The petroleum potential of the passive continental margin of South-Western Africa : a basin modelling study

• Main Author: Schmidt, Sabine
• Other Authors: Littke, Ralf
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Publikationsserver der RWTH Aachen University 2004
• Subjects: info:eu-repo/classification/ddc/550; Namibia; Kontinentalrand; Kohlenwasserstofflagerstätte; Prospektion; Muttergestein; Geochemie; Geowissenschaften; Beckenmodellierung; Kohlenwasserstoffpotenzial; Südatlantik; Kudu; organische Geochemie; Muttergesteine; South Atlantic Ocean
• Online Access: https://publications.rwth-aachen.de/record/59749; https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121508%22

The Petroleum Potential of the Continental Margin of South-Western Africa - A Basin Modelling Study The hydrocarbon potential of the continental margin of south-western Africa was assessed with means of a 2D basin modelling study of the hydrocarbon generation, migration and accumulation of the Kudu gas field. The basin model is based on well and seismic data from offshore Namibia and constrained by geochemical data on source rocks, natural gas samples and hydrocarbons desorbed from near-surface sediments. The modelling was conducted with the basin modelling software PetroMod (IES, Germany). The source rock samples investigated in this study originate from different phases concerning the opening of the South Atlantic Ocean. Lacustrine source rocks deposited during the Permian prerift phase are represented by the Whitehill and Irati shale samples from onshore Namibia and Brazil, respectively, and by samples from the Cruz del Sur well, offshore Argentina. Marine and terrestrial source rocks of Barremian to Aptian age deposited during the drift phase of the Atlantic opening were drilled in the wells Kudu 9A-2, Kudu 9A-3 (offshore Namibia), DSDP 361 (offshore South Africa), and Cruz del Sur (offshore Argentina). High petroleum generation potential was recognised for marine Aptian rocks from the DSDP 361 well, Neocominan and Paleozoic rocks from the Cruz del Sur well and for Permian lacustrine Irati shale samples. The dry Kudu gas with only minor condensate quantities is reservoired in the feather edge of a seaward dipping reflector sequence in predominantly aeolian sandstones. Remarkable about the gas field is that its reservoir is overlain by Aptian shales which are supposed to act as seal and source rock simultaneously. The 2D basin model confirms the possibility of downward hydrocarbon expulsion from the Aptian source shales in the underlying Aptian to Barremian reservoir. The downward expulsion is driven by the pressure gradient between the due to hydrocarbon generation high pressured shale and the lower ...