四川盆地中部侏罗系大安寨段储集层微观结构及油气意义  

Reservoir micro structure of Da'anzhai Member of Jurassic and its petroleum significance in Central Sichuan Basin, SW China

作　　者：庞正炼[1] 陶士振[1] 张琴[1] 杨家静[2] 张天舒[1] 杨晓萍[1] 范建玮[1] 黄东[2] 韦腾强 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油西南油气田公司勘探开发研究院,成都610051

出　　处：《石油勘探与开发》2018年第1期62-72,共11页Petroleum Exploration and Development

摘　　要：应用岩心分析、铸体和荧光薄片鉴定、常规和场发射扫描电镜观察对四川盆地中部侏罗系大安寨段储集层微观特征进行定性研究,同时借助压汞、纳米CT及氮气吸附定量刻画大安寨段储集层的储集空间尺寸与形态。将大安寨段储集岩分9类,储集空间分4大类14亚类,确定亮晶介壳灰岩是最有利储集岩类。刻画出小于1μm的储集空间占该储集层储集空间体积的91.27%,形态以缝状为主,并具良好连通性。通过建立储集空间模型,揭示出裂缝为主的微米级储集空间和纳米级孔、缝构成双重介质。储集空间以纳米级为主的大安寨段储集层资源丰度低,井控储量小,形成低产特征,但孔缝双重介质维持了该储集层长期产油,而缝状储集空间及发育的裂缝则是该储集层未采用致密油开发技术亦可规模产油的关键。Based on the qualitative study of microscopic reservoir features using core analysis, cast and fluorescence thin sections inspection, scanning electron microscope （SEM） and field emission scanning electron microscope （FESEM） and quantitative examination of pore size and geometry using mercury injection, nano-CT and nitrogen adsorption, reservoir rock of Da＇anzhai Member were divided into 9 types, while storage spaces were divided into 4 types and 14 sub-types. The study shows that sparry shelly limestone is the most promising reservoir type. Pores that smaller than 1 μm in diameter contribute 91.27% of storage space volume. Most of them exhibit slot-like geometry with good connectivity. By building up storage space models, it was revealed that micron scale storage spaces mainly composed of fractures and nanometer scale pores and fractures form multi-scale dual porosity system. Low resource abundance, small single well controlled reserve, and low production are related to the nano-scale pore space in Da＇anzhai Memer, whereas the dual-porosily system composed of pores and fractures makes for long-term oil yield. Due to the existence of abundant slot-like pore space and fractures, economic tight oil production was achieved without stimulations.

关 键 词：四川盆地中部 侏罗系 大安寨段 介壳灰岩 储集空间 结构特征 多尺度裂缝 

分 类 号：TE122.2[石油与天然气工程—油气勘探]