川西须家河组致密砂岩气藏水平井钻井关键技术  

Key techniques of horizontal drilling through Xujiahe tight sandstone gas reservoirs in the western Sichuan Basin

作　　者：刘伟[1,2] 高德利[1] 王世泽[2] 蒋祖军[2] 潘登雷[3] 

机构地区：[1]中国石油大学(北京) [2]中国石化西南油气分公司工程技术研究院 [3]中石化西南石油局井下作业分公司

出　　处：《天然气工业》2011年第4期80-83,130-131,共4页Natural Gas Industry

基　　金：中石化重点攻关项目"川西须家河组致密气藏水平井钻进技术先导性试验"(编号:SG10065)的部分成果

摘　　要：四川盆地西部上三叠统须家河组储层具有埋藏较深、非均质性强、岩石致密、破裂压力高等特性。对于该类致密砂岩气藏要获得较好的开发效果需钻遇裂缝发育带,然而常规直井、定向井钻遇裂缝概率小,很难获得理想产能,因而水平井钻井便成为高效开发该类气藏的重要手段。钻井周期长、事故率高、钻井成本高是目前该区水平井钻井面临的瓶颈难题。为此,从三压力剖面、井壁稳定性以及实钻资料分析入手,提出了利于该区须四段和须二段水平井安全、快速钻井的井身结构方案;从技术、经济两方面分析了旋转导向钻井技术在须家河组水平井应用的可行性,推荐在造斜段应用旋转导向、在水平段采用常规随钻测量(MWD)施工的轨迹控制方案,并配套与之相适应的轨迹设计方案;提出了利于润滑防卡和保障井壁稳定的钻井液配套技术方案;通过分析钻井液排量、密度等因素对井眼净化的影响,提出了6条具体的井眼净化技术措施。所形成的水平井钻井关键技术已成功应用于该区3口井,与第一批完钻水平井相比,机械钻速提高18.94%,钻井周期缩短28.47%。The upper Triassic Xujiahe gas reservoirs in the western Sichuan Basin are featured by large burial depth,strong heterogeneity,tight sands,high fracture pressure,and so on.To achieve a better result in gas recovery here,the wells have to be drilled through those well-developed fractures.However,the previous conventional vertical wells or directional wells could hardly meet with the fractures so the expected productivity was difficult to be obtained.That is why the horizontal well drilling has become an important method for effective development of such gas reservoirs even though its major bottleneck problems include a long drilling cycle,a high accident ratio,and a high cost.In view of this,through an analysis of the 3-pressure profile,the wellbore stability,and actual drilling data,a casing program is developed for safe and fast horizontal drilling through the second and fourth members of the Xujiahe formations.And after a feasibility study is made on the application of rotary steering technology in horizontal drilling through Xujiahe formations in terms of technology and economics,it is recommended to adopt rotary steering in build-up section drilling and conventional measurement while drilling(MWD) trajectory control in horizontal section drilling,with proper matching trajectory designed.A drilling fluid formulation helpful for lubrication and wellbore stability is also developed.In addition,through a deep investigation into the effects of drilling fluid flow rate and density on well cleaning,6 pieces of well cleaning advices are made.After all the above technical measures were used in 3 wells in this area,in comparison with the previously drilled horizontal wells,the ROP have been increased by 18.94%,and the drilling cycle shortened by 28.47%.

关 键 词：四川盆地西部 晚三叠世 致密砂岩气藏 水平井 井身结构 旋转导向 随钻测量 井眼净化 

分 类 号：TE377[石油与天然气工程—油气田开发工程]