A multiple-porosity method for simulation of naturally fractured petroleum reservoirs

This paper describes the application of the method of ''Multiple Interacting Continua'' (MINC) to the simulation of oil recovery in naturally fractured reservoirs. A generalization of the double-porosity technique, the MINC-method permits a fully transient description of interporosity flow, using numerical methods. The method has been successfully applied in the past to geothermal reservoir and chemical transport problems. In this paper, we present examples to demonstrate the utility of the MINC-method for modeling oil recovery mechanisms and field applications in fractured reservoirs. Specifically, results for water imbibition in individual matrix blocks obtained with the MINC method are compared with results from the conventional double-porosity method and with calculations using a detailed discretization of matrix blocks. The MINC-calculations are found to be accurate to better than 1 percent at all times, while double-porosity results can have large errors for matrix blocks of low permeability or large size. In addition, the MINC-method is used to match published results for five-spot waterfloods, and to study the coning behavior of a single well in the north China oil field. All results show that the MINC-method provides accurate predictions of the behavior of naturally fractured reservoirs, while requiring only a modest increase in computation workmore » in comparison to the double-porosity method. 21 refs., 15 figs., 5 tabs.« less