鄂尔多斯盆地新安边地区长71储层特征

Characteristics of Chang 71 reservoir in Xin'anbian area of Ordos basin

通过对岩石薄片、扫描电镜观察,同时结合沉积相、储层等大量的地质资料,对鄂尔多斯盆地新安边地区储层特征展开综合分析。结果表明,长71储层岩性主要为细粒砂岩;长71储层的孔隙类型以溶蚀孔和粒间孔为主,并含少量晶间孔和微裂隙,属于特低孔特低渗储层;该储层成岩作用主要有四类:压实作用、胶结作用、溶解作用和压溶作用。其中,溶解作用对储层物性的改善起建设性作用,而压实、胶结和压溶作用对储层孔隙起破坏作用。

Through the observation of thin section and scanning electron microscope,combined with a large number of geological data such as sedimentary facies and reservoirs,the reservoir characteristics of Xin'anbian area in Ordos basin are comprehensively analyzed.The results show that the lithology of Chang 71 reservoir is mainly of sandstone,the pore types of the reservoir are mainly dissolution pore and intergranular pore,with a small amount of intergranular pore and micro fracture,which belongs to ultra-low porosity and low permeability reservoir.There are four types of diagenesis:compaction,cementation,dissolution and pressure dissolution.Among them,the dissolution plays a constructive role in improving reservoir physical properties,while the compaction,cementation and pressure dissolution damage the reservoir pores.