摘要
四川盆地川东地区相国寺构造为一狭长高陡构造,地面出露上三叠统须家河组到下三叠统嘉陵江组等老地层,地层倾角变化大,浅层存在煤矿及石膏矿采空区域,而经多年开采的二叠系长兴组、茅口组气藏压力系数仅为0.2,主力气藏石炭系的压力系数更只有0.1,这已成为储气库建设的一大钻完井技术难题。为此,根据该地下储气库钻井复杂地质剖面、储气库盖层密封性及储层专打要求,提出了优化布井方式及井型、井身结构的实施技术方案;制订了以气体钻井解决上部易漏失层、下部低压产层应用PDC+螺杆钻具钻井技术的快速钻井措施;石炭系低压储层采用油管+筛管方式完井以保护储层。在XC4等井现场应用表明,6口试验井平均机械钻速达4.0 m/h,同比前期先导试验井提高164%,建井周期较前期试验井缩短一半,高效优质地完成了储气库的钻完井工作。所形成的7项安全快速钻完井配套保障技术可为类似地质区域建设地下储气库提供借鉴。
Xiangguosi structure in the eastern Sichuan Basin is a narrow steep structure, where old strata from the Upper Triassic Xujiahe Fm to the Lower Triassic Jialingjiang Fm are exposed on the surface, so formation dip changes widely, there are stope out areas in the shallow coal mines and gypsum mines; moreover, after years of production, the Permian Changxing Fm and Maokou Fm gas reservoirs are only 0.2 in pressure coefficient, and the major Carboniferous gas reservoir is only 0.1 in pressure coefficient, posing a big challenge to the drilling during the gas storage construction. In view of this issue, according to the complex geologic pro- file, cap sealing and special reservoir drilling requirements of the gas storage, a technical scheme with optimized well placement mode, well type and hole structure was put forward. The fast drilling measures of drilling the upper formations prone to leakage with air drilling and lower low-pressure formations with PDC plus screw drill were formulated; and tubing plus screen pipe completion was recommended to protect the low-pressure Carboniferous reservoirs. The application of this scheme in Well XC4, etc. shows that the six test wells have an average ROP of 4.0 m/h, 164% faster than the earlier pilot wells, and the construction cycles of these wells are cut to half, leading to the high quality completion of drilling and completion operation with high efficiency. The seven safe and fast drilling and completion technologies formed in this study can be valuable references for gas storage construction in those sim- ilar areas.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2015年第3期93-97,共5页
Natural Gas Industry
关键词
四川盆地
川东地区
地下储气库
低压
气体钻
治漏
安全
快速
钻井技术
Sichuan Basin
East
Gas storage
Low pressure
Air drilling
Leakage control
Safety
Fast drilling technology
