Thermal recovery steam in-situ burning

The past year saw the greatest expansion of steam projects in California since secondary-recovery engineers began experimenting with steam in earnest some 5 yr ago. Of the state's 41,000 oil wells, perhaps 6000 felt or were scheduled to feel the impact of steam. It is estimated that something like 300 steam generators presently are a work, representing double, or more, the number at work a year ago. The guidelines to success in steam injection include the following: (1) depth no greater than 3000 ft, and preferably shallower; (2) net sand thickness of at least 50 ft; (3) reserves of at least 1200 bbl per acre-ft; (4) reservoir pressure sufficient to move production quickly; and (5) low water-oil ratio to minimize heat loss. A history is given of each field where thermal-recovery methods are being practiced. Although steam soaks hold the spot light, firefloods continue to expand in California. Many engineers predict that fire, not steam, will be the ultimate tool in cleansing the state's shallow, low-gravity oil sands of their last drops of oil. A list of those projects presently active is given.