Case Histories of Three In-Situ Combustion Projects

Abstract

All three of these Texas thermal recovery projects-Glen Hummel, Gloriana, and Trix-Liz-are engineering and economic successes. As with any advanced recovery process, such success is due mainly to a thorough understanding of the reservoir geology, the mineralogy, and the fluid system as they apply uniquely to each reservoir, and to the application of this understanding to project design. project design. Introduction During the past 60 years many schemes have been proposed for increasing the rate and ultimate yield proposed for increasing the rate and ultimate yield from petroleum reservoirs. The most promising methods have received research attention and some have been field tested. The general consensus is that no single oil recovery method can be optimally applied to all reservoirs. The selection of a displacement process, whether it be solution gas drive, gravity process, whether it be solution gas drive, gravity drainage, waterflooding, gas drive, miscible displacement or thermal recovery, is based on a combination of technical and economic factors. Historically, the most economically successful process for supplementing recovery energy has been process for supplementing recovery energy has been waterflooding. However, waterflooding, although monetarily rewarding in most cases, does leave in the reservoir a relatively large percentage of the oil originally in place. Much effort has been directed by the industry toward understanding and reducing the proportion of the original oil remaining in the proportion of the original oil remaining in the reservoir when the reservoir's economic productive limit is reached. As a result of this effort, several advanced processes have been researched and field tested. processes have been researched and field tested. The advanced oil-displacement processes can be classified into three broad categories:1. Thermal recovery processes, which convert arelatively small fraction of the in-place orproduced oil by a kinetic reaction to energy forreducing the viscosity of the rest of theremaining oil,2. Miscible displacement processes, which concentrateattention on the crude-oil properties,3. Sophisticated waterfloods, in which the physicalproperties, such as the viscosity, surfacetension, and density of an aqueous displacingphase are manipulated. In-situ combustion has been demonstrated to be a viable recovery process in crude-oil systems having gravities ranging from 12 degrees to 40 degrees API. This process has already undergone extensive field testing in a process has already undergone extensive field testing in a wide variety of reservoirs. The management of the in-situ-generated heat and the distribution of air flow has been improved through the simultaneous injection of air and water and through rate control of producing wells. Glen Hummel In-Situ Combustion Project The Reservoir The Glen Hummel field, situated in Wilson County, Tex., was discovered in Oct., 1963. The reservoir is Eocene in age and is in the Poth "A" sand formation of the Upper Midway group. The development of the field was completed in early 1965 with the drilling of 32 producing wells. The average depth of the Glen Hummel reservoir is 2,432 ft subsurface. The reservoir dips from northwest to southeast approximately 200 ft over a distance of 5,000 ft. The reservoir was formed by a stratigraphic trap bounded on the northwest, or updip side, by a sealing fault, and on the southeast, or downdip side, by an inactive aquifer. The lateral extremities of the reservoir are terminated by thinning out of the sand into shale. P. 784