An Improved Study of Emulsion Flooding for Conformance Control in a Heterogeneous 2D Model with Lean Zones

Use of oil-in-water (O/W) emulsion has shown its potential for conformance control in heterogeneous porous media, yet it is essential to understand how to improve the conformance control performance in the heterogeneous 2D model with lean zones before it is applied in the fields. In this paper, an O/Wemulsion-based conformance control method is improved through newly designed flow tests and optimized modeling study. A heterogeneous 2D model was designed with a high water mobility zone (HWMZ) and a low water mobility zone (LWMZ) separated by a horizontal injection well to mimic real oil sands with lean zones (top- or bottomwater) and with application of horizontal wells. Optimal conformance control strategies were proposed and examined in the 2D model by injecting correspondingly designed O/W emulsions. In an improvement of our previously proposed emulsion flow model (Ding et al. 2020c), we introduce the real phenomena of permeability reduction (PR) coefficients in this paper to describe the three ambiguous coefficients: flow distribution coefficient (gamma), plugging coefficient (alpha), and retention rate coefficient (a). This newly developed model can incorporate with characteristics of the emulsion and the heterogeneous porous media through the introduction of the experimentally derived PR coefficient. It is well established in COMSOL Multiphysics (R) (COMSOL AB 2005), and the modeling results show good agreement with the experimentally monitored results in the three types of flow tests. This work bridges experimental and mathematical studies on emulsion flow in 2D models associated with lean zones and is able to provide a guide on optimal emulsion design and injection strategy for optimal conformance control performances.

Automated summary

This paper improves an oil-in-water emulsion-based conformance control method through newly designed flow tests and optimized modeling study. It proposes and examines optimal conformance control strategies in a 2D model with a high water mobility zone and a low water mobility zone, separated by a horizontal injection well to simulate real oil sands with lean zones and horizontal wells. The newly developed model incorporates characteristics of the emulsion and heterogeneous porous media through the introduction of experimentally derived permeability reduction coefficients.