Geochemical evaluation of source rock potential of formations penetrated by Muamba-1 well in block 5, Kwanza Basin, Angola

Abstract

This study addresses the challenges posed by unsuccessful exploration in Block 5 of the Kwanza Basin, Western Angola, and sought to evaluate source rock constraints affecting the development of petroleum potential herein. It employed geochemical techniques, centering on the Muamba-1 Well, to provide a comprehensive analysis of the geochemical factors influencing hydrocarbon prospects in the region. The analysis methodology involved the use of geochemical techniques, utilizing source rock extracts and gas chromatography data. The study covered the entire stratigraphy penetrated by the Muamba-1 Well, enabling a thorough examination of the source rock constraints within Block 5. The results obtained reveal that the Cuvo, Binga, Mucanzo and Catumbela Formations exhibit good to excellent source rock potential. In contrast, the Upper Bucomazi Formation indicates poor potential. The Cuvo, Binga and Mucanzo Formations show mixed gas and oil potential, with a prevalence of gas, while the Catumbela Formation predominantly demonstrates oil potential aligning with their respective depositional environments. Despite the rich organic matter content and favorable potential, the generation potential in Cuvo is low, primarily immature in regards to petroleum generation. In this context, the Binga and Mucanzo Formations stand out as the only mature zones with Catumbela placed in immature zone. Depositional environment results suggest that the Binga and Mucanzo Formations exhibits both terrestrial and marine organic matter deposited in oxic to sub-oxic conditions, while Catumbela Formation contain marine/algal organic matter deposited under reducing conditions but subjected to biodegradation. The geochemical study of Muamba-1 Well Formations provides valuable insights into the understanding of source rocks in Block 5. Findings derived from the analysis of geochemical data across all five major Formations intersected by the Muamba-1 Well indicate a spectrum of source rock potential in Block 5, ranging from poor to good.