四川盆地南部龙马溪组页岩气藏井壁强化钻井液技术  

Strengthening drilling fluid technology for shale gas reservoirs in the Longmaxi Formation,southern Sichuan Basin

作　　者：罗平亚 李文哲[1,3] 代锋 李道雄 钟成旭 白杨 LUO Pingya;LI Wenzhe;DAI Feng;LI Daoxiong;ZHONG Chengxu;BAI Yang(Petroleum Engineering School,Southwest Petroleum University,Chengdu,Sichuan 610500,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Engineering Technology Research Institute of PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610031,China;Sichuan Changning Natural Gas Development Co.,Ltd.,PetroChina Southwest Oil&Gasfield Company,Yibin,Sichuan 644012,China;Shale Gas Research Institute of PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China)

机构地区：[1]西南石油大学石油与天然气工程学院 [2]“油气藏地质及开发工程”国家重点实验室•西南石油大学 [3]中国石油西南油气田公司工程技术研究院 [4]中国石油西南油气田公司四川长宁天然气开发有限责任公司 [5]中国石油西南油气田公司页岩气研究院

出　　处：《天然气工业》2023年第4期1-10,共10页Natural Gas Industry

基　　金：国家重点研发计划课题“井筒稳定性闭环响应机制与智能调控方法”(编号:2019YFA0708303);四川省科技计划资助项目“杰出青年科技人才——油田含聚污水处理”(编号:2020JDJQ0057);“四川青年科技创新研究团队”(编号:2020JDTD0018);中国石油—西南石油大学创新联合体科技合作项目(编号:2020CX040102、2020CX040201)。

摘　　要：四川盆地南部地区(以下简称川南)页岩气资源丰富,历经十余年研究与实践,目前已经实现了页岩气规模化和商业化开发,但是在钻进下志留统龙马溪组目的层时井下复杂严重且发生频繁、事故多、起下钻趟数多、耗时长,是至今仍然没有能够很好解决的重大钻井技术难题。为了降低开发综合成本、大幅度缩短钻完井周期从而使页岩气开发具有显著的经济效益,最有效的途径之一就是形成适用的页岩气藏井壁强化钻井液技术。为此,通过研究页岩地层岩石物性及特征,发现钻井液对地层微纳米裂缝封堵能力不足导致滤液侵入是致使该区龙马溪组页岩气藏井壁坍塌失稳的主要原因之一;针对上述情况,制备纳米封堵剂高质量本征态石墨烯纳米片,并提出了二维纳米石墨烯片界面强吸附黏着封堵理论;进而基于紧密堆积原理优选了适用于粒度级配的微米刚性封堵剂,形成了适用于川南龙马溪组页岩气藏井壁强化钻井液技术。现场应用结果表明,该技术在稳定井壁和强化井壁方面具有突出的效果,并且所研制的钻井液综合性能均优于现场井浆。结论认为,该项研究成果为实现该区页岩气效益开发提供了技术支撑。The southern Sichuan Basin(hereinafter referred to as South Sichuan)is rich in shale gas resources.Over more than one decade of research and practice,the large-scale and commercial development of shale gas has been realized.However,when drilling the Lower Silurian Longmaxi Formation,it is a major drilling technical problem that has not been solved well so far because of serious downhole complexity,frequent occurrence,frequent accidents,large number of trips and long time.Therefore,in order to reduce the comprehensive development cost and greatly shorten the drilling and completion period,one of the most effective ways is to form a suitable shale gas well wall strengthening drilling fluid technology.Therefore,by studying the petrophysical properties and characteristics of shale formation,we found that the insufficiency of drilling fluid to seal micro and nano fractures in the formation leads to filtrate intrusion,which is one of the main reasons for the wall collapse and instability of Longmaxi shale gas reservoir in this area.In view of this,high-quality intrinsic graphene nanosheets with nano plugging agents were prepared,and the plugging theory of strong adsorption and adhesion at the interface of two-dimensional nano graphene sheets was proposed.Based on the tight packing principle,the micron rigid plugging agent suitable for particle size distribution was optimized,and the strengthening drilling fluid technology suitable for shale gas reservoirs of Lower Silurian Longmaxi Formation in south Sichuan was formed.The field application results show that this technology has outstanding effect in stabilizing and strengthening borehole wall,and the comprehensive properties of the drilling fluid developed are superior to the field slurry.It is concluded that the research results provide technical support for the beneficial development of shale gas in this area.

关 键 词：页岩气 钻井液 井壁强化 纳米石墨烯片 微米刚性封堵剂 四川盆地南部 下志留统龙马溪组 

分 类 号：TE254[石油与天然气工程—油气井工程]