This paper was prepared for the Improved Oil Recovery Symposium of the Society of Petroleum Engineers of AIME, to be held in Tulsa, Okla., April 22–24, 1974. 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 paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made. 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 discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract A combustion drive project has been underway for 1-1/2 years at Brea-Olinda, Orange County, California. Air injection was commenced in one fault block early in 1972, and in a second adjacent block early in 1973. One compressor supplies 5 MM scf/d of air to the two injection wells at a maximum pressure of 1200 psig. About 22 production wells are in communication with the two injection wells as evidenced by increased hitrogen in their produced gas. So far, the large increases in oil production have occurred in wells downstructure from the injection well in the first fault block. The original injection well for the second block has been replaced by another well nearer the top of the structure in an attempt to improve oil recovery from that block. The reservoir is First Miocene sand dipping 45 degrees at depths of 3000–4000 feet. Oil gravity is 22 degrees API. Oxygen utilization is 100%. Spontaneous ignition occurred in about one week. Principal Conclusion: Principal Conclusion: We believe that burning from the top down in a steeply dipping reservoir maximizes oil recovery. Introduction Fireflooding has been extensively pilot tested by the industry during the past two decades. Sufficient information is now available to make it possible to select reservoirs from which fireflooding will recover economic amounts of additional oil. As with other secondary and tertiary recovery methods, technological success (stimulated oil recovery) may occur with or without economic success (profit). The desire to recover more of the oil in place from fields before they are abandoned will favor the use of fireflooding where applicable. Increases in the price of crude oil, supporting larger production costs, will make fireflooding appear promising in some of the fields for which it has been rejected in the past as insufficiently rewarding. The information in this paper is presented in the spirit that these increased expectations for fireflooding are real and enduring. HISTORY OF DEVELOPMENT OF BREA OLINDA The discovery well at Brea-olinda was completed about 1884. The field is now credited with 2,300 proved acres (FIGURE 1). Oil production has been about 350,000,000 barrels from more than 1,250 wells.