资源描述:
《低渗透油藏地压裂水平井三线性流试井模型.doc》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、低渗透油藏的压裂水平井三线性流试井模型作者简介:姚军,男,1964年3月生,1984年毕业于华东石油学院采油工程专业,2000年获中国石油大学(华东)油气田开发工程专业博士学位,现为中国石油大学(华东)石油工程学院院长、教授、博士生导师,主要从事油气田开发工程的教学与科研工作。军殷修杏樊冬艳致学(中国石油大学(华东), ,266555)摘 要:针对低渗透存在启动压力梯度的特点,建立了压裂水平井的三线性不稳定渗流的数学模型,并得到其在Laplace空间的解析解;通过Stehfest数值反演和Duha
2、mel原理得到了考虑井筒储存和表皮系数影响的压裂水平井井底压力值,最后对影响因素进行了研究,结果表明:启动压力梯度存在时,压裂水平井井底压力及压力导数曲线都呈上翘趋势,且启动压力梯度越大,曲线越高,上翘的时间也越早;人工裂缝导流能力主要影响裂缝和区域II双线性流出现时间的早晚;当裂缝间距达到一定值时,裂缝径向流才会出现,且裂缝间距越大,裂缝径向流持续时间越长;储容比ω影响压力导数曲线“凹子”的宽度和深度,ω越小,“凹子”越宽越深;窜流系数决定“凹子”的位置,λ越小,“凹子”就越靠右;井筒储集系数C
3、D主要影响曲线的早期续流段。关键词:启动压力梯度;三线性流模型;压裂水平井;解析解;试井分析中图分类号:TE353文献标识码:ATrilinear-FlowWelltestModelOfFracturedHorizontalWellInLowPermeabilityReserviorYAOJun,YINXiu-xing,FANDong-yan,SUNZhi-xue(CollegeofPetroleumEngineering,ChinaUniversityofPetroleum,Qingdao266
4、555,China)Abstract:Accordingtothecharacteristicsofthethresholdpressuregradientforlowpermeabilityreservior,amathematicalmodeloftrilinear-flowunsteadypercolationforfracturedhorizontalwellisestablished;thendeducedfromitsanalyticalsolutioninLaplacespace.B
5、ottomholepressureoffracturedhorizontalwellsisgotafterconsideringwellborestorageandskinfactorbyStehfestnumericalinversionandDuhamelpricipcle,finallydiscussingtheinfluencefactorsofthebottomholepressureoffracturedhorizontalwells.Thestudyresoultshowedthat
6、thethresholdpressuregradientmadethedimensionlesspressureanditsderivativecurvesgoupinlatetime,thebiggerthethresholdpressuregradient,thehigherthecurveandtheearlierthecurvegoingupappears;thefracturedconductivitymainlyinfluencetheappearedtimeofbilinear-fl
7、ow;thefractureradialflowappearsonlywhenthefractureinterspacingachievessomeextent,andthelargerthespaceis,thefractureradialflowlastslonger;storativityratioωinfluencesthehollow’swidthanddepthofthepressurederivativecurve,thesmallertheω,thewiderthedeeperho
8、llow;crossflowcoefficientλdecidesthepositionofhollow,thesmallertheλ,themoreright-handthehollow;wellborestoragecoefficientCDmainlyaffectstheearlyfreewheelingsegmentofthecurve.Keywords:thethresholdpressuregradient;trilinear-flowmodel;fracturedho