KR100440993B1 - Flameless combustor - Google Patents

Abstract

A flameless combustor eliminates the flamme as a radiant heat source, which 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. The present invention lowers the autoignition temperature by placing a catalytic surface within the desired combustion chamber. Temperatures are maintained above the catalyzed autoignition temperature but less than the noncatalyzed autoignition temperatures for noncatalyzed reaction. Thus, the amount and location of reaction can be controlled by varying the amount and distribution of catalyst within the burner. Removing heat from the combustion chamber in amounts that correspond to the oxidation of fuel within different segments of the combustion chamber can result in low temperatures and relatively even distribution of heat from the burner.

Description

{FlAMELESS COMBUSTOR}

U.S. Patent Nos. 4,640,352 and 4,886,118 disclose the recovery of oil by conduction heating a low permeability underground lipid layer containing oil. Low-permeability geological layers include diatomaceous earth, geological coal and contain- ing shale (oil shale). Low permeability geological layers do not meet secondary oil recovery methods, such as steam, carbon dioxide, or fire flooding. The flooding material preferentially tends to penetrate the low permeability lipid layer through the crevices. Injection material bypasses most of the geological layer hydrocarbons. Conversely, conduction heating does not need to transport fluid to the lipid layer. Thus, the oil in the lipid layer is not bypassed as in the flooding process. When the temperature of the lipid layer is increased by conduction heating, the vertical temperature profile tends to become relatively uniform since the lipid layer usually has relatively uniform thermal conductivity and specific heat. The transport of hydrocarbons during the heat transfer process is due to pressure expansion, evaporation and thermal expansion of the oil and water present in the pores of the geologic rock. Hydrocarbons travel through small crevices created by the expansion and evaporation of oil and water.

U.S. Patent No. 5,255,742 discloses a non-salt combustor useful for heating an underground lipid layer utilizing preheated fuel gas and / or combustion air, wherein the fuel gas is mixed with combustion air in small increments sufficient to eliminate flames. Therefore, the generation of NO _x is almost eliminated, and the cost of the heater can be greatly reduced because of the cheap components. However, in the case of preheating the fuel gas according to the method described in this prior art document, coke may be produced without adding CO ₂ , H ₂ , or steam to the fuel gas. Furthermore, since it is necessary to operate at a temperature exceeding the non-catalytic autoignition temperature of the fuel gas mixture, it is only time consuming to start the operation with the known heater.

Catalytic combustors are also known. For example, U.S. Patent No. 3,928,961 discloses a catalyst-supported thermal combustion device in which the production of NO _x is eliminated by combustion below the spontaneous ignition temperature of the fuel but substantially below the temperature that produces nitrogen oxides do.

For example, U.S. Patents 5,355,668 and 4,065,917 disclose metal surfaces coated with an oxidation catalyst. This patent proposes a catalyst coated surface on a component of a gas turbine engine. U.S. Patent No. 4,065,917 proposes the use of a catalyst coated surface for the start-up of a turbine and also suggests a step of limiting the mass transfer of the start-up operation.

Non-salt flammable and non-flammable combustion methods according to the claims of claims 1 and 16 are disclosed in U.S. Patent No. 3,817,332. In the known method, the fuel and the oxidant are supplied to the combustion chamber via separate supply lines, which is expensive but necessary to avoid premature burning of the fuel in the supply line.

The present invention relates to an apparatus and method for non-salt combustion.

1 shows a combustor according to the invention;

Figure 2 is a plot of methane consumption versus temperature in a test apparatus illustrating the present invention.

It is an object of the present invention to provide an incombustible combustor capable of initially mixing fuel and oxidizer and to provide a combustion distribution determined by the distribution of the catalyst surface in the combustion chamber.

It is also an object of the present invention to provide a combustion method and a combustion apparatus that are non-salt-free and do not require the addition of additives in the fuel gas stream to prevent the production of coke. In another aspect, an object of the present invention is to provide a combustion method and a combustion apparatus that minimize the generation of NO _x . These and other objects are achieved by a non-salt combustor for burning fuel and oxidizer mixture,

A combustion chamber communicating with an inlet and a combustion product outlet;

Mixed fuel and oxidant supply in communication with the inlet; And

And a catalyst surface in the combustion chamber for oxidizing a predetermined amount of fuel to a temperature not exceeding the non-catalyzed spontaneous ignition temperature of the fuel and oxidizer mixture.

Since the temperature due to the adiabatic combustion of the fuel-oxidant mixture is avoided, the non-halogen combustor of the present invention minimizes the production of nitrogen oxides. Therefore, no other measures are required to eliminate or prevent the formation of nitrogen oxides. Relatively uniform distribution of heat over a large area and a long distance is possible, and because of the low combustion temperature, relatively inexpensive components for the combustor of the present invention can be used.

Acceptable catalyst materials include noble metals, semiprecious metals, and transition metal oxides. In general, known oxidation catalysts are useful in the present invention. Mixtures of these metals or metal oxides may also be useful.

The non-salt combustor of the present invention is particularly useful as a heat injector for heating an underground lipid layer for recovery of hydrocarbons. In addition, the catalyst surface improves the operability of the heat injector and the operation start operation. According to the invention, it is not necessary to transfer the fuel and the oxidant to separate combustion tubes in the heating injector. As a result, the cost is greatly reduced.

Further, according to the present invention, there is provided a method of heating an underground geological layer by an incombustible combustor. The method according to the invention comprises the following steps:

Providing a combustion tube forming a downhole combustion chamber in a wellbore in a lipid layer to be heated;

Supplying fuel and an oxidant to the combustion chamber through an inlet;

Flowing the fuel and oxidant mixture along a catalyst surface in a combustion chamber that oxidizes a predetermined amount of fuel at a rate such that an average temperature in the combustion chamber is maintained below a non-catalyzed spontaneous ignition temperature of the fuel and oxidant mixture; And

Flowing the combustion product through the combustion product outlet conduit in the vessel to the surface.

Preferably, the combustion chamber is formed by a well casing and a lower portion of the plug near the bottom of the well casing, wherein the catalyst surface is coaxially suspended in the well casing, Lt; RTI ID = 0.0 > and / or < / RTI >

Also preferably, the hanging tube is used as an inlet conduit for mixed fuel and air, and an annular space between the hanging tube and the well casing is used as an outlet conduit for the combustion product, and vice versa.

The foregoing and other features, objects and advantages of the combustion apparatus and the combustion method according to the present invention will become apparent from the accompanying drawings.

In general, non-salt combustion is achieved by sufficiently warming the combustion air and the fuel gas, when the two streams are mixed, the temperature of the mixture exceeds the autoignition temperature of the mixture, but oxidation Lt; / RTI > Without the catalyst surface, the non-salt combustion will occur by preheating the stream to a temperature in the range of about 815 ° C to about 1260 ° C and then mixing the fuel gas with combustion air in relatively small increments.

In the presence of an effective catalytic surface, the temperature of the oxidation reaction occurring in the zone affected by the catalytic surface is very low. The lowered temperature is hereinafter referred to as catalysed spontaneous ignition temperature. In the tube flow, the fluid in the boundary layer in contact with the catalyst surface will be oxidized almost quantitatively, but if the bulk temperature is maintained below the non-catalyzed spontaneous ignition temperature of the mixture, there will be little oxidation outside the boundary layer. Thus, the reaction in the temperature range between the catalysed spontaneous firing temperature and the non-catalyzed spontaneous firing temperature limits mass transfer at a relatively temperature-independent rate. This is proposed in the literature such as U.S. Patent No. 4,065,917. In the present invention, the reaction mechanism of this mass transfer limitation is utilized to control the heat generation distribution in the combustion chamber of the non-salt combustor. By balancing heat generation and heat removal, the average stream temperature of the mixed oxidant, fuel, and combustion products can be maintained between the catalyzed auto-ignition temperature and the non-catalyzed auto-ignition temperature.

The heater of the present invention can be controlled by such variables as fuel-oxidant ratio, fuel-oxidant flow rate. Depending on the particular application, the thermal load may also be controlled.

The main characteristic of the non-salt combustor of the present invention is that the heat is removed along the axis of the combustion chamber so that the temperature is kept well below the adiabatic combustion temperature. For this reason, the production of NO _x s is almost eliminated, and the metallurgical conditions are greatly reduced, so that a comparatively inexpensive combustor can be obtained.

Figure 1 shows a combustor in a heating injection well in which the present invention may be practiced. The lipid layer (1) to be heated is below the topsoil (2). The drill jets 3 extend through the topsoil, preferably to a location near the bottom of the geological layer to be heated. The wells are shown as vertical wells, but they can be oblique or horizontal. Hydrothermally recoverable hydrocarbons can also be recovered by a parallel drive method by installing a horizontal heat injection well in the horizontally shattered lipid layer. Horizontal heaters are useful for shallow containment shale. The horizontal heater can also be effectively used in heating thin layers to limit heat loss to the topsoil and base arm. In the embodiment shown in Fig. 1, the casing 4 is provided in the drill hole. The bottom of the drill hole can be bonded with cement (7) with properties suitable to withstand high temperatures and transmit heat. Cement 8, which is a good thermal insulator, is preferred for top of drilling to prevent heat loss from the system. The combustion mixture conduit 10 extends from the wellhead (not shown) to the bottom of the drill hole.

High-temperature cement suitable for cement-bonding casings and conduits within high-temperature zones is useful. Examples of this are disclosed in U.S. Patent Nos. 3,507,332 and 3,180,748. An alumina content of greater than about 50 weight percent based on cement slurry solids is preferred.

In a shallow geological layer, it is advantageous to directly hammer-perforate the heater in the geological layer. When the heater is hammer-pierced directly into the lipid layer, it is not necessary to cement the heater into the lipid layer, but the upper portion of the heater may be cemented to prevent fluid loss to the surface.

In the embodiment of Fig. 1, the diameter of the casing 4 can be selected according to the cost of the casing and the heat transfer rate of the geological layer. Casing is generally the most expensive component of the injection well due to the need for metallurgy. As the casing diameter increases, the heat that can be transferred to the lipid layer also increases significantly. In view of the initial cost and heat transfer capability from the wells, a casing generally having an inner diameter between about 10 and about 20 cm is optimal.

A cement plug (23) is shown at the bottom of the casing, which is pressed under the casing during the cement joining operation to push the cement out of the bottom of the casing.

The catalyst surface 20 is provided in the combustion chamber 14 to provide a limited zone of low oxidation reaction temperature. For the distribution of heat release within the combustion chamber, the catalyst surface 20 is provided as a coating that covers at least a portion of the inner and / or outer surface of the lower portion of the conduit 10. The catalyst surface is sized to achieve a nearly even temperature distribution along the casing. Since a nearly even temperature profile in the casing is achieved, the thermal distribution in the lipid layer to be heated becomes more uniform. Further, if the thermal distribution in the lipid layer becomes almost uniform, heat can be used more efficiently in the hydrocarbon recovery process by conduction heating. In addition, the more uniform the temperature profile, the lower the maximum temperature for the same heat release. Because the constituent materials of the burner and well systems define the maximum temperature, an even temperature profile will increase the possible heat release for the same constituent material.

As the combustion products rise above the heated geological bed in the wellhead, heat exchange occurs between the combustion air and the fuel gas flowing below the flow conduit and the ascending combustion products. This heat exchange not only conserves energy but also enables the non-halogen combustor to which the present invention is directed. Since the fuel gas and the combustion air are sufficiently warmed as they move down the respective flow conduit, the temperature of the mixture of the two streams at the final mixing point exceeds the catalyzed autoignition temperature of the mixture, It will be below the autoignition temperature. Flame as a radiant heat source is avoided by combustion on the catalyst surface and by non-chlorinated combustion in the boundary layer close to the effective catalyst surface. Thus, the heat is inherently uniformly transferred from the well.

In the operation of the combustor of the present invention, it is important to remove heat from the combustion chamber along the length of the combustion chamber. When the present invention is applied to a drilling heat injector, heat is transferred to the lipid layer around the drill hole. The heaters of the present invention can also be used in other applications, such as steam generators and chemical industry process heaters and reactors.

The fuel gas and the combustion air are delivered to the drill hole floor through the mixed fuel and oxidant supply shown as annular volume surrounding the combustion product conduit. Mixed fuel and air react at the site of the well adjacent to the catalyst surface 14 forming the combustion products. The combustion products rise above the drilling rig and exit the exhaust well (not shown) through the combustion product conduit 10 in the wellhead. The combustion products from the exhaust can exit to the atmosphere through the exhaust stack (not shown). Alternatively, even if it is not necessary to remove nitrogen oxide because it is not present, the combustion gas may be treated to remove contaminants. It is also desirable to recover additional energy from the combustion products by the expansion turbine or heat exchanger.

When the fuel gas is preheated for the non-catalytic, non-salt combustion, too much carbon is generated unless the carbon-forming inhibitor is included in the fuel gas stream. Therefore, by operating the heater at a temperature lower than the temperature at which carbon is formed, there is no need to provide the carbon formation inhibitor. This is another important advantage of the present invention because the use of carbon inhibitors increases the volume of gas passing through the heater and thus the required size of the conduit.

The start of the low temperature operation of the well heater of the present invention can utilize flame combustion. The initial ignition may be accomplished by injecting a spontaneous ignition material, an electric igniter, a spark igniter, temporarily lowering the igniter to the igniter, or an electric resistance heater. Preferably, the temperature of the burner is rapidly heated to a temperature at which the non-salt combustion is maintained to minimize the time during which the flame is present in the crucible. The rate at which the burner is heated is typically limited by the thermal gradient the burner can withstand.

The combustion mixture conduit can be used as a resistance heater to raise the combustor to operating temperature. To use the conduit as a resistance heater, an electrical lead 15 is connected to the combustion mixture conduit 10 near the well head under the electrical isolation coupling, using a clamp 16 or other connection means to provide electrical energy Can supply. Electrical grounding may include one or more electrically conductive centralizers (17) around the bottom of the bore hole around the combustion mixture conduit (10). The centralizer on the combustion mixture conduit on the electrical riser central riser is an electrically insulated centralizer. Preferably, sufficient heat is supplied so that the combustion mixture exceeds the catalyzed autoignition temperature at the location of the initial catalyst surface, Lt; RTI ID = 0.0 > ignition temperature.

The thickness of the combustion mixture conduit can be varied for heat release in a pre-selected section of the fuel conduit length. For example, in a well heating injector application, it is desirable to electrically heat the lowermost portion of the drill hole to ignite the mixed gas stream with the highest concentration of fuel and burn the fuel before the exhaust gas flows back through the drill hole. The illustrated thin section 21 provides a hot surface for the commencement of operation of the combustor in the combustion mixture conduit.

The oxidation reaction temperature of the fuel gas-oxidant mixture is lowered by providing a noble metal surface or other effective catalytic surface. The catalyst surface is preferably provided on the inner surface, the outer surface, or both the inner and outer surfaces of the combustion product conduit 10. Alternatively, a tubular or other noble metal containing surface, or surface, may be separately installed in the combustion chamber. For example, the combustion product annulus outside the combustion gas conduit may provide another noble metal coated surface. This additional catalyst surface allows complete combustion to occur within the wellhead where heat generation is desired.

The initiation of the operation of the non-salt combustor of the present invention can be improved by supplying a supplementary oxidant during the start-up phase or by using a fuel having a low spontaneous ignition temperature such as hydrogen. Preferred supplemental oxidizing agents include supplemental oxygen and nitrogen oxides. Hydrogen may be provided with the natural gas stream and may also be provided as a shift gas in the presence of carbon monoxide and carbon dioxide.

The work-initiating oxidant and / or fuel is preferably used only until the combustor is heated to a temperature sufficient to be able to operate with methane (natural gas) as fuel and air as the oxidant (i.e., Of the catalyzed spontaneous ignition temperature of < / RTI >

U. S. Patent No. 5,255, 742 discloses the use of an electrical resistive nichrome heater to generate heat for commencement of operation of an incombustible combustor. In the practice of the present invention, the electric heater may be used.

A noble metal such as palladium or platinum, or a precious metal, a base metal, or a transition metal may be coated on the surface in the combustion chamber by electroplating, thereby improving the oxidation of the fuel at low temperatures. Thus, the metal is optionally oxidized to provide a catalytically effective surface. This catalyst surface was found to be very effective in promoting oxidation of methane in air at a low temperature of 260 ° C. The reaction occurs rapidly on the catalyst surface and in the adjacent boundary layer. If a large catalyst surface is provided in the combustion chamber, there is an advantage that the operating temperature range of the non-halogen combustor can be greatly increased.

[Example]

Using a thermal reactor, the temperature at which the oxidation reaction takes place is achieved by the various mixtures of fuel, oxidant and catalyst surface. The reactor was a 2.54 cm stainless steel pipe wrapped with an electric resistance heating coil and covered with an insulator. Below the insulator adjacent to the outer surface of the pipe was a pair of thermocouples for temperature control. In addition, a thermoelectric pair was also provided at the inlet, middle, and outlet of the inside of the pipe. Catalyst activity was tested by suspending the test ribbon in stainless steel strip with noble metal or precious metal coating on the pipe. Preheated air to a temperature below the desired test temperature was injected into the electrically heated test section of the pipe. The power to the electrical resistance heater was varied until the desired temperature was obtained in the test compartment to achieve the steady state as measured by the thermocouple set inside the pipe. Next, the fuel was injected into the stream of preheated air through the mixed T-tube and allowed to flow to the electrically heated test section. Four platinum ribbons of 1/8 inch (= 0.32 cm) wide and about 16 inches (= 40 cm) long or 3/8 inch (= 0.95 cm) wide coated with platinum or palladium on both sides and about 1/16 Stainless steel strips with an inch (= 0.16 cm) thickness and a length of about 16 inches (= 40 cm) were suspended in a pipe to test the catalytic activity. The addition of fuel increased the temperature in the inner intermediate and exit thermoelectric pairs when the test compartment contained catalyst coated strips or noble metal ribbon and was at or above the catalyzed spontaneous ignition temperature. Below the catalysed spontaneous ignition temperature, this temperature was not observed. In the absence of catalyst coated strips or noble metal ribbon, a temperature increase was observed by heating the test section to the autoignition temperature of the fuel. The measured non-catalyzed and catalyzed spontaneous firing temperatures are summarized in Table 1, and the measured non-catalyzed or catalyzed spontaneous firing temperatures are referred to as measured spontaneous firing temperatures.

It can be seen that adding N ₂ O to the fuel stream from the table greatly reduces the measured autoignition temperature of the mixture. In addition, the inclusion of hydrogen as fuel and the presence of the catalyst surface significantly reduce the dynamic spontaneous ignition temperature.

Test the results of a 2.54 cm reactor when applying a distributed combustor using a 3.048 m long test combustor. A 2.54 cm outer diameter fuel gas line was provided within the 5.08 cm inner diameter combustion line. The fuel injection line provided a fuel conduit to the fuel injection port located near the inlet end of the combustion line. A 5.08 cm internal combustion wire was placed in the insulation pipe and a pair of thermocouples were placed along the fuel supply line. Two different combustion lines were used. One burner line was made from a "HAYNES 120" alloy strip. On one side of the strip was electroplated with palladium to an average thickness of 0.000254 cm. The strip was then braided, swaged and welded to the 3.048 m long pipe by palladium coating on the inner surface. The other burner line was a standard 7.62 cm pipe of "HAYNES 120" alloy. Using a " MAXON " burner, the combustion gases are fed into the 3.048 m long combustion pipe and mixed with the effluent from the " MAXON " burner in the mixing zone between the burner and the combustion line by varying the amount of air and / . In order to maintain a uniform temperature in the combustion line, three electric heaters, each with its own regulator, were placed along the length of the outer and combustion lines.

A series of tests were performed with a heater with a palladium coated combustion wire and a heater with a non-palladium coated combustion wire. The fuel gas is injected through the fuel gas inlet at a rate of about 0.635 m < ³ > / hour at a temperature of 15.5 DEG C and at atmospheric pressure, and the burner air and the second air at a rate of about 374 m < ³ & Containing air. A rich fuel gas was supplied to the burner to provide the desired temperature at the inlet of the combustion line. The percentage of combusted injected methane appears as a function of the combustion line inlet temperature in FIG. 2 for the catalyzed arrangement (line A) and the non-catalyzed arrangement (line B). It can be seen from FIG. 2 that the minimum temperature of the apparatus that can be operated is about 260 ° C and 55% of the methane is oxidized by the palladium coated combustion line. The minimum temperature of operation may be less than 260 占 폚, but the usable device could not be operated at a temperature lower than 260 占 폚. When using a combustion line without palladium coating, partial oxidation of methane occurs at about 704 ° C, and oxidation of methane occurs rapidly at a temperature of about 816 ° C. At temperatures above 871 ° C, the presence of the palladium surface is not affected by the rapid and complete oxidation of methane with or without palladium surfaces.

The temperature dependence of methane oxidized below 704 ° C tends to prove that methane is rapidly oxidized within the boundary layer at the surface of the palladium surface and that the migration of methane to the boundary layer, rather than kinetics, . At temperatures above about 704 DEG C, thermal oxidation predominates and is temperature dependent due to the thermal oxidation.

Claims (19)

An incombustible combustor for burning fuel and oxidizer mixture, comprising: a combustion chamber (14) in communication with an inlet and a combustion product outlet (10); And a catalyst surface (20) in the combustion chamber (14) The combustor further comprises a mixed fuel and oxidant supply (22) in communication with the inlet; Wherein the catalyst surface (20) oxidizes a predetermined amount of fuel to a temperature that does not exceed the non-catalyzed spontaneous ignition temperature of the fuel and oxidizer mixture. The non-salt combustor according to claim 1, wherein the catalyst surface (20) comprises a component selected from the group consisting of noble metals, semiprecious metals, transition metal oxides and mixtures thereof. The non-salt combustor of claim 1, wherein the catalyst surface (20) comprises palladium. The non-salt combustor according to claim 1, wherein the catalyst surface comprises (20) platinum. The flameless combustor according to claim 1, further comprising a preheating zone (22) in which heat exchange takes place between the fuel and the oxidant mixture and the combustion products. 6. The method of any one of claims 1 to 5, wherein said combustor is designed to heat an underground geological layer by burning fuel and oxidant mixture; Wherein said combustion chamber (14) is formed by one or more combustion tubes (4, 10) located in a well body in a lipid layer to be heated; Wherein the combustor comprises a combustion gas outlet (10) located within the well and allowing combustion products to flow to the surface. 7. An incombustible combustor according to claim 6, characterized in that the area of the catalyst surface (20) is distributed in the combustion chamber (14) such that the temperature in the combustion chamber (14) is essentially constant. 7. An incombustible combustor according to claim 6, characterized in that the combustion chamber (14) is formed by at least one tubular pipe (4, 10) located in the well. 7. The incombustible combustor according to claim 6, wherein the combustion gas outlet is an annular space (22) surrounding the combustion tube (4). 7. An incombustible combustor according to claim 6, wherein the combustion gas outlet is a tube (10) in the combustion chamber (14). 7. An incombustible combustor according to claim 6, characterized in that the combustion chamber (14) comprises an annular volume between the tube (10) and the casing (4). 12. An incombustible combustor according to claim 11, wherein the tube (10) is a conduit for returning combustion products to the wellhead. 7. An incombustible combustor according to claim 6, characterized in that said tube (10) is a conduit comprising another part of the combustion chamber (14). 6. A method according to any one of claims 1 to 5, wherein the catalyst surface (20) is provided by a catalyst coating covering the inner surface, the outer surface, or at least a portion of the inner and outer surfaces of the tube (10) Wherein the combustible combustor is a non-combustible combustor. 6. An incombustible combustor according to any one of claims 1 to 5, wherein the inlet is located at one end of the combustion chamber (14), and the outlet is located at the other end of the combustion chamber. A method for heating an underground lipid layer by non-saline combustion, comprising the steps of: providing a combustion tube (10) forming a downhole combustion chamber (14) in a drill hole (3) inside a lipid layer (1) to be heated; (20) in a furnace (14), the method comprising the steps of: Further comprising feeding the fuel and oxidant mixture through the inlet to the combustion chamber (14); The catalyst surface 20 oxidizes a predetermined amount of fuel at a rate such that the average temperature in the combustion chamber 14 is maintained below the non-catalyzed spontaneous ignition temperature of the fuel and oxidant mixture; Further comprising the step of allowing the combustion product to flow to the surface through the combustion product outlet conduit (10) in the interior of the well (3). 18. The apparatus according to claim 16, wherein the combustion chamber (14) is formed with a well casing (4) and a lower portion of a plug (23) near the bottom of the well casing (4) Provided on the inner surface, the outer surface, or the inner surface and the outer surface of the suspension pipe 10, which is coaxially suspended in the axial direction of the suspension pipe 10 and coaxially suspended in the axial direction of the suspension pipe 10 and maintains axial space between the lower end of the suspension pipe 10 and the plug 23 And heating the underground lipid layer by non-salt combustion. The method according to claim 17, characterized in that the suspension pipe (10) is used as a mixed fuel and air inlet conduit and an annular space (22) between the suspension pipe (10) and the well casing Wherein the method further comprises the step of heating the underground lipid layer by non-salted combustion. A method according to any one of claims 16 to 18, characterized in that the method is used for heating a hypo-permeable underground containing shale lipid layer (1).