天然气勘探与开发2023，Vol.46Issue(4)：13-26,14.DOI:10.12055/gaskk.issn.1673-3177.2023.04.002
构造作用约束下的川中龙女寺地区茅口组白云岩储层成因分析
Genesis analysis on tectonism-controlled dolomite reservoirs in Maokou Formation,Longnvsi area,central Sichuan Basin
摘要
Abstract
The Middle Permian Maokou Formation has been one of the major gas-producing horizons in the Sichuan Basin for more than half a century.A new exploration upsurge targeting the dolomite reservoirs has been set off in recent years.However,the lack of system-atical study on the genetic mechanisms of various reservoirs limits progressive exploration.To clarify the characteristics and genesis of do-lomite reservoirs in the second member of Maokou Formation in the Longnvsi area of central Sichuan Basin,the genetic mechanisms of the reservoirs were investigated with the tectonism and using the data of outcrops,drilling,logging,and seismic interpretation.The results show that,(i)the dolomite reservoirs in the Maokou Formation are primarily composed of fine-to medium-crystalline dolomites formed by the dolomitization of beach grainstones;(ii)the reservoir spaces are dominantly made of hydrothermal impact-induced vugs and non-selective karst vugs,followed by structural fractures and karst fissures which play an important role in hydrothermal migration and reservoir seepage enhancement;(iii)the Hercynian Emei taphrogeny and the basement faulting controlled by the northward subduction of the Mian-lue Ocean induced the formation of the northern Sichuan platform basin in the Late Middle Permian,and controlled the distribution of beach grain-stones at the margin of the platform basin;(iv)affected by the high paleogeothermal gradient,remnant marine-originated fluids,and abun-dant magnesium ions from hydrothermal fluids migrating along faults,the beach grainstones were dolomitized extensively;(v)the Hercynian fault-fracture-hydrothermal activity and the Indosinian fault-fracture activity controlled the space formation of the dolomite reservoirs;and(vi)tectonism is the key controlling mechanism for the formation of dolomite reservoirs.The areas where faults are concentrated should be focused on for progressive exploration.关键词
白云岩储层/茅口组二段/龙女寺地区/储层特征/储层成因/构造作用Key words
Dolomite reservoir/The second member of Maokou Formation/Longnvsi area/Reservoir characteristic/Reservoir gene-sis/Tectonism引用本文复制引用
方进,张连进,郑斌嵩,李顺,刘芳兰,梁新玉,彭军..构造作用约束下的川中龙女寺地区茅口组白云岩储层成因分析[J].天然气勘探与开发,2023,46(4):13-26,14.基金项目
中国石油西南油气田公司川中油气矿项目"龙女寺地区茅口组气藏储层展布及有利区优选"(编号:XNS 川中矿 JS 2022-135). （编号:XNS 川中矿 JS 2022-135）
