关键词: 东尼日尔盆地, 裂谷盆地, Termit坳陷, Dibeilla-1井, 重大发现, 勘探潜力

Abstract: The East Niger Basin, which belongs to western section of Central Western Africa Rift System (WCARS), is a Mesozoic- Cenozoic rift basin developed on the Precambrian-Jurassic crystallized basement. It is characterized by a great transgression in the Late Cretaceous, and the superimposition of the Early Cretaceous and Paleogene rifting. The Paleogene assemblage is the main play that developed on the widely distributed marine source rocks of Late Cretaceous. Several foreign oil companies have made extensive exploration in the East Niger Basin since 1970, and commercial oil was encountered in the Dinga faulted terrace. CNPC started hydrocarbon exploration in the Termit Depression in June 2008. In order to discover more additional oil reserves within a short time span, how to evaluate and to map out quickly the potential petroleum fairways was the main challenge for Chinese explorationists. The Araga slope, standing opposite to the Dinga faulted terrace, was eventually considered as one of the most potential exploration trends based on a fully petroleum migration and accumulation study. Consequently, theWell Dibeilla-1 was proposed and optimized to test the Dibeilla prospect, which came out as a great discovery. Taking into account for the subsequent drilling of the Well Dibeilla N-1 and Well Admer-1, approximately 90 million tons of OOIP were estimated under Dibeilla structural zone. The success of the Well Dibeilla-1 brought about the naissance of a new petroleum accumulation zone after the Dinga faulted terrace in the Termit Depression. Moreover, it showed a bright future of the exploration in the adjacent Block Bilma.

Key words: East Niger Basin, rift basin, Termit Depression, Well Dibeilla-1, great discovery, exploration potential