The oil droplet displacement behavior under pressure driven water flooding has been investigated by using molecular dynamics (MD) simulation. The oil (dodecane) and water (SPC/E) model have been first validated by comparing the PVT properties with the NIST web-book data. Then the temperature dependence of surface tension (IFT) of oil/water system has been studied. There is a around 11% decrease in IFT with increasing temperature from 283 to 360 K at P = 1 atm, where IFT reaches to 46.28 mN/m. For water flooding simulation, the interactions between water, oil and silica pore surface have been investigated. The simulation results show water average superficial velocity is proportional to the external force exerted on water molecules, or the pressure gradient. The oil displacement speeds (vs) has also been determined, and it finds a proportional relation between vs with the pressure gradient. The droplet deformation has been characterized by the advancing and receding contact angle.