Abstract: Improved methods and apparatus are disclosed for confining ohmic heating currents to a subsurface formation in the use of in situ ohmic heating for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. Spacing between emplaced electrodes and the number of electrodes employed are controlled to cause coupling between electrodes for more uniform and higher temperature heating. Electrode designs are disclosed which suppress spurious earth currents which would heat other formations not of interest. Suppression of electrode end currents is accomplished by the use of distinct rings of insulation, control of the applied potential along the electrode, and injection or withdrawal of fluids at distinct locations along the electrode.

Abstract: A method for heat injection into a subterranean formation is provided. The method utilizes flameless combustion and a gas fired heater having an electrical heated surface for ignition of the gas. The absence of a flame eliminates the flame as a radiant heat source and results in a more even temperature distribution throughout the length of the burner. Flameless combustion is accomplished by preheating the fuel and the combustion air to a temperature above the autoignition temperature of the mixture. Preheating hydrocarbon fuel requires the inclusion of a carbon formation suppressant such as carbon dioxide or steam to prevent carbon formation.

Abstract: A method of stimulating injection wells having a wellbore. The method includes the steps of placing a heater at or near the bottom of the well, adjacent to the area to be treated, energizing the heater to release heat energy, flowing a solvent past the heater to the area to be treated to contact solid wax deposits to mobilize the wax deposits, removing the mobilized wax and the solvent from the well area, and injecting waterflood water into the well and into the passageways that were previously blocked by the wax deposits. In one embodiment there is a further pretreatment step of selecting an appropriate thief zone blocker fluid and injecting the same into the well to selectively obstruct the thief zones. In a further embodiment there is a further pretreatment step of choosing an appropriate oil zone blocking fluid and injecting the same into the well prior to the injection of the thief zone blocking fluid to protect the same.

Abstract: In-situ decontamination of soil is accomplished by providing electromagnetic energy of relatively short wavelengths from an array of applicators (antennas), inserted into a borehole array that encompasses the contaminated zone. The borehole array geometry is designed according to the soil's thermophysical properties. Electromagnetic energy heating and heat transfer mechanisms are used to raise the temperature of the soil to the desired level for vaporization of contaminants while at the same time avoiding excessive heat loss from the much larger array size. Heating is maintained throughout the contaminated zone after the final temperature has been reached by proper compensation of the envelope heat loss. Contaminants are evaporated by the heating. Contaminant vapors are collected by vapor collection pipes and/or a gas cover over the soil being heated. The contaminant vapors are then reduced in volume to manageably safe levels and then treated and/or disposed of.

Abstract: An in situ method for removal of contaminants from soil imposes a vacuum on the soil through perforated heater wells that are positioned in the soil. The heater wells heat the soil to elevated temperatures by thermal conduction. The heater wells are permeable to vapors which emanate from the soil when heated and which are drawn towards the heater wells by the imposed vacuum. An impermeable flexible sheeting on the soil surface reduces the amount of air that is being pulled into the heater well from the atmosphere. A thermal insulator covers the soil surface and reduces heat losses from the soil surface. The heater wells are connected to a vacuum manifold for collection of vapors. A heat front moves away from the heater wells through the soil by thermal conduction, and the superposition of heat from a plurality of heater wells results in a more uniform temperature rise throughout the well pattern.

Abstract: Optimum antenna-like exciters for heating earth media which may be used to recover hydrocarbons. A high frequency power supply is connected to an exciter emplaced in the subsurface formation which radiates high frequency power. The exciters include one or more conducting cylinders which make up monopole and dipole antenna-like apparatus. Substantially uniform heating of the subsurface formation is provided thus suppressing excessive heating of edge and power input regions. The equal distribution of electric fields eliminates intense electric fields which would normally exist thus mitigating excessively heated regions and providing substantially uniform heating of the subsurface formation.

Abstract: A method of stimulating production from an oil well by removing solid wax deposits from a production zone an electrical resistance heater comprised of a packed bed of spherical heating elements lowered through the tubing on a wireline and placed adjacent to the perforations. Solvent is pumped through the heater to raise its temperature by 200.degree. C. and then into the formation to contact wax deposits. The solid wax deposits are liquified and together with the oil and the solvent form a single liquid phase. The wax is then removed from the formation by placing the well back on production. Because the invention completely avoids the use of either water or gas, the saturation of the water and gas phases in the formation is minimized, thereby maximizing the mobility of the liquid phase containing the wax and facilitating the removal of the liquified wax from the treatment area before it reprecipitates.

Abstract: This invention describes a method of stimulating production from an oil well by removing solid wax deposits from a production zone. An electrical resistance heater comprised of a packed bed of spherical heating elements is lowered through the tubing on a wireline and placed adjacent to the perforations. Solvent is pumped through the heater to raise its temperature by 200.degree. C. and then into the formation to contact wax deposits. The solid wax deposits are liquified and together with the oil and the solvent form a single liquid phase. The wax is then removed from the formation by placing the well back on production. Because the invention completely avoids the use of either water or gas, the saturation of the water and gas phases in the formation is minimized, thereby maximizing the mobility of the liquid phase containing the wax and facilitating the removal of the liquified wax from the treatment area before it reprecipitates.

Abstract: An in-situ method of extracting oil from a hydrocarbon bearing layer such as oil-shale or tar sands lying beneath a surface layer comprises applying a radiofrequency excitation signal to the hydrocarbon bearing layer through a system of electrodes. The electrodes are inserted into a matrix of holes drilled through the surface layer and into the hydrocarbon bearing layer. A coaxial line extending through the surface layer is connected to the electrodes extending into the hydrocarbon bearing layer. The electrodes have a length that is an integral number of quarter wavelengths of the radiofrequency energy. A matching network connected between the coaxial cable and a respective one of the electrodes maximizes the power flow into each electrode. The electrodes are excited uniformly in rows and as a "balanced-line" RF array where adjacent rows of electrodes are 180.degree. out of phase.

Abstract: A down-hole oil well heater for improved recovery of oil includes a heating element comprising a sheet of electrically conductive paper which generates heat as a result of resistance to current flow therethrough and spaced apart, primary conductor elements preferably in the form of thin metal strips attached, as by sewing, to the conductive paper to provide uniform distribution of current flow through the paper from one conductor element to the other. Secondary conductor elements are electrically connected to said primary conductor elements and controller means are electrically connected to such secondary conductor elements for controlling the flow of electricity to the electrically conductive paper. The heating element covers a portion of conventional oil well tubing and is sandwiched between layers of electrically nonconductive, insulating material.

Abstract: A process to clear pipelines carrying fluids viscous and/or rich in organic residues includes the introduction of a heating element inside a pipeline carrying the fluids through a coupling spool which is intercalated in the fluid-carrying pipeline. Simultaneously an electric current is applied to the heating element so that the heat generated by the heating element is transmitted to the viscous fluid or to the compacted residual mass inside the fluid-carrying pipeline, causing the detachment of those residues from the internal wall of the pipeline and re-establishing the conditions for fluid flow.

Abstract: An oil well tool and method for its use for removing accumulated deposits along an oil well tubing in a downhole pump operated oil well is disclosed. The tool when in use is untethered and adapted to be lowered through an oil well tubing under its own weight and the forces of gravity. The tool includes: a heating and scraping portion that removes the deposits as the tool is lowered through the tubing, a set of seals for preventing pumped fluids from passing through or around the tool, and a mechanism for setting the seals at a desired location along the tubing. With the seals set and the pump operating, the tool is raised up through the well tubing with the pumped fluids to a wellhead storage position.

Abstract: A downhole steam and hot water generator for use in other than a non-vertical oil well casing and particularly adapted for use in horizontal drilled wells that includes an elongated housing with a front and rear end, fluid discharge apparatus positioned in the upper portion of said housing connected to an upper chamber therein, water distribution apparatus associated with the housing to pass water into the lower portion of the housing, and electrodes within said water to boil or vaporize water into steam for transfer to a horizontal petroleum pool to reduce the viscosity of the petroleum for pumping.

Abstract: A separate heat source, such an a skin effect heater, is added to a subterranean heat exchanger and oxygen combustion device for upgrading viscous crude oil feeds. An insulated wire is integrated with combustion oxygen supply piping to form the skin effect heater operating in conjunction with the heat exchanger. The separately controlled heater output allows a reduction of the heat from the combustion device reduced quantities of combustion products. The improvement down-sizes or eliminates excess combustion product removal facilitates and also preheats the oxygen supply. The skin-effect heater and heat exchanger combination adds heat gradually and increases feed residence time at the desired upgrading temperature and pressure conditions. Alternative embodiments can be used to treat heavy crudes within a producing well.

Abstract: Electrical power sources and systems for heating in or adjacent to an oil well or other mineral well, or for heating other earth media, each comprising an A.C. heating generator that generates an A.C. heating current at a selected heating frequency substantially different from the conventional 50/60 Hz frequency used by power companies; the heating generator may comprise an A.C. to D.C. converter for developing an intermediate D.C. output of predetermined amplitude from a conventional 50/60 Hz A.C. input, and a solid state switching circuit for repetitively sampling the D.C. output of the converter at the selected heating frequency, usually in a range of 0.01 Hz (or even lower) up to about 35 Hz. A heating rate control varies the energy content and the frequency of the A.C. output to suit well requirements.

Abstract: A method of creating a protocol for oil extraction or for enhancing oil extraction from oil reservoirs. A process of devising and applying a customized electromagnetic irradiation protocol to individual reservoirs. Reservoir samples are tested to determine their content, molecular resonance frequencies and the effects of electromagnetic field on their compounds. Electromagnetic field frequencies, intensities, wave forms and durations necessary to heat and/or crack individual molecules and produce plasma torches is determined. Equipment are selected and installed according to the results of the laboratory tests and the geophysics of the mine. Dielectric constant of the formation is reduced by draining the water and drying it with electromagnetic energy.

Abstract: Electrical heating system for mineral wells, particularly oil wells, in which the reservoir or "pay zone" is heat stimulated or some well components (e.g., the tubing) are heated, or both, by electrical power supplied to a multi-perforate electrode have the operating efficiency enhanced by effectively terminating the heating electrode, at both its top and bottom, at a distance inwardly of the pay zone equal to at least three times the diameter of the well casing. In some systems the electrical power connection to the main heating electrode is made through a section of the production tubing of the well, with an electrical contactor interconnecting the tubing and the electrode in the level of the pay zone; these systems also provide electrical isolation, within critical height limits, for the production tubing and the pump rod. Delivery of electrical power downhole of the well may be accomplished through an electrical cable, which may or may not be appropriately armored.

Abstract: An electrical resistance subterranean heater is provided which is cemented directly in a well borehole without a casing in the borehole within the zone to be heated. The absence of the casing results in an economical installation.

Abstract: An apparatus and method are disclosed for producing thick tar sand deposits by preheating of thin, relatively highly conductive layers which are a small fraction of the total thickness of a tar sand deposit, with horizontal electrodes and steam stimulation. The preheating is continued until the viscosity of the tar in a thin preheated zone adjacent to the highly conductive layers is reduced sufficiently to allow steam injection into the tar sand deposit. The entire deposit is then produced by steam flooding.

Abstract: An electrical resistance heater is provided which utilizes a copper-nickel alloy heating cable. This metallurgy heating cable is significantly less prone to failure due to localized overheating because the alloy has a low temperature coefficient of resistance. Used as a well heater, the heating cable permits heating of long segments of subterranean earth formation with a power supply of 400 to 1200 volts.

Abstract: An apparatus and method are disclosed for producing thick tar sand deposits by electrically preheating paths of increased injectivity between an injector and producers, wherein the injector and producers are arranged in a triangular pattern with the injector located at the apex and the producers located on the base of the triangle. These paths of increased injectivity are then steam flooded to produce the hydrocarbons.

Abstract: An apparatus and method are disclosed for producing thick tar sand deposits by preheating of thin, relatively conductive layers which are a small fraction of the total thickness of a tar sand deposit, with horizontal electrodes. The preheating is continued until the viscosity of the tar in a thin preheated zone adjacent to the conductive layers is reduced sufficiently to allow steam injection into the tar sand deposit. The entire deposit is then produced by steam flooding.

Abstract: Method and apparatus for corrosion inhibition in an electromagnetic heating system for heating a portion of a mineral fluid deposit adjacent an oil well or other mineral fluid well, in situ. The preferred apparatus includes a power source, that develops a high amperage heating current, over 100 amperes, at a heating frequency usually in a range of from 0.01 Hz or lower to 35 Hz, in a heating circuit that includes a main heating electrode downhole of the well and a return electrode. The power source also supplies a very low amplitude, controlled D.C. bias current to those electrodes, maintaining the main electrode at a neutral or negative polarity for corrosion protection. The D.C. bias current is monitored and maintained below a given minimum level, usually about one ampere, to extend the effective life of the return electrode and to minimize corrosion protection costs.

Abstract: A method of producing fluids from subterreanean reservoirs containing hydrogen sulphide and especially those reservoirs where elemental sulphur or hydrogen polysulphides are present. The method describes the use of a jet pump, chemical injection, and downhole electrical heaters to prevent the deposition of elemental sulphur within the production tubulars of wells penetrating such reservoirs by raising the pressure, temperature, and sulphur solvency of fluids being produced up these wells. In this way, subterranean reserves of sulphur and hydrogen sulphide which were previously unproducible or too expensive to produce can be commercially exploited.

Abstract: An in-situ method is disclosed for removing contaminants from surface and near-surface soil by imposing a vacuum on the soil beneath a impermeable flexible sheet and then heating the soil with an electric surface heater that is positioned on the soil surface under the sheet. The heater is permeable to vapors which emanate from the soil when heated. A permeable mat, which may also be a good thermal insulator, separates the heater from the impermeable sheet and provides a conduit for flow of vapors to openings in the sheet. The openings, in turn, are connected to a vacuum manifold for collection of the vapors. A vacuum pump evacuates the region under the impermeable sheet such that the sheet, mat, and heater are pressed firmly against the soil surface by atomospheric pressure. The soil contaminants are removed by vaporization, steam distillation, and/or thermal decomposition.

Abstract: An RF transmission line is located horizontal to the surface of a region of earth to be decontaminated. The transmission line is driven by a constant current RF source thereby causing induction heating of the soil therebeneath. An array of transmission lines may be required depending upon the size of the area to be decontaminated. The array may be moved slowly along tracks or other mobile carrier, in a direction horizontal to the earth's surface and perpendicular to the transmission line in order to achieve more uniform heating. In an alternative embodiment, a second array may be interspersed with the first array and the RF source switched between the arrays to achieve more uniform heating. Heat losses from recondensation of vapors at the surface and/or from radiation may be reduced by heating the air used for removing the vapors and by providing a radiant surface above the array and heating said array to the desired target temperature.

Abstract: An electrode comprising a molybdenum rod is received within a conductive collar formed of graphite. The molybdenum rod and the graphite collar may be physically joined at the bottom. A pair of such electrodes are placed in soil containing buried waste material and an electric current is passed therebetween for vitrifying the soil. The graphite collar enhances the thermal conductivity of the combination, bringing heat to the surface, and preventing formation of a cold cap of material above the ground surface. The annulus between the molybdenum rod electrode and the graphite collar is suitably filled with a conductive ceramic powder that sinters upon the molybdenum rod, protecting the same from oxidation as graphite material is consumed, or a metal powder which liquefies at operating temperatures. The center of the molybdenum rod, used with a collar of separately, can be hollow and filled with a powdered metal, such as copper, which liquefies at operating temperatures.

Abstract: A technique of heating a subterranean oil bearing formation comprises determining a thermal harmonic frequency of the formation and applying a form of alternating current to the formation that includes the thermal harmonic frequency to increase the temperature of the formation. Heated oil is produced from the formation. A standard three phase ac power source is converted to dc and then chopped to single phase ac so substantially all of the purchased power can be delivered to the well.

Abstract: A method is disclosed for producing thick tar sand deposits by preheating of thin, relatively conductive layers which are a small fraction of the total thickness of a tar sand deposit. The thin conductive layers serve to confine the heating within the tar sands to a thin zone adjacent to the conductive layers even for large distances between rows of electrodes. The preheating is continued until the viscosity of the tar in a thin preheated zone adjacent to the conductive layers is reduced sufficiently to allow steam injection into the tar sand deposit. The entire deposit is then produced by steam flooding.

Abstract: Corrosion inhibition apparatus in an electromagnetic heating system for in situ downhole heating in an oil well or other mineral fluid well that includes an A.C. power source for a high amperage, low frequency heating current (e.g. over 50 amperes at 0.01 to 35 Hz) and a D.C. bias source for generating a low amplitude (e.g., less than one ampere) current for corrosion inhibition, both sources connected to a downhole electrode. The bias source includes at least one semiconductor device, connected in the main A.C. heating circuit, in a bias circuit that develops a net D.C. voltage differential of the polarity required for corrosion inhibition in response to the A.C. heating current.

Abstract: A method and apparatus for reducing the accumulation of paraffin within an oil well that includes forming an electric circuit contact between the oil well sucker rod and tubing and connecting a power source to the sucker rod and tubing. An electric current is applied to the sucker rod in order to generate heat thereat. Preferably a rolling circuit contact is offset from the sucker rod to form a moving contact between the sucker rod and tubing, and in a preferred form a section of the sucker rod and pump is made of a material having a greater electrical resistance to increase the heat generated in a region of high paraffin accumulation. In another embodiment circuit assemblies are provided in the production string to alter the region being heated as the sucker rod reciprocates.

Abstract: A collar for electrically insulating between upper and lower tubing sections in which load bearing insulating materials in the collar are isolated from fluids both interior and exterior the collar.

Abstract: A steam generator is located downhole in a well for generating steam to cause viscous crudes to flow out adjacent walls. A packer is mounted above the steam generator. A connector box is located between the packer and the steam generator. An electrical cable extends alongside tubing into the well and into a window in the tubing located just above the packer. The cable extends through a passage in the packer and into the connector box. Feedthrough connectors in the connector box connect the power cable with lead wires extending upward from the steam generator. Heat pipes extend from the connector box upward through the packer. The heat pipes contain gas which circulates to aid in dissipating heat from the connector box.

Abstract: An electrical heating system for an oil well of the kind comprising a well bore extending through and below an oil producing formation to afford a rathole of substantial depth, the well including an electrically conductive first casing section from the earth surface down through the overburden, an electrically conductive second casing section continuing down through the oil producing formation, and a third casing section in the rathole. The first and second casing sections are usually steel pipe. An electrical power supply is connected to primary and secondary electrodes for conductive heating of a portion of the oil producing formation; the primary electrode is an uninsulated portion of the second casing section. The third casing section constitutes an insulator for electrical isolation of the rathole.

Abstract: Permeability of a highly permeable zone in a subterranean formation is reduced by injecting an oil external emulsion of an aqueous solution of alkali metal silicate. Emulsion adjacent the well bore is broken by the application of microwave. Released alkali metal silicate then forms a plug of gel at this point, through contact with formation brines, which holds the rest of the emulsion in place until it breaks down and gels. In one aspect a second internal phase containing a gelation agent is provided to accelerate gelling.

Abstract: Process for in situ recovery of carbonaceous values from underground petroleum impregnated media such as oil shale, under controlled radiation from a microwave distributing source adjacent the media, e.g. in a borehole, effected in the absence of air, such that the radiation is distributed at least initially at incrementally increasing power and/or at least initially in intermittent interval cycles of on and off duration of the microwaves, for selective pyrolysis of the organic content of the media to liquid, vapor and gas form as the case may be under autogenous pressure in the pores of the media for driving the organic constituents therefrom for appropriate recovery, e.g. via the borehole, including breakup of larger molecules, e.g.

Abstract: A steam generator is located downhole in a well for generating steam to cause viscous crudes to flow out adjacent wells. A packer is mounted above the steam generator. A connector box is located between the packer and the steam generator. An electrical cable extends alongside tubing into the well and into a window in the tubing located just above the packer. The cable extends through a passage in the packer and into the connector box. Feedthrough connectors in the connector box connect the power cable with lead wires extending upward from the steam generator. Cooling fluid passages in the packer allow circulation of cooling fluid from the surface to cool the components. The packer is hydraulically set by water supplied to the cooling fluid passages. A disk ruptures after the packer has been set to enable circulation of the cooling fluid.

Abstract: A method and apparatus for forming an electrically conductive externally insulated casing for an oil well of the type in which the casing carries electrical current to a primary heating electrode positioned downhole, using multiple prefabricated casing segments; each casing segment is a long steel pipe having a female thread coupling on one end and a male thread on the other end. Each segment has an insulator covering, over substantially all of its length, that has a figure of merit (erl)/.DELTA. of no more than 4.times.10.sup.8 so that the shunt impedance of the casing to ground can be kept substantially greater than the spreading resistance of the primary heating electrode. The preferred casing segment insulation is in two layers, including a hard, durarable inner layer subject to water degradation and an outer water-impervious layer usually applied as tape.

Abstract: Heating systems for mineral wells (e.g. oil wells) employ electrical power sources, sometimes operating at relatively high frequencies, that are connected to the well casing and production tubing so as to provide a coaxial line electrical heater projecting down into the well. The heating pattern of the coaxial line is effectively controlled so that most of the power is dissipated as heat, primarily in the tubing, above a depth D above which paraffins or other condensible constituents would tend to condense or otherwise impair the flow of mineral fluid up through the production tubing. The applied electrical power is controlled so that the fluid is kept approximately at or only somewhat above the flow impairment temperature for constituents of the fluid. In some embodiments the system is extended to provide heating of a portion of the deposit formation adjacent to the well.

Abstract: A microwave heating applicator usable in preformed holes in mansonry and the like for heating and dehumidifying areas around the holes is formed from a length of coaxial transmission line. Radiating elements are formed in the outer conductor of the coaxial line for providing an asymmetrical radiation pattern. The radiating elements are provided by forming circumferential axial discontinuities in the outer conductor, each discontinunity having a pair of non-parallel cut edges formed in the outer conductor encircling the line, leaving an asymmetrical open area extending axially between the cut edges. One of the cut edges may describe a plane perpendicular to the coaxial line's z axis while the other cut edge describes a plane which is not perpendicular to the coaxial line z axis. The radiating elements may be provided at intervals along the coaxial line.

Abstract: An invention for supplying power to a well. In one embodiment power heats a tubing from adjacent the surface to a selected level to prevent the formation of solids. The tubing is heated by passing an electric current therethrough. In one form the tubing is insulated from the wellhead and the casing down to a selected level where an electrical connection is made between the tubing and casing. Current is applied to the tubing at a point below an insulating tubing collar. In another form an insulated conduit is run into the well to a selected depth and connected to the tubing. Electrical power is connected to the tubing and to the insulated conduit.In another form a sucker rod is electrically insulated from the tubing down to a selected depth. The sucker rod includes a non-conducting section such as a fiberglas sucker rod. A conduit is run through the fiberglas rod and connected to the steel sucker rod therebelow.

Abstract: An electrical resistance heater capable of generating heat at different rates at different locations along its length comprises a continuous and unitary electrical conductor having a thickness which is different at different locations along its length.

Abstract: A thermally-enhanced oil recovery method and apparatus for exploiting deep well reservoirs utilizes electric downhole steam generators to provide supplemental heat to generate high quality steam from hot pressurized water which is heated at the surface. A downhole electric heater placed within a well bore for local heating of the pressurized liquid water into steam is powered by electricity from the above-ground gas turbine-driven electric generators fueled by any clean fuel such as natural gas, distillate or some crude oils, or may come from the field being stimulated. Heat recovered from the turbine exhaust is used to provide the hot pressurized water. Electrical power may be cogenerated and sold to an electric utility to provide immediate cash flow and improved economics. During the cogeneration period (no electrical power to some or all of the downhole units), the oil field can continue to be stimulated by injecting hot pressurized water, which will flash into lower quality steam at reservoir conditions.

Abstract: The tubing of a cased petroleum well is heated for any purpose such as to prevent deposition of solids by coupling a microwave source to the well annulus at the surface and transmitting the waves down the annulus.Special coupling means is provided to couple at the annulus to accommodate the arbitrary positions of naturally occurring microwaves in the annulus of the well.

Abstract: A water-containing region at or near the surface of the earth, such as a landfill, that is contaminated with hazardous materials is decontaminated by heating the region with bound radio frequency energy from a bound-wave transmission line excitor array disposed outside the region to a temperature to boil water and thereby increase the permeability of the region. The heating is continued by dielectric heating after water has boiled from at least a portion of the region to heat the portion to elevated temperatures substantially above the boiling point of water. The materials may then be rendered innocuous in situ in a number of ways, as by pyrolysis, thermally assisted decomposition, or reaction with an introduced reagent, such as oxygen. The materials may also be driven from the region, as by distillation or by evaporation and steam drive and then collected and disposed of, as by incineration.

Abstract: A method for starting up the production of hydrocarbonaceous fluid from a wellbore which has been shut-in for a time such that the ratio of water to hydrocarbon present in the hydrocarbonaceous fluid in the wellbore is sufficiently high as to make it uneconomic to produce hydrocarbonaceous fluid from said wellbore, the improvement comprising heating the reservoir around said wellbore and the hydrocarbonaceous fluid contained therein suficiently to cause the said hydrocarbonaceous fluid to be substantially less viscous and to cause at least some thermal expansion of said hydrocarbonaceous fluid whereby the water to hydrocarbon ratio is decreased to a value at which hydrocarbonaceous fluid can be economically produced from said wellbore and thereafter starting up production of hydrocarbonaceous fluid from said wellbore.

Abstract: A corrosion-resistant metal pipe, and a process for producing the same, such as may be used in an electrode unit for electrically heating underground hydrocarbon resources or for conveying corrosive materials. The pipe may be produced in any desired length. In one embodiment, the corrosion-resistant pipe includes a base pipe element composed of at least two corrosion-resistant pipes joined by welding. The two pipes are stripped at adjacent ends of a first coat made of a glass-mica molded body formed on both inner and outer surfaces of the pipe. A plurality of communication holes are formed in the joint provided by welding the pipes. A second coat formed of a glass-mica molded body is then provided on both inner and outer surfaces of the joint with the second coat continuous with the first coat.

Abstract: Method and apparatus for enhancing liquid hydrocarbon production through a single traditional producing borehole recognizing traditional producing well spacing from a slowly producing formation by use of non-uniform heating through interrelated electrode arrays surrounding the borehole. Heating the formation around the borehole through an interrelated electrode array designed for the formations geometry and geophysics favorably redistributes the pressure gradient throughout the formation for a substantial distance beyond the borehole permitting net energy effective production. One optimum electrode array may consist of ring electrodes or electrode segments so disposed as to electrically approximate a ring. Electrically conductive well bore casing in the formation may be used as an electrode. A return electrode of low impedance disposed close to the surface of the earth may be utilized.

Abstract: In the in-situ retorting of oil shale using radio frequency electrical energy, an applicator is inserted into a borehole and energized at a radio frequency. A protective device protects the applicator from expansion of the oil shale formation. The protective device includes an end plate attached to the applicator and a plurality of elements surrounds the applicator and is in contact with the end plate so as to prevent the oil shale formation from contacting the applicator.

Abstract: An oil and water-containing subterranean reservoir can be heated in a manner capable of inducing an economically feasible production of oil from zones which were initially so impermeable as to be undesirably unproductive in response to injections of oil recovery fluids. Treatment zones of specified thickness are conductively heated from boreholes arranged in a specified pattern of heat-injecting and fluid-producing wells and heated to above about 600.degree. C.