纯化油田湖相滩坝薄储层含油性差异及控制因素

纯化油田滩坝储层岩性复杂,泥岩、砂岩和碳酸盐岩呈薄层状频繁互层,不同储层的物性差异明显。综合运用岩心、测井、扫描电镜、物性实验和生产动态等资料,对储层含油性差异及控制因素进行了研究。结果表明:研究区发育坝、砂质滩、颗粒滩、泥晶滩及浅湖泥5种微相,物源、成岩作用、沉积微相和储层厚度均对储层含油性有控制作用。优质储层在垂向上有分层性,纯上砂层组砂岩储层优于纯下砂层组碳酸盐岩储层,其中成岩作用改造作用明显,钙质胶结使砂岩物性变差,溶蚀作用使鲕粒灰岩孔渗性优于泥晶灰岩;平面上有分区性,与沉积微相密切相关,坝、砂质滩最好,颗粒滩次之,泥晶滩最差;同一相带内又受储层厚度影响,厚度越大产油越好。

Differences and Controlling Factors of Oilbearing in Thin Reservoir of Lake Facies Beachbar in Chunhua Oilfield

The reservoir lithology in Chunhua oilfield is very complicated. Thin layered mudstone, sandstone and carbonate frequently display as alternating layers, with prominent different reservoir quality. By using the core analysis, logging data, scanning electron microscope, analysis assay data and production data comprehensively, differences and controlling factors of reservoir quality have been analyzed. It is showed that bar, sandy beach, particle limestone beach, grain beach and muddy beach developed well in the study area. Reservoir quality is evidently controlled by provenance, diagenesis, sedimentary micro facies and reservoir thickness. Sand reservoir quality of the upper part of Chunhuazhen sand groups is better than limestone reservoir quality of the lower part of Chunhuazhen sand groups. Diagenesis has a significant impact on reservoir quality. Calcareous cementation make physical property of sand reservoir bad. Particle limestone reservoir quality is better than grain limestone by the reason of heterogeneous dissolution. Bar and sandy beach are favorable sedimentary facies for high quality reservoirs in this area, particle limestone beach is the second, and grain beach is the lowest. Thickness of reservoirs within same facies impacts the production, large thickness reservoirs has a high production.