志丹延安组下部储层特征与物性影响因素

Research on the characteristics of Yan′an formation reservoir of Zhidan area

目的研究志丹延安组下部储层特征,分析储层物性的影响因素,为储层的分类评价提供依据。方法根据储层岩性和实测物性资料,结合铸体薄片、压汞、扫描电镜等实验方法反映出的孔隙结构特征,从宏观和微观两个角度,统计不同地质因素对物性的影响程度。结果研究区储层岩性主要为中粒、细粒长石岩屑质石英砂岩。储集空间以剩余原生粒间孔为主,溶孔次之。孔隙结构以小孔隙—粗喉道为主,储层孔隙结构微观非均质性强。结论该区储层的物性主要受沉积作用和成岩作用的共同影响;不同沉积微相储层的物性差异较大;溶蚀作用产生的次生孔隙改善了储层物性。

Aim To determine the character of reservoir, and find the affecting factors of reservoir and provide a reliable basis for reservoir evaluation. Methods The analysis of data of the measured property, and measurement of different samples of physical parameters, combined with casting sections, mercury injection experiment, SEM, experimental method were used, from the perspective of macroscopic and microcosmic, to petrophysically analyze the geological factors affecting to the reservoir properties. Results The research presented that the lithologic character of reservior mainly induded fine to mideum-grained feldspar lithic quartzite sandstone. The oores are mainly of residual intergranular pore and emponer. Fine pore-coarse throats are the main pore configuration, the microhetero gencity of pore configuration is intensive. Conchmion The main factors contributing to physical properties are deposition and diagenesis, accumulation properties are various in the different sedimentary microfacies, dissolution plays an important role in improving the properties by producing secondary porosity.