摘要
下寒武统麦地坪组—筇竹寺组是扬子地区重要的烃源岩发育层位,对震旦系—古生界油气勘探具有重要意义。为明确四川盆地稀井区震旦系—寒武系勘探领域烃源条件,基于探井与露头样品系统分析、测井评价与地震反演,分层次、分层段刻画了麦地坪组—筇竹寺组烃源岩展布,厘定了以其为烃源灶的含油气系统边界,指出了有利勘探区带。(1)中上扬子区麦地坪组烃源岩总厚度主要为5~200m,优质烃源岩厚0~100m,局限分布于克拉通内部和边缘裂陷区。(2)筇竹寺组烃源岩总厚度主要为50~450m,优质烃源岩厚5~250m;筇竹寺组烃源岩具有“三段式”发育特征,优质烃源岩主要发育在筇一段和筇二段下部,筇三段主要为低有机质丰度的差烃源岩。其中,筇一段烃源岩厚10~300m,平面分布特点与麦地坪组烃源岩相似,为早寒武世海侵初期产物;筇二段烃源岩厚度为30~200m,在中上扬子克拉通广泛分布,为最大海侵期产物;筇三段差烃源岩厚数米至数十米,分布范围与筇二段相当。(3)中上扬子区麦地坪组—筇竹寺组烃源岩厚度分布受克拉通内部与边缘裂陷展布、同沉积断裂发育、震旦纪末期古地貌和后期剥蚀作用等多种因素控制。(4)下寒武统烃源岩生烃潜力巨大,生烃强度为(20~140)×10^(8) m^(3)/km^(2),存在两个规模生烃中心,以其为烃源灶的含油气系统可划分为德阳—安岳克拉通内裂陷震旦系—二叠系复式含油气系统和城口—巴东—五峰克拉通内裂陷震旦系—奥陶系复式含油气系统,在两大复式油气系统内优选了7个有利勘探区带。
A set of important source rock is developed in the Lower Cambrian Maidiping Formation(Є1m)-Qiongzhusi Formation(Є1q)in the Yangtze region,which is of great significance for the petroleum exploration of the Sinian-Paleozoic.In order to clarify source rock conditions in the exploration field of the Sinian-Cambrian with sparse wells in Sichuan Basin,the systematic analysis of wells and outcrop samples,logging evaluation and seismic inversion are conducted to characterize the distribution ofЄ1m-Є1q source rocks by sequences and sections,define the boundary of petroleum system with the source kitchen of this set of source rocks,and propose the favorable exploration zones.The study results show that:(1)The total thickness ofЄ1m source rocks mainly ranges in 5-200 m,and that of the high-quality source rocks is 0-100 m in the Middle-Upper Yangtze region,with the development area limited to the intracratonic and marginal rifts.(2)The total thickness ofЄ1q source rocks is between 50-450 m,and that of the high-quality source rocks is in the range of 5-250 m.TheЄ1q source rocks have the characteristics of“three sections”,that is,the high-quality source rocks are generally developed in the first member and lower part of the second member,while the poor-quality source rocks with low organic carbon content are developed in the third member.Among them,source rock in the first member ofЄ1q has a thickness of 10-300 m,with the similar distribution characteristics to that ofЄ1m,which is the product of the early transgression in the Early Cambrian.The source rock in the second member ofЄ1q has a thickness of 30-200 m and a wide distribution area in the Middle-Upper Yangtze region,which is the product in the maximum transgression period.The thickness of the poorquality source rock in the third member ofЄ1q ranges from several meters to tens of meters,and the distribution area is similar to that of the second member.(3)The thickness of source rocks ofЄ1m-Є1q is controlled by multiple factors,such as the distribution o
作者
付小东
陈娅娜
罗冰
李文正
刘冉
王小芳
和源
谷明峰
姜华
Fu Xiaodong;Chen Ya’na;Luo Bing;Li Wenzheng;Liu Ran;Wang Xiaofang;He Yuan;Gu Mingfeng;Jiang Hua(PetroChina Hangzhou Research Institute of Geology;PetroChina Southwest Oil&Gasfield Company;PetroChina Research Institute of Petroleum Exploration&Development)
出处
《中国石油勘探》
CAS
CSCD
北大核心
2022年第4期103-120,共18页
China Petroleum Exploration
基金
国家科技重大专项“深层古老含油气系统成藏规律与目标评价”(2017ZX05008005)
中国石油天然气股份有限公司重点科技项目“深层—超深层油气富集规律与区带目标评价”(2018A-0105)。
关键词
下寒武统
优质烃源岩
测井评价
地震反演
含油气系统
四川盆地
Lower Cambrian
high-quality sources rock
logging evaluation
seismic inversion
petroleum system
Sichuan Basin
