下寺湾油田长2油组储层特征及其影响因素分析

通过薄片、扫描电镜和压汞法等分析测试手段,从储层岩石学特征、成岩作用、孔隙类型和孔喉特征等方面开展了下寺湾油田长2油组的储层微观特征研究,分析了储集空间类型、孔喉分布特征、成岩作用以及影响储层物性的主要因素。研究结果表明,长2油组储集岩为低成熟度砂岩;主要经历了压实、胶结、粘土矿物转化和溶蚀等成岩作用,成岩作用较弱,对储层物性影响较小;孔隙类型包括残余粒间孔隙、溶蚀粒间孔隙、溶蚀粒内孔隙等等,其中残余粒间孔隙是研究区的主要孔隙类型;孔吼分布特征是孔喉分散,分选性差,偏于略粗歪度,储集性能总的来说较差,驱油效率较低。

Reservoir features and affecting factors on Chang2 oil group in Xiasiwan oilfield

study on reservoir microcosmic features on chang2 oil group in Xiasiwan oilfield through the microslide, scanningelectron microscopy and mercury-injection method. The reservoir microcosmic features include petrologic features ,diagenesis , pore types, pore throat characteristics ,and so on. Then analyse their main affecting factors . The findings show that the rock component is lower degree of ripeness.The diagenesis mainly are compaction , cementation , clay mineral translation and denudation. Reservoir physical property is affected lightly by the weaker diagenesis. Pore types include residual intergranular pore, katatectic intergranularpore, katatectic intraparticle pore, and so on. The residual intergranular pore is the main pore type in research region;The pore throat is dispersal and its degree of sorting is poor,but its radius is slight thickness. So the reservoir ability is poorer and the oil displacement efficiency is lower.