吴起油田G区块长9₁油层组储层特征研究及储层评价

Study on Reservoir Characteristics and Reservoir Evaluation of Chang 9₁ Formation in Block G of Wuqi Oilfield

摘要: 为了对低渗透油区长9₁储层特性进行研究，本文依据现有的岩心铸体薄片资料、扫描电镜图像、高温压汞实验数据以及常规的物性测试数据等，对G区块长9₁储层的岩石学特征、孔隙类型、孔隙结构特征以及物性特征等进行了深入的分析和研究，从而明确了该储层的物性特征，并对储层进行了综合评价，以期可以准确地预测研究区内有利储集带的分布，指导后期的油气勘探开发。通过研究分析可知，吴起油田G区块长9₁储层的岩性主要以长石岩屑砂岩、岩屑砂岩、岩屑长石细砂岩为主；储层的孔隙类型以颗粒间孔为主，微裂缝占比最小；孔隙结构属于小孔微细喉型；平均孔隙度为7.2%，平均渗透率为0.27 mD。长9₁储层可以分为I、II、III类三种类型。其中I类和II类储层的物性相对来说更好、开发动用程度较高，是勘探开发的主要类型。

Abstract: In order to study the characteristics of Chang 9₁ reservoir in low permeability oil area, based on the existing core cast thin section data, scanning electron microscope images, high temperature mercury injection experimental data and conventional physical property test data, this paper deeply analyzes and studies the petrological characteristics, pore types, pore structure characteristics and physical properties of Chang 9₁ reservoir in block G. The physical characteristics of the reservoir are defined, and the reservoir is comprehensively evaluated, in order to accurately predict the distribution of favorable reservoir belts in the study area and guide the later oil and gas exploration and development. Through research and analysis, it can be known that the lithology of Chang 9₁ reservoir in block G of Wuqi Oilfield is mainly composed of feldspar lithic sandstone, lithic sandstone, and lithic feldspar fine sandstone; the pore type of the reservoir is mainly intergranular pores. The proportion of micro-cracks is the smallest; the pore structure belongs to the small-pore and micro-throat type; the average porosity is 7.2%, and the average permeability is 0.27 mD. The Chang 9₁ reservoir can be divided into three types: Type I, II, and III. Among them, type I and type II reservoirs have relatively better physical properties and a higher degree of development and production. They are the main types of exploration and development.