海相油气地质2023，Vol.28Issue(4)：381-390,10.DOI:10.3969/j.issn.1672-9854.2023.04.005
川北地区茅口中晚期斜坡相沉积特征及其油气地质意义
Sedimentary characteristics of slope facies in mid-late stage of Moukou Formation in northern Sichuan Basin and its petroleum geological significances
摘要
Abstract
Recently,a great exploration breakthrough has been made in shoal porous reservoir of Maokou Formation in northern Sichuan Basin.Based on the latest drilling and seismic data,the stratigraphy,sedimentology and geochemistry of Maokou Formation in northern Sichuan Basin has been studied.The results show that:(1)The slope facies is developed in Maokou Formation of Well JG1,which confirms the differentiation of platform and trough occurring in mid-late stage of member-2 to late stage of member-3 of Maokou Formation.(2)The middle and upper part of member-2 of Maokou Formation develops the lower slope subfacies,which is mainly composed of grey-black micrite limestone and silty limestone,with storm deposits,silicon interlayer and lamellation developed.The storm deposition sequences that can be recognized mainly include combination of erosion surface and biodetritus bedding,combination of biodetritus bedding and graded bedding,combination of erosion surface and biodetritus bedding and horizontal bedding,combination of erosion surface and gravel bedding.The member-2 of Maokou Formation develops upper slope subfacies,which consists of bioclastic micritic limestone and micrite bioclast limestone reflecting low-energy sedimentary environment,and the paleontology is a combination of shallow water organisms,with sediment structure of biological burrows and imbricated bedding developed.(3)The slope facies in the northern Sichuan Basin constitutes a continuous shallow sedimentary sequence in the vertical direction,and spreads along the Jiange-Langzhong line in a northwest direction.The slope and platform margin form the progradational sedimentary model of rimmed platform.(4)Organic geochemical analysis shows that the lower slope subfacies have a high abundance of organic carbon,among which tempestite is the best with TOC up to 15%,which has high-quality hydrocarbon generation potential.The study clarifies the period and plane position of platform and trough differentiation,and provids support for expanding the exploration of shoal porous reservoir of Maokou Formation.The discovery of high-quality hydrocarbon source rock in the lower slope subfacies can contribute to establish a variety of reservoir formation mode in the Maokou Formation,which is of great significance to evaluate the resource potential of the Maokou Formation in northern Sichuan Basin.关键词
斜坡相/沉积特征/沉积演化/勘探领域/茅口组/川北地区Key words
slope facies/sedimentary characteristics/sedimentary evolution/exploration field/Maokou Formation/northern Sichuan Basin分类
能源科技引用本文复制引用
蒋航,张玺华,陈聪,高兆龙,山述娇,罗平,陈延贵,李天军,胡罗嘉..川北地区茅口中晚期斜坡相沉积特征及其油气地质意义[J].海相油气地质,2023,28(4):381-390,10.基金项目
本文受国家科技重大专项"大气田富集规律与勘探关键技术"子课题"四川盆地二叠系—中三叠统天然气富集规律与目标评价"(编号:2016ZX05007-004)资助 （编号:2016ZX05007-004）
