The Congo Deep Sea Fan: Enlightening Reservoir Complexity in Turbiditic Systems using 2D High Resolution Seismic and Multibeam Data

Vittori, Jaques, Elf Exploration and Production R&D, Pau, France, Bruno Savoye, Brest, France, Alain Morash, Elf E&P R&D, Pau, France, Lorette Anquelle, Elf E&P R&D, Pau, France, Francis-Lucie Spy-Ander son, Elf E&P R&D, Pau, France, and Michel Lopez, Lille 1 University, France

Abstract

The Congo deep sea fan has recently been surveyed by a unique set of data including more than 18,000 km of 2D high resolution seismic spanning the range from multibeam bathymetry to 3.5 KHz and air gun multichannel. This data set covers an area in excess of 200,000 km² from the canyon head to the most recent depositional lobes 700 km downslope. In this two year project co-sponsored by ELF and IFREMER, the construction and lateral evolution comprehension of the recent fan has been our primary target and a chronostratigraphic and architectural model has been established through careful mapping and picking.

More recently however, emphasis has been put on detailing specific morphologic features with strong downstream reservoir implications. Where possible, shallow reservoir geometries have been enhanced by comparing the newly acquired profiles with existing 3D. Multibeam coverage of the lower part of the canyon shows strong similarities with seismic attribute maps of structurally controlled turbiditic channel complexes. The same data acquired over complex lobe and channel avulsion zones has ascertained some of the models used for prospect understanding and evaluation but also for 3D reservoir modeling in ELF Geocenter. Particular sub-kilometer scale morphologic features recognized in the levees have been mapped, and sedimentary and/or structural processes responsible for such geometries have been reviewed.