Numerical Simulation of an Enhanced Oil Recovery Process of Toe to Heel Air Injection (THAI)

Abstract

This paper offers an innovative method to test various scenarios for toe-to-heel air injection wells, to meet the demands for new technology and methods using in-situ combustion coupled with steam injection. It presents research conducted over the last few years on the numerical simulation of the toe-to-heel air injection enhanced heavy oil recovery process. Reservoir simulations were used to evaluate multiple variables and scenarios, leveraging the integrated workflow capabilities of software while maximizing the effective time for performance analysis. Included are discussions of the workflow process, a description of base model details, well array testing results (i.e., four patterns combining horizontal and vertical wells), a comparison of injection air rate in the toe-to-heel air injection process versus a conventional in-situ combustion method, and sensitivities in oxygen concentration and injection rate, which led to increased recovery through the application of toe-to-heel air injection technology. The effects of heterogeneities on the development of the toe-to-heel air injection process are also examined, along with multisegmented well model benefits demonstrated in the reservoir simulation software tool (ECLIPSE). Additionally, coke deposition during combustion was simulated, showing that toe-to-heel air injection does not affect the fluid flow dynamics process. Based on our research study, this analysis of the best scenario for toe-to-heel air injection well placement efficiently produces nonconventional hydrocarbon accumulations by delivering increased process control on the combustion front.

Analyzing Chemical Reaction Models for in Situ Combustion Process

“…The analysis of Qinj generally aims at conducting an economic study of a project, since the injection of air could slow or stop after the production of the bank of oil (Green & Wilhite, 1998;Prats, 1982;Rojas et al, 2010).…”