1.China United Coalbed Methane Co.,Ltd.,Beijing ; 2.Henan Polytechnic University,Jiaozuo 454010,China;3.China University of Petroleum,Beijing ,China

为解决煤层气超短半径水平井煤层坍塌、煤粉产出造成的频繁修井等问题，维持超短半径水平井连续稳产生产，探讨超短半径水平井筛管完井工艺进行可行性，重点研究不同材料管柱的屈服弯曲半径，采用Wellplan软件进行超短曲率半径条件下管柱可通过性分析，优化设计管柱组合。基于煤粉颗粒分布、运移速度、过流面积等因素进行高密度聚乙烯（HDPE）筛管参数设计，采用有限元分析法进行筛管屈服强度分析。设计高密度聚乙烯（HDPE）筛管专用送入工具及下入工艺研究，进行案例设计分析，探讨工艺可行性。结果表明：直径116 mm尺寸井眼在曲率半径不小于12 m的情况下可下入直径40 mm高密度聚乙烯（HDPE）筛管完井，筛管本体不发生塑性变形，筛孔附近出现部分塑性变形，塑性变形的体积占筛管实体体积的14.58%，为井筒流体通过提供稳定通道。筛孔可阻挡较大的煤粉颗粒进入井筒造成卡泵，T型割缝具备一定清洁功能，减少煤粉颗粒卡塞割缝。研究结果推进煤层气超短半径水平井工艺技术发展。

In order to solve the problems of coal seam methane short radius horizontal well collapse and frequent work-over caused by pulverized coal production,and to maintain the continuous stable production of ultra-short radius horizontal wells,this paper discusses the feasibility of the completion technology of the screen pipe in the ultra-short radius horizontal well.The yield bending radius of different material columns is studied and Wellplan software is used to analyze the pass ability of the tube column under the condition of ultra-short radius of curvature.and the design of the pipe column combination is optimized.Thescreen parameters of high-density polyethylene(HDPE) were designed based on the distribution of pulverized coal particles,the speed of movement and the overflow area.The finite element analysis was used to analyze the yield strength of the screen.The design of special running-in tool and running-in process for high density polyethylene(HDPE) screen tube is studied,and case design analysis is carried out to explore the feasibility of the process.The results show that the wells with a diameter of 116 mm can be drilled into a 40 mm high-density polyethylene (HDPE) screen tube with a radius of curvature of not less than 12 m.The screen body does not plastically deform and some plasticity appears near the screen hole.The volume of plastic deformation accounts for 14.58% of the solid volume of the screen,providing a stable passage for the well-bore fluid to pass.The mesh hole can block the larger coal powder particles from entering the borehole and avoidblockage.The T-shaped slotting has a certain cleaning function.The results of this paper are intended to promote the development of process technology for ultra-short radius horizontal wells of coalbed methane.