非常规条件下超深漏失井尾管固井作业——以云安002-7井为例  

Liner cementing of ultra-deep absorption well under unconventional conditions: A case study of Yun'an Well 002-7 in the Yun'anchang structure,East Sichuan Basin

作　　者：马勇[1] 姚坤全[1] 付华才 陈敏 刘德平 

机构地区：[1]中国石油西南油气田公司工程技术与监督部 [2]中国石油川庆钻探工程公司川东钻探公司 [3]中国石油川庆钻探工程公司

出　　处：《天然气工业》2012年第9期71-73,133-134,共3页Natural Gas Industry

摘　　要：四川盆地东部云安厂构造云安002-7井φ177.8mm尾管固井集超深井、大斜度井、高压气井和窄安全密度窗口于一身。φ215.9mm井眼段经长时间、多次堵漏,消耗了大量钻井液(1 418.1m3),仍未达到常规固井作业的不溢不漏、通井畅通、井眼清洁等要求,已难提高井筒承压能力。井眼状况表现出漏层多且位置不确定、液面不在井口、气层多、钻井液密度高(1.80g/cm3)、裸眼段长(2 538.28m)且井眼轨迹复杂等特点。为此,针对下套管过程中的出口不返、不具备分段循环条件、无法排后效、尾管悬挂器可能提前坐挂等技术难点,采取了针对性的下套管作业防阻卡、保水眼畅通以及正注反挤工艺保环空水泥浆对接等三大技术措施,确保了尾管安全顺利下至设计井深。测井解释结论表明:φ215.9mm井眼段的高压气层得到了有效封固,固井质量可满足下一步安全钻井作业需要。该井φ177.8mm尾管固井的成功为今后类似复杂气井固井作业提供了有力的技术支持。The Yun'an Well 002-7 at the Yun'anchang structure in East Sichuan Basin is a ultra-deep and highly deviated well with high pressure and the drilling fluid had a narrow density window when the cementing with φ177.8 mm liner was done in this well.Plugging had been carried out several times at φ215.9 mm borehole section for a long time,consuming a large amount of drilling fluid(1418.1 m3),but the borehole section still failed to meet the conventional cementing requirements like neither overflow nor leakage,smooth drifting,clean borehole,etc.In addition,it is difficult to increase the bearing capacity of well shaft.From the perspective of borehole conditions,lost circulation was found in many layers at different positions,the liquid level was lower than the wellhead,several gas-bearing horizons were involved,drilling fluid density was quite high(1.80 g/cm3),open hole section was very long(2538.28 m),and borehole trajectory was complicated.In order to solve technical problems in inserting the liner casing,such as failure to return at wellhead,lack of circulation by sections,inability to discharge residuals,and liner hanger setting down too early,the following measures were taken to allow the liner to be successfully inserted into the hole to the designed depth: casing obstruction prevention,nozzle congestion prevention,and positive pumping-reversal squeezing of slurry for perfect cementing.The logging results show that the high-pressure gas reservoir at φ215.9 mm borehole section is effectively sealed and cementing quality meets the requirement of the next phase of safe drilling operation.The successful cementing with φ177.8 mm liner provides strong technical support for cementing in similar complicated gas wells in the future.

关 键 词：非常规 超深漏失井 尾管固井 井口失返 正注反挤 四川盆地东部 云安厂构造 

分 类 号：TE256[石油与天然气工程—油气井工程]