Pattern of Development Wells for Deep-Water Turbidity Sandstone Reservoirs in West Africa

Faced with the problems of complex connectivity and high costs of drilling and completion in deep-water turbidity sandstone reservoirs, a set of sparse well patterns with high production should be established to realize the economical and effective development for this kind of oilfield. Based on the sedimentary characteristics and the development extent of faults in turbidity sandstone reservoirs, the deep-water turbidity sandstone reservoirs are divided into three types. Based on the interwell interference test, the spacing of injection and production wells was determined, and the well patterns under different sedimentary characteristics were established. In view of the characteristics of longitudinal multi-stage turbidity channels or overlapping lobes, the well pattern of directional wells through multiple layers is proposed. For the stably and widely developed single-stage lobe reservoir, the well pattern of long horizontal wells is proposed. For the turbidity sandstone reservoir with densely developed faults, a pattern of long horizontal wells through faults and multiple sand bodies is suggested. With the application of the above well pattern, the average oil recovery of the reservoirs will exceed 45%. Hence, the efficient development under this kind of well pattern is realized. This well pattern has certain guiding significance for the similar deep-water turbidity sandstone reservoirs.