| Hydrocarbon resource is rich in West Africa. The coast region along West Africa belongs to typical passive continental margin,which experienced three evolution stages, i.e. the pre-rifting stage during Late Paleozoic-Early Mesozoic (continental craton stage) time, the rifting stage since Middle-Late Mesozoic time and the passive continental margin stage by the end of Mesozoic -Tertiary time. Genesis of the rift in the northern part is different with that in middle-southern part of the basin in rifting time and ways. During the evolutionary process of the basin
that was controlled by the regional tectonic-sedimentary development,three main sets of source rocks and several sets of reservoir rocks developed. The source rocks include the pre-salt lacustrine shale in the rifting stage and the post-salt marine shale and the marine-delta shale in the passive continental margin stage. The reservoir rocks are the lacustrine clastic rock in the rifting stage, and carbonate rock, shoreside sandstone, turbidite and deltaic sand stone in the passive continental margin stage. The Aptian salt rock acts as the main regional cap and various struc tures and traps form, such as fault-blocks, fault-anticlines,salt structures, rolling anticlines, growth fault and others,which control the hydrocarbon enrichment and distribution in the coast region. |
