力學(xué)大會(huì)2015集水平井體積壓裂水力裂縫擴(kuò)展形態(tài)數(shù)值模擬研

*（中石油勘探開(kāi)發(fā)廊坊分院，河北廊坊規(guī)技術(shù)縫儲(chǔ)層標(biāo)壓應(yīng)開(kāi)發(fā)racPD擬應(yīng)裂討應(yīng)擾裂形顯(1壓間間應(yīng)擾縫；(擾顯發(fā)轉(zhuǎn)縫遠(yuǎn)處應(yīng)應(yīng)(3通過(guò)racP縫行擬體導(dǎo)引水平井分段多簇壓裂技術(shù)是實(shí)現(xiàn)非常規(guī)油氣藏儲(chǔ)層體積改造的重要技術(shù)1，通許多學(xué)者對(duì)水力裂縫的擴(kuò)展進(jìn)行了研究：Olon2008）2基于位移不連續(xù)法對(duì)多裂縫同步壓裂及順序壓裂擴(kuò)展形態(tài)進(jìn)行了研究；（2013）3從巖石斷裂動(dòng)力學(xué)角度出發(fā)用力學(xué)分析和數(shù)值模擬相結(jié)縫在天然裂縫處的轉(zhuǎn)向擴(kuò)hni等（2015）4基于二階位移不連續(xù)法對(duì)水力裂縫的擴(kuò)展及轉(zhuǎn)向進(jìn)行了研究； 分量σi,σi i

AssDs

N

AsnDni1to N N jσnAns N N j

在大多數(shù)壓裂施工的現(xiàn)場(chǎng)縫擴(kuò)展的主要因素為壓裂液粘韌性6時(shí)縫尖端的應(yīng)力強(qiáng)度因子Ktip在小于斷裂韌KIc時(shí)縫也能夠擴(kuò)展。因此我們假定水力裂縫的動(dòng)態(tài)擴(kuò)展速率遵循亞臨界裂縫擴(kuò)展方程7：V

tip IcmaxIc

22

IIsin2 IIsin2強(qiáng)度因子，KII為剪切型應(yīng)力強(qiáng)度因子。KK分別由裂尖單元的法向位移不連續(xù)Di和切向位移不連續(xù)Di確定 K0.806 K0.806 ：

展形態(tài)。在3.1節(jié)和3.2節(jié)分別模擬常規(guī)分段多簇壓裂和Texas兩步法（TexasTwoStep否是否是 表ν段間距簇間距5--每個(gè)壓裂段裂縫累積擴(kuò)展長(zhǎng)度達(dá)到

Rn

分別測(cè)試Rn=1,2,。；第三段裂縫生長(zhǎng)情況類(lèi)似于第二段裂縫 000 -150- -150- -150- (a)Rn=1,(c)Rn=2,(e)Rn=5,000 -150- (b)Rn=1,

-150- (d)Rn=2,

-150- (f)Rn=5,000 0 0 -150- 0 TTSMRn=1,

TTSMRn=2,

TTSMRn=5,

縫1,,,等.頁(yè)巖氣體積改造技術(shù)現(xiàn)狀及對(duì)我國(guó)的啟示.石油鉆采工藝,2011,33(2):2OlsonJE.Multi-fracturepropagationmodeling:Applicationstohydraulicfracturinginshalesandtightgassands.42ndUSRockMechanicsSymposium,2008.3.頁(yè)巖氣儲(chǔ)層水力裂縫轉(zhuǎn)向擴(kuò)展機(jī)制.大學(xué)學(xué)報(bào):自然科學(xué)版,2013,37(5):BehniaM,GoshtasbiK,ZhangGQ,etc.NumericalmodelingofhydraulicfracturepropagationandEuropeanJournalofEnvironmentalandCivilEngineering,2015,19(2):CrouchSLandStarfieldAM.Boundaryelementmethodsinsolidmechanics,1sted.Lodon:GeorgeAllen&Unwin,AdachiJ,SiebritsE,PeirceA,etc.Computersimulationofhydraulicfractures.InternationalJournalofRockMechanicsandMiningSciences,200744:739~757.OlsonJE.Jointpatterndevelopment:effectsofsubcriticalcrack-growthandmechanicalcrackinction.JournalofGeophysicalResearch,1993,98(B7).12251~12265.黃志標(biāo).斷裂力學(xué).華南理工大學(xué),OlsonJEandTaleghaniAD.Modelingsimultaneousgrowthofmultiplehydraulicfracturesandtheir ctionnaturalfractures.SPEHydraulicFracturingTechnologyConference,JoH.Optimizingfracturespacingtoinducecomplexfracturesinahydraulicallyfracturedhorizontalwellbore.SPEAmericasUnconventionalResourcesConference,2012.NUMERICALSIMULATIONOFHYDRAULICFRACTUREPATTERNWITHHORIZONTALWELLVOLUMEFRACTURINGTECHNIQUEWANG XIU LU(LangfangBranchofPet ResearchInsituteofPetroleumExploration&Development,LangfangHorizontalwellvolumefracturingisakeytechniqueofunconventionaloilandgasdevelopment.Thegoalofreservoirstimulationistoincreasethestimulatedreservoirvolumeandcomplexityoffracturenetwork.Basedondiscementdiscontinuitymethod,CrackPG2Dwasdevelopedtosimulatehydraulicfracturepropagationandstressinterference.Withthissimulator,theeffectsofstressinterference,relativetreatmentnetpressureandfracturingmodeonhydraulicfracturepatternarediscussed.Resultsshowthat:(1)Simultaneousmulti-clusterfractureinitiationisapttoformpreferentialmainfracturebecauseofstagestressinterferenceandclusterstressinterference.(2)Atthenearsideofwellbore,fracturepropagationdeflectsandnon-narfractureareformed;Atthefarsideofwellbore,thedegreeofstressinterferencedecrease,andthefracturegrowsalongthedirectionperpendiculartotheminimumhorizontalprincipalstress.(3)Byconductingsimulationofhydraulicfracturepatterninadvance,thesimulationresultshavea