四川盆地文井—明月地区大安寨段储层研究

A study of the reservoir of Da'anzhai Member in Wenjing-Mingyue area of Sichuan Basin

文井—明月地区大安寨段是川中地区的主要产油层,储层具有明显的特殊性。其储集岩类主要为介壳灰岩和含泥介壳灰岩,原生孔隙在强烈的压实和胶结作用影响下消耗殆尽,但喜山期的构造作用在其灰岩段中产生了一定数量的构造缝,这些构造缝在后期溶蚀过程中可形成少量溶蚀孔、洞,与层理缝和方解石解理缝构成了大安寨油藏的主要储集空间和渗流通道,属于典型的特低孔-裂缝型储层。储层的分布主要受到滨浅湖高能介壳滩和裂缝发育程度的影响。

The Da＇anzhai Member in Wenjing-Mingyue area is the major oil-producing horizon in central Sichuan,where the reservoir has apparent peculiarity and the reservoir rocks are mainly composed of shell limestone and muddy shell limestone.At the same time,the primary pores have died out because of the impact of intense compaction and cementation,but in the shell limestone,tectonic action in Xi＇shan period created some structural fractures,in which a small number of dissolved pores and holes occurred during late dissolution.These structural fractures together with laminar fractures and calcite cleavages in rocks compose the chief reservoir space and percolating passage in Da＇anzhai reservoir.In the study area,the reservoir is characterized by typical extremely low porosity-fracture,and the distribution of the reservoir is chiefly affected by the sedimentary facies and the development extent of fractures.