Comeback for fire floods

For awhile in the 1950's, it looked as if the symbol of the campaign to stimulate California's lazy oil would be the air compressor, which furnished the air necessary to support underground combustion in a number of pilot fire floods. Then in the 1960's the steam generator took over, quickly displacing the air compressor as the trend in thermal recovery swung to steam. Now it seems as if fire floods may be on the way back. In situ combustion will recover 20 to 30% more oil than steam at no different operating cost, with little difference in capital investment, and under a wider range of reservoir conditions. In situ combustion has demonstrated capability of handling as much as 100 ft of sand, gravities from 10$ to 38$, and depths as great as 5,000 ft. An operation can look forward to recovering 35 to 50% of the oil in place at the time the burn was started, compared with a range of 25 to 40% for steam. Production is tied to the amount of air going into the ground. Once that has been built up to capacity, there is a constant rate of production almost to the end of the lifemore » of the property without the rapid peaks and rapid tail-offs of steam. Several in situ combustion operations are listed and described.« less