大规模加砂压裂完井工具冲蚀定量模拟计算及工具优化  

Quantitative erosion simulation calculation and optimization for large-scale sand fracturing completion tools

作　　者：伍强 杨云徽 刘生国 张瑶 WU Qiang;YANG Yunhui;LIU Shengguo;ZHANG Yao(Petroleum Engineering Technology Research Institute of Sinopec Southwest Oil&Gas Branch,Deyang,Sichuan 618000,China;Sinopec Southwest Oil and Gas Branch Gas Production Plant 2,Nanchong,Sichuan 637000,China;Sinopec Southwest Petroleum Engineering Company Downhole Operations Branch,Deyang,Sichuan 618000,China)

机构地区：[1]中石化西南油气分公司石油工程技术研究院,四川德阳618000 [2]中石化西南油气分公司采气二厂,四川南充637000 [3]中石化西南石油工程公司井下作业分公司,四川德阳618000

出　　处：《油气井测试》2024年第4期37-43,共7页Well Testing

基　　金：中国石化重大项目“川西须二气藏钻完井及储层改造关键技术”(P21040-3)。

摘　　要：须家河致密砂岩气藏120 MPa超高压、长时间大排量加砂压裂作业对管柱冲蚀影响,导致完井管柱出现变形、断裂、球座磨损、分段球不到位等问题。基于冲蚀磨损理论,选择出分段管柱中四处冲蚀严重部位,利用Ansys软件进行建模,采用动静态结合方法,计算得到了大规模加砂压裂施工管柱变径处的冲蚀程度定量值,明确了油管短节与滑套球座为冲蚀严重位置,有针对性地对冲蚀最严重位置进行了结构优化及材质优选。油管变扣短节优选Q125钢级管材可兼顾强度及经济性;改进滑套上接头变径处台阶倒角控制在30°以内,滑套球座顶部优化设计为弧形结构,球座采用硬质合金材质,优化改进后的滑套冲蚀程度比原结构降低66.5%,经川东北须家河组YL15、YL171、YL6等多口井成功应用,优化改进的压裂管柱满足了超高压加砂压裂长时间施工需求。The 120 MPa ultra-high-pressure,long-duration,high-displacement sand-fracturing operations in the Xujiahe tight sandstone gas reservoir have significant erosion impacts on the completion string,leading to various problems including well string deformation,fracture,ball seat wear,and improper positioning of sectional balls.Based on erosion wear theory,four severely eroded sections of the segmented string were identified.Using Ansys software,a model was developed to quantitatively evaluate the erosion extent at the diameter transition points of the large-scale sand fracturing string,employing a combination of dynamic and static methods.The short tubing joint and the sliding sleeve ball seat were identified as the most erosion-prone areas,and targeted structural optimization and material selection were conducted for these critical points.For the variable diameter short tubing joints,Q125 grade tubing was selected for its balance of strength and cost-effectiveness.The chamfer angle at the diameter transition of the sliding sleeve upper joint was controlled within 30°,the top of the sliding sleeve ball seat was redesigned with an arc shape,and the material for the ball seat was altered to hard alloy.After these optimizations and improvements,the sliding sleeve exhibited a 66.5%reduction in erosion compared to the original structure.The improved fracturing string was successfully applied in several wells in Xujiahe formation in the Northeast Sichuan,including well YL15,well YL171,and well YL6,meeting the demands of ultra-high-pressure,long-duration sand fracturing operations.

关 键 词：超高压 大排量 冲蚀 油管短节 滑套球座 加砂压裂 模拟计算 ANSYS有限元分析 

分 类 号：TE357[石油与天然气工程—油气田开发工程]