Fire flood recovery process effects upon heavy oil properties

The steady decline in proven conventional oil deposits world wide has increased the emphasis on the use of heavy oil and bitumen. Most of the heavy oil and oil sand deposits share the common problem of providing very little or no primary production. They require a reduction in viscosity of the oil to make it flow. The oil in place and the reservoir characteristics are generally studied carefully to determine the design of the recovery process most applicable to the deposit and to evaluate its potential. Many of these same characteristics are also used to evaluate the oil with respect to upgrading, refining and final usage in the form of products. A variety of processes have been developed most of which utilize heat either in the form of steam or combustion to mobolize the oil in the reservoir. These processes vary considerably from rather mild conditions for steam stimulation to quite severe for combustion recovery. Figure 1 shows a typical schematic of an insitu combustion process. Many variations of forward combustion are used in the field to produce oil. Depending upon the severity of the recovery process in the recovered oil may be similar to the oil in the depositmore » or may be highly modified (oxidized, polymerized or upgraded). A memorandum of Understanding was signed by the Governments of the United States of America, Canada and the Provinces of Saskatchewan and Alberta to study different aspects of the problems related to the recovery of oil from heavy oil and sand deposits. One phase of the study is to determine the effects of different methods of in-situ recovery on the composition of recovered bitumen and heavy oils. This paper describes the findings from a study of fireflood process in a heavy oil deposit located in the Cummings formation of the Eyehill Field in Saskatchewan, Canada.« less