Quasi-3D fracture acidizing simulation based on discrete virtual internal bond method

Abstract

Fracture acidizing (FA) is the most effective stimulation technique for carbonate reservoirs. It involves the hydro-chemical coupling process. To more efficiently simulate FA, a quasi-3D discretized virtual internal bond (DVIB) is developed, in which a certain height is assigned to each bond and the rock is considered to consist of heterogeneous quasi-3D bond cells. The fracture is allowed to transversely cut through these bond cells. The macro fracture aperture fluctuation is characterized by the various apertures embedded in micro bonds. As the acid fluid flows through the fracture, the acid dissolves the bond to widen the aperture. The bond permeability is associated with the its aperture. Through this approach, the complicated hydro-chemical coupling process is reduced to 1D bond dissolution problem, which significantly improves the efficiency of FA simulation. The simulation examples show that the acid reactant transportation, the acid etching behaviors and the fracture acidizing process can be well simulated. It provides an efficient approach to FA simulation.