Evolution of Deep-Water Sinuous Channel Offshore Cameroon, West Africa, Using 3D Seismic Data

Anh Ngoc Le

doi:10.46717/igj.54.1f.2ms-2021-06-22

Abstract

Using newly acquired 3D seismic data, the deep-water sinuous channel has been discovered in the Miocene sequence on the continental margin of Cameroon, West Africa. The investigation is using high-resolution 3D seismic data, covering an area of 1500 km2, with the water depth ranging from 400 m - 2000 m. Two submarine channel systems have been documented in the northern part of the study area, the offset stacked channel and North-Northeast – Southwest channel. The offset stacked channel dimension is about 3 km wide, c. 20 km long and c. 500 ms TWT thick, extending from east to west. The evolution of this channel can be divided into three stages based on the changes in channel scale, geometry, and fill type. In the initial stage, the channel is characterized as symmetry ‘U’ shaped, bidirectional onlap, high amplitude reflections, inferring to high energy flow and sand-prone channel fill. In the following stages, the channel reduced the size and flow energy. North-Northeast – Southwest channel developed at the end of the Miocene. It is c. 3 km wide, 20 km long, 50 ms TWT thick, indicating a new sediment source for the study area. At the end of the Miocene, both channel systems show a high sinuously as an indicator of low energy flows. Uplift in the Late Miocene possibly leads to the compacted channel complex which is appeared in the anticline form, giving a great hydrocarbon trap potential for the study area.

Highlights

With the development of high-resolution 3D seismic techniques, nowadays, deep-water processes have a much better understanding
Two channel systems have been discovered in the northern area including offset stacked channels and N-NE – SW channels (Figs. 4 & 5)
While the offset stacked channel shows a long-term development in the entire Miocene, the N-NE –SW channels developed in the Late Miocene

Summary

Introduction

With the development of high-resolution 3D seismic techniques, nowadays, deep-water processes have a much better understanding. The interest in the submarine channel, the main element to transport material from shallow to deep water, has got more attention lately (Posamentier and Kolla, 2003; Gee and Gawthorpe, 2006; Gee et al 2007; Macauley and Hubbard, 2013). In West Africa, submarine channels have been documented in offshore Angola (Gee and Gawthorpe, 2006), Congo (Gay et al, 2003), and th e Niger delta (Zhao et al, 2018). They are often characterized as channel complex with levees.

Methods

Results

Discussion

Conclusion