四川盆地大中型气田分布特征及勘探前景  

Medium to large gas fields in Sichuan Basin: Distribution characteristics and exploration prospects

作　　者：刘辉[1] 韩嵩[1] 叶茂[1] 战薇芸[1] 吴雪峰[1] 未勇 陈尘[1] Liu Hui;Han Song;Ye Mao;Zhan Weiyun;Wu Xuefeng;Wei Yong;Chen Chen(Exploration and Development Research Institute, PetroChina Southwest Oil ＆ Gasfield Company, Chengdu, Sich- uan 610041, China)

机构地区：[1]中国石油西南油气田公司勘探开发研究院

出　　处：《天然气勘探与开发》2018年第2期55-62,共8页Natural Gas Exploration and Development

基　　金：中国石油西南油气田公司科学研究与技术开发项目"四川盆地碳酸盐岩气藏资源潜力分析及勘探规划指标预测研究"(编号:20170301-12)

摘　　要：大中型气田储量规模大,对增加能源储备,减少对外依存度起到至关重要的作用;同时其稳产周期长,具有较好的经济效益。根据已发现的大中型气田分布特征,从古构造运动、区域沉积环境方面分析烃源条件、储层规模、油气聚集等形成大中型气田的主控因素,探讨其下一步勘探方向。结果表明:(1)四川盆地大中型气田以海相层系为主,集中分布于"三隆、两台缘、两拗陷"地区,以岩性、复合圈闭气藏为主;(2)大型构造运动形成的2大古裂陷槽、2大沉积拗陷、4大古隆起、5大侵蚀面控制了大中型气田的成藏,即古裂陷槽、沉积拗陷控制生烃中心,侵蚀面控制规模储层发育,古隆起控制早期油气聚集;(3)充足的烃源供给、层状规模储层、大型圈闭及适时形成的古隆起是形成大中型气田的关键,继承性的大型古今构造叠合区是形成特大型气田最有利区。结论认为:(1)川西北上古生界台缘带是继高石梯—磨溪地区震旦系—下古生界之后重要接替领域;(2)川东"达州—开江"古隆起和台缘带是重要突破领域;(3)川中"乐山—龙女寺"古隆起区北斜坡是重要拓展勘探领域;(4)川西南雷口坡组、栖霞组台缘带是盆地积极准备的勘探领域。There are large amounts of reserves in medium to large gas fields, which play a crucial role in enhancing energy reserves and reducing foreign dependence. Besides, these fields are often characterized by long and stable production period, and better economic benefits. In this study, based on some distribution characteristics of discovered medium to large gas fields, Sichuan Basin, the effects of palaeo-tectonic movements and regionally depositional setting on their formation were analyzed from three aspects of source conditions, reservoir scale, and hydrocarbon accumulation. Results show that in these medium to large gas fields, Sichuan Basin,（1） marine strata are dominant, and mainly distributed in such belts as ＂three uplifts, two platform margins, and two depressions＂, and gas reservoirs of lithologic and composite traps are dominant;（2） gas accumulation is affected by two palaeo-aulacogens, two sedimentary depressions, four palaeo-uplifts, and five erosion surfaces arose during major tectonic movements, meaning that a hydrocarbon-generating center is controlled by the palaeo-aulacogens and sedimentary depressions, large reservoir development by the erosion surfaces, and early hydrocarbon accumulation by the palaeo-uplifts, respectively; and（3） sufficient source supply, massive and stratified reservoirs, sizeable trap, and timely formed palaeo-uplifts are key contributors to generating these medium to large gas fields, whereas an overlap area of bigger inherited ancient and modern structures is the most favorable for shaping a supergiant gas field. In conclusion, in Sichuan Basin, there are four important exploration domains replacing the Sinian-Lower Paleozoic in Gaoshiti-Moxi area, sequential including the Upper Paleozoic platform margin belt in northwestern basin, the Dazhou-Kaijiang palaeo-uplift and platform margin belt in eastern basin, the northern slope of Leshan-Longnvsi palaeo-uplift in central basin, and the platform margin belts of Leikoupo and Qixia formations in southwestern basin

关 键 词：四川盆地 优质规模储层 古隆起 台缘带 大中型气田 主控因素 勘探方向 

分 类 号：P618.13[天文地球—矿床学]