Numerical Model of the Production Behavior for the Ordinary-type Water-dissolved Natural Gas Reservoir During Water Reinjection

Abstract

This paper presents a numerical model to predict the proceeding of the reinjection water front within the Ordinary-type water-dissolved natural gas reservior. The model decribes two dimensional flow of gas and water through the reservior. Dilution of dissolved gas by the mixing of water poor in gas has been taken into account, and the decreasing gas concentration can be esimated by considering the process as a variable bubble-point problem.
Numerical dispersion caused by solving the flow equation with finite difference method is discussed. A calculation example shows the difference between the results by this model and the traditional one phase model for the production gas water ratio and the bottom-hole pressure.