Thermally-enhanced oil recovery method and apparatus

A system of apparatus for stimulating the flow of oil from a reservoir formation traversed by a bore hole,

• a well bore extending from the surface to an oil reservoir,
• an elongated cylindrical support member suspended concentrically within said well bore for supporting a downhole production string.
• electric heating means connected to said support member adjacent to said reservoir providing heat to water or steam circulated through said well bore,
• a gas turbine-driven electric generator positioned at the surface of said well bore for producing electrical power,
• heat exchange means connected to a source of water and positioned to supply water in heat exchange with the exhaust from said turbine to produce pressurized hot water,
• injection means positioned centrally within said support member and having a lower portion positioned to conduct said pressurized hot water from the surface to said heating means,
• said injection means comprising a small-diameter insulated tube enclosed at the bottom and having orifices in the side wall adjacent to said electric heating means and being adapted to expand said water to reservoir pressure and inject same into contact with said heating means to convert the water into high pressure steam, and
• said electric heating means comprising a plurality of electric resistance heaters, completely insulated electrically from injected water and formation fluids positioned circumferentially about said hot water injection tube,
• said small-diameter insulated tube being adjacent to said electric resistance heaters and adapted to expand said water to reservoir pressure and inject same into contact with said electric resistance heaters to convert the water into high pressure steam, said electric resistance heaters being the sole source of heat for vaporizing said pressurized hot water,
• means to direct said high pressure steam from said electric resistance heaters into said oil reservoir to heat the same to stimulate the flow of hydrocarbons therefrom.

An injection-heater for injecting high-pressure steam into a well formation comprising

• an elongated axially extending tubular member adapted to be secured on the lower end of a conduit supported in a well bore,
• said tubular member being enclosed at its bottom end and having a series of apertures in its side wall adjacent thereto,
• heating means comprising a plurality of elongated electric heating elements circumferentially disposed about said tubular member bottom end adjacent to said apertures,
• said electric heating means comprising a plurality of electric resistance heaters, completely insulated electrically from injected water and formation fluids positioned circumferentially about said tubular member,
• (said tubular member being adapted to receive water conducted from the surface through said conduit and to expand said water to well formation pressure and inject same into contact with said heating means to convert the water into high pressure steam, and)
• said tubular member being adjacent to said electric resistance heaters and adapted to receive water conducted from the surface through said conduit and to expand said water to reservoir pressure and inject same into contact with said electric resistance heaters to convert the water into high pressure steam, said electric resistance heaters being the sole source of heat for vaporizing said pressurized hot water, and
• means to direct said high pressure steam from said (heating means) electric resistance heaters into said well formation to heat the same to stimulate the flow of hydrocarbons therefrom.