塔里木万米科探井垮塌机理研究及技术对策  

Mechanisms of and Technical Measures for Solving Borehole Wall Instability in Ten-Thousand-Meter Scientific Exploration Wells in Tarim Basin

作　　者：刘锋报[1] 孙金声 尹达[1] 罗绪武 LIU Fengbao;SUN Jinsheng;YIN Da;LUO Xuwu(PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000;CNPC Engineering Technology R&D Company Limited,Beijing 102206;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shangdong 266580)

机构地区：[1]中国石油塔里木油田分公司,新疆库尔勒841000 [2]中国石油集团工程技术研究院有限公司,北京102206 [3]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《钻井液与完井液》2024年第6期709-718,共10页Drilling Fluid & Completion Fluid

基　　金：中国石油天然气集团有限公司科学研究与技术开发项目“万米超深层油气资源钻完井关键技术与装备研究”(2022ZG06)。

摘　　要：针对塔里木油田台盆地区超深、特深地层井壁失稳机理研究不足、认识不清等难题,对目标地区志留系、奥陶系和寒武系5595~10900 m露头岩石开展了系列研究。分析得出,地层发育平均尺寸在300~800 nm之间的微纳孔缝为钻井液侵入提供了有利通道,导致压力传递、提高了地层坍塌压力;水和油在泥岩表面接触角分别为5.8°和5.3°,在灰岩表面接触角分别为42.5°和15.6°;泥岩吸水率为2.74%、吸油率为3.63%,灰岩吸水率为1.42%、吸油率为2.14%;志留系和桑塔木泥岩、阿瓦塔格泥质白云岩在水中的滚动回收率分别为86.3%、92.9%和98.2%,灰岩和白云岩滚动回收率基本为100%,部分地层由于水化分散造成岩石内聚力强度降低,这些均是导致井壁失稳的主要机理。根据井壁失稳机理,使用抗超高温高效微纳米封堵剂及抗超高温抗盐聚合物降滤失剂,并构建一套特深井防塌水基钻井液体系,通过强化钻井液的封堵性,降低钻井液滤失量、减少钻井液侵入,降低地层坍塌压力;通过提高钻井液的抑制性,减少地层水化分散,提高岩石内聚力强度,实现解决塔里木深部复杂地层井壁失稳的难题。In Tarim Basin,borehole wall instability has been an issue encountered in deep and ultra-deep well drilling in the Taipen block,the studies of which are insufficient and the understanding of the mechanisms of which is not clear.In laboratory studies,cores taken from the outcrop rocks of the Silurian,Ordovician and Cambrian strata buried at depths between 5,595 m and 10,900 m in the Taipen block were analyzed,and it was found that fractures with opening sizes between 300 nm and 800 nm are good passages for the invasion of a drilling fluid;borehole pressure is easy to transfer across these fractures and the collapse pressure of the formation is hence increased.The contact angles of water and oil on the surfaces of the mudstone are 5.8°and 5.3°respectively,the contact angles of water and oil on the surfaces of the limestone are 42.5°and 15.6°,respectively.The percent water adsorption and the percent oil adsorption of the mudstones are 2.74%and 3.63%,respectively,and those of the limestones are 1.42%and 2.14%,respectively.The percentages of the recovery of the Silurian system rocks,the Sangtamu mudstone and the Awatage argillaceous dolomite on hot rolling test are 86.3%,92.9%and 98.2%,respectively,and those of the limestone and the dolomite are both basically 100%.Part of the formations,because of the hydration effect and dispersion in water,have the rock cohesion reduced.These are the main mechanisms that cause borehole wall instability.Based on the mechanisms of borehole wall instability understood,a water based drilling fluid was formulated with a high efficiency nanometer plugging agent,a salt-resistant polymer filter loss reducer and other additives for ultra-deep well drilling.The nanometer plugging agent and the filter loss reducer are all ultra-high temperature resistant.By enhancing the plugging capacity,reducing the filtration rate of the drilling fluid and minimizing the amount of the drilling fluid lost into the formations,the collapse pressures of the formations are reduced.By improving the inhibitiv

关 键 词：万米特深井 井壁失稳机理 防塌对策 

分 类 号：TE254.4[石油与天然气工程—油气井工程]