四川盆地广安地区上三叠统须家河组四段低孔渗砂岩成岩相类型划分及半定量评价

成岩相是在一定沉积和成岩环境下经历了一定成岩演化阶段的产物，包括岩石颗粒、胶结物、组构和孔洞缝特征及其演化的综合面貌。成岩相的研究已成为低孔渗砂岩当前勘探阶段的研究重点。将广安地区须家河组四段划分为五种成岩相类型:粗中粒砂岩火山岩屑较强溶蚀低孔特低渗成岩相、火山岩屑弱溶蚀—强压实特低孔超低渗成岩相、中细粒砂岩压实致密相、中粗粒岩屑石英砂岩硅质胶结致密相以及方解石胶结致密相，并建立了不同类型成岩相的测井曲线特征。在单井成岩相分析基础上，通过编制成岩相的厚度百分含量等值线图、厚度等值线图、成岩相平面分布图等对成岩相进行了半定量化评价。

Diagenetic Facies Types and Semiquantitative Evaluation of Low Porosity and Permeability Sandstones of the Fourth Member Xujiahe Formation Guangan Area, Sichuan Basin

Diagenetic facies are results of diagenetic evolutions under special depositionl and diagenetic environ-ments, including grains, cements, and textures integrated features. The study of diagenetic facies is important to low porosity and permeability sandstones in current exploration phases. This paper divided forth member of Xujiahe system of Guangan region into five diagenetic types, and set up the logging characteristics of each diagenetic facies. After sin-gle wells diagenetic facies analysis, this paper has semiquantitatively evaluated forth member of Xujiahe Formation of Guangan area by authorizing thickenss percentage content contour diagrams, thickenss content contour diagrams, areal distribution graph of diagenetic facies.