准噶尔盆地南缘超深井天X井尾管精细控压固井技术  

Liner Cementing through Precise Pressure Control in the Ultra-Deep Well Tian-X Located at the Southern Margin of the Junggar Basin

作　　者：费中明 刘鑫 张晔 张小建 蒋世伟 沈磊 杨祖富 FEI Zhongming;LIU Xin;ZHANG Ye;ZHANG Xiaojian;JIANG Shiwei;SHEN Lei;YANG Zufu(NO.1 Cementing Company,BHDC,Renqiu,Hebei 062552)

机构地区：[1]中国石油集团渤海钻探工程公司第一固井分公司,河北任丘062552

出　　处：《钻井液与完井液》2023年第3期391-396,共6页Drilling Fluid & Completion Fluid

基　　金：中国石油集团渤海钻探工程有限公司项目“准噶尔南缘超深井固井技术研究与应用”(2020ZD01F-04)部分研究成果。

摘　　要：天X井是准噶尔盆地南缘冲断带霍玛吐背斜带安集海背斜的一口集团公司风险探井。该井六开Ф139.7 mm尾管固井地层高低压并存、裸眼段长、环空间隙小,同时目的层砂岩段孔隙发育地层油气活跃,钻进期间多次发生漏失,地层压力窗口仅有0.02 g/cm^(3),井筒压力无法动态平衡,容易出现下套管及固井期间溢流、井漏等复杂情况,固井质量无法保障。为了解决该井固井施工难题,尝试实践了精细控压固井技术,通过与精细控压装备配合,进行下套管、固井各阶段井口压力控制,保证漏点、溢点在安全密度窗口范围内,实现井筒内压力平衡的目的。该井固井采取精细控压一次上返的尾管固井工艺,制定针对性的固井技术措施,最终顺利完成了天X井固井施工,经IBC测井解释,封固段合格率为100%,降密度后喇叭口正常不窜气。该技术为南缘区块窄密度窗口井固井施工提供了宝贵的经验及借鉴意义。The well Tian-X is an exploratory well located at the Anjihai anticline(an anticline in the Huomatu anticline zone)in the south edge thrust belt in the Junggar Basin.The 6th interval(Ф139.7 mm)penetrates a long open hole section of the well with coexistence of high and low pressure zones and narrow annular clearance,and the sandstone reservoir is developed with abundant pores and has active oil and gas.The safe drilling window in this interval is only 0.02 g/cm^(3),and mud losses have frequently happened during drilling.Narrow safe drilling window also causes difficulties in dynamically balancing the formation pressures and problems such as well kick and mud losses during casing running are quite prone to happen,resulting in poor cementing quality.To solve these problems,precise pressure management during casing running has been performed.Using the precise pressure management equipment,pressures at the wellhead during casing running and well cementing can be precisely controlled an the pressures at the points of mud losses an points of well kicks along the borehole were controlled in the scope of the safe window,thereby realizing pressure balance inside the wellbore.In cementing the liner string,the wellhead pressure was precisely controlled and the cement slurry returned to the designed depth in one circulation,and the cementing techniques were designed specifically to suit for the wellbore conditions.The well cementing job was performed successfully.IBC well logging interpretation shows that the job quality of the cementing section is 100% qualified, no gas channeling occurred at the bell nipple when mud density was reduced. This technology has provided a precious experience and reference significance for cementing wells with narrow drilling windows at the south edge of the Junggar Basin.

关 键 词：精细控压固井 尾管固井 窄密度窗口 溢流 井漏 

分 类 号：TE256[石油与天然气工程—油气井工程]