Petroleum geological characteristics and exploration orientation in strike-slip rift basin group in central Africa

doi:10.3969/j.issn.1672-7703.2023.03.008

Abstract

Abstract: The central African strike-slip rift basin group was composed of the Mesozoic-Cenozoic continental rift basins influenced by the Central African Shear Zone (CASZ), showing complex and diverse structures, as well as low exploration degree. The unclear understanding of hydrocarbon accumulation rules restricted the exploration and discovery in the region. Based on the analysis of basin structure, sedimentary system, hydrocarbon accumulation assemblage characteristics, as well as the discovered oil and gas fields, the hydrocarbon enrichment rules and main controlling factors are summarized, and the exploration potential and orientation are analyzed. The study results show that the central African strike-slip rift basin group experienced multi-stage extensional, strike-slip and reversed tectonic activities after the Early Cretaceous, which significantly controlled the sedimentary strata, structural features and hydrocarbon accumulation; Influenced by reservoir-cap rock assemblages and tectonic evolution, there are great differences in oil discoveries and plays in various basins in the central African strike-slip rift basin group, showing hydrocarbon distribution characteristics of “rich in the west and poor in the east, and light in the lower part and heavy in the upper part”; The main controlling factors for hydrocarbon enrichment include the effective hydrocarbon kitchen, tectonic activity and fault; Doba Basin in the west has the most abundant oil and gas resources, with several sets of hydrocarbon accumulation assemblages developed and large-scale oil and gas resources discovered in the Upper and Lower Cretaceous, and the Lower Cretaceous lithologic and buried-hill traps are the main exploration orientation in the future; For Doseo Basin in the central part, there is a lack of the regional cap rocks in the Upper Cretaceous, and the main exploration targets include the Lower Cretaceous sandmudstone association, and fault anticline and fault block traps formed by strike-slip activities, as well as the potential bedrock buried hill; Salamat Basin in the east has no proved effective hydrocarbon accumulation assemblage, which shows a limited exploration potential.

CLC Number:

TE122.1

He Wenyuan, Wang Li, Wang Wangquan, Xiao Kunye, Du Yebo, Wu Yadong, Ma Mingfu, Pan Chunfu. Petroleum geological characteristics and exploration orientation in strike-slip rift basin group in central Africa[J]. China Petroleum Exploration, 2023, 28(3): 90-99.

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