资源描述：
《气体钻井钻杆冲蚀规律研究》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、气体钻井钻杆冲蚀规律研究第31卷第6期20l0年I1月石油ACTAPETROIEISINICAVoI.31No.6Nov.2010文章编号:0253—2697(2010)06—1{/13-05气体钻井钻杆冲蚀规律研究祝效华刘少胡童华(1.西南石油大学油气藏地质及开发工程国家重点实验室四川成都610500;2.西南石油大学机电工程学院四川成都610500)摘要:针对气体钻井岩屑造成钻柱严重冲蚀的问题,基于气一固两相流和冲蚀理论,建立了环空岩屑运移模型.在Eulerian坐标系下求解气体连续相流场,在Lagrangian坐标系下对离散相岩屑粒子
2、进行了碰撞求解,采用Grant和Tabakoff公式求解岩屑粒子冲蚀速率,借助实验数据验证了仿真模型.利用该模型研究了气体钻井中钻杆居中以及不同钻杆偏心率,井径扩大率,注气量和机械钻速下环空岩屑粒子运移规律和钻杆冲蚀特性.研究表明,岩屑对钻杆接头及下坡面本体的冲蚀比钻杆本体及接头上坡面严重;钻杆偏心和井径扩大都使局部冲蚀速率峰值增大,且偏心越严重,井径扩大越大,局部冲蚀速率峰值增速越大;机械钻速增大,导致钻杆局部冲蚀速率峰值近乎线性增加;在工程常用注气量范围内,注气量对冲蚀速率峰值和冲蚀速率平均值的影响很小.根据冲蚀规律提出如下建议:减小钻
3、杆斜坡坡度可减少钻杆接头及下坡面的局部冲蚀;采用低转速的空气锤钻井工艺可减缓因偏心引起的局部冲蚀;井眼扩大较大时,增大注气量,通过改变岩屑粒子轨迹,可减少岩屑对钻杆本体的多次冲蚀.关键词:气体钻井;气固两相流;岩屑运移;冲蚀;钻杆;计算流体动力学;数值模拟中图分类号:TE821文献标识码:AAstudyonthedrillpipeerosionlawingasdrillingZHuXiaohua,LIUShaohuTONGHua(1.StateKeyLaboratoryofOil—GasReservoirGeology&Exploi
4、tation,SouthwestPetroleumUniversity,Chengdu610500,China:2.MechatronicEngineeringCollege,SouthzvestPetroleumUniversity,Chengdu610500,China)Abstract:Erosionofdrillstringsbycuttingsisveryseriousingasdrilling.Basedonthegasandsolidtwophaseflowdynamicsande—rosiontheory,thepresen
5、tpaperestablishedatransportmodelforannuluscuttings.Acontinuousgasphaseflowfieldwassolvedun—dertheEuleriancoordinatesystem,andthecollisionsolutiontodiscrete—phasecuttingparticleswasobtainedundertheLagrangiancoordinatesbyapplyingtheGrantandTabakoffformulaetocalculatetheerosi
6、onrateofcuttingparticlesandverifyingthesimulatingmodelwiththeaidofexperimentaldata.Then,thismodelwasappliedtostudyvariousproblemsencounteredingasdrilling,suchasthedrill—pipecentralization,differenteccentricityofdrillpipes,enlargementofwellborediameter,volumeofgasinjection,
7、transportlawofannuluscuttingparticlesattherateofpenetration(ROP),anderosionfeaturesofdrillpipes.Thestudiesdemonstratedthatcuttingserodedthedrill—pipejointanditslowerslopingsurfacemoreseriouslythanthedrill—pipebodyandtheupperslopingsurfaceofthejoint.Boththedrill—pipeeccentr
8、icityandtheenlargementofwellborediameterwouldincreasethepeakvalueofthelocalerosionrate,an
