川西南地区茅口组柱状凹陷异常体分布特征及成因  

Distribution and origin of the columnar sag anomalies of Maokou formation in southwestern Sichuan basin

作　　者：杨柳 臧殿光 徐宝亮 邓绍强 周跃宗 郭鸿喜[2] YANG Liu;ZANG Dianguang;XU Baoliang;DENG Shaoqiang;ZHOU Yuezong;GUO Hongxi(Southwest Geophysical Research Institute,Bureau of Geophysical Prospecting Inc.,PetroChina,Chengdu,Sichuan 610213,China;Exploration Unit of Southwest Oil&Gas Field Company,PetroChina,Chengdu,Sichuan 610041,China)

机构地区：[1]中国石油东方地球物理公司西南物探研究院,四川成都610213 [2]中国石油西南油气田分公司勘探事业部,四川成都610041

出　　处：《石油地质与工程》2020年第5期19-24,共6页Petroleum Geology and Engineering

基　　金：中国石油天然气股份有限公司重大科技专项“西南油气田天然气上产300亿立方米关键技术研究与应用”(2016E–0603)。

摘　　要：基于高精度三维地震资料、相干切片及模型正演,并参考塔里木盆地奥陶系"断溶体"的已有认识,对川西南地区新发现的中二叠统茅口组柱状凹陷异常体分布特征及成因进行分析。结果表明,此类异常体在川西南地区广泛发育于北东向基底走滑断裂附近,地震剖面上表现为垂向多组同向轴连续下凹,从茅口组顶部延伸至震旦系基底,相干切片上为环形或似环形特征。结合已有地质资料分析,认为此类异常体主要为热液溶蚀成因,兴凯地裂时期形成,于峨眉地裂时期活化的北东向基底走滑断裂是其分布的主控因素。研究结果对扩大川西南地区勘探领域、增储上产具有一定的意义。Based on high-precision 3 D seismic data, coherent slices, and forward modeling, and referring to the existing understanding of the"Faulted Solution"of the Ordovician in the Tarim basin, the newly discovered reservoir type of the middle Permian Maokou formation in southwestern Sichuan-columnar sag volume distribution characteristics and causes are analyzed. The results show such anomalous bodies are widely developed near the strike-slip faults of the northeastward basement in southwestern Sichuan. The seismic profile shows continuous downward sag of multiple sets of isotropic axes, extending from the top of the Maokou formation to the Sinian basement. Coherent slices are circular or ring-like features. Based on the analysis of the existing geological data, it is considered that such anomalous bodies are mainly caused by hydrothermal dissolution. The northeast strike-slip fault activated during the Emei rift during the Xingkai rift is the main controlling factor for its distribution. The study is of certain significance for expanding the exploration areas and zones in Southwest Sichuan and increasing reserves and production.

关 键 词：川西南地区 茅口组 凹陷异常体 走滑断裂 热液溶蚀 

分 类 号：TE111.2[石油与天然气工程—油气勘探]