Patent ID: 9097110
Filing Date: 2015-08-04
Classification: E21B

Abstract:
1. A method of recovering oil from a viscous oil reservoir, the method comprising: receiving electrical power from an electrical grid which is fed by at least one fluctuating electricity supply; generating steam by heating water within a first fluid stream with an electrical heater that is powered by at least a portion of the received electrical power; adjusting a heat output from the electrical heater to at least partially correspond with an estimated excess power supply on the electrical grid; generating steam by heating water within a second fluid stream with fired-heater; adjusting a heat output from the fired-heater to at least partially compensate for fluctuations in the electrical heater heat output; injecting the steam generated from the first fluid stream, the second fluid stream, or mixtures thereof over time into a viscous oil reservoir to mobilize the viscous oil; and producing mobilized oil from the viscous oil reservoir; wherein the fired-heater and the electrical heater are within a common vessel in a surface facility.