摘要
为了提高延长油田致密油水平井的环空密封能力、保证多级缝网压裂开发效果,对水泥浆进行了功能化改性。结合该油田南部致密油储层特征、水平井井身结构和多级缝网压裂对固井水泥浆性能的要求,建立了套管-水泥环-地层受力模型,分析得到了水泥石杨氏模量与界面压力的关系图版,并据此设计了水泥浆;对丁苯胶粉进行了粒径优选、表面处理,并与甲酰胺及无机盐复配制得高强微弹剂,辅之以其他外加剂,形成了满足性能要求的高强微弹水泥浆。研究发现,水泥石杨氏模量越低、地层杨氏模量越高、压裂施工压力越低、井眼扩大率越小,则满足环空密封要求的水泥石抗压强度越小;与空白样相比,高强微弹水泥浆抗压强度提高51.8%、杨氏模量降低10.5%、抗折抗拉强度提高75.0%以上。该水泥浆在延长油田南部10余口致密油水平井进行了现场应用,水平段固井质量合格率达95%以上,分段压裂时未发生窜流。研究结果表明,高强微弹水泥浆可以提高延长油田致密油水平井压裂后的环空密封性,具有推广应用价值。
In order to improve the sealing ability of the annulus and ensure the multi-stage fracture-network fracturing development effect of tight oil horizontal wells in Yanchang Oilfield,the cement slurry had been functionally modified. Combined with the characteristics of tight oil reservoirs in the south part of this oilfield,horizontal well casing program and the requirements of multi-stage fracture-network fracturing on cement slurry properties,a casing-cement ring-formation force model was established,and the relationship chart between the Young 's modulus of the cement paste and the interfacial pressure was obtained.The particle size and surface treatment of styrene-butadiene rubber powder were optimized,and the high-strength micro-elastic agent was prepared by compounding formamide and inorganic salts,supplemented by other additives.After that,it was possible to form the high-strength micro-elastic cement slurry satisfying the requirements of this chart.The study found that the lower the Young's modulus of the hardened cement,the larger the Young's modulus of the formation,the lower the fracturing pressure and the smaller the hole enlargement rate,the lower the required compressive strength of the cement paste that met the requirements of annulus sealing would be.The developed cement slurry had perfect high-strength micro-elastic properties.Compared with the blank samples,the compressive strength was 51.8% higher,the Young's modulus was 10.5% lower,and the anti-breaking/tension strength was 75.0% higher.The cement slurry had been applied in more than 10 wells in the south part of the Yanchang Oilfield.The qualified rate of cementing quality in the horizontal section was over 95%,and no channeling occurred in the staged fracturing.The study results showed that the highstrength micro-elastic cement slurry could improve the post-fracturing sealing performance of tight oil horizontal wells in the Yanchang Oilfield,and demonstrated potential for widespread adoption.
作者
王涛
申峰
展转盈
马振锋
刘云
侯云翌
WANG Tao;SHEN Feng;ZHAN Zhuanying;MA Zhenfeng;LIU Yun;HOU Yunyi(Research Institute,Shaanxi Yanchang Petroleum (Group) Co.,Ltd.,Xi'an,Shaanxi,710075,China;Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning),Xi'an,Shaanxi,710075,China;Research Center for Exploration & Development Technology,Yanchang Oil Field Co.,Ltd.,Yan'an,Shaanxi,716000,China)
出处
《石油钻探技术》
CAS
CSCD
北大核心
2019年第5期40-48,共9页
Petroleum Drilling Techniques
基金
国家科技重大专项“陆相页岩气水平井高效低成本钻完井技术”(编号:2017ZX05039003)资助
关键词
致密油
水平井
高强度
微弹性
水泥浆
丁苯胶粉
延长油田
tight oil
horizontal well
high strength
microelasticity
cement slurry
styrene butadiene rubber powder
Yanchang Oilfield
