Downhole combustion unit and process for tecf injection into carbonaceous permeable zones

Abstract

A downhole combustion unit for creating a high temperature, high pressure, thermal energy carrier fluid or TECF inside a drill hole, which can be injected into a hydrocarbon, permeable zone for mining and producing hydrocarbons therefrom. The combustion unit includes an outer well-bore casing cemented in place in the drill hole. An inner well-bore casing, with injection holes in a lower portion thereof is used as a combustion chamber. The inner casing is suspended inside the outer casing. The configuration of the concentric outer and inner casings provide an outer annulus therebetween for receiving a natural gas fuel and water mixture from a ground surface and circulated downwardly under pressure. Compressed air and steam are circulated down the inside of the inner casing. A glow plug may be attached to a lower end of an electric power cable and suspended inside the combustion chamber for better control in igniting the fuel and water mixture in the compressed air and steam mixture creating the TECF. The TECF is discharged out the bottom of the combustion unit and into a permeable, hydrocarbon zone.