Depositional Elements of Deepwater Channels and Their Evolution

Deepwater channel deposits have been a kind of significant exploration target in recent oil and gas exploration. To study the depositional elements of the deepwater channels and their evolution has, therefore, become an important task for geologists. In this paper, deepwater channel elements of the Lower Congo Basin were selected as cases for study, based on seismic attribute maps and seismic facies analysis from 3D seismic data. The integrated analysis reveals that channels filling deposits consist of five elements, including basal lag deposits, slump deposits, LAP, levee deposits, and abandoned channels from bottom up. Each channel suffered an evolution of five stages, i.e. channel incision, lateral amalgamation, aggradation, levee deposition and abandonment with time. The evolution of channels is controlled by sea-level fluctuation, development of gravity flow and slope equilibrium.