超低压易漏地层钻井液新技术

1996年12月PETROLEUM　DRILLING　TECHNIQUESDec.,1996!钻井泥浆#超低压易漏地层钻井液新技术宫新军　陈建华　成效华(山东东营　257064) 提要　简要介绍了低密度可循环泡沫钻井液的配方试验及性能特点。胜利油田5口井在古潜山构造地层中应用该钻井液,成功地解决了超低压地层严重井漏问题,保护和解放了油气层,创造了良好的经济效益和社会效益。主题词　低压油气藏　石灰岩　井漏　泡沫钻井液　正电胶　发泡剂　稳定剂　胜利油田一、问题的提出胜利油田草桥、孤南、桩西等地区存在着古潜山构造地层(风化壳以下)。此类地层岩性为石灰岩,连通性好,孔隙度高,但孔隙压力极低。钻进至古潜山构造地层时,经常发生只进不出的严重井漏,有的井漏失近1000m3钻井液(堵漏时间达数月之久),有的井因漏失而报废,造成巨大的经济损失。经过对井漏后井内液面高度的长期观察和特性分析,认为古潜山构造地层的孔隙压力梯度明显低于地层水柱压力梯度。为此,进行了大胆的设想:如果能卡准地层界面,在钻至古潜山构造地层前就把技术套管下至风化壳以上3～5m处,然后采用密度低于1100kg󰃗l的钻井液钻开风化壳地层(在古潜山构造层段继续用低密度钻井液钻进,待完钻后用筛管完井),不仅可以避免严重井漏,同时能防止超低压油气层的污染。根据以上设想,胜利油田钻井泥浆公司研制出了低密度可循环泡沫钻井液,并在现场应用成功。二、配方及试验低密度可循环泡沫钻井液是由气体、起泡胶体材料、稳泡剂、发泡剂组成的稳定性良好的分散体系。其配方如下:起泡胶体基浆(可为淡水、盐水或预水化膨润土浆)+2%MMH(浓度10%正电胶)+015%～1%WPS(稳泡剂)+011%～015%DM21(发泡剂)。发泡剂是根据API推荐的评价标准评选的。稳泡剂和发泡剂的评选方法是:H2O+稳泡剂+发泡剂高速搅拌后,倒入带有刻度的量筒中,观察泡沫的变化情况,记录发泡体积及半衰期,评价其发泡能力和泡沫的稳定性。试验结果如下:密度0175～1100kg󰃗l,API滤失量5～10ml,塑粘20～30mPa・s,动切力10～25Pa,pH值9～11。试验表明,该体系具有良好的常规性能和流变性能,抗温、抗污染能力较强,适应于现场作业。三、现场施工工艺1.进入古潜山构造地层前,由地质技术人员把关,卡准古潜山地层的界面。在界面以上5m左右下入技术套管。2.下完技术套管并注水泥封固后,清理循环系统,检查搅拌器、泥浆枪,做到灵活好用。3.配制足够数量起泡胶体基浆。把整个循环系统和井筒内的原有井浆替成起泡胶体基浆,并均匀循环。4.循环中,按配方加入稳泡剂。循环均匀后,加入发泡剂。钻进中不断地充气和发泡,以满足密度和流变性能的要求。5.在钻井液密度和流变性能达标以及各种设备能正常运转的前提下,钻开古潜山构造地层界面。6.在钻进过程中,严密观察循环出口情况,准确测量返出钻井液密度。以返出量正常为原则,根据实际需要加入发泡剂,以调整钻井液密度;并不断地充气和发泡,使钻井液能产生充足的泡沫和保持良好的流变性能。四、应用效果经过室内试验与评价,近两年来胜利油田草古102-斜3井、孤南7-61井等五口井先后应用低密度可循环泡沫钻井液进行施工,成功地解决了以往钻古潜山构造地层时严重井漏问题,(下转62页)ventionWashoverSpearAbstraet:Thedrop2preventionwashoverspearcandomillingandfishingoperationinonetrip.Theapplicationofthemodifieddrop2preventionwashoverspearinWR45220geothermaldirectionalwellhasshownthatthewashoverspeariswell2designedandeasytooperate.Keys:washoverpipe,drop2prevention,washoverspear,keyseat(well),sticking,fishingtool,geothermalwell,directionalwell,Huabeioilfield,WR45-20wellXingLanchao,WangDefuandZhenShuiquan,engi2neersandseniorengineerofPetroleumDrillingMachineFactory,MGMR.DesignModelsofBits’CrownProfilesAbstract:ThisarticlesummerizesfourbasiccrownprofilesbystudyingcrownprofilesofexistingPDCbitsanddiamondbitsathomeandabroad.Thearticlealsodevelopsfourdesignmodelsofcrownprofileswhichcanbeusedfortwostylesbits’design,andabtainsseriesofformulae.Keys:PDCbit,computer2assisteddesign(CAD),opti2mumdesign,mathematicsmodelPengYeandWangFuxiu,assistantengineerandengi2neerofDrillingTechnologicalResearchInstitute,ShengliOilfield.SelectionandFieldExperimentofComple-tionMethodforCoal-formedGasWellAbstract:Coal2formedGas(CFG)wellcompletionisverydifferentfromoilandgaswellcompletion.AccordingtothecharacteristicsofCFGwell,thispaperputforwardthebaseandmethodofCFGwellcompletionselection.BasdonthegeologicalfactorsofAnyangarea,thewellcompletionmethodselectionwasperformed.Keys:coal2formedgas,gaswell,openholecomple2tion,linercompletion,perforatedcompletion,method,drainagegasrecovery,desorption,pressure,fieldtesting,Anyangcity,Mei’an21wellZhengFenghui,engineerofNo15SurveyingandEx-plorationTeamofMGMR.InvestigationandApplicationofCavitatingWaterJetinDrillingAbstract:Cavitatingwaterjet,whichisobtainedbyartificiallyinducingcavitationdamageinhighpressurewa2terjet,isakindofnoveljetandcangreatlyenhancethecleaningandcuttingactionwithoutincreasingthepump

ca2pacity.Thispaperreviewstheadvancesintheinvestiga2tionsofcavitatingwaterjetincludingthebasictheory,theinducingmethodsandthepatentedbitsandnozzlesofthejetforoildrilling.Keys:cavitation,fluidics,nozzle(drilling),efficiency,impact,pressure,venturitube,turbulentflow,jetvelocityLiGenshengandShenZhonghou,professorsofPetroleumEngineeringDepartment,UniversityofPetroleum(Huadong).EnglishTranslator:LiGensheng EnglishCorrector:LiuDangsheng EnglishEditor:HeJinnan(上接26页)收到了良好的效果。基本数据见表1。低密度泡沫钻井液基本数据表1　井　号钻进井段m钻时h进口密度kg󰃗l出口密度kg󰃗l草古1022296110～9901061000175～01770179～0181草古1022斜3101415～10581371670184～01860185～0187孤南72605166015～16741081000184～01860188～0190孤南7261165110～180010171000178～01800190～0192孤南8252165016～179810161000187～01890189～0191五、几点认识1.低密度可循环泡沫钻井液具有半衰期长、泡沫强度高、携岩性能好、可循环性好、不影响泥浆泵上水等特点,且投资小,效益高,工艺简单。2.胜利油田实践证明,低密度可循环泡沫钻井液技术能成功解决以往古潜山构造地层严重井漏问题。其技术关键是钻至古潜山地层前卡准地层界面,及时下入技术套管,保证地层界面以上井眼的稳定性。3.古潜山构造地层往往是很好的储层。严重井漏可使大量的钻井液和堵漏材料漏入储层而造成地层损害,投产井产量很低,有的甚至不出油。采用低密度可循环泡沫钻井液施工,可避免因地层漏失而引起的地层损害,投产井都获高产,有的井产量达到100t󰃗d以上。这为勘探开发低压和超低压油气层开创了一条新路,对完善油气层保护技术具有重要的意义。4.根据胜利油田古潜山构造地层钻井统计,以往每口井平均漏失钻井液500m3以上。采用低密度可循环泡沫钻井液以后,由于避免了地层漏失,可节约直接成本20万元以上。根据投产资料分析,采用低密度可循环泡沫钻井液后单井平均增产10t󰃗d以上,一年可净增产值360万元以上。由此可见,利用低密度可循环泡沫钻井液解决超低压地层严重井漏问题,可获得良好的经济效益和社会效益。●1996-08-22收稿;1996-11-12改回作　者　简　介宫新军,1962年生。1983年毕业于大庆石油学院应用化学专业。一直从事钻井液与完井液的科研和生产管理工作。现为胜利油田钻井泥浆公司研究所所长,高级工程师。陈建华,1964年生。1983年毕业于重庆石油学校油田化学专业。现为胜利油田钻井泥浆公司研究所副所长,工程师。成效华,1964年生。1985年毕业于胜利石油学校钻井专业。现任胜利油田钻井泥浆公司研究所助理工程师。・26・PETROLEUM　DRILLING　TECHNIQUES Dec.,1996technologicalkeysandperformanceindexesofMMHmudwhichwassuitforLinpanarea.Italsodiscussedsomeim2portantproblemsofMMHusage.Keys:polymermud,MMH,mudperformancecontrol,rheology,fieldtesting,application,Linpanoilfield,ShenglioilfieldLiuZhaokang,HuangHefuandShuDayou,engineerandseniorengineersofNo11DrillingCompanyofDian2gianguiOilExplorationBureau.DrillingFluidTechnologyinTuo30WellAbstract:Accordingtoformationcharactersandexpe2rienceofadjacentwells,conventionaldispersed,finedipersed,siljconstabilizedandaerateddrillingfluidsys2temswererespectivelyadoptedindifferentintervalsofTuo30wellinLiaoheoilfield.Inordertomeettherequirementsofevaluationalwellanddirectionalwell,theingredientsofaerateddrillingfluidandthatusedinadjacentstraightwellweremodified.ItprovedthatusingdifferentdrillingfluidsystemsindifferentintervalsofTuo30wellwassuccess2ful.Theaerateddrillingfluidwithstandedtestsoflongopenhole,hightemperature,orientationandcoring.Keys:aerateddrillingfluid,dispercant,organosiliconcompound,stabilizer,lubricant,anti2sloughingmud,direc2tionalwell,coring,welltemperature,Tuo30Well,LiaoheoilfieldSongXueyanandQinYonghong,engineerandheadengineerofMudCompanyofNo12DrillingCompany,LiaohePetroleumExplorationBureau.DiscussionofDrillingFluidTechnologyinLunpolaBasin,TibatAbstract:AccordingtotheformationcharactersofLunpolabasin,Tibet,andtheexperienceofseveralcom2pletedwellintreatingsuchdrillingtroublesaswellslough,lostcirculationanddrillpipesticking,XL4welladoptedthepolypotassiumshieldingtemperarypluggingdrillingfluidsystem,whichhadfunctionsofblockingandsloughresistance.Itprovedthatthissystemandrelativeengineeringtechnologicalmeasurescouldmeettherequire2mentsofwelldrillingandcompletion.Iteffectivelypre2ventedtheoccuranceofwellsloughandlostcirculationinNiu2,3intervalsofEogeneinLunpolabasin.Itprotectedthehydrocarbonreservoirandgotremarkableeconomicbenefit.Keys:holecaving,lostcirculation,anti2sloughingmud,temperarypluggingagent,m