ABSTRACT
This paper presents the results of a comprehensive study of Mobil's MOCO-T air combustion project in Kern County, CA. Since initial air injection in January 1960, over 63 BCF of air have been injected, representing over 30 times the estimated pore volume of the burned regions at 500 psig. Cumulative oil production to date is approximately 16.5 MMBO. Recent increases in project maintenance costs, excessive waste gas production and treatment expense, as well as new regulatory limitations on hydrocarbon emissions prompted a review of the technical and economic viability of the project.
The study centered around the estimation of current incremental oil due to air injection, which was derived using several analytical and empirical methods. The relative contributions of other potential recovery mechanisms were estimated analytically. The sum of these predicted contributions matched the cumulative production quite well. In addition to estimating volume of oil produced by combustion, theoretical burn volumes were calculated and mapped for each of six reservoir subzones. These maps were confirmed using well log and field data.
Several economic scenarios, including status quo operation, project expansion, and suspension of air injection, were investigated. Where possible, actual operating cost and revenue data were used.
