Hydrocarbon Accumulation Pattern and Exploration Direction in Southern Chad Basin

Abstract

AbstractThe Southern Chad Basin is a Cretaceous-Paleogene rift basin developed along the Central African Shear Zone (CASZ). The Southern Chad Basin can be subdivided into three depressions, namely Doba, Doseo and Salamat. This basin went through four evolution phases: rifting, sagging, strike-slip and inversion. This paper focuses on hydrocarbon accumulation pattern and exploration direction in different depressions of Southern Chad Basin. Controlled by depositional settings and reservoir-seal combination, the hydrocarbon distribution in Southern Chad Basin is characterized as “prolific in the west and poor in the east, normal oil in the lower payzone and heavy oil in the upper payzone”. Oil are both found in upper and lower Cretaceous lacustrine sandstones in Doba depression. However, lower Cretaceous become the only target in Doseo and Salamat depression. Effective source kitchen, structural history, faults/seals combination are key conditions for hydrocarbon accumulation. There is huge exploration potential in Southern Chad Basin. Future exploration directions includes: lithological or basement traps in Doba depression, inverted structures in Doseo depression and central uplift in Salamat depression.KeywordsSouthern Chad BasinInversionAccumulation patternExploration direction