Abstract: The Lower Congo Basin has developed large-scale deep-water channel deposits, which are the primary type of hydrocarbon reservoirs. To address the unclear understanding of the internal channel unit stacking patterns and migration modes, a study on deep-water channel deposition models was conducted. This research utilized three-dimensional seismic data and RGB spectral decomposition attribute fusion techniques to investigate the sedimentary characteristics of different channel architectural levels and reconstructed the depositional process of turbidite channels in the study area. The key findings are as follows: the study area is characterized by a down-stepping confined channel system, comprising three phases of aggradational and progradational complex channels. The lower complex channels exhibit planar straight geometries with vertically stacked individual channels, while the middle complex channels form low-sinusosity belts with laterally stacked individual channels. The upper complex channels show high-sinusosity and meandering planar geometries, with individual channels laterally connected or isolated. These three phases of compound channels correspond to three stages: erosional base, main deposition, and late abandonment. Reservoir formation occurred during the main depositional stage of the channel system. This study clarifies the sedimentary characteristics and stacking patterns of different channel architectural units, and establishes a depositional model for deep-water channels in the study area. The findings hold significant geological implications for the development strategies and efficient production of similar hydrocarbon reservoirs.

Key words: Lower Congo Basin, deep-sea channel, constitutive patterns, sedimentary processes, RGB spectral decomposition fusion