Patent ID: 7360588
Filing Date: 2008-04-22
Classification: E21B

Abstract:
1. A heater system for heating a subsurface formation, comprising: a first conduit positionable in the subsurface formation; a second conduit positioned in the first conduit; a fuel conduit positioned in the first conduit; a first oxidizer coupled to the fuel conduit and in fluid communication with the second conduit and the fuel conduit, wherein the first oxidizer is configured to oxidize a mixture of oxidant from the second conduit and fuel from the fuel conduit to produce heat and exhaust products, and wherein the exhaust products from the first oxidizer join the fluid in the second conduit to flow downstream; a second oxidizer coupled to the fuel conduit and in fluid communication with the second conduit and the fuel conduit, the second oxidizer positioned downstream of the first oxidizer, wherein the second oxidizer is configured to oxidize a mixture of oxidant from the second conduit and fuel from the fuel conduit to produce heat and exhaust products, and wherein the exhaust products from the second oxidizer join the fluid in the second conduit to flow downstream.