Hot-Water Drive

As hot water for secondary recovery need only fulfill injection requirements, supply and treatment problems are less severe than those of steam-boiler feed water. Salt water can usefully be employed and may even be of advantage in the case of swelling clays. Field observations and laboratory studies indicate a very efficient heat utilization. Under suitable conditions, at least 50% more oil may be recovered than with cold-water drive. There is doubt about the ultimate recovery because of a tendency to lateral instabilities. Preventive measures to combat this tendency are discussed.