Overview of Air Injection Potential for PEMEX
Air injection has proven successful in applications to non-fractured reservoirs and its use, in the 1990’s, was extended beyond its original heavy oil reservoir applications to include light oil reservoirs having high reservoir temperatures and appropriate oil compositions. No studies or field applications of this technology in naturally fractured reservoirs have, however, been documented in the literature.
Based on the fact that most of Mexico’s current oil production and reserves, about 97 and 70 percent respectively, come from naturally fractured carbonate reservoirs, a means for obtaining high recovery in these reservoirs is needed. Since water is limited in availability and nitrogen can be quite expensive, it was decided to assess the potential of air injection technology in such applications to Mexican naturally fractured reservoirs. An overview of the potential of this process is presented in this paper, as well as an analysis of the impact that air injection could have when compared to alternative secondary and enhanced oil recovery technologies currently feasible for application in Mexico.
Details are also presented of an ongoing project that aims first to investigate, through experimental, theoretical and numerical simulation work, the feasibility of injecting air in naturally fractured carbonate reservoirs. This comprises selecting a reservoir for evaluation, preparing a thorough reservoir description, and developing a concept by which gravity forces can mitigate the effects of the fractures. This paper will also describe plans to implement, monitor, and evaluate a pilot test in a Mexican reservoir if the process looks feasible.
Exploring and Producing Fractured Reservoirs
2004 AAPG International Conference and Exhibition Technical Program