Abstract: A method for retarding temperature loss of fluid being produced in a well employs a fluid of low thermal conductivity in the tubing annulus. The tubing annulus extends between the production casing and the production tubing. It extends from a packer at the lower end of the tubing annulus to a wellhead. The fluid in one case is low density gas created by a partial vacuum. A vacuum is drawn on the tubing annulus to reduce the air density, which in turn reduces the amount of heat that convection currents can carry. In another example, the tubing annulus fluid is viscous hydrocarbon liquid. The hydrocarbon liquid also has a low thermal conductivity. Heat is supplied to the fluids being produced through the tubing annulus by a heater cable that extends into the well.

Abstract: Apparatus and method are provided for electrically heating subsea pipelines. An electrically insulating layer is placed over the pipe in the segment of the pipeline to be heated and electrical current is caused to flow axially through the steel wall of the pipe. In one embodiment (end fed), an insulating joint at the host end of the pipeline is used to apply voltage to the end of the segment. At the remote end an electrical connector is used to conduct the electrical current to a return cable or to a seawater electrode. A buffer zone of the pipeline beyond the remote end is provided. Separate electrical heating may also be applied in the buffer zone. Electrical chokes may be used in different arrangements to decrease leakage current in the pipeline outside the heated segment. In another embodiment (center fed), voltage is applied at or near the midpoint of the segment to be heated through an electrical connector and no insulating joint is used.

Abstract: The present invention provides a heater cable (10) that may be deployed in a wellbore to elevate the temperature of the wellbore above the temperature of the surrounding fluid and the formation. One or more fiber optic strings are included in or are carried by the heater cable. The heater cable carrying the fiber optics is placed along the desired length of the wellbore. At least one fiber optic string measures temperature of the heater cable at a plurality of spaced apart locations. Another string may be utilized to determine the temperature of the wellbore. In one aspect of this invention, the heater cable is heated above the temperature of the wellbore. The fluid flowing from the formation to the wellbore lowers the temperature of the cable at the inflow locations. The fiber optic string provides measurements of the temperature along the heater cable. The fluid flow is determined from the temperature profile of the heater cable provided by the fiber optic sensors.

Abstract: Apparatus and method for melting material in the annulus of an oil or gas well and thereby sealing the annulus to prevent shallow gas leakage and the like. Conveniently, the material is positioned within the annulus between the production and surface casing of the well and above the well cement. A heating tool is lowered into position and provides the necessary heat to melt the material. The heating tool may be removed following the sealing of the annulus.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may also uniformly increase a porosity of a treated portion of the formation.

Abstract: Apparatus and method for melting metal in the annulus of an oil or gas well and thereby sealing the annulus to prevent shallow gas leakage and the like. Conveniently, eutectic metal is positioned within the annulus between the production and surface casing of the well and above the well cement. An electrical inductive tool is lowered into position and used to provide the necessary heat to melt the metal. The electrical inductive tool may be removed following the sealing of the annulus. Radioactive tracers may be used with the eutectic metal to confirm the desired location for the melt to occur.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat and pressure applied to the formation may be controlled so that a majority of the hydrocarbons produced from the formation have carbon numbers less than 25. Conditions may be controlled to produce low quantities of olefins in condensable hydrocarbons produced from the formation and low quantities of olefins in non-condensable hydrocarbons produced from the formation.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heating may be controlled such that at least a selected amount of a total organic carbon content of the hydrocarbon material in the formation may be converted into formation fluids.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may also be applied to the formation to increase a permeability of the formation. The permeability may increase uniformly throughout the treated portion of the formation. The permeability may increase to a relatively high permeability as compared to the initial permeability.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. A formation to be treated may produce a relatively large amount of condensable hydrocarbons and/or a relatively large amount of non-condensable hydrocarbons. Hydrocarbons within the formation may have a relatively high initial elemental hydrogen weight percentage.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. A portion of the mixture may be a condensable component that includes a relatively small amount of olefins and a relatively small amount of tri- and higher order aromatics.

Abstract: A well heater is provided, the heater effective for heating earth surrounding a wellbore from the wellbore, the well heater including: a) a resistive heating element, the resistive heating element traversing a segment of the wellbore to be heated; b) more than one ceramic insulators, the ceramic insulators defining a channel through which the resistive heating element passes; and c) a support element connected to at least one ceramic insulator, the support element effective for conducting heat from the ceramic insulator and radiating heat to the wellbore wall, and to support the weight of the electrical resistance element and the ceramic insulators through the connection to the at least one ceramic insulator. The wellbore heater of the present invention is easily fabricated from available materials, and provides a reliable and inexpensive wellbore heater.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. An unpyrolyzed section may be left between two substantially pyrolyzed sections to inhibit subsidence of the formation.

Abstract: An electrical heating method and apparatus for minerals wells having a metallic fluid admission section located adjacent a hydrocarbonaceous reservoir of a heterogeneous reservoir that has at least two longitudinally spaced producing intervals having different thermal heat transfer characteristic. The method includes providing a downhole electrically energized heater having at least two independently controlled heating elements spaced longitudinally apart from each other. At least one of the heating elements is positioned near a first of the producing intervals adjacent the fluid admission section. The second of the heating elements is positioned near a second of the producing intervals adjacent the fluid admission section.

Abstract: A method of heating gas being produced in a well reduces condensate occurring in the well. A cable assembly having at least one insulated conductor is deployed into the well while the well is still live. Electrical power is applied to the conductor to cause heat to be generated. Gas is allowed up past the cable assembly and out the wellhead. The heat retards condensation, which creates frictional losses in the gas flow.

Abstract: A method and apparatus for unplugging a well or pipe obstructed by a gas hydrates. According to the invention, a moving heating element is applied against one end of the hydrate plug, and is displaced axially in the tube or the pipe towards the other end, so as to cause the plug to melt progressively from one end to the other. Application to the oil industry, in particular in off-shore wells.

Abstract: A system for pumping and heating viscous fluids in a wellbore includes electrical power supplies, a switchboard, conductors, and a submergible pumping system having a pump and a submergible electric motor. The electrical power supplies are coupled to the submergible pumping system through a switchboard and conductors that supply electrical power to the motor. The electrical power supplies provide direct or alternating current and include protective circuitry. The submergible pumping system may be supplied with electrical power to motor stator windings to generate heat to raise the temperature and lower the viscosity of adjacent viscous fluids.

Abstract: A microwave heating system is provided including a microwave generator, a fluid pipeline having an upstream section and a downstream section, and a waveguide assembly connected to the microwave generator. The waveguide assembly includes a microwave distributor positioned in the fluid pipeline at a junction between the upstream section and the downstream section. The microwave distributor is in substantially straight line alignment with the upstream section proximal to the junction, while the downstream section is in substantially right angle alignment with the upstream section proximal to the junction. The microwave heating system substantially prevents or remediates gas hydrate blockages in the upstream section of the fluid pipeline at extended distances from the microwave generator. The microwave heating system may also simultaneously control a function of a device remotely positioned on the upstream section or power the remote device.

Abstract: The present invention is a system permanently installing measuring sondes against the inner wall of a pipe (1) such as a well or a tube. Measuring sondes (8) are respectively associated with coupling devices (2) that are brought to their coupling points in the pipe by means of an elongate support element (3) such as a cable or a tube. Each coupling device (2) comprises a deformable element (6) made of a shape-memory alloy that is deformed in order to allow displacement thereof along the pipe, and that is brought back to its expanded (convex) shape for example by means of a hot fluid stream that is injected in the pipe by means of a pump (P). In this expanded position, it immobilizes coupling device (2) and presses the sonde (8) against pipe (1) while mechanically decoupling the sonde from support element (3). The support element may be withdrawn if not serving another purpose.

Abstract: The tool comprises one or more core-coil assemblies 2 jacketed in an non-magnetic and electrically insulating, tubular outer housing, 10. The housing enables high power transfer efficiency. A structural skeleton 20 extends longitudinally through the tool for axially reinforcement. The core-coil assemblies 2 are encapsulated in epoxy 77 to mechanically rigidify and protect them as well as to isolate the coil windings 51 from the power bus 23 extending longitudinally of the core-coil assemblies through a peripheral busway 60, 61.

Abstract: An subsea pipeline system having jumpers (short segments connecting equipment or wells and the main segments) that can be electrically heated is provided. The jumpers are heated by induction coils placed around the jumpers, either before placing the jumpers subsea or afterward. Electrical power may be supplied to the induction coils from current flow in the walls of the heated segment of pipeline or from an external source such as from a subsea transformer or ROV.

Abstract: A heater is disclosed, the heater including: a porous metal sheet heating element; and an electrical insulating material surrounding the porous metal sheet heating element; wherein there is no casing surrounding the porous metal sheet heating element.

Abstract: 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.

Abstract: A power cable for an ESP is used also for heating well bores in cold climates. An electrical switch is located within a wellbore at a selected location in the power cable. The electrical switch is provided to selectively short out the conductors within the power cable, thereby allowing the power cable above the switch to be used as a resistive heating element to thaw the wellbore. While the switch is open, power supplied to power cable drives ESP in a normal manner.

Abstract: An apparatus for use down a bore hole to reduce the viscosity of a hydrocarbon-containing fluid in the bore hole. The apparatus includes a housing having a size for disposition in the bore hole. At least one ultrasonic transducer is carried by the housing. The ultrasonic transducer preferably has an active element changeable from a first shape to a second shape in the presence of an electromagnetic field. An electromagnetic field is provided through at least a portion of the active element to change the shape of the active element. An acoustic element is coupled to the active element for providing ultrasonic energy to the hydrocarbon-containing fluid in the bore hole. A method for reducing the viscosity of a hydrocarbon-containing fluid in a bore hole is additionally provided.

Abstract: A system allows the pumping of viscous fluids from a wellbore. The system includes a submergible pump and a pump intake through which a fluid may be drawn. A submergible electric motor powers the submergible pump, and a heater is connected in the pumping system to heat the wellbore fluid. Additionally, a combination of heaters may be employed to heat the desired production fluid both externally to the pumping system and internally to the pumping system.

Abstract: A method and apparatus for subterranean thermal conditioning. The first step involves providing a tubular magnetic induction apparatus. The second step involves positioning the magnetic induction apparatus into a subterranean environment. The third step involves supplying voltage waves to the magnetic induction apparatus thereby inducing a magnetic field in and adjacent to the magnetic induction apparatus to thermally condition the subterranean environment. This method and apparatus has application in the petroleum and mining industries.

Abstract: The wireline release includes a shaft having one end releasably connected to the end of the wireline by a connector and being held in the latched position by a fusible material ring. Upon activating heaters in the cable head from the surface via conductors in the wireline, the fusible material ring is melted allowing the shaft, under the tension of the wireline, to shift to an unlatched position whereby the connector releases the wireline from the shaft and cable head. The connector includes a plurality of collet members which, in the latched position, are biased into the connection with the end of the wireline and are then released upon being shifted to the unlatched position where the collet members move to a disengaged position.

Abstract: A heater is disclosed, the heater comprising: a heating element effective to generate radiant energy; a casing surrounding the heating element separated from the heating element; and support material between the casing and the heating element wherein the support material comprises a granular solid material that is translucent to radiant energy in the peak wavelength of energy which is radiated by the heating element at operating temperatures. The translucency of the support material is such that at least 50% of the radiant energy emitted by the heating element is radiated to the casing.

Abstract: 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.

Abstract: A method and apparatus for producing (e.g. heavy oil) through a wellbore which passes through a permafrost layer. To maintain an acceptable flow temperature inside the production tubing, a heating element (e.g. electrical power cable having its leads short-circuited) is lowered down the production tubing to generate heat inside the tubing when electricity is supplied thereto. A sensor is provided to sense the temperature inside the tubing and activate a source to supply electricity to the cable whenever the temperature inside the production tubing drops below the desired temperature.

Abstract: A system for heating viscous fluids in a wellbore includes a submergible pumping system comprising a pump and submergible electric motor. A heating unit is coupled to the pumping system and is supplied with electrical energy through a cable used to supply electrical energy to the motor. The heating unit may include a direct or alternating current heater and protective circuitry. The heating unit may be supplied with electrical energy through the motor stator windings or via a jumper arranged in parallel with the stator windings. Switches may be included in the heating unit and in a motor base for energizing the motor and the heating unit based upon sensed temperatures of the viscous fluids surrounding the pumping system.

Abstract: A well fluid sampling tool and method for retrieving reservoir fluid samples from deep wells. The sampling tool is lowered to the required depth, an internal sample chamber is opened to admit well fluid at a controlled rate, and the sample chamber is then automatically sealed. The temperature of the sampled well fluid is maintained at or near initial as-sampled temperature to avoid the volumetric shrinkage otherwise induced by temperature reduction, mitigate precipitation of compounds from the sample, and/or maintain the initial single-phase condition of the sample. The sample chamber is thermally insulated, provided with a storage heater, electrically heated, given a high hear capacity, and/or pre-heated to sample temperature.

Abstract: 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.

Abstract: The present invention provides a system for cooling antenna assemblies, such as subterranean RF antennas used to heat geological formations. The invention generally includes a radio frequency (RF) generator, a waveguide operatively connected to the RF generator and to the antenna, a supply of cooling gas and a cooling gas delivery tube. In one embodiment, a housing encloses the antenna, with the antenna and the waveguide defining a gas enclosure. The supply of cooling gas in this embodiment includes a regulated gas supply, a desiccator and a heat exchanger through which the gas passes. The cooling gas delivery tube is in fluid communication with the supply of cooling gas and extends downwardly within the gas enclosure to deliver cooled, dried gas to the gas enclosure. An alternative embodiment employs a coaxial transmission line as the waveguide, with the coaxial line having an inner tubular member received within a lumen of an outer tubular member.

Abstract: An electrical heating system for enhancing production from an oil well, particularly an oil well of the kind commonly known as a horizontal well, the well including an initial well bore extending downwardly from the surface of the earth through one or more overburden formations and communicating with a producing well bore extending from the initial well bore into at least one oil producing formation. The producing well bore may or may not be truly horizontal The heating system includes an electrode array comprising a plurality of at least three tubular, electrically conductive heating electrodes extending through the producing well bore. Each electrode has a given length, usually two to three meters, and a smaller diameter D. The sum of the electrode lengths is substantially less than the length of the producing well bore. The electrodes are spaced from each other by isolation sections; the length of an isolation section is much greater than the electrode diameter D.

Abstract: A heater cable is strapped alongside tubing in a well to heat the production fluids flowing through the tubing. The heater cable has three copper conductors surrounded by a thin electrical insulation layer. An extrusion of lead forms a protective layer over the insulation layers. The lead sheaths have flat sides which abut each other to increase heat transfer. A metal armor is wrapped around the lead sheaths of the three conductors in metal-to-metal contact. Three phase power is supplied to the conductors, causing heat to be generated which transmits through the lead sheaths and armor to the tubing.

Abstract: A system for using a ferrite element to convert RF energy into heat consists only of the ferrite element, an RF generator and a cable connecting the ferrite element to the RF generator. No external impedance matching mechanism is needed, and the preferred form of the ferrite has a Curie temperature in excess of 150.degree. C., and has a lower cutoff frequency of about 10 KHz. The specific best mode ferrite element includes a formulation of MnO.sub.0.45 Zn.sub.0.3 FeO.sub.0.25 Fe.sub.2 O.sub.4. One use of the circuit is in the mining industry.

Abstract: Low-flux-leakage cables and cable terminations for an A.C. electrical heating system that heats a fluid reservoir around a mineral fluid well, usually an oil well; the system utilizes A.C. electrical heating power in a range of 25 to 1000 Hz. The well has a borehole extending down through overburden formations and through a subterranean fluid reservoir; the well includes an electrically conductive upper casing in the overburden, an electrically conductive heating electrode located in the reservoir, and an electrically insulating casing between the upper casing and the heating electrode. The cable extends down through the upper casing and is connected to the heating electrode to supply electrical power to the electrode. The power cable has two or three electrical conductors which are electrically isolated from each other, enclosed within a steel sheath.

Abstract: A downhole radial flow steam generator for oil wells that includes an annular casing and a water passage extending therethrough with a porous medium between the casing and passage with electrode means within the generator to heat the water into steam or hot water wherein the fluid is directed radially through the medium and the annular casing into a preselected earth strata to heat oil therein and reduce its viscosity for pumping to the surface.

Abstract: A.C. electrical heating system for heating a fluid reservoir (deposit) in the vicinity of a mineral fluid well, usually an oil well, utilizes A.C. electrical power in a range of 25 Hz to 30 KHz. The well has a borehole extending down through an overburden and into a subterranean fluid (oil) reservoir. There is a well casing including an upper electrically conductive casing around the borehole in the overburden, and at least one electrically conductive heating electrode located in the reservoir to deliver heat to the reservoir. An electrically insulating casing is interposed between the upper casing and the heating electrode. An electrically isolated conductor extends down through the casing. The heating system further includes an electrical A.C. power source having first and second outputs; the power source is usually located at the top of the well.

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 device for removing deposits such as asphalt, hydrates, and paraffins from petroleum and natural gas production strings and pipelines include a tubular housing divided into a heating section at a forward end and a ballast section at a rear end, the heating section containing an electrically conducting heating medium and an electrode, and the part of the housing forming the heating section is made of an electrically conducting material, the electrode being connected to one pole of an electrical power supply and the part of the housing forming the heating section being connected to another pole of the electrical power supply, so that the heating medium and the heating section are heated by the power supply.

Abstract: A standoff insulator and support for an elongated power cable disposed adjacent to a fluid conducting tubing string for a fluid production well utilizing an electric submersible pump connected to the tubing string. The pump power cable is held in a standoff, thermally insulated position from the tubing string by an elastomer insulator body having opposed concave surfaces engageable with the power cable and the tubing string and a flexible strap trained through a slot along one side of the insulator and through a channel on the opposite side of the insulator. The strap includes a buckle for receiving a distal end of the strap whereby the strap is tensioned and secured to clamp the insulator between the power cable and the tubing string using strap tensioning and crimping tools, respectively.

Abstract: An electric downhole heating system for formation heat treatment in the field of oil and gas production contains a separate wiring chamber, heating chamber, and cooling chamber, the latter being inserted between the wiring chamber and the heating chamber. The heat treatment is carried out by inserting the heater in a borehole to be treated. A gas, preferably nitrogen or air, is brought to the heater with a hose or tube. The gas flows through the wiring chamber and cooling chamber, and is heated by following a tortuous path in the heating chamber before it is expelled from the heater.

Abstract: A control system for well stimulation equipment including a source of electrical power, a source of injection fluid, a fluid injection system, and a downhole electrical heater, electrically connected to the source of electrical power includes one or more of temperature and pressure sensors both above and below grade for the purpose of monitoring process conditions. The sensor output is gathered in a computational unit and then manipulated for process control. The control system includes a response time which is defined as the time between a no flow condition at the heater and a shutting off of power, which response time is used to establish a temperature set point for the well stimulation equipment. A method of stimulating hydrocarbon recovery is also disclosed.

Abstract: A diathermal water heater for the rapid and controlled heating of water and like fluids. A diathermal heating chamber uses electrical oscillations to heat liquids flowing through it. By means of feedback circuitry, the electrical oscillations are controlled to provide liquids at a constant temperature. Household and industrial quantities of hot water, wet steam and dry steam may be generated by the water heater. The heater itself is compact and can be used to provide one pipe plumbing to provide water at controlled heated temperatures.

Abstract: An in-situ method of extracting contaminants from a soil volume comprises applying a radiofrequency (RF) excitation signal to heat the soil with an array of electrodes. The electrodes are inserted into the contaminated volume or inserted into a matrix of holes drilled into the volume. A first row of electrodes is electrically coupled to a shield of a coaxial cable, with a second row electrically coupled to the central conductor of the coaxial cable. RF energy is applied to pairs of electrode rows through the coaxial cable and a matching network is installed in front of the electrode-row pair to maximize power flow into the electrode-row pair. This results in very evenly distributed voltages which results in even heating. A balanced-to-unbalanced transformer (balun) is installed at the input to the matching network to prevent the deposition of RF energy outside the target volume and creation of voltages that could be hazardous to personnel.

Abstract: Microwave energy may be used to dielectrically heat a medium, which can remediate the medium. An apparatus or a system employing this concept is well-suited for various environmental applications, such as in-situ remediation of soil, sludge or spills. The system comprises a microwave energy source having a preselected microwave frequency for emitting microwave energy. The system also comprises a wave-guide section having a cross-section dimensioned in accordance with the wavelength of the microwave frequency for transmitting microwave energy. A broadband mode converter may be disposed in alignment with the wave-guide section. An applicator element is disposed in alignment with the broadband more converter for applying microwave energy directly to the medium without confining the medium, thereby removing contaminants from the medium.

Abstract: A method for heat injection into a subterranean diatomite formation is provided. The method utilizes a heater that is placed directly in the diatomite formation without cement around the heater. Diatomite is very soft, and will quickly fill in around the heater, operation of the heater will sinter the diatomite and significantly increase the original thermal conductivity and strength of the diatomite.