Significance of Large Quaternary Mass Transport Deposits on Exploration and Development of the Nile Fan, Offshore Egypt
C. Simon Newton1, R. Craig Shipp2, Ahmed Farouk3, Erik D. Scott4, and Timothy M. Farnham2
1 Dalhousie University, Halifax, NS
2 Shell International Exploration and Production Inc, Houston, TX
3 Cairo University, Cairo, Egypt
4 Shell Egypt NV, Cairo, Egypt
Interpretation of a large grid of 2D and 3D conventional seismic data on the Nile fan in offshore Egypt reveals a stratigraphically complex Quaternary section up to a kilometer thick. This near-surface section is dominated by alternating intervals of submarine channel systems and mass-transport deposits (MTDs). Regional mapping reveals at least seven large MTDs, each containing more than a 100 km3 of displaced sediment. These MTDs are older and stacked on the central Nile Fan, and become younger and offset to each other on the western Nile Fan. There appears to be a strong link between the MTDs and the location of submarine channel systems. Each of these large MTDs has a headwall scarp at the shelf edge or on the upper slope that creates a wide dip corridor of sediment evacuation. Channels systems appear to occupy these evacuation corridors immediately after most of these distinct mass failure episodes.
Understanding this regional succession of events and recognition of the resultant Quaternary stratigraphy has contributed in at least three ways to industry exploration and development of the deepwater Nile fan. First, the recognition of these relationships between submarine channel systems and MTDs is an analog for a deeper objective-level play concept. Second, more confidence is gained in identification of potential drilling hazards by understanding the regional stratigraphic significance of each depositional interval that a proposed well path will penetrate. Third, the complex and irregular seafloor is better understood in the context of its potential impact on future deployment of subsea infrastructure.