鄂尔多斯盆地化子坪地区延长组长6沉积特征及其与油藏分布关系探讨

Study on the Depositional Feature and the Relation between It and Reservoir Distribution in Chang6 of Yanchang Formation, Huaziping Area, Ordos Basin

根据岩性、沉积结构与构造、测井相综合分析认为,本区长6油层组为三角洲前缘亚相沉积,可细分为三角洲前缘水下分流河道、分流间湾微相。水下分流河道砂体为其主要的储集层。这些砂体横向上复合连片往往呈带状展布,岩性以细粒长石砂岩为主,残余粒间孔和次生溶蚀孔为主要的孔隙类型。通过沉积相与油藏分布的关系研究,认为油气的聚集受沉积微相的控制,水下分流河道砂体为长6油层组良好的储集层,是有利的油气聚集场所。

According to the lithology, structure and construction of sedimentary and logging facies, it analyzes that Chang-6 reservoir group in Huaziping area is front-delta deposition subfacies. In the paper, it divides sedimentary microfacies into the underwater distributary channel and the inter-distributary deposits. The distributary channel deposits is the main sandbody. The sandbody distributes as strip forms with upward transverse, it＇s generally fine-grained feldspathic sandstone. The main reservoir space is the residual interparticle porosity and the secondary solution porosity. Through the studies of the relationship between sedimentary facies distribution and reservoir distribution, the accumulation of oil and gas are controlled by sedimentary mierofacies, the distributary channel deposits is the good reservoir of Chang6 as well as the place beneficial for oil and gas accumulation.