Thermal stimulation ups injection rate 800% in Indiana field

Thermal stimulation of water-injection wells in a waterflood being considered for abandonment has improved injection rates by 800-1,000% and increased oil-production rate by 85%. Besides these rate increases, results of the thermal-stimulation treatments showed that improved injection profiles can be obtained; desired injection rates are possible at lower pressures; injection-well density can be reduced in some cases; and cost is low enough to substantially improve waterflood profits. In general, the treatment consists of clearing the casing and the well bore of fluids at a maximum air-injection rate, staying within pressure limitations. Crude oil is then injected into the well and displaced into the reservoir. The heater is then lubricated into the well and turned on while maintaining the injection rate of the crude oil. Temperature is gradually increased from 800$ to 1,000$F. by reducing the injection rate. Combustion is continued for 10 days, at which time the heater is pulled and water injected. Six injection wells have been treated in this reservoir with injection-rate increases averaging 800% and 3 wells exceeding 1,000%. Oil production increased approximately 85% as a result of the improved injection rates. A graph summarizes the treatment results.