In Situ Combustion In Combination With Water Flooding

Abstract

Publication Rights Reserved This paper is to be presented at the 39th Annual Fall Meeting of the Society of Petroleum Engineers on Oct. 11–14, 1964, in Houston, Tex., and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper. Abstract This paper presents the results of a tube run analysis of a two-stop recovery process-in situ combustion followed by a water flood. Recovery under the process has been studied as a function of oil gravity and the timing of the switch from air to water injection. The effect of these variables on the burning, steam flooding and hot water flooding phases of the process is discussed. The results of the tube runs have also been compared with previously published data for the various thermal methods of recovery. The timing of the switch from air to water injection is of primary importance as it is the main determinant of the extent of the steam flood. The timing for the start of water injection limits the amount of heat generated by the burn and, therefore, the energy left behind the flame front. The longer the period of time before water injection, the greater the thermal energy for steam generation. Other determinants of the extent of steam flooding are the size of the liquid bank ahead of the burn plus the reduction in gas permeability it causes, and the distance which the bank has to move before steam break-through is possible. Introduction The thermal methods of secondary recovery have been the subject of many articles and patents since the early 1930's. The results of these publications will not be reviewed by this paper except as background for and in comparison with the results of the experimental work to be reported. For a general review of the thermal processes, the reader is referred to the paper recently published by Gates and Ramey. For the reader who desires a more detailed look at the processes the papers by Martin et al and Wilman et al are recommended. Gates and Ramey mention some of the variations on the combustion recovery process and point out that little data is available on most of the variations. Due to the lack of data pertaining to the combination of in situ combustion and water flooding, a series of laboratory runs was undertaken to investigate the process. VARIATIONS OF THE FORWARD COMBUSTION PROCESS The variations of the forward combustion process have had two basic aims:to increase the utilization of the thermal energy generated by the combustion, andto overcome the operational limitations of the process. There are also two general types of variations. The first type maintains active combustion through-out the process, while the second type uses a two step approach with combustion active in only the first step.