Patent ID: 8327932

Claim:
A method of recovering energy from a subsurface hydrocarbon containing formation, comprising: introducing an oxidizing fluid in a wellbore positioned in at least a first portion of a subsurface hydrocarbon containing formation, wherein at least a part of the first portion of the subsurface hydrocarbon containing formation has been subjected to an in situ heat treatment process prior to introduction of the oxidizing fluid, and wherein the part comprises a treatment area comprising elevated levels of coke substantially adjacent the wellbore; increasing a pressure in the wellbore by introducing the oxidizing fluid under pressure such that the oxidizing fluid substantially permeates a majority of the treatment area and initiates a combustion process; allowing heat from the combustion process to transfer to some of the fluids in the treatment area; decreasing the pressure in the wellbore such that at least some heated fluids from the part of the formation are conveyed into the wellbore; and transferring the heated fluids conveyed into the wellbore to the surface to a heat exchanger configured to collect thermal energy.