Process for recovery of oil

Claim 1

IN A PROCESS FOR INCREASING THE PRODUCTION OF OIL FROM AN OIL-BEARING FORMATION PENETRATED BY A PRODUCTION WELL AND A HEATER WELL SPACED FROM THE PRODUCTION WELL, THE IMPROVEMENT COMPRISING DRILLING THE HEATER WELL WITHIN THE DRAINAGE AREA OF THE PRODUCTION WELL AT A DISTANCE OF FROM ABOUT 50 TO ABOUT 100 FEET, INJECTING HEAT INTO THE FORMATION AT THE HEATER WELL AT A RATE SUFFICIENT TO RAISE THE BOTTOM HOLE TEMPERATURE IN THE PRODUCTION WELL TO AT LEAST 200*F. WITHIN TWO WEEKS AFTER CONNECTING INJECTION OF HEAT AT THE HEATER WELL TO FORM A ZONE HAVING A TEMPERATURE GREATER THAN 200*F. AROUND THE PRODUCTION WELL, THEREAFTER REDUCING THE RATE OF INJECTING HEAT INTO THE FORMATION AT THE HEATER WELL WHILE PRODUCING OIL AT DUCTION WELL, AND CONTINUING THE INJECTION OF HEAT INTO THE FORMATION AT THE HEATER WELL WHILE PRODUCING OIL AT THE PRODUCTION WELL TO MAINTAIN THE TEMPERATURE IN THE PRODUCTION WELL IN THE RANGE OF 200* TO 600*F.