconnectionwithintheSchlumbergerfirewallallows for easy, secure movement of condentialdataandenablestheinvolvementofremotewitnessesinextensivetestswhiledrilling.Thefacilityalsoprovideshands-onexperienceforSchlumbergeremployeesandclients,includingtestingofrig-upandtransportlogistics,andtraining of rig crews for complex deployment.WidearraysoftestshavebeenrunatCTF,ranging from feasibility to precommercializationand system integration. Tests associated with thelatestgenerationLWDtoolsTeleScopehigh-speed telemetry-while-drilling service, EcoScopemultifunctionlogging-while-drillingserviceandStethoScopeformationpressure-while-drillingservicehave been run at CTF. The tests run onthesetoolswerecomparedwithresultsfrompreviousgenerationLWDtoolsoverthesameintervals in the same well and also with wirelinelogsrunoverthesameintervals.Full-scalequalicationtestsofthenewestwhile-drillingtoolspriortofieldtestingenabledearlydebuggingofthetoolsandhelpedtopreparetheseservicesforsuccessfulintroductiononcommercialwells.3Clearly,thisfast-tracktooldevelopmentwouldnothavebeenfeasiblewithout CTF.Testing Integrated SystemsSITisespeciallybenecialforcriticaldevelop-ment projects that must integrate many types ofwellsandtools.Theincreasingnumberofcomplex, deep offshore wells has heightened thevalueofperformingSIT,potentiallymakingSITanintegralpartofarisk-managementplanforhigh-prole critical projects.CompletionSIThasbeenperformedseveraltimesoverthepastyearatCTFandSRC,simulatingascloselyaspossibleactualwellconditionsindifferentpartsoftheworld.CompletionSITobjectivesincludeassemblyprocedures,interfaceverication,installationoptimization,interventiontestingandcontin-gencyplanning.Animportantgoalistoreducethe learning curve through customized personnel62 Oileld Review3. Adolph B, Stoller C, Archer M, Codazzi D, El-Halawani T,Perciot P, Weller G, Evans M, Grant BJ, Grifths R,Hartman D, Sirkin G, Ichikawa M, Scott G, Tribe I andWhite D: No More Waiting: Formation Evaluation WhileDrilling, Oileld Review 17, no. 3 (Autumn 2005): 421.4. Edment B, Elliott F, Gilchrist J, Powers B, Jansen R,McPike T, Onwusiri H, Parlar M, Twynam A andvan Kranenburg A: Improvements in Horizontal GravelPacking, Oileld Review 17, no. 1 (Spring 2005): 5060.5. The customized changes to the completion assemblyincluded a proprietary seal system, allowing bypass ofmultiple control lines and multiple-choke-position ow-control valves that are set hydraulically. The gravel-packer circulating housing allowed slurry to be pumpedinto the annulus between the screen and the casing. Ithas a sleeve designed to close when the gravel-packpumping operation is completed.6. The customized gravel-pack system features a single-trip service tool that provides a mechanism for packersetting and testing, uid circulation and gravel-pack (GP)operation in a highly deviated wellbore. The GPcirculating housing is specially modied toaccommodate the inner completion string without therisk of opening the port sleeve.>Cameron Texas Facility. This facility is equippedwith a drilling rig for performing drilling,borehole-measurement and system integrationtests. The rig is capable of handling three-jointstands of drillpipe and is equipped with high-volume mud pumps. The rig is mounted on railsfor convenient access to different well slots witha wide variety of directional wells that can beused for both openhole and cased-hole tests.>Slack-off and pickup weight data during completion installation. The chart shows the effect of dragon the lower completion installation (left). A maximum overpullthe difference between the slack-off ttand pickup weightsof more than 200,000 lbf observed at TD would have caused tubing stress abovethe specied rating. Based on the information gained during the SIT and data collected for the lowercompletion slack-off and pickup weight, the wellbore was cleaned out and the annular uid waschanged to reduce friction. These steps reduced overpull to less than half the lower-completion value(right). The measurement of drag encountered during the inner completion installation was used to ttimplement procedural changes both during the test and in the extended-reach offshore well.DepthDepthHookload HookloadLower Completion Installation Inner Completion InstallationSimulated slack-off weightsSimulated pickup weightMeasured slack-off dataMeasured pickup dataWinter 2005/2006 63training and experience across service providers,third parties and client operations.In one SIT example, the rst of its kind for anextended-reachwell,anintelligentow-controldevice was placed within a triple-zone, cased-holegravelpackinatestwellatSRC (right).4Thecompletionassemblyincorporatedanumberofnewlycustomizeditems,includingproprietarysealassemblies,reducedoutside-diameterow-control valves and a hydraulically set, single-trip,step-boregravel-packsystemwithadedicatedservice tool and modied circulating housing.5TheSIT plan for this well also included a full downholesystem test at SRC, followed by verication of thewellheadandcontrol-lineinterfacesonlocationpriortoequipmentmobilizationoffshore.Thesetests provided the optimum method for identifyingkeyinstallationrisksandwereusedtosubsequentlymodifyprocedurestoreducenonproductive time or failures.SeveralspecicissueswereaddressedinthisSIT.Theissuewasinterfacetestingofthelowersandfacecompletionwiththeintelligentinnercompletion,particularlythefrictionaleffectsofmultiplelong-sealassemblies,theircorrectpositioningspaceoutwithinthewellbore, equipment eccentricity alignment, andminimization of seal-bore scratching and fatiguepriortolandingthecompletion.Second,dragandwearissuesfortheinnercompletionwhilerunningthroughahighlydeviatedenvironmentwereexamined.Thirdwastestingofamodiedsingle-triphydraulicallysetgravel-packsystemutilizing a step-bore and dedicated service tool.6Finally,SITwasusedtooptimizerunningmultiplehydraulicandelectric-controllineswhile minimizing the number of splices to reduceinstallation time and risk.SITprovedthefeasibilityofthecompletiondesign,thecapabilitytoinstalltheequipmentsuccessfully and the devices reliability for zonalisolation.Atotalof35recommendationsbasedontheSITwereincorporatedintothepreparationandinstallationproceduresasbestpractices,contingenciesorspecial-attentionitemsduringtheactualwellinstallation.Asubsequentoffshoreinstallationwascompletedwithminimalnonproductivetime,especiallyconsideringthehigh-dragenvironmentencounteredduringgravelpacking,withamaximumdifferenceofmorethan200,000 lbf[890 kN]betweenslack-offandpickupweightattotaldepth(TD)(previouspage,right).KnowledgegainedduringtheSITwasusedtocalibratetheinstallationdragmodelthatensured successful space out and landing.>A three-zone, cased-hole gravel-pack (GP) intelligent completion layout used for system integrationttesting (SIT) (left). Installation of the inner completion string during the SIT was conducted at the ttSchlumberger Reservoir Completions Technology Center in Rosharon, Texas (bottom right). The GP ttpacker system includes the isolation packer and circulating housing. As part of the SIT, additionalttests on the wellhead called stack-up tests were performed in collaboration with the wellheadsupplier on location (top right). ttProduction packerInner intelligent completionGP packer systemLower sandface completionGP packer systemScreensGP packer systemBottom packerPressure gaugePressure gaugeFlow-control valveFlow-control valvePressure gaugeFlow-control valveBullnoseNo-go locatorSealsBlast jointsBlast jointsSealsSealsScreensScreensThe three zones were individually stimulatedand tested using the ow-control valves, provingzonalisolation.Downholeproductiondata,whichareusedforallocationofproduction,arecurrentlycapturedbyusingInterACTreal-timemonitoringanddatadelivery.Theprojectfrominceptionthroughplanning,testingandexecutionwas accelerated for completion withina 12-month time frame.Inanotherexample,amonth-longSITofseveralnewlydesignedcompletiontoolswasperformedattheCTFinapurpose-builtcasedwell with an extended horizontal leg to simulateas closely as possible the conditions anticipatedduringanoffshoreinstallation(right).Theobjectiveofthistestwastoinvestigateanyinterfaceissuesandtoverifyqualityassuranceandqualitycontrol,assemblyprocedures,operatingproceduresandtheaccuracyofthecontingency plans. Additionally, it was importanttoidentifyandimplementlessonslearned,includingchangestothedesignandproceduresthatwouldresultinincreasedefficiency,reliabilityorfunctionalityintheoperators eld application.Knowledgegainedduringthetestsledtoimprovementsintheinterventionphase.Anewnippleprofileusedinconjunctionwiththeexpandableshiftingtoolforthetubing-isolationvalvewasredesignedtoovercomeanincom-patibilitywiththepreviouslychosenconfig-uration.Additionaltestswithtractorsforconveyancewerealsoexploredinconjunctionwithvariousinterventionmethodstoavoidthecoiledtubinglockup,orhelicalbuckling,anticipatedatcompressiveloadsgreaterthan2,500 lbf [11.1 kN] that were observed during SIT.Additionally,morethan60differentactionitemsrelated to safety, outlined procedures, equipmentmodications and best practices were recorded toincrease efciency, reliability and functionality.Testingintegratedsystemshasprovidedprovenlong-termcostsavings,bothbysolvingproblemspriortorsteldinstallationandbylessonslearnedtoimproveefciencyandtoreduceinstallationandnonproductivetime.Despitedetailedpre-engineeringstudiesthathad been performed, SIT claried the limitationsof what could be planned and veried in advanceand demonstrated the importance of conductinga eld trial in a condential manner and withoutrig-time constraints.Theabilitytotailorintegrationtestsinacontrolledandrelativelylow-costenvironmentallowsoperatorsandservicecompaniesaliketosignicantlyreducethelearningcurveandrisk.Testfacilities,especiallythoseequippedwitha64 Oileld Review7. Fontenot KR, Lesso B, Strickler RD and Warren TM:Using Casing to Drill Directional Wells, OileldReview 17, no. 2 (Summer 2005): 4461.8. A retrievable system for drilling with casing is requiredfor directional wells because of the need to recoverexpensive directional drilling and guidance equipment,to replace failed equipment before reaching casingpoint, and to quickly and cost-effectively accessformations below a casing shoe. A wireline retrievabledirectional-drilling assembly, positioned in the lowerend of the casing, replaces the directional tools used>A subsea openhole gravel-pack (GP) completion used in a system integrationttest at CTF. The upper (green) and lower (blue) completion assembliesincorporated a number of newly designed completion toolsa gravel-packservice tool for gravel-pack operation (not shown here), single-assemblyintegrated products with permanent gauge and chemical injection, and threedifferent types of isolation valves.Tubing hangerLanding stringSurface-isolationvalveSafety valveProduction packerNipple profileContraction jointSealsFIV Formation IsolationValve systemCasing extensionScreensTubing-isolation valveCasingChemical injectionand pressure gaugeGP packer systemCentralizerUpper completionLower completionin a conventional bottomhole assembly. For more onretrievable tools for drilling with casing operations:Tessari R, Warren T and Houtchens B: Retrievable ToolsProvide Flexibility for Casing Drilling, presented at theWorld Oil 2003 Casing Drilling Technical Conference,Houston, March 67, 2003.9. Borland B, Watts R, Warren T and Lesso B: Drilling HighAngle Casing Directionally Drilled Wells with Fit-for-Purpose String Sizes, paper IADC/SPE 99248, presentedat the IADC/ SPE Drilling Conference, Miami, Florida,USA, February 2123, 2006.Winter 2005/2006 65full-scale drilling rig, such as the CTF, expand thehorizonsofwhatcanbeachievedinsimulatingcomplex well plans and testing new technologiesin collaboration with oil and gas companies andother third-party contractors.A Collaborative Project: Directional Drillingwith CasingIn recent years, drilling with casing has steadilygainedacceptancebecauseitoffersincreasedwell control and safety, enhanced efciency anddemonstratedcostsavings.7Althoughthemostsignicantsavingscanbeachievedinoffshoreenvironments,drillingwithcasinginmatureassetspresentssignificantchallenges.Wellsdrilledfromaplatformaretypicallydirectional,anddrillingdeviatedwellswithcasingmayrequiremodicationstorigorplatformequip-mentthatcouldaffectproductionataprohibitivecostinanoffshoreoperationalenvironment.Also,alearningcurvetypicallymust be developed with the rst few wells drilledin a new application area.ConocoPhillips, an industry leader in applyingretrievableCasingDrillingtechnology,hasmultipleoffshoreassetsinwhichdrillingwithcasing has the potential to help deal with knownwell-constructionproblems.8Inmatureelds,such as the Eldsk eld offshore Norway, reservoirdepletion leads to well-stability concerns. Drillingwithstandarddrillpipemayrequireextracasingstringstoavoidwell-stabilityproblemsthatarecausedbydepletedformationpressures.Inadditiontosolvingdrillingproblems,thetechnologyofdrillingwithcasinghasthepotential to reduce the number of casing strings,whichcouldleadtoimprovedwell-constructionefciency and substantial cost savings.AcollaborativeprojectofConocoPhillips,TescoandSchlumbergerwasundertakentodesignandtestdirectionaldrillingwithcasingfortwowellsplannedforEldskeldin2006.Theplannedwellsweretobedrilledfromacommon wellhead with 1033 -in. and 733 -in. casing.Atthestartoftheproject,drillingwithcasingtools did not exist in these sizes and operationalproblemsrelatedtodirectionalwellsrequiredredesign of the existing hardware.Thehighrisksassociatedwithsetting,directionallydrillingandretrievingthesenewtoolswithmodicationsinuntestedboreholesizeswarrantedtestingthistechnologyindirectionalwellsinanonshoreeld.Buttherewereadditionalconcernsaboutthisapproach.First,withmultiplepartners,itwasdifculttoconductatestthatwouldbenettheoperatorbutpotentiallyhavelittleornobenettotheotherpartners.Quantifyingthecostsandriskswas complicated.Second, because pay-zone targets and accom-panyingdirectional-welltrajectoriesfrequentlychangeasnewinformationislearnedabouttheeld,adirectionalbuildproleinonecasingsection may be moved to another section becauseof a change in a geological model. These changesinthewellplanseverelyconstrainedthetestobjectives. Third, commercial wells are drilled tocompletion. The very nature of testing a drillingprocess, such as drilling with casing, may lead toproblems that are signicant enough to abandonthetestorwell.Onceasectionofdirectionaldrilling with casing is started, it must be nished.If there are problems with the tools, the ability torevert to directional drilling with drillpipe has tobeanavailableoption.Thisfail-safenatureofwellconstructionrequiredextensiveplanningand budgeting of costs.Theseissues,commoninwellconstruction,made it difcult to test new technologies for onebusinessunitintheeldsofanotherbusinessunit,evenforlargemultinationaloperatororganizations.Severalmonthswerespentinmodifyingwelldesignsbeforethedecisionwasmadetolookforadifferentapproach.Thealternative was to utilize CTF.Twotestswereplanned.ThewellsatCTFwould mirror the directional sections, build ratesandoperationalparameterssuchasmudowratesthatarerequiredforEldskwells.9Therstwellwouldtestsettingandretrievingthe755 -in.-casingbottomholeassembly(BHA)toolsinhorizontaldrillingoperations.Thesecondwould test the 10 3 -in. system with multiple buildrates,kickingoffadirectionalwellfromthevertical section.ThersttesttookplaceinJuly2005inapreviouslydrilled,high-angleboreholeatCTFwith 1333 -in. casing, which included about 600 ft[183 m] of horizontal section (below). Tests wereconductedforsettingandretrievingtheBHAinthe vertical section and at well deviations of 45and90.AdirectionaldrillingwithcasingBHAincorporatingarotarysteerablesystem(RSS)>Well prole of the horizontal well at the Cameron Texas Facility for testing directional drilling withcasing (bottom). Four bottomhole assembly (BHA) setting and retrieval operations at vertical andvarious inclinations are shown. Test 5 included about 850 ft of horizontal drilling. Rig personnel havetthe ability to break equipment down and make minor design changes based on the test taking placeon the nearby rig, such as the Tesco crew here (top). Briengs that include safety guidelinesare held each day of the tests to outline procedures for the next 12 hours. During these and otherdirectional drilling with casing tests, two daily briengs included ConocoPhillips, Tesco andSchlumberger personnel (right). ttTest 1Test 2Test 3 Test 4Test 5Drill 850 ft horizontallyBHA setting and retrieval testsplanned at 0, 45 and 90Previously drilled well with1034-in. casing to 3,769 ftDepthDistancewastested (below).10Thetestalsoincludedthedirectionalperformanceofthisequipment.AcommandwassenttotheRSStoturnthewellpath to the right, at 1.0/100 ft [1.0/30 m]. After300 ft[91.4 m],asecondcommandwassenttoturn to the left, at 3.0/100 ft [3.0/30 m]. Finally,acommandwassenttomaintainaconstantinclination and azimuth until the end of the test.Therstturnwasaccomplishedat1.4/100ft[1.4/30 m],thesecondturnhada4.3/100-ft[4.3/30-m] rate and the third command resultedinaconstantazimuth.About850ft[259m]ofnew horizontal borehole was drilled.Setting and retrieving the drilling with casingBHAswereachievedusingwireline.However,because of the high well inclination, pumping thetoolsdowntheboreholewasalsotested.TheBHAwassuccessfullysetandretrieved.Itwasthen reset and then released using a pumpdown66 Oileld Review>Directional drilling with casing BHA used in the 7 5 -in. test (left). The PowerDrive rotary steerable assembly included a motor that was run inside the ttshoe joint of the casing to provide adequate drilling rotational speed while minimizing casing rotation to control wear and fatigue. The directional drillingwith casing BHA has a stick-out, or length, below the casing shoe of 85 ft [25.9 m], whereas a typical vertical BHA has a stick-out of only 15 ft [4.6 m]. Thedirectional performance of the rotary steerable system for three PowerDrive settings is shown (bottom right). Test results indicate the degree of success ttof the horizontal drilling test. Tesco and Schlumberger personnel are seen making up the BHA (top right). ttMotor bit boxInternal tandemstabilizerVibration sensorsub9778 -in. underreamerNondirectionalmotorDrill LockAssembly (DLA)MWD system7558 -in. casingshoeExternal tandemstabilizerPolycrystallinediamond compact(PDC) bitPowerDrive rotarysteerable systemInclination, degreesMeasured depth, ftAzimuth, degreesRightLeft803,600 3,800 4,000 4,200 4,400 4,600828486889092949698158156154152150148146144142140Winter 2005/2006 67releasing tool without a wireline attachment. Ata targeted depth, the releasing tool landed in theprofilenipple,releasingthedrilllockandallowingBHAretrieval,thuscompletingafullfunctional test of the hardware.Adownholevibrationsensorsubwasrunabovetheunderreamertomonitorlateralandtorsionalaccelerations.Shocksduringtheearlierpartoftherunwereofgreaterintensity,buttaperedofflater.TheseshockshavethepotentialofcausingdamagetotheRSS.Afullinspectionofthetoolsdemonstratedthattheysufferednoneofthedamageseenpreviously,probablybecauseofthemodicationstotherotary steerable tool to make it more robust. Thesmall-diameter BHA used in drilling with casingisstillsusceptibletoexcessivevibrationsandshocksandwillcontinuetobemonitored.However,modelingtomitigateshocksandimprovementsintoolrobustnesshavegreatlyreduced this problem.The 1033 -in. test took place in November 2005.A previously installed 1333 -in. casing had been setverticallyatabout2,000ft[609.6m].Thewirelineinstallationforthe755 -in.testusedanupper wireline sheave suspended below the rigsconventionaltravelingblock,whereasthe 1033 -in.testusedaxedcrownsheaveandsplitblock to match the equipment on the Eldsk rig.ThedirectionalBHAdesignwassimilartothatusedinthe755 -in.test.AnRSSandMWDtoolwereusedfordirectionalcontrolinthepilotsection of the BHA (left).DownholevibrationmeasurementsshockcountsweretransmittedupholeinrealtimefromtheMWDtool.Shockcountswerealsorecorded downhole in the RSS. Additionally, threesensorpackageswereplacedintheBHA;oneabove the underreamer and two below it, betweentheMWDtoolandRSS.Downholerecordedmeasurementsincludedannularpressure;lateral,axialandtorsionalshocks;rotationalspeed;torque;andweight-on-bit.TwoBHAsofdifferent lengths were used to test differences invibration response.Thedatasetfromthistestisthemostextensiverecordingofdownholedataevercollectedduringanoperationinvolvingdrillingwith casing. Data were recorded while kicking offasidetrackplug,traversingthroughamazeofotherboresdrilledfromthesameparentboreholeanddrillingtoabout850ftwhilebuildingangletoabout20.Thewellwasdirectionallydrilled,rstwithalowbuildrateof 0.5/100 ft [0.5/30 m] and then a higher rateof 3.0/100 ft.ThedrillingmechanicsanddynamicsdatagatheredduringthesetestshaveledtorecommendationsintacticalchangesthatwillimprovewelldesignsfortheConocoPhillipsNorway operations at Eldsk.Expanding Horizons in Quality AssuranceDesigningequipmentthatcanwithstandtheextreme environmental and drilling conditions ofglobaloileldswhilemakinghighlysensitivemeasurementscontinuestobeincrediblychallenging. As tools become more complex andhydrocarbons hide in ever more difcult settings,theriskandcostsassociatedwithapplyingnewtechnologieswillonlyincreaseinthefuture.Therefore,qualifyingoileldtechnologiespriorto their introduction in the eld is essential.Withtheneedtomitigateexposuretohazardousoileldenvironmentsandkeepcostsincheck,remotetestinginvolvingclientsandengineeringandtestfacilitiespersonnelhasbeenagrowingtrend.Thehigh-bandwidthconnectivitywithintheSchlumbergernetworkrewallprovidestheabilitytoconducttestscondentiallyandinvolveexpertswhomightbethousands of miles away.11Thebenetsofmaintainingandoperatingtestcenters,includingfulldrillingcapability,arewell-established.Rapiddeploymentof high-performanceenablingtechnologiesintheeldandanincreasingdemandforcomplex,multidisciplinary,turnkeycompletionprojectsaresomeofthereasonsforthenecessityof testfacilitiessuchasSRCandCTF.Infact,thelimitsoftestingareprescribedonlybythe creativity boundaries of the technology developers.The future is likely to see an increased numberofcollaborativeprojectsbetweenoperators,servicecompaniesandthird-partysupplierstotestnewlimitsoftechnologyandprovidebothquality and safety assurance in tough, geologicallycomplex drilling environments. RG10. Copercini P, Soliman F, Gamal ME, Longstreet W, Rodd J,Sarssam M, McCourt I, Persad B and Williams M:Powering Up to Drill Down, Oileld Review 16, no. 4(Winter 2004): 49.11 Aldred W, Belaskie J, Isangulov R, Crockett B,Edmondson B, Florence F and Srinivasan S:Changing the Way We Drill, Oileld Review 17, no. 1(Spring 2005): 4249.>Directional drilling with casing BHA used in the1033 -in. test. The BHA used in the 1033 -in.-casingttest is the heaviest and longest BHA ever usedin directional drilling with casing. The BHA hasa stick-out of 122 ft [37.2 m], and the BHA weighstthree times the weight of a BHA used in the7 5 -in. test.Uppervibration sub10334 -in. casingshoePowerDrive rotarysteerable system12334 -in. underreamerMotor sleevestabilizerNondirectionalmotorDrill LockAssembly (DLA)MWD systemLowervibration subsInternal tandemstabilizerRoller reamerPolycrystallinediamond compact(PDC) bit