Numerical Study of the effect of inlet velocity on oil reservoirs water flooding process at pore scale for different surface wettability

Every year, more oil reservoirs experience pressure drop and production rate decreases. The water flooding process is one of these conventional methods to increase oil production. The velocity of the injected fluid into the porous medium under different physical conditions can extract different amounts of oil from the pores. Due to the spatial geometry and composition of the pores, the velocity of the fluid entering each pore has a wide range. In this study, the effect of fluid velocity in three pores with hydrophilic, hydrophobic and neutral wettability surfaces has been investigated. This was done using numerical simulation with ANSYS-Fluent software at the scale of a 1 mm pore containing medium viscosity oil. The results of this study show that for a pore with single output in the state of hydrophilic cavity and neutral wettability, all oil is removed from the pore at all speeds. But for a pore with two outlets, only if the surface of the hole is hydrophilic, all the oil is removed, and for the pore with neutral wettability, 78% of the oil volume is removed. For the pore with hydrophobic surface, less oil was removed from the pore by increasing the velocity of the inlet fluid and the recovery coefficient was achieved between 63.7% and 98.5%.