川南泸州深层页岩气井套变主控因素与防控对策  

Influencing factors and prevention measures of casing deformation in deep shale gas wells in Luzhou block,southern Sichuan Basin,SW China

作　　者：韩玲玲 李熙喆[2] 刘照义 段贵府 万玉金[2] 郭晓龙[2] 郭伟[2] 崔悦 HAN Lingling;LI Xizhe;LIU Zhaoyi;DUAN Guifu;WAN Yujin;GUO Xiaolong;GUO Wei;CUI Yue(University of Chinese Academy of Sciences,Beijing 100049,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]中国科学院大学,北京100049 [2]中国石油勘探开发研究院,北京100083 [3]东北石油大学,黑龙江大庆163318

出　　处：《石油勘探与开发》2023年第4期853-861,共9页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目“渝西深层页岩气高产主控因素及效益开发技术研究”(2022KT1205)。

摘　　要：基于四川盆地南部(简称川南)泸州区块构造展布特征和断裂发育特点,应用微地震、测井、地应力等资料,总结深层页岩气井套变特征,明确套变机理与主控因素,建立套变风险评估图版并提出针对性的套变风险防控对策。研究表明:压裂激活断裂滑移是川南泸州深层页岩气井套变的主控因素,工区断裂逼近角主要为10°~50°,占比65.34%,临界激活孔隙压力增量为6.05~9.71 MPa。对于地质因素导致的套变,防控措施主要有避让风险断裂、选择应力机制因子低值区布井两个方面。对于工程因素导致的套变,防控措施主要有4个方面:①布井时尽量避让高激活风险和高滑移风险断裂,无法避开时尽量选择远离断裂中心位置的区域;②优化井筒参数,调整井筒方位可在一定程度上降低作用在套管上的剪应力,降低套变程度;③优化井身结构设计,在不影响优质储集层钻遇率的基础上,确保水平井弯曲段曲率半径大于200 m;④优化压裂施工参数,增大避射距离、降低单次施工压力、增加段长等是降低套变风险的有效措施。Based on structural distribution and fault characteristics of the Luzhou block,southern Sichuan Basin,as well as microseismic,well logging and in-situ stress data,the casing deformation behaviors of deep shale gas wells are summarized,and the casing deformation mechanism and influencing factors are identified.Then,the risk assessment chart of casing deformation is plotted,and the measures for preventing and controlling casing deformation are proposed.Fracturing-activated fault slip is a main factor causing the casing deformation in deep shale gas wells in the Luzhou block.In the working area,the approximate fracture angle is primarily 10°–50°,accounting for 65.34%,and the critical pore pressure increment for fault-activation is 6.05–9.71 MPa.The casing deformation caused by geological factors can be prevented/controlled by avoiding the faults at risk and deploying wells in areas with low value of stress factor.The casing deformation caused by engineering factors can be prevented/controlled by:(1)keeping wells avoid faults with risks of activation and slippage,or deploying wells in areas far from the faulting center if such avoidance is impossible;(2)optimizing the wellbore parameters,for example,adjusting the wellbore orientation to reduce the shear force on casing to a certain extent and thus mitigate the casing deformation;(3)optimizing the casing program to ensure that the curvature radius of the curved section of horizontal well is greater than 200 m while the drilling rate of high-quality reservoirs is not impaired;(4)optimizing the fracturing parameters,for example,increasing the evasive distance,lowering the single-operation pressure,and increasing the stage length,which can help effectively reduce the risk of casing deformation.

关 键 词：四川盆地 泸州区块 页岩气井 套变机理 断裂激活 风险评估 套变防控 

分 类 号：TE345[石油与天然气工程—油气田开发工程]