海相油气地质2025，Vol.30Issue(5)：413-424,12.DOI:10.3969/j.issn.1672-9854.2025.05.003
非洲碳酸盐岩大型油气田特征及主控因素
Characteristics and controlling factors of large carbonate oil and gas fields in Africa
摘要
Abstract
Large carbonate hydrocarbon fields have long been a global research focus.Statistical analysis of IHS data reveals that Africa's giant carbonate oil and gas fields are mainly distributed in five basins:the Sirte,Pelagian,and Eratosthenes basins in North Africa,and the Lower Congo and Kwanza basins in West Africa.Among them,Sirte Basin accounts for 48.2%of Africa's total carbonate oil and gas reserves,making it the most prolific.Through detailed analysis of 19 large carbonate oil and gas fields,the conclusions are drawn as following:(1)The passive-margin marine transgressions associated with the Late Cretaceous-Eocene opening of the Neo-Tethys Ocean and South Atlantic are prerequisites for large-scale hydrocarbon accumulation in carbonate rocks,with the main reservoirs developed in the Cretaceous,Paleocene,and Eocene strata.(2)Unlike deep-water carbonate rocks,the shallow marine sedimentary environment and low latitude warm and humid climate after the breakup of Gondwana continent control the scale distribution of reservoirs and source rocks,forming various types of reservoirs mainly composed of bioclastic limestone,with dolomite,foraminifera limestone,oolitic limestone,and reef limestone as secondary reservoirs,and high-quality source rocks mainly composed of shallow marine shale.(3)During the base-level rise period(lowstand to transgressive system tracts),multiple sets of marine shale(source)-carbonate rock(reservoir)-shale(cap)combinations tend to develop.Subsequently,through sedimentary burial and tectonic processes,structural traps and stratigraphic-lithologic traps are primarily formed,leading to hydrocarbon accumulation.(4)The widely developed limestones,grainstones,and dolomites,along with diagenetic processes,governs the effective reservoirs and physical properties of large carbonate oil and gas fields.Large oil reservoirs are characterized by moderate to high porosity and moderate to low permeability,whereas large gas reservoirs typically exhibit moderate to low porosity and moderate to high permeability.From the distribution of recoverable oil and gas reserves in African carbonate rocks,there is still a huge exploration space,and the mature theoretical techniques in the genesis and characterization of carbonate reservoirs in China are worthy of further referencing.关键词
碳酸盐岩/储层特征/大型油气田/成藏特征/主控因素/非洲Key words
carbonate rocks/reservoir characteristics/large oil and gas fields/characteristics of hydrocarbon accumula-tion/main controlling factors/Africa分类
石油、天然气工程引用本文复制引用
肖坤叶,赵宁,陈亚京,蔺子墨,索晓飞,马雪莹,周鸿璞,欧亚菲..非洲碳酸盐岩大型油气田特征及主控因素[J].海相油气地质,2025,30(5):413-424,12.基金项目
本文受国家科技重大专项"新一轮全球油气资源智能化评价与综合选区技术"(编号:2025ZD1400800)、中国石油天然气股份有限公司基础性前瞻性重大科技专项课题"基于大数据的常规油气可采资源智能化评价技术研发"(编号:2023ZZ0702)资助 （编号:2025ZD1400800）
