4678results about "Tunnel/mines ventillation" patented technology

A process is disclosed for the in situ conversion and recovery of heavy crude oils and natural bitumens from subsurface formations using either a continuous operation with one or more injection and production boreholes, which may include horizontal boreholes, or a cyclic operation whereby both injection and production occur in the same boreholes. A mixture of reducing gases, oxidizing gases, and steam are fed to downhole combustion devices located in the injection boreholes. Combustion of the reducing gas-oxidizing gas mixture is carried out to produce superheated steam and hot reducing gases for injection into the formation to convert and upgrade the heavy crude or bitumen into lighter hydrocarbons. Communication between the injection and production boreholes in the continuous operation and fluid mobility within the formation in the cyclic operation is induced by fracturing or related methods. In the continuous mode, the injected steam and reducing gases drive upgraded hydrocarbons and virgin hydrocarbons to the production boreholes for recovery. In the cyclic operation, wellhead pressure is reduced after a period of injection causing injected fluids, upgraded hydrocarbons, and virgin hydrocarbons in the vicinity of the boreholes to be produced. Injection and production are then repeated for additional cycles. In both operations, the hydrocarbons produced are collected at the surface for further processing.

A method and apparatus is disclosed for heating of formations using fired heaters. The method includes the steps of: providing a wellbore within the formation to be heated, the wellbore comprising a casing within the formation to be heated, a tubular defining, in the inside of the tubular, a flowpath for hot gases from the surface to a point in the wellbore near the bottom of the formation to be heated, and a volume between the tubular and the casing providing a flowpath for hot gases from near the bottom of the formation to be heated to the top of the formation to be heated, wherein the flowpaths are in communication with each other near the bottom of the formation to be heated and the volume between the casing and the tubular at the top of the formation to be heated is in communication with a point above the surface, and insulation for a portion of the length of the wellbore within the formation to be heated between the flowpath for hot gases from the surface to the point in the wellbore near the bottom of the formation to be heated and the flowpath for hot gases from near the bottom of the formation to be heated to the surface; and supplying a flow of hot gases to the flowpath for hot gases from the surface to a point in the wellbore near the bottom of the formation to be heated.

A combustor method and apparatus is provided. The method utilizes flameless combustion with one or more of three improvements to enhance ignition of the flameless combustor. A catalytic surface can be provided within a combustion chamber to provide flameless combustion at least in the vicinity of the catalytic surface at a temperature that is much lower than the autoignition temperature of fuel in air without the presence of the catalytic surface. Nitrous oxide or supplemental oxygen may also be used as an oxidant either instead of air or with air to reduce ignition temperatures. Further, electrical energy can be passed through the fuel conduit, raising the temperature of the conduit to a temperature above which the fuel will ignite when combined with the oxidant.

A method and apparatus are described for creating a fluid seal in a subterranean well structure having a fluid seal defect. The method comprises introducing a meltable repair material proximate a structure in a subterranean well which has a fluid seal defect or enhanced seal capacity is required or it is desired to temporarily or permanently hydraulically isolate a portion the well or strengthen the structural integrity of well tubulars or tubular hangers. Exothermic reactant materials are located proximate the meltable repair material. The exothermic reactant material is ignited or an exothermic reaction otherwise initiated which supplies heat to and melts the meltable repair material into a molten mass. The molten mass flows and solidifies across the structure and the fluid seal defect to effect a fluid seal in the subterranean well structure or the structural integrity is enhanced. Examples of preferred exothermic reactant materials include thermite, thermate, fusible chemical reactants such as ammonium chloride and sodium nitrate, and oxidizers and accompanying hydrocarbon based fuels. Examples of preferred meltable repair materials include solder or brazing materials and eutectic metals which expand upon cooling and solidifying from a molten state.

A system and method of drilling and/or perforating uses a laser beam to remove material, such as to perforate the casing, cement and formation or drill a well bore. The system and method can further or alternately encompass material analysis that can be performed without removing the material from the well bore. The analysis can be performed apart from or in connection with drilling operations and/or perforating the casing, cement and formation. The analysis can be used in a feed back loop to adjust material removal, adjust material analysis, determine the location of future material removal, and for other uses.

Certain embodiments provide a heater. The heater includes a ferromagnetic member. The heater also includes an electrical conductor electrically coupled to the ferromagnetic member. The electrical conductor is configured to conduct a majority of time-varying electrical current passing through the heater at about 25° C. The heater is configured to provide a first heat output below the Curie temperature of the ferromagnetic member. The heater is configured to automatically provide a second heat output approximately at and above the Curie temperature of the ferromagnetic member. The second heat output is reduced compared to the first heat output.

A process may include providing heat from one or more heaters to at least a portion of a subsurface formation. Heat may transfer from one or more heaters to a part of a formation. In some embodiments, heat from the one or more heat sources may pyrolyze at least some hydrocarbons in a part of a subsurface formation. Hydrocarbons and/or other products may be produced from a subsurface formation. Certain embodiments describe apparatus, methods, and/or processes used in treating a subsurface or hydrocarbon containing formation.

Certain embodiments provide a system including a heater. The heater includes one or more electrical conductors. The heater is configured to generate a heat output during application of electrical current to the heater. The heater includes a ferromagnetic material. A conduit at least partially surrounds the heater. A fluid is located in a space between the heater and the conduit. The fluid has a higher thermal conductivity than air at standard temperature and pressure (STP) (0° C. and 101.325 kPa). The system is configured to provide (a) a first heat output below a selected temperature when time-varying electrical current is applied to the heater, and (b) a second heat output near or above the selected temperature when time-varying electrical current is applied to the heater.

Certain embodiments provide a heater. The heater includes an inner electrical conductor. A heater section at least partially surrounds the inner electrical conductor. The heater section is configured to generate an electrically resistive heat output during application of time-varying electrical current to the heater section. The heater section includes ferromagnetic material. An outer electrical conductor at least partially surrounds the heater section. An applied time-varying electrical current is configured to propagate through the inner electrical conductor and the outer electrical conductor in substantially the same direction. The applied time-varying electrical current is configured to propagate through the heater section in a substantially opposite direction. The heater provides a first heat output when time-varying electrical current is applied to the heater below a selected temperature, and a second heat output approximately at and above the selected temperature during use. The second heat output is reduced compared to the first heat output.

Certain embodiments provide a method for treating a hydrocarbon containing formation. The method includes applying electrical current to one or more electrical conductors located in an opening in the formation to provide an electrically resistive heat output. The heat is allowed to transfer from the electrical conductors to a part of the formation containing hydrocarbons so that a viscosity of fluids in the part and at or near the opening in the formation is reduced. Gas is provided at one or more locations in the opening such that the fluids are lifted in the opening towards the surface of the formation. The fluids are produced through the opening.

Certain embodiments provide a method for treating a subsurface formation. The method includes providing one or more explosives into portions of one or more wellbores selected for the explosion in the formation. The wellbores are formed in one or more zones in the formation. The explosives are controllably exploded in one or more of the wellbores such that at least some of the formation surrounding the selected wellbores has an increased permeability. One or more heaters are provided in the one or more wellbores.

A method for heating heavy oil inside a production well. The method raises the subsurface temperature of heavy oil by utilizing an activator that has been injected below the surface. The activator is then excited with a generated microwave frequency such that the excited activator heats the heavy oil.

A method and apparatus for providing fluid flow into a wellbore in which an apparatus having at least one laser energy output is lowered into the wellbore and the at least one laser energy output is directed at a wall of the wellbore. At least a portion of the wall is heated using the at least one laser energy output, whereby flow of a fluid into the wellbore is initiated and/or- enhanced.

Certain embodiments provide a method for treating a subsurface formation. The method includes using heaters to form a heated portion of the subsurface formation. A production conduit is used to direct formation fluid in a vapor phase from the heated portion of the subsurface formation towards a surface of the subsurface formation. Condensate of the vapor phase formation fluid is formed in or near the production conduit. Condensate of the vapor phase formation fluid is diverted to a desired location.