加长钻杆关键参数设计研究

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关键词：加长钻杆；静力学模型；多体动力学；井眼轨迹；钻具参数；接触力中图分类号：TE921 文献标识码：A DOI：10.12473/CPM.202502047

Abstract：Extendeddrillpipeis animportantdrilling tool thatuses veryfewcollars．When appliedto complex wells（e.g.deep wellsand long horizontal wels），itcan effectively reduce operational risks that are possibly induced byfailure incidentsatconnections，thereby loweringoperational costs，and improving theoveralsafety andeconomic benefits of drilling operations.This paper discusses the designof key parameters of extendeddrillpipe，forwhich there isno systematicand scientific guidance.First，using the statics model of extended drillpipe， theforce and deformation behaviorsof thedrilpipe inwelbore were systematicallyrevealed，and two typical types ofcontactbetween extendeddrilpipeandsidewallwereclearlyidentified，layingatheoreticalfoundationforsubsequent analysis.Then，combining withthe multibody dynamics modeloffull-holedrilstringsystem，three groups ofsystematicalnumerical simulation experiments weredesignedandconductedto investigate theimpactsof three keyfactors（dogleg severity，drillpipesize，and steel grade）on the maximum allowable lengthof extendeddrillpipe.Furthermore，three typical well conditions（deep vertical well，extended-reach horizontal well，and complex-structure welltargeting multiplehorizons）wereselectedfordetailed simulationanalysis toverifythe effectiveness and superiority of extended drillpipeapplication incaseofdiferent well types．Theresults show that，in thecurvedsection，thedrillpipelength decreases monotonically withthe increasing dogleg severity，and inthevertical sectionand atthesame bending moment，alongerdrillpipe is more prone to contact with the lowersidewall. The extended drillpipe is recommended to be designed with a size above 127mm （5in）and a material above steel gradeS35.Theresearch conclusions providetechnical supportto thekeyparameterdesign and fieldapplication of extended drillpipe.

Keywords：extended drillpipe；statics model；multibody dynamics；wellbore trajectory；drillpipe parameter; contact force

0 引言

随着油气勘探开发的目标日趋复杂化，在超深井和水平井的钻井作业中面临井深增加、水平段延伸等技术难题[1-4]，包括井眼清洁困难、井下摩阻扭矩增大、卡钻风险上升、接卸钻具效率低下以及井控难度提升等。（剩余12488字）