THE STUDY OF CHANNEL SEDIMENT ARCHITECTURE AND EVOLUTION PATTERN OF RESERVOIR IN NIGER BASIN

As an important type of reservoir in deep water, the deep sea channel is extremely rich in oil and gas resources. In recent years, it has become a key area for deep sea oil exploration and development. However, it is still very difficult to identify and characterize the internal architecture boundaries of a channel. Based on 3D seismic, well logging and core data, the internal structural boundaries of the West African X reservoir channel are successfuly difined by this paper, as the channel evolutionary model is established. Research shows that the boundaries of the channel system in the study area can be defined by the differences in seismic facies characteristics. In a deep sea channel system, there are three types of boundaries: confined, semi-confined and unconfined; the boundaries of a composite channel can be defined according to the principle of “vertical staging” and “lateral zoning”, whereas the boundary of a single channel can be identified and characterized by changes in the amplitude of channel boundary. There are two migration modes: unilateral migration and downstream swing migration on plane, and unidirectional lateral migration on section. The channel characterized by lateral migration and the downstream swing section presents the characteristics of multi-phase swing and overlap of channels. The evolution of the channel system can be divided into four stages: initial formation, rapid development, stable development, and disappearance of the channel, corresponding to a complete sea level change cycle.