深井封隔器解封时套管挤压失效风险评估方法及应用  

Risk Assessment Method and Field Application for Casing Collapse Failure During Packer Unsetting in Deep Oil Wells

作　　者：伍兴东 王鹏博 裴东东 何勇[1] 李宁博 许红林 张智 WU Xingdong;WANG Pengbo;PEI Dongdong;HE Yong;LI Ningbo;XU Honglin;ZHANG Zhi(No.4 Oil Extraction Plant,Sinopec Northwest Oilfield Company,Shaya,Xinjiang 842200,China;Safety and Environment Protection Technology Supervision Center of PetrChina Liaohe Oilfield Company,Panjin,Liaoning 124010,China;School of Petroleum and Natural Gas Engineering,Chongqing University of Science and Technology,Chongqing 401331,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu,Sichuan 610500,China;Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石化西北油田分公司采油四厂 [2]中国石油辽河油田公司安全环保技术监督中心 [3]重庆科技大学石油与天然气工程学院 [4]油气藏地质及开发工程国家重点实验室 [5]西南石油大学

出　　处：《钻采工艺》2024年第3期170-176,共7页Drilling & Production Technology

基　　金：重庆市自然科学基金项目“基于弹塑性接触模拟的页岩气井套管-水泥环界面微观泄漏模型和控制机制”(编号:CSTB2022NSCQ-MSX0989)和油气井建井安全四川省青年科技创新研究团队专项计划“页岩气井筒完整性及安全”(编号:2020JDTD0016)共同资助。

摘　　要：封隔器解封时,环空液柱快速下沉将产生明显抽吸压力,导致封隔器解封后生产套管挤毁事故时有发生,给深部高温高压油井安全生产带来巨大挑战。基于规范中套管有效外压力的计算方法,考虑环空液柱下沉流速及其诱导的环空抽吸压力,建立了封隔器解封时套管有效外压力计算方法,针对现场实例井研究了封隔器解封对套管等效支撑内压力和套管挤压失效风险的影响规律。结果表明,封隔器解封时油管液面深度越大、封隔器胶筒外径与套管内径环空间隙越大,环空抽吸压力值越大,套管内等效支撑内压力当量密度越低,套管挤压失效风险越大。为降低套管挤压失效风险,建议提高封隔器胶筒解封后变形恢复能力,同时封隔器解封前油管内应尽量补满液体。研究成果为确保深部高温高压油井安全生产提供重要理论依据和技术支撑。When the packer is unsetted,the rapid sinking of the annulus fluid column will produce obvious suction pressure,which will lead to collapse accident of the production casing.Based on the calculation method of casing effective external pressure in the specification,the calculation method for the casing effective external pressure during packer unsetting was established considering the annulus fluid column sinking velocity and annulus suction pressure induced.The influence law of packer unsetting on casing effective support internal pressure and casing collapse failure risk was studied.The results showed that:When the packer is unsealed,the greater the depth of the tubing fluid,the greater the annulus gap between the outer diameter of the packer rubber cylinder and the inner diameter of the casing,the greater the annulus suction pressure,the lower the equivalent pressure density within the casing support,and the greater the casing failure risk.In order to reduce the risk of casing collapse failure,it is recommended to improve the deformation recovery ability of the rubber cylinder after the packer is unsetted.At the same time,the tubing should be filled with fluid as much as possible before the packer is unsetted.The research results provide important support to ensure the safe production of deep high temperature and high pressure oil wells.

关 键 词：套管 封隔器 解封 挤压失效 抽吸压力 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]