四川盆地二、三叠系碳酸盐岩大气田类型及其成藏规律  

Types and gas accumulation patterns of large Permian and Triassic carbonate gas reservoirs in the Sichuan Basin

作　　者：张奇[1] 文龙[1] 徐亮[1] 夏茂龙[1] 陈盛吉[1] 邓思思[1] 

机构地区：[1]中国石油西南油气田公司勘探开发研究院

出　　处：《天然气工业》2012年第1期33-38,120,共6页Natural Gas Industry

基　　金：国家科技重大专项"大型油气田及煤层气开发"(编号:2011ZX05007-003)

摘　　要：四川盆地二、三叠系碳酸盐岩大气田分属3种类型,即台地边缘礁滩气藏、台地相粒屑滩与白云岩气藏、风化壳复合圈闭气藏,分析研究其成藏规律对于寻找下一步勘探有利区带具有重要意义。研究结果表明:①台地边缘礁滩气藏储层相控特征明显,烃源供给与成藏过程受古隆起与现今构造控制,早期运聚,晚期调整;②台地相粒屑滩与白云岩气藏多为晚期成藏,多套薄储层叠加,有效的断裂疏导体系是获得规模气藏的关键;③风化壳复合圈闭气藏储层受沉积相、岩溶作用控制,颗粒岩叠加同生、表生岩溶改造是形成风化壳储层的关键,风化壳优化了烃源岩、储集层、圈闭、盖层搭配条件,断层、地层接触关系构成断面、侧面与上部"倒灌"等多种方式充注,早期成藏,晚期调整。Large Permian and Triassic carbonate gas reservoirs in the Sichuan Basin can be classified into 3 types,namely reef-bank gas reservoirs on platform margin,grain bank and dolomite reservoirs within platform,and weathering crust compound trap reservoirs.The analysis of their gas accumulation patterns is significant for identifying future exploration targets.The reef-bank gas reservoirs on the platform margin are obviously controlled by sedimentary facies.The process of hydrocarbon generation and accumulation is controlled by the paleohighs and current structures.This type of reservoirs is featured by early hydrocarbon migration and accumulation and late adjustment.The grain bank and dolomite reservoirs within the platform are mostly formed at the late stage.The superimposition of multiple thin reservoirs and effective fault carrier systems are critical to the formation of large scale gas reservoirs.The weathering crust compound trap reservoirs are featured by superimposition of grain stones and hypergenetic karstification,which are critical to the formation of weathering crust reservoirs.The weathering crust improved the conditions of source rocks,reservoirs,traps and seal combinations,so the contact between faults and formations resulted in many modes of hydrocarbon charging from fault plane,flank,and top side.This type of gas reservoirs was formed in the early stage and modified in the late stage.

关 键 词：四川盆地 二叠纪 三叠纪 碳酸盐岩 台地边缘礁滩 台地相 风化壳 大气田 成藏规律 

分 类 号：P618.13[天文地球—矿床学]