Performance of Thermal Recovery Processes in a Middle Eastern Reservoir

Abstract

Abstract Primary oil recovery is usually very low which leaves large quantities of oil retained by capillary and viscous forces. Enhanced Oil Recovery (EOR) techniques are used to recover these retained hydrocarbons volumes. Thermal recovery is an EOR technique which is usually used to enhance oil production from heavy oil reservoirs. In thermal recovery methods, hot fluids, such as steam or hot water, are injected into hydrocarbon strata to reduce the retaining forces responsible for oil entrapment and enhance recovery efficiency. In Middle East, heavy oil deposits are encountered in many countries. The maturity status of the current major oil producing fields in addition to the current high energy demands are main contributors to the current interest in developing heavy oil resources. Therefore, the need to predict the performance of thermal EOR processes in these heavy oil accumulations is of a major importance. The targeted reservoir in this study occurs at shallow depths, ranging from 500 – 1000 feet and is widely spread. Apart from two cyclic steam stimulation pilots conducted during the 80';s, this reservoir was left undeveloped for the past years due to the high sulfur content and extraction cost. The findings of these pilots indicate the suitability of this reservoir to thermal recovery methods. In this paper, the performance of hot water flooding, in a sector area of the targeted reservoir is simulated under different well arrangements. Various reservoir/design parameters were considered to evaluate the cumulative oil recovery in terms of the cumulative heat injected. The results show some cases where the economics of thermal recovery applications can be improved by a proper heat management. Moreover, the paper highlights the functional relationships between cumulative oil recovery and cumulative heat injected under the investigated reservoir/design parameters.