Abstract: Deep-water turbidites, due to their genesis, often display dramatic lateral variations, which makes the internal connectivity of the reservoir relatively complex. In deep-water exploration, flow barriers play a very important role in not only connectivity, along with other main factors, but also in effects of water injection between wells. Therefore, it is important to study how to depict flow barriers inside a reservoir between channels, and to characterize connectivity within a sand-body to optimize well locations and improve efficiency of water injection. Through a comprehensive study of the outcrops of gravity flow in the Gannan Area of China, along with logging, seismic, and production data of the Z group in the AKPO Oilfield in Nigeria, we analyze the formation of flow barriers, their distribution within sand bodies in complex water channels, and their effects on water injection. The results show that, for the injection and production well pairs, flow barriers that affect the sand-body connectivity exist in scatter, linear, and composite patterns. The patterns of the effects of injection and production can be linear, wavy, and scattering; the increase in water cut also differs in production wells of different injection and production patterns.

Key words: deep-water oil exploration, turbidite, flow barrier, connectivity, connectivity mode, outcrop in Gannan Area