窄压力窗口井段精细控压压力平衡法固井设计方法与应用  

Design and application of well cementing technology based on the precise managed pressure balancing method in narrow pressure window hole sections

作　　者：郭建华 郑有成[2] 李维[2] 李斌[1] 袁彬 徐璧华[3] Guo Jianhua;Zheng Youcheng;Li Wei;Li Bin;Yuan Bin;Xu Bihua(Engineering Technology Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610017,China;PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石油西南油气田公司工程技术研究院 [2]中国石油西南油气田公司 [3]“油气藏地质及开发工程”国家重点实验室·西南石油大学

出　　处：《天然气工业》2019年第11期86-91,共6页Natural Gas Industry

基　　金：国家科技重大专项“四川盆地大型碳酸盐岩气田开发示范工程——大型深层碳酸盐岩气藏钻采技术研究与应用”（编号：2016ZX05052-003）;中国石油天然气股份有限公司重大科技专项“西南油气田天然气上产300亿立方米关键技术研究与应用——四川盆地高温高压含硫深井超深井钻井、完井及试油技术研究与应用”（编号：2016E-0608）

摘　　要：四川盆地复杂深井、超深井钻进受套管层序的限制,同一裸眼井段通常钻遇多个压力系统,纵向地层出现窄安全密度窗口,虽然钻井常采用控压钻井(MPD)技术保证了安全有效钻进,但也给下部小间隙尾管固井带来了巨大的挑战,因而开展既能满足四川盆地小间隙尾管固井质量又能保证窄度安全密度窗口地层固井安全的固井工艺技术研究具有重要的现实意义。为此,在借鉴控压钻井成功应用的基础上,提出了精细控压平衡压力法固井技术:在注水泥设计时将环空流体静液柱压力设计为欠平衡(略低于地层孔隙压力),然后利用精细控压钻井装置MPD在井口节流产生回压或施加井口补偿压力,使注水泥过程通过井口压力和流体在环空的流动摩阻达到平衡孔隙压力,注水泥结束后环空继续施加一定的补偿压力,防止静压不足与水泥浆失重造成候凝期间环空窜流。四川盆地某探井(超深井)应用该技术后,全井段固井水泥胶结合格率为97%,胶结质量优的井段为76%。结论认为,该技术无需增加其他设备,仅借助控压钻井的设备就能实现高顶替效率下的固井施工安全和固井质量提升。In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density window is observed in vertical strata.The application of managed pressure drilling(MPD)technique which is often used in well drilling ensures the safe and efficient drilling,but it also brings about great challenges to the small-gap liner cementing at the lower part.Therefore,it is of great practical significance to research a cementing technology that can not only satisfy the quality requirement of small-gas liner cementing,but also ensure the safe cementing in the strata with narrow safety density window.In this paper,a cementing technology based on precise managed pressure balancing method was proposed by referring to the successful application of MPD technique.According to the cementing design,the hydrostatic column pressure of annulus fluid is underbalanced(slightly lower than the formation pore pressure),and then a precise managed pressure drilling device is adopted to produce back pressure through wellhead restriction or apply wellhead compensation pressure,so that the balanced pore pressure can be reached in the process of cementing via the wellhead pressure and the flow friction of fluid in the annulus.After the cementing is completed,a certain compensation pressure is applied to the annulus continuously to prevent annulus channeling during waiting on cement caused by insufficient static pressure and slurry weight loss.After this technology was applied to an ultradeep exploration well in the Sichuan Basin,the qualification rate of borehole cementing quality reached 97%,and the well sections with good cementing quality accounted for 76%.In conclusion,this technology needs no additional equipment,and only by virtue of the MPD equipment,it can achieve safe cementing construction and cementing quality improvement under high displacement efficiency.

关 键 词：窄安全密度窗口 精细控压 尾管 固井 注水泥 井漏 平衡压力 四川盆地 

分 类 号：TE2[石油与天然气工程—油气井工程]