油气井射孔对固井水泥环损伤范围的试验  

Experiment on damage of cement sheath induced by perforation in oil and gas wells

作　　者：闫炎 管志川[2] 王庆 许玉强[2] 廖华林[2] YAN Yan;GUAN Zhichuan;WANG Qing;XU Yuqiang;LIAO Hualin(Key Laboratory of In-situ Property-Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030600, China;School of Petroleum Engineering in China University of Petroleum(East China), Qingdao 266580, China;CNPC Engineering Technology Research & Development Company Limited, Beijing 102206, China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030600 [2]中国石油大学(华东)石油工程学院,山东青岛266580 [3]中国石油集团工程技术研究院有限公司,北京102206

出　　处：《中国石油大学学报（自然科学版）》2022年第3期81-88,共8页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：中国石油天然气集团有限公司重大科技项目(ZD2019-183-005);中国石油大学(华东)研究生创新工程(YCX2020020)。

摘　　要：射孔弹起爆后侵彻井筒与地层的同时,同样会破坏孔道周围的套管与水泥环。一旦水泥环出现微裂缝或固井界面出现微环隙将会在后续开发过程中诱发环空窜流。针对此问题,基于螺旋射孔方式,采用4种型号射孔弹进行大型射孔打靶试验,分析射孔后水泥环与固井界面的破坏特征,并讨论两种水泥浆配方下射孔弹装药量、射孔密度对井筒局部失封范围的影响。结果表明水泥环内锥形孔道周围齿状微裂纹发展区域靠近固井二界面;孔道周围套管与水泥环形变能力的差异形成一界面马鞍形的脱黏区域;采用小药量射孔弹、降低射孔密度、改善水泥浆配方可减小水泥环内部损伤范围与界面脱黏区域,利于后期压裂过程中井筒密封完整性的保持。In the perforation process of oil and gas wells using explosive bullet,the well casing and cement sheath around the perforation hole can be damaged,with micro-cracks generated in the cement sheath and micro-annular channels formed at the casing-cement interface,which can lead to fluid channeling in the subsequent production process.In this study,large-scale perforation experiments were conducted using explosive bullets with different trajectories to simulate the perforation process,and the damage characteristics of cement sheath and casing-cement interface were investigated under a spiral trajectory perforation condition.The influence of the explosive load and perforation density on the damage of the cement sheath was analyzed with two cement slurry formulations.The experimental results show that the micro-cracks generated around the perforation hole were close to the cement-formation interface.The difference of casing and cement deformation contributes to the formation of a saddle-shaped debonding zone at the casing-cement interface around the perforation hole.Perforation using low explosive charge,low perforation density and optimized cement slurry formula can reduce the damage of the cement sheath and the debonding area of the cementing interface,which is also beneficial for maintaining the wellbore integrity during later stages of hydraulic fracturing and production.

关 键 词：螺旋射孔 水泥环 损伤范围 裂缝 密封完整性 

分 类 号：TE21[石油与天然气工程—油气井工程]