The Discussion Of The Displacement Efficiency Evaluation Methodology Of The Water Drive Sandstone Reservoir In the Wenchang Oilfield

The actual recovery degree of the high permeability reservoirs in Wenchang A oilfield is 67.9% now, which is much larger than the measured value of early core water displacement efficiency of 57.21%. Therefore, the traditional water displacement efficiency is unreasonable, on the other hand, the core water displacement efficiency is 81.73% recently. The microscopic study of water flooding shows that, the water drive is a process of rebuilding the reservoir. With the changes of wettability, pore structure and property about reservoirs, the water displacement efficiency is changing. In this text, water displacement efficiency is divided into static state and dynamic state. The dynamic oil displacement efficiency is used to describe the water displacement efficiency in same stage of water drive sandstone reservoirs, and the artificial simulation and reservoir engineering methods are established combined with the dynamic oil displacement efficiency evaluation technology. The research results show that dynamic water displacement efficiency is gradually increased with water drive multiple increased. Finally, the dynamic water displacement efficiency is applied to the numerical reservoir simulation, and the two-phase fluid flow dynamic model is established.The non-uniformed displacement pattern is realized in the numerical simulation, which is more in line with the law of reservoir development, and the refinement numerical simulation research is realized to improve the understanding accuracy of oilfield residual oil.