Controls On Sequence Development and Preservation Offshore Namibia: Implications For Sequence Stratigraphic Models and Hydrocarbon Prediction

Joanne G. Bagguley and Sarah Prosser

Regional seismic interpretation of the passive margin offshore Namibia has enabled a sequence stratigraphic framework to be established for this previously understudied region. Within this framework potential hydrocarbon plays -- for example the location of source, seal and reservoir rocks -- can be pin-pointed.

The history of sequence stratigraphic models suggests that the passive margin offshore Namibia should provide an ideal setting for applying and testing sequence stratigraphic concepts. Results from this study however suggest that alongside the documented controls in sequence stratigraphy (i.e. tectonics, eustacy and sediment flux), additional factors act to influence sequence development and preservation along this margin.

Detailed seismic interpretation of the post rift section of the Namibian margin has led to the identification of a number of erosional and depositional events; for example, channels, canyons and slumps. Seismic facies analysis allows causative mechanisms to be inferred for the different geometries observed. In addition, the recognition of characteristic seismic facies enables reservoir and non-reservoir targets to be identified, thus aiding the prediction of potential hydro carbon plays.

Backstripping studies provide further information as to the evolution of the Namibian margin. For example, estimates can be made regarding changes in the rates of tectonics and sedimentation and the relative importance of these factors on the development of the margin can assessed.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California