四川盆地中部侏罗系大安寨段致密油高产稳产主控因素

摘要

By systematically analyzing the basic geological characteristics of tight oil in Jurassic Da'anzhai Member in the middle of Sichuan Basin (Central Sichuan area) and combining with a large number of exploration and development data,we examine the main controlling factors and exploration direction for high and stable production of tight oil.Tight oil in the Da'anzhai Member has the following characteristics:large and low abundance resources;generally tight,relatively high quality reservoirs;adjacent source rocks and reservoirs,favorable migration and accumulation of oil;extensive oil-bearing pores.Development practice reveals that the high and stable production oil wells for tight oil are mainly distributed in fractured vuggy reservoirs in the shore-lacustrine sedimentary subfacies,and fractures are very important in affecting the high and stable production of tight oil in the Da'anzhai Member.Natural gas plays an important role (gas drive) in petroleum migration and accumulation and high production of oil wells.Combined with the characteristics of high and stable production,exploration and development results,drilling cost and other factors,it is considered that the Da'anzhai Member located in the middle and south part of Sichuan Basin is a promising field for exploration and development of tight oil in the Jurassic of the Sichuan Basin.%通过系统分析四川盆地中部地区(川中地区)大安寨段致密油的基本地质特征,结合大量勘探开发数据,解剖致密油高产稳产主控因素及勘探方向.大安寨段致密油具有如下特征:资源量大,丰度低;储集层总体致密,发育相对优质储集层;源储一体(或紧邻),油气运聚有利;不同类型孔隙普遍含油,连续分布.开发实践揭示,致密油高产稳产井主要分布在滨湖沉积亚相中的裂缝-孔洞型储集层中,裂缝在大安寨段致密油高产稳产影响因素中至关重要,天然气在石油运聚以及油井的高产中起到了重要驱动(气驱)作用.结合高产稳产特征、勘探开发成效以及钻井投资成本等因素综合评价认为,川中南部地区的大安寨段为四川盆地侏罗系致密油效益勘探开发的现实领域.