川中地区侏罗系大安寨段沉积相及有利岩石组合分析  

Sedimentary Facies and Favorable Rock Assemblages of Jurassic Da′anzhai Member,Central Sichuan

作　　者：黄董 曾德铭[1] 王兴志[1] 谢圣阳 张芮 张少敏[2] 郭奕浩 Huang Dong;Zeng Deming;Wang Xingzhi;Xie Shengyang;Zhang Rui;Zhang Shaomin;Guo Yihao(Southwest Petroleum University,Chengdu,Sichuan 610500,China;PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China)

机构地区：[1]西南石油大学,四川成都610500 [2]中国石油西南油气田分公司,四川成都610041

出　　处：《特种油气藏》2023年第1期65-73,共9页Special Oil & Gas Reservoirs

基　　金：中国石油-西南石油大学创新联合体项目“四川盆地侏罗系湖相页岩油地质理论技术研究与有利区评价”(2020CX050000)。

摘　　要：针对川中地区侏罗系大安寨段沉积相划分不精细,有利岩石组合及有利勘探区不明确的问题,利用3口全取心井的岩心描述和6条野外剖面观察结果,结合薄片鉴定、测井解释及有机地球化学分析方法,对研究区岩石类型、沉积相类型、沉积相分布及沉积模式、岩石组合及有利勘探区进行研究。研究结果表明:岩石类型划分为10种;沉积相划分为滨湖、浅湖、半深湖3个亚相,以及半深湖泥、生物滩、重力流等10种微相;公山庙—莲池—营山一线为沉积中心,为半深湖环境,识别出C、D、E共3种岩石组合类型;南充—渠县—仪陇一线为呈环状发育的浅湖环境,识别出A、B、F共3种岩石组合类型。研究成果可由常规致密油拓展至页岩油勘探领域,通过TOC、孔隙度、渗透率、压裂效果等评价指标,认为A型岩石组合在断裂和裂缝匹配下,是致密油碳酸盐岩的有利勘探组合,F型为最有利页岩油勘探组合,主要分布于浅湖相大一亚段—大二a亚段。研究成果对页岩油下一步勘探有重要指示意义。In view of the imprecise sedimentary facies division,unclear favorable rock assemblage and undefined favorable exploration area of Jurassic Da′anzhai Member in Central Sichuan,a study was conducted on the rock type,sedimentary facies type,sedimentary facies distribution,sedimentary model,rock assemblage and favorable exploration area in the study area by the core description of three fully cored wells and the observation results of six field profiles in combination with thin slice identification,logging interpretation and organic geochemical analysis methods.The study results show that Rock was divided into 10 types.The sedimentary facies was divided into 3 subfacies(shore lake,shallow lake and fairly deep lake)and 10 microfacies(including fairly deep lake mud,organic bank and gravity flow).Gongshanmio-Lianchi-Yingshan line is the sedimentary center developed in a fairly deep lake environment,and three rock assemblage types(C,D and E)were identified.Nanchong-Quxian-Yilong line was circularly developed in a shallow lake environment,and three rock assemblage types(A,B and F)were identified.The study results were applied from conventional tight oil to shale oil exploration.According to the TOC,porosity,permeability,fracturing effect and other evaluation indicators,it was considered that Type A rock assemblage was a favorable combination for tight oil carbonate rock exploration under the matching of fractures and cracks,and Type F was the most favorable combination for shale oil exploration,which was mainly distributed in the shallow lake facies at Sub-member 1 to Sub-member 2a of Da′anzhai Member.The study results are of great significance for shale oil exploration in the future.

关 键 词：川中地区 大安寨段 沉积相 岩石组合 有利勘探区 

分 类 号：TE121.1[石油与天然气工程—油气勘探]