Permeability characterization and directional wells initial productivity prediction in the continental multilayer sandstone reservoirs: A case from Penglai 19-3 oil field, Bohai Bay Basin

Based on study on the main factors affecting the initial productivity of directional wells in multilayer sandstone reservoirs of Penglai 19-3 oil field, a permeability interpretation model based on lithofacies constraint was established, and an initial productivity prediction formula for directional wells in offshore multilayer sandstone reservoirs was derived. Permeability and oil saturation are the main factors affecting initial productivity of directional wells in Penglai 19-3 oil field. Using core, scanning electron microscope, casting thin section, logging and production data, and a new permeability interpretation model considering the influence of macro sedimentary characteristics and microscopic pore structure was built. On the basis of permeability correction, resistivity increase ratio is introduced to characterize the effect of oil saturation, to modify the Vandervlis productivity formula of directional wells to get an initial productivity prediction equation suitable for continental multilayer sandstone reservoirs. The study results show that the permeability considering petrographic constraints and the production forecasting formula including resistivity increase ratio are more accurate.