四川盆地中三叠统-上三叠统马鞍塘组天然气藏特征和有利勘探地区  

The gas reservoir characteristics and advantageous exploration areas in Middle Triassic Leikoupo Formation-Upper Triassic Ma'antang Formation in Sichuan Basin

作　　者：秦川[1] 刘树根[1] 汪华[2] 孙玮[3] 李德星[4] 杨荣军[5] 张长俊[1] 吴熙纯[1] 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,成都610059 [2]中国石油西南油气田公司勘探开发研究院,成都610051 [3]成都理工大学地球科学学院,成都610059 [4]中国石油辽河油田分公司勘探开发研究院,辽宁盘锦124010 [5]中国石油勘探开发研究院西北分院,兰州730020

出　　处：《地质科学》2011年第1期258-272,共15页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中石化前瞻性项目"华南古板块地裂运动与海相油气前景"(编号:PH08001)资助

摘　　要：四川盆地中三叠统雷口坡组勘探已近40年,但迄今为止只发现了两个大中型气藏。近年来,雷口坡组钻井油气显示活跃,展示了良好的勘探前景。四川盆地中三叠统气藏储层主要位于底部雷一段、顶部雷三—雷四段,天然气主要来源于上二叠统龙潭组和上三叠统须家河组烃源岩,各气藏天然气组分特征也不尽相同,储集空间均以各类次生溶蚀孔隙为主,多为低-中孔低渗的孔隙型或裂缝—孔隙型储层。气藏盖层发育,均具备良好的直接盖层和区域盖层条件。上三叠统马鞍塘组储层主要位于其顶、底部的(藻)砂屑灰岩和泥晶灰岩,烃源岩和盖层与雷三、雷四段成藏条件相似。本文将四川盆地中三叠统-上三叠统马鞍塘组生储盖组合特征概括为两种类型:1)上二叠统龙潭组烃源岩+雷一—雷二段滩相储层+雷口坡组膏盐盖层;2)上三叠统烃源岩+雷三—雷四段—马鞍塘组底部(礁)滩相储层和(或)风化壳古岩溶储层+上三叠统泥质盖层。将来的油气勘探应更加重视对第二组合的关注。龙门山中南段前缘地区应是中三叠统雷三—雷四段和上三叠统马鞍塘组油气勘探最有利的地区。The exploration history of Middle Triassic Leikoupo Formation is about 40 years in Sichuan Basin, but there are only two large-and medium-sized gas pools found till today. Recently, the hydrocarbon shows in Leikoupo Formation were found during drilling and revealed a good exploration prospect for the unit. The reservoir rocks of Middle Triassic gas pools are mainly located in the base（ T2l1） and top of the formation（T2l3-T2l4 ）with low-medium porosity and low permeability,and the hydrocarbon source rocks were Upper Permian Longtan Formation and Upper Triassic Xujiahe Formation, respectively. The component of natural gas in Middle Triassic was varied. The main reservoir spaces are various secondary dissolved pores, and the reservoir type is porous or fractured-porous. The sealing of gas pools is well-developed with good direct and indirect cap rocks. The reservoir rocks of Upper Triassic Ma＇antang Formation are calcarenite and micrite located at the base of the unit,and its source rock and seal are similar to the gas pools in the top of Leikoupo Formation （T2l3-4）. The characteristics of the source- reservoir-seal plays of Middle-Upper Triassic in Sichuan Basin are divided into two types： 1 ） upper Permian Longtan Formation source rock＋the reservoir rocks in the first-second segment of Leikoupo Formation（ T2l1-2 ） ＋the anhydrite-salt seal in Leikoupo Formation ; 2 ） Upper Triassic source rock＋the reservoir rocks in the third-fourth segment of Leikoupo Formation（T2l3-4） and in upper Triassic Ma＇antang Formation＋the mudstone seal in the Upper Triassic. The frontier area of the central-southern segment of Longmen Mountain should be the prospect area of the oil-gas exploration in the top Leikoupo Formation （T2l3-4） and Ma＇antang Formatioon in Sichuan Basin.

关 键 词：四川盆地 中三叠统 马鞍塘组 天然气藏 勘探前景 

分 类 号：P534[天文地球—古生物学与地层学] TE121[天文地球—地质学]