石油实验地质2024，Vol.46Issue(3)：460-471,12.DOI:10.11781/sysydz202403460
川东—川北地区二叠系茅口组沉积演化及其油气地质意义
Sedimentary evolution and petroleum geological significance of Permian Maokou Formation in eastern and northern Sichuan Basin
摘要
Abstract
In recent years,the Permian Maokou Formation of the Sichuan Basin shifted focus.Previously,targe-ting high points and exploring along the long axis were common.Now,the strategy emphasizes finding shoal grainstone reservoirs with pores,leading to significant breakthroughs and making the Maokou Formation a hotspot for exploration.This change requires strong support from sedimentary evolution studies.The eastern and northern Sichuan regions are notable for distinct tectonic and sedimentary features within the Maokou Formation,suggesting promising exploration potential.Analysis of the logging data from 386 wells was conducted and sedimentary facies analysis was carried out using field profiles and drilling cores.Combining the logging curves with sedimentary facies,the sedimentary evolution of the Maokou Formation in the study area was analyzed.Findings reveal a gentle carbonate slope from the first member to the lower submember of the second member.The stratigraphic thickness and sedimentary facies are generally influenced by the ancient Central Sichuan Palaeouplift,with low-energy shoals developing locally.A transition to a rimmed carbonate platform occurs from the upper submember of the second member to the third member,with stratigraphic thickness and sedimentary facies showing a northwest to southeast orienta-tion.The platform develops sequentially from platform facies to platform margin,slope,and shelf facies from west to east,with high-energy shoals developing in the platform margin.Sedimentation history indicates two distinct rise to fall processes of the relative sea level during the Maokou Formation sedimentary period,corresponding to the first member to the lower submember of the second member,and the upper submember of the second member to the third member.The formation of shoal grainstone reservoirs with karst and dolomitization in the gentle slope during the first period was controlled by regional sea level changes,tectonic activities,and the type of carbonate platform.Potential hydrocarbon source rocks developed in submarine troughs during the second period.The region holds promise for unconventional oil and gas exploration,particularly on the west side of the trough with high-energy shoals on platform margins.关键词
沉积演化/海槽/油气勘探/茅口组/川东—川北Key words
sedimentary evolution/marine trough/oil and gas exploration/Maokou Formation/eastern and northern Sichuan Basin分类
能源科技引用本文复制引用
曹华,谢静平,李天军,胡广,山述娇,田辰,张玺华,彭翰林,刘沛云,陈聪,高兆龙,胡罗嘉..川东—川北地区二叠系茅口组沉积演化及其油气地质意义[J].石油实验地质,2024,46(3):460-471,12.基金项目
中国石油科技部创新联盟体项目"深层高演化天然气成藏机制、示踪技术及油气富集区带优选"(2020CX010302)资助. （2020CX010302）
