A Prediction Method for Conduction Heating of Reservoirs by Steam Injection

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the 42nd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Oct. 1–4, 1967. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. 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, with the paper, may be considered for publication in one of the two SPE magazines. A method of reservoir heating involving heat conduction from a thin steam channel within the pay has been investigated. Solutions using a simplified heat flow model are provided to estimate steam injection rate, growth of steam zone and temperature distribution as a result of injecting steam into either a fracture or a thin section of the pay. Equations are also presented to obtain temperature distribution after termination of steam injection. Calculated results show the effects of injection rate, temperature, pay thickness, and well spacing. The conduction heating process can be applicable for raising the entire reservoir to a moderate temperature in a relatively short time. Other advantages over the conventional steam drive are also discussed. It has been shown that a direct steam drive operation which degenerates into steam channeling through a thin section of the pay can be carried on as a conduction heating process. Introduction A direct steam drive process which requires that steam flows through the entire vertical section of the pay suffers from a number of disadvantages. A large quantity of heat is needed to move the steam front through a reservoir, especially with thick pay and high steam temperature. Heat losses into the under and overburden formation also retard the movement of the steam zone. Unless the well spacing is close and/or a very high steam injection rate is used, the project can be too long to be economic. In addition, many heavy oil reservoirs are unsuitable for the direct steam drive process because the oil viscosity is too high. While the oil viscosity in the hot water bank ahead of the steam zone is reduced, the interwell area or the region around the producing wells remains at the original reservoir temperature with no reduction in oil viscosity. Therefore, the oil production rate remains relatively low for a good portion of the project life. A thermal recovery technique called conduction heating may overcome these disadvantages by providing a rapid means of heating a reservoir.