Evaluation of Chela Formation in the Kambala-Livuite area, southern Block 0, Cabinda, Angola.

摘要

The abundance of good reservoir and source rocks offshore Cabinda, Angola, makes the area an attractive and successful hydrocarbon province. Block 0, offshore Cabinda, lies in the Lower Congo basin along the western coast of Africa. The stratigraphy of Block 0 consists of two major oil-rich sequences: the rift sequence (primarily lacustrine) and the post-rift sequence (primarily marine). These are separated by a thick section of evaporites, and thus are referred to as the pre-salt sequence and post-salt sequence, respectively.; The Chela Formation, mid-Aptian in age, was deposited before the salt. It consists of sandstones and conglomerates locally interbedded with carbonates. It is the youngest unit of the pre-salt sequence. The top of the Chela Formation is gradational into the salt, whereas the base of the Chela unconformably overlies older pre-salt units. The regional pre-Chela unconformity corresponds to the "break up unconformity" developed as a direct response of Gondwanaland rifting that resulted in the opening of the South Atlantic Ocean and culminated with the separation of the South American and African continents. (Abstract shortened by UMI.)