摘要
重点风险探井河探1井四开钻遇超高压油气层,二开Ø244.5 mm套管抗内强度60 MPa,关井能力不足,存在井控风险。为保障本井Ø177.8 mm套管回接固井的正常施工,通过室内实验开展加重材料及外加剂的优选,采用球形铁粉加重材料,配置出满足该井注水泥塞施工的密度2.60 g/cm^(3)水泥浆体系,在160℃、170 MPa条件下,48 h强度24.5 MPa,168 h强度28.1 MPa,滤失量23 mL。现场采用批混批注的方式,结合精细控压技术,实现了注水泥塞全过程的压力平衡,顺利完成了该井注水泥塞施工,水泥塞质量合格。应用结果表明,配置的2.60 g/cm^(3)超高密度水泥浆适用于类似的超高压固井施工,通过精细控压,可以解决钻井液密度不足以压稳地层、窄安全密度窗口固井时存在的压力波动问题,为后续同类井控压注水泥塞及控压固井积累了经验。
The key risk exploratory Well Hetan 1 encountered oil-gas layers with ultra-high pressure during drilling in the fourth section,while the internal strength of theØ244.5 mm casing in the second section is 60 MPa,which is insufficient to shut in the well,posing well control risks.In order to ensure the normal construction of cement plugback withØ177.8 mm casing in this well,weighting materials and admixtures were screened through indoor experiments.A cement slurry system with a density of 2.60 g/cm^(3),suitable for cement plug injection construction in this well,was prepared by adding spherical iron powder as weighting material.Under conditions of 160℃and 170 MPa,the strengths of the cement slurry system after 48 hours and 168 hours were 24.5 MPa and 28.1 MPa,respectively,with a filtration loss of 23 mL.On-site construction was carried out using the batch mixing and batch injecting method,combined with precise pressure control technology,achieving pressure balance throughout the cement plug injection construction process.The cement plug injection construction in this well was successfully completed,and the quality of the cement plug met the standards.The application results show that the cement slurry system with an ultra-high density of 2.60 g/cm^(3)is suitable for similar ultra-high-pressure cementing operations.And through precise pressure control,it can solve the pressure fluctuation issues when the drilling fluid density is insufficient to stabilize the formation and during cementing with narrow safe density window,which brings experience for subsequent pressure-controlled cement plug injection and pressure-controlled cementing in similar wells.
作者
党冬红
徐文光
杨杰
和建勇
费中明
蒋世伟
卢三杰
DANG Donghong;XU Wenguang;YANG Jie;HE Jianyong;FEI Zhongming;JIANG Shiwei;LU Sanjie(The First Cementing Company,CNPC Bohai Drilling Engineering Co.,Ltd.,Renqiu 062552,Hebei,China;North China Division,CNPC Bohai Drilling Engineering Co.,Ltd.,Renqiu 062552,Hebei,China)
出处
《石油钻采工艺》
CAS
北大核心
2023年第3期284-288,共5页
Oil Drilling & Production Technology
基金
中国石油天然气集团公司科研项目“复杂超深井固井密封完整性技术研究”(编号:2021DJ4105)。
关键词
河套盆地
固井
水泥塞
超高密度水泥浆
精细控压
安全密度窗口
Hetao Basin
cementing
cement plug
ultra-high-density cement slurry
precise pressure control
safe density window
