四川盆地涪陵北部二叠系茅三段火山碎屑岩储层预测及油气勘探潜力  

Reservoir prediction and gas exploration potential in Mao3 Member pyroclastic rock of Permian in northern Fuling area of Sichuan Basin

作　　者：董清源[1,2] 徐旭辉 李国发 王彬权[2] 裴思嘉 DONG Qingyuan;XU Xuhui;LI Guofa;WANG Binquan;PEI Sijia(China University of Petroleum,Beijing 102249,China;SINOPEC Geophysical Research Institute Co.,Ltd.,Nanjing 211103,China)

机构地区：[1]中国石油大学(北京),北京102249 [2]中石化石油物探技术研究院有限公司,江苏南京211103

出　　处：《天然气地球科学》2025年第3期508-518,共11页Natural Gas Geoscience

基　　金：中国石化科技部项目(编号:P22138)资助.

摘　　要：四川盆地涪陵北部二叠系茅三段火山岩整体勘探程度较低,受川东二叠系火山喷发机构影响控制,纵向上发育多种类型的火山岩,其中火山碎屑岩是实现规模增储的新领域。明确涪陵北部二叠系火山碎屑岩的分布特征及勘探潜力是研究的首要问题。以钻井、野外露头、地震等资料为基础,从茅三段火山岩的岩石学特征、火山碎屑岩储层特征及油气成藏特征入手,探讨研究区火山碎屑岩气藏勘探潜力。结果表明:①涪陵北部茅三段火山碎屑岩储层受岩相、构造、成岩作用控制,储集空间为孔隙和裂缝的复合体,岩溶地貌及裂缝改造作用越强,储集条件越好;②茅三段火山碎屑岩被上、下的泥岩、灰岩、沉凝灰岩等稳定岩性组合所包裹,具有低频、底界中—弱波峰、层间断续杂乱的地震反射特征及中—高密度、相对高阻抗的岩石物理特征,结合岩相、裂缝、地貌及储层厚度等控制因素,预测有利储层主要分布于研究区东北部,厚度介于10~20 m之间,面积约为73.7 km^(2);③茅三段火山碎屑岩储层具有“双源控烃、近源聚集”的成藏特征,天然气生烃强度大,源储盖时空匹配关系良好,具有较大勘探潜力,可在研究区东北部有利储层区进行老井复试和探井部署。The overall exploration level of volcanic rocks in the Mao3 Member of the Permian in northern Fuling,Sichuan Basin is low.Controlled by the Permian volcanic eruption mechanism in eastern Sichuan,various types of volcanic rocks developed vertically.Among them,pyroclastic rocks are a new way to achieve large-scale reserve increase.Defining the distribution characteristics and exploration potential of Permian pyroclastic rocks in the northern Fuling area is the primary issue in the research.Based on the data of drilling,outcrop and seismic,the exploration potential of pyroclastic gas reservoir in the research area is discussed based on the petrological characteristics of the volcanic rocks,the reservoir characteristics of pyroclastic rock and the hydrocarbon accumulation characteristics of the Mao3 Member.The results show that:(1)The reservoir is controlled by lithofacies and tectono-diagenesis,and the reservoir space is a complex of pores and fractures.The stronger the karst landform and fracture transformation,the better the reservoir conditions.(2)The pyroclastic rocks of Mao3 Member are covered by stable lithologic association such as mudstone,limestone and tuff,which have the characteristics of low frequency,medium-weak wave peak at the bottom,intermittent and disorganized seismic reflection between layers,and the petrophysical characteristics of medium-high density and relatively high impedance.Combined with the controlling factors such as lithofacies,fractures,geomorphology and reservoir thickness,it is predicted that the favorable reservoir is mainly distributed in the northeast of the working area,with a thickness of 10-20 m and an area of about 73.7 km^(2).(3)The volcanic clastic reservoir in the Mao3 Member has the characteristics of“double source hydrocarbon control and near source accumulation”,high hydrocarbon generation intensity of natural gas,good spatio-temporal matching relationship of source cap,and great exploration potential,which can be used for old well retesting and exploration well depl

关 键 词：四川盆地 涪陵北部 茅三段 火山碎屑岩 储层预测 成藏匹配 勘探潜力 

分 类 号：TE121[石油与天然气工程—油气勘探]