Modeling the water transport in water invasion channel with water invasion unit numerical simulation based on intelligent proxies

For gas reservoirs with edge water, water easily transport into the gas reservoir along the water invasion dominant channel, which results that the water production is higher than expected during the development of gas wells, and then affects the production of gas wells. We had derived a water invasion unit numerical simulation model of oil–water two-phase (WINS). It simulated the water invasion dynamic change in the hyperosmotic zone. But the Buckley–Leverett water flooding front propulsion equation is no longer applicable to the saturation tracking method in the gas reservoirs. The main reason is that the fluid transport between the gas–water two-phases is different from the traditional incompressible fluid transport. In this paper, a new water invasion unit numerical simulation method based on intelligent proxies and optimal control theory in complex gas reservoirs (WINS-G) is proposed. Compared with the WINS, the saturation tracking method of water invasion channel is improved. And it demonstrates a new insight into the water transport in water invasion channel. Through the discussion of model fitting efficiency, it is found that the number of invalid grids is reduced by WINS-G based on the idea of proxy model, and the work efficiency is improved by automatic history fitting on the basis that the model can meet the basic requirements of accuracy.