RU2582694C2 - Ignition of underground coal bed in method for underground coal gasification, ucg - Google Patents

Abstract

FIELD: coal industry.

SUBSTANCE: group of inventions relates to versions of device for ignition of underground coal bed and can be used for underground coal gasification. Device comprises a system of ignition, positioning system, transducer and controller. Ignition system includes means of ignition and device for igniting underground coal bed from inside of well channel or well liner, enclosed in the well channel. Positioning system includes flexible tubing connected with device for ignition and passing through well head inside of well channel for installation of device for ignition in desired place inside the well channel. System additionally contains flexible pipeline drum for transportation and distribution of tubings.

EFFECT: technical result consists in improving reliability of device for igniting underground coal bed.

15 cl, 18 dwg

Description

Field of Invention

The present invention relates to a method and apparatus for firing an underground coal seam for in-situ processing of coal into a gaseous product.

BACKGROUND OF THE INVENTION

Underground coal gasification (CCGT) is a method in which a gaseous product is obtained from a coal seam by in-situ heating of coal with an oxidizing agent. The gaseous product is usually called synthetic gas or synthesis gas and is used, for example, as a feedstock for electricity or chemical production.

The processing of coal into a gaseous product takes place in a well, typically comprising a channel of the type of well that passes through the coal seam. Such a channel can be formed by one or more boreholes drilled in a coal seam in fluid communication with each other. The channel is also in fluid communication with the injection well, production well, as well as with one or more ignition or auxiliary wells passing from the surface of the earth to the well channel. Typically, an oxidizing agent is introduced into the well channel through an injection well to facilitate combustion. Typically, the ignition source to initiate combustion of the coal seam is introduced into the well channel through the ignition well. Combustion can also be initiated using an incendiary device, as a result of which an incendiary device capable of igniting coal is introduced into the well channel through an ignition or injection well.

An underground coal bed gasifier is generally referred to as a coal gas generator. Gasification takes place near the combustion zone of the well / gas generator, and the coal is partially oxidized to produce a gaseous product with a low or medium calorific value. Hot gaseous product flows from the gasification zone and leaves the earth from the wellhead of the production well. After combustion or gasification of coal, a gasification cavity inside the coal seam is developed and the channel increases in size.

One of the main tasks of vocational schools is the underground ignition of coal, in particular, in a safe and cost-effective way. Various methods have been proposed and applied. One such method involves discharging hot coal or lowering an electric heat resistance device into a vertically protruding ignition well, directly into the intended combustion zone, and then injecting oxygen into the combustion zone through the injection well, so that the combustion is autogenous. Another method involves the discharge of volatile chemicals, such as triethylborane or silane, which spontaneously ignite upon contact with air, to initiate ignition, followed by the supply of fuel for ignition and an oxidizing agent to the intended combustion zone, so that combustion is autogenous.

One of the problems associated with CCGT is that the combustion front created in the combustion zone does not always move along the coal seam, as is supposed in theory, and the practically coal seam may need to be re-ignited in different gasification areas along the coal seam to maximize the production and life cycle of a coal gas generator.

One of the problems associated with CCGT when using a borehole channel extending substantially horizontally through a coal seam is that more than one vertically protruding ignition well (borehole) may be necessary for igniting / re-igniting a coal seam / gasifier in several places, since the installation of injection wells is an expensive and time-consuming process. However, the use of triethylborane or silane can be dangerous for service personnel, due to the peculiarity of the high volatility of the material in contact with air, and any mistake when working with such materials can lead to their contact with air, which can cause fires or explosions.

Summary of the invention

An object of the present invention is to provide a method or device for igniting (or re-igniting) coal from an underground coal seam in a safe and / or cost-effective manner, or providing the public with a useful or commercial choice.

In accordance with a first aspect of the present invention, there is provided an ignition device for igniting underground coal seams from within a well channel passing through a formation, said device comprising:

an ignition system comprising ignition means and an ignition device for igniting underground coal seams from within the well channel; and

a positioning system comprising a flexible tubing connected to the ignition device and extending inside the well channel to place the ignition device in a desired location within the well channel.

In accordance with a second aspect of the present invention, there is provided an ignition system comprising ignition means and an ignition device for igniting an underground coal seam.

In accordance with a third aspect of the present invention, there are provided ignition means for igniting an underground coal seam.

In accordance with a fourth aspect of the present invention, there is provided an ignition tool for igniting an underground coal seam.

According to a fifth aspect of the present invention, there is provided a positioning system comprising a flexible tubing extending inside a borehole to accommodate an ignition tool at a desired location within the borehole.

In accordance with a sixth aspect of the present invention, a method for firing an underground coal seam from within a well channel passing through the seam is provided, said method comprising the following steps:

(1) moving the device for ignition of the ignition device into the well channel; and

(2) igniting an underground coal seam in one or more places inside the channel of the well using an ignition tool,

wherein the ignition device comprises:

an ignition system comprising ignition means and an ignition device; and

a positioning system comprising a flexible tubing connected to the ignition device and extending inside the well channel to place the ignition device in a desired location within the well channel.

The numbers from the first to sixth aspects of the present invention are described below, including detailed descriptions of embodiments of the sections of the invention.

The invention is particularly suitable for well channels that extend horizontally or substantially horizontally despite the fact that the coal seam / gas generator or vice versa extends non-vertically or non-linearly. Thus, the invention is particularly suitable for firing up zones of coal seams that are not located directly beneath or directly adjacent to the bottom of an injection, firing or other auxiliary well.

Ignition aids can ignite a coal seam in any suitable manner. The ignition means can directly ignite the coal seam, or ignite a combustible fluid (e.g., liquid or gas) inherent in the well channel or supplied to the well channel (e.g., supplied either in the form of a liquid or gas, or in a solid state).

In one embodiment, the ignition means comprise an electric spark generator (eg, a spark plug) and a power source for generating a spark. The power source may be located above ground or the spark generator may be driven by a formation turbine and a transformer connected by electrical connection to the spark generator. The means of ignition may further comprise a source of fuel for ignition and / or a source of oxidizing agent for the further initiation and / or combustion of the refueling fuel.

In another embodiment, the ignition means comprise an electric thermistor (for example, a glow plug) and a power source for supplying power to the resistor. A resistor can, for example, generate about 180 kW of heat. The power source may be located above ground or the spark generator may be driven by a formation turbine and a transformer connected by electrical connection to a resistor. The ignition means may further comprise an oxidizing agent source for further initiating and / or burning the refueling fuel.

In another embodiment, the ignition means comprise at least one type of ignition chemical (ignition chemical source). The ignition chemical may be a self-igniting substance — for example, a liquid such as triethyl borane, a gas such as silane, a solid such as phosphorus or an alkali metal, or a self-igniting chemical and a mixture of hydrocarbons such as triethyl borane vaporized into methane, or a self-igniting chemical and an inert gas such as triethyl borane and nitrogen. The flow of a hydrocarbon or inert gas helps transport / vaporize a self-igniting chemical reagent or cork / piston flow of a self-igniting chemical reagent to an ignition device. The means of ignition may also further comprise a source of fuel for ignition and / or a source of oxidizing agent for the further initiation and / or combustion of refueling fuel.

In yet another embodiment, the ignition means comprise pure oxygen or substantially pure oxygen directly igniting a coal seam. The ignition means may further comprise an oxidizing agent source for burning refueling.

The ignition device may be of any suitable size, shape and design, and may be made of any suitable type of material or materials. In its simplest form, the ignition device can be made in the form of an end nozzle for a flexible tubing. In a more complex form, the ignition device may include ignition means and / or other components of the ignition device.

The ignition device may comprise a device body. The housing may be a single structure or may contain two or more connected parts of the housing. The housing may be made of any suitable material or materials, including stainless steel and carbon steel. If the ignition tool / case has a protective part (for example, a core extrusion device or a gas cylinder cap), this part can be made of metallic or non-metallic materials, such as plastics or rubbers, which can be deformed or molten.

The ignition tool or device body may have any suitable outer diameter and length. For example, the ignition tool or device body may have an external diameter of, for example, about 2 inches, 3 inches, or 4 inches. Preferably, the ignition tool or device body has a diameter of about 2 inches.

Parts of the housing can be screwed together. The housing may or may not contain ignition equipment. The fixture body may have an inlet end and an outlet end, and they may be located at opposite ends of the body. The output end of the housing may be conical or other in shape, so as to reduce resistance when the ignition tool moves to the intended location within the coal seam. The inlet end of the housing may be adapted to be connected to a flexible tubing.

The ignition device can be connected to the flexible tubing in any suitable manner. The fixture body may be connected to the flexible tubing in a sealed or non-sealed manner. The housing of the ignition device can be detachably connected or permanently connected to a flexible tubing. Preferably, the housing is connected to the end of the flexible tubing by screw thread or welding.

The flexible tubing may be of any suitable size, shape and design and may be made of any suitable material or materials. More specifically, the flexible tubing may have any suitable length and diameter. Preferably, the flexible tubing is made of metal, such as stainless steel, carbon steel or copper. The flexible tubing may be a single structure or contain two or more connected pipe parts. A preferred outer diameter for the flexible tubing is a two inch diameter.

A flexible tubing may comprise one pipe (conduit) connected to the device body. The flexible tubing may alternatively comprise at least one inner pipe (inner pipe) extending inside the outer pipe (outer pipe), in which one or both of the inner and outer pipes are connected to the fixture body. That is, the flexible tubing may comprise at least one inner pipe and an outer pipe that extend concentrically relative to each other. More than one inner pipe may extend within one outer pipe. A preferred diameter of the outer tube is two inches, while the preferred diameter of the inner pipe is _^3/4 inches.

The positioning system may further comprise a flexible drum from which the flexible tubing is unwound. The flexible drum may be of any suitable size, shape, and construction, and may be made of any suitable material or materials. Preferably, the flex drum may unwind the flex tubing having a length of at least 300 m, 400 m, 500 m, 600 m, 700 m, 800 m, 900 m, 1000 m, 1100 m and 1200 m.

The source of fuel for ignition can supply fuel for ignition to or in the immediate vicinity of the device for ignition, either inside a flexible tubing or outside the tubing, but in the channel of the well. The ignition fuel may be in a solid state or in the form of a fluid, such as a gas or liquid. The ignition fuel may be a combustible hydrocarbon-based liquid such as methane, propane, butane, or mixtures thereof. The ignition fuel may be a self-igniting gas or liquid. The source of fuel for ignition may be a tank / cylinder of compressed combustible gas or liquefied gas. The ignition fuel source may be directly or indirectly connected to the flexible tubing in an airtight manner.

The ignition device may comprise an oxidizing agent source that can supply the oxidizing agent to or in the immediate vicinity of the ignition device, either inside the flexible tubing or outside the flexible tubing but in the borehole. The oxidizing agent may be in a solid or liquid state, but preferably in the form of a fluid such as air (about 20% oxygen), air or another gas / gas mixture enriched with oxygen (more than about 20% oxygen, or from about 30% up to 80% oxygen), or substantially pure oxygen. The oxidizing agent source may comprise, for example, an air compressor, a reservoir / cylinder of compressed air or oxygen, an air separation unit, or a tank / cylinder of liquid oxygen. The oxidizing agent source may be connected directly or indirectly to the flexible tubing in a sealed manner. The oxidizing agent source may be connected directly or indirectly to the wellhead of the injection well, so that the oxidizing agent is preferably injected into the well than into the flexible tubing.

The source of the chemical reagent for ignition can supply the chemical reagent for ignition to or in the immediate vicinity of the device for ignition, either inside a flexible tubing, or outside the flexible tubing, but in the borehole. As already mentioned, the ignition chemical may be in a solid state or in the form of a fluid, such as a gas or liquid. The source of the chemical reagent for ignition may be a tank / cylinder, under pressure or not under pressure, containing such a chemical reagent. The ignition chemical may be a self-igniting gas or liquid. The source of the chemical reagent for ignition can be connected directly or indirectly to the flexible tubing in a hermetic manner.

As already mentioned, a flexible tubing may comprise one pipe. The pipe can be used to transfer one or more electrical cables / lines (for power supply or data) from the surface of the earth to the body of the ignition device. The pipe can be used to supply fuel for ignition and / or a chemical reagent for ignition in the device for ignition.

As already mentioned, a flexible tubing may contain two or more pipes (pipelines) or more than two pipes, in which case the pipes may extend concentrically (one inside the other). The inner tube may supply ignition fuel and / or the ignition chemical to the ignition device housing. The outer tube may supply oxidizer to the ignition fixture body. The outer pipe can also transmit electrical cables (power or data) to the ignition device.

For an ignition device containing one pipe (“single flexible tubing”), an oxidizing agent injected into the well may leak from the outside of the pipe. The ignition device also contains one pipe, while the fuel for ignition and / or the chemical reagent for ignition, injected into the well, can flow inside the pipe. For an ignition device containing concentric tubes (“concentric tubing winding”), an oxidizing agent injected into the well may flow inside the outer pipe (preferably, like the well itself, outside the outer pipe) and the ignition fuel may flow in the inner pipe.

When using one pipe or concentric pipes, the (external) pipe can be made of stainless steel or carbon steel. If air is used as an oxidizing agent, the outer pipe can be made of carbon steel and the inner pipe can be made of copper. If air or oxygen is used as an oxidizing agent, the outer pipe may be made of stainless steel and the inner pipe may be made of copper or stainless steel.

The flexible tubing may further serve to accommodate other components of the ignition device, including components of the ignition device, sensors, and, as already mentioned, power or data cables.

The flexible tubing may comprise heat exchange structures such as ribs or guide ribs extending from the tubing of the flexible tubing to cool the inside of the tubing.

A flexible tubing may include positioners, such as ribs or guide ribs, that extend from the tubing of the flexible tubing and help adjust the position of the ignition tool within the borehole (or casing liner, if present). That is, they help center the ignition tool inside the borehole channel (or casing liner, if present).

The ignition device may comprise at least one inlet in the housing in fluid communication with at least one pipe from a flexible tubing. However, the connection should not be airtight. The inlet may be of any suitable size and shape. The inlet may be provided with a simple hole in the housing or pipe (sleeve), which extends inside and / or outside the housing. An electrical cable, sensor, or other component of the ignition assembly may pass through the inlet. The ignition fuel and / or the ignition chemical may be supplied through an inlet.

The ignition device may include a first inlet connected to an inner pipe that supplies ignition fuel and / or an ignition chemical to the housing. The ignition device may include a second inlet connected to an outer pipe that delivers an oxidizing agent or conducts a cable (power or sensor) or sensor to the device body.

The ignition device may include at least one outlet in the device body, which is in fluid communication with at least one inlet. That is, the ignition device may include a channel extending between the inlet and the outlet. However, the connection should not be airtight. The outlet may be of any suitable size and shape. The outlet may be provided with a simple hole in the housing or pipe (sleeve), which extends inside and / or outside the housing. A reduced diameter outlet may, for example, help direct the flame away from the fixture body.

The device body may include a removable cap or plug (core extrusion device) covering the outlet of the body, which can be separated from the rest of the body before ignition. The cap or cap may have a rounded, long or conical shape. Disconnection can be achieved by any suitable method. For example, an increase in gas pressure due to an oxidizing agent, a stream of fuel for ignition, or a chemical reagent for ignition through the housing, can be used to disconnect the cap or plug. The cap / plug element can be frictionally fitted to the rest of the fixture body. If the stem of the plug is in the form of a plug, then it can be frictionally seated on the outlet of the housing using an o-ring that extends around the stem.

In addition to the inlet (s) and the outlet (s), the ignition device may have one or more intakes passing through the housing to inject oxidizer / gas from the borehole into the housing passage using the Venturi effect when the ignition fuel and / or an oxidizing agent flows through a passage to an outlet from the housing.

The ignition device may comprise a mixing chamber located inside the device housing in which the ignition fuel, oxidizing agent and / or ignition chemical are mixed. Mixing can be achieved in any suitable way. Typically, by a method including providing turbulence and / or resistance to the flow of gases through the mixing chamber. To this end, the mixing chamber may comprise at least one mixing structure or device, such as a venturi device, one or more baffles (for example, spirals) or other turbulence generators located inside the mixing chamber (which create a pressure differential for mixing the two gas flows) or which define the walls of the mixing chamber. The mixing structure or device may, for example, be integral with the device body or may be a separate component inserted into the device body. In one embodiment, the mixing structure or device is made in the form of a Venturi device located inside the mixing chamber.

The ignition device may include a diffuser designed to control the characteristics of the mixture of gases leaving the outlet of the device housing. Any suitable type of diffuser, such as a perforated plate, can be applied.

The ignition device may comprise baffles extending from the outer surface of the device body to deflect a gas stream (such as an oxidizing agent) from the lower region of the device body, so that the lower region is not cooled by the gas stream.

The ignition device may comprise heat exchange structures, such as ribs or guide ribs extending from the device body, for cooling the outlet from and / or inside the body.

The mixing chamber may be defined by the fixture body and the diffuser plate extending transversely across the fixture body near the outlet of the housing.

The ignition device may include a support for holding the ignition means or other components inside the device housing or outside the housing. Any suitable type of support may be used. The support may, for example, be made integrally with the device body or may be a separate component inserted into the device body. In one embodiment, the support is made in the form of a spacer sleeve or spacer bolt that fit snugly inside the fixture body and support means for igniting the inner region of the sleeve.

The ignition device may include a non-return / return valve (ball and spring, spring-loaded valve flap, etc.) to prevent the back flow of fuel for ignition and the gaseous product (synthesis gas) up the flexible tubing.

A flexible tubing may comprise a non-return / return valve (ball and spring, spring-loaded valve flap, etc.) installed inside the pipe to prevent backflow of the gaseous product (synthesis gas) up the pipe.

The ignition device may include one or more sensors for detecting and reporting statuses in the ignition device, the adjacent ignition device, the borehole and / or the adjacent coal seam. Any suitable type of sensor may be used. For example, a sensor can be: a thermocouple for measuring temperature in a borehole, a coal seam or an ignition device, etc .; a gas sensor for measuring the nature of the gas in the well / channel of the well; a pressure sensor for measuring pressure in the well / channel of the well; an optical sensor for monitoring a well, a channel of a well or a coal seam; or a position sensor for reporting the location of the ignition tool in the well / channel of the well. The sensor can be connected to the external housing of the ignition device or placed inside the pipe of the housing of the device for ignition or a flexible tubing, or both. The sensor electrical cable may extend inside the flexible tubing and inside or outside the fixture body.

The ignition device may include a controller operable to initiate ignition, including providing electrical energy or fuel for ignition, an oxidizing agent, or emitting a combustible chemical reagent for ignition. The controller may comprise a control cabinet. The controller may comprise a piping system fluidly coupled to a flexible tubing and an ignition chemical, an ignition fuel, and an oxidizing agent.

The controller can be controlled remotely by the ignition device to (1) control the ratio in the mixture of the fuel for ignition / chemical reagent for the ignition and oxidizer, (2) monitor the combustion of the mixture and (3) control the supply of electrical energy to the ignition. The controller may comprise a voltage and current measuring device and a control device connected to the electric incendiary device by means of an electric cable passing through the flexible tubing.

The controller may consist of control, non-return and shut-off valves, flow measuring devices and pressure relief devices. Such devices allow you to measure and control the flow rate during injection of the oxidizing agent and fuel for ignition, respectively. It also allows the purge of fuel for ignition using inert gases such as nitrogen. The oxidizer / fuel mixture for ignition can be controlled using a device for measuring flow, such devices can either be powered by a pneumatic drive, manually damped, turned 90 degrees, or driven by an electric drive.

The controller may include overpressure protection, filtration, flow measurement devices in addition to an isolation valve. The logic control device may allow the oxidizer / ignition fuel to flow according to the required parameters. In the event of a power failure or oxidizer loss, the logic control can stop the flow of fuel for ignition.

A source of oxidizing agent (e.g., an air or liquid compressor or oxygen gas storage tank or generator, etc.), an ignition fuel (e.g., compressed gas or water cylinders, etc.) and an ignition chemical (e.g. compressed gas or water cylinders, etc.) can be connected to the manifold piping system and in addition to the flexible tubing and to the wellhead of the injection well. The power source (generator) can be connected by electrical connection to the controller and optionally with an electric cable and a sensor cable passing through a flexible tubing. The controller can be mounted on a slide for easy transport.

The controller can supply electrical energy to the ignition device for: igniting the fuel for the ignition / chemical reagent for the ignition / oxidizing mixture; monitoring the state of the flammable mixture and the gradual increase in the flow of the oxidizing agent, as well as gaseous fuel for ignition up or down, when re-igniting the mixture, if the ignition goes out before ignition is reached in the coal seam; and, as soon as the ignition is not extinguished, there is a gradual increase in the flow of fuel for ignition, and then the oxidizer, or vice versa, depending on the ratio achieved for stable ignition, until ignition is achieved in the coal seam.

The controller controls the fuel / oxidizer ratio between the lower flammability limit (LFL) of the fuel and the upper flammability limit (UFL) of the fuel. This ensures, not only that the gas mixture in the ignition device can be ignited, but that the ignition will be stable.

After combustion has been achieved, the method in accordance with the invention further includes the step of maintaining the oxidizing agent at a level to maintain combustion.

In order to continue the implementation of the method of underground gasification of coal through a coal seam, it may be necessary to move the ignition devices to a new ignition site, where coal in the immediate vicinity of the new ignition site can be ignited and create a new combustion zone to continue ignition along the coal seam and obtain the optimal coal resource consumption. At the new ignition site, the energy generated during the gasification process is sufficient to maintain the temperature in the new combustion zone at a level that contributes to chemical reactions.

Thus, in order to support, in particular, the movement of the combustion zone, the flexible tubing and the ignition device can be extended along the coal seam and periodically re-ignite, not only to maintain combustion in the combustion zone, but also to initiate a subsequent combustion zone in coal seam. Therefore, the method in accordance with the invention further includes the step of moving the ignition tool along the coal seam. Although this is most applicable to substantially horizontal boreholes / boreholes, the invention can also be applied to a vertical or deviated well or wells that have a combination of designs.

Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

A brief description of the graphic materials

Figure 1 shows the general features of an ignition device configured to ignite an underground coal seam in accordance with an embodiment of the present invention;

Figure 2 shows parts of ignition devices (using a single flexible tubing) for igniting an underground coal seam in accordance with embodiments of the present invention;

Figure 3 shows parts of ignition devices (using concentric flexible tubing) for igniting an underground coal seam in accordance with embodiments of the present invention;

Figure 4 shows parts of ignition devices (using a single flexible tubing) for igniting an underground coal seam in accordance with embodiments of the present invention;

Figure 5 shows a part of an ignition device (using a single flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention;

Figure 6 shows part of a device for ignition (using a single flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention;

7 shows a part of an ignition device (using a single flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention;

On Fig depicts a part of the device for ignition (using a single flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention;

Figure 9 shows part of an ignition device (using a single flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention;

Figure 10 shows part of an ignition device (using concentric flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention; and

11 shows a portion of an ignition device (using concentric flexible tubing) for igniting an underground coal seam in accordance with an embodiment of the present invention.

Detailed Description of Embodiments

On graphic materials, similar item numbers indicate similar features.

Referring first to FIG. 1, an ignition apparatus 150 is shown for firing an underground coal seam 151. There, an injection well 152 is shown having a wellhead 153 and a well channel 154 extending from the top of the inclined portion of the well 152 through the coal seam 151.

The ignition device 150 comprises an ignition system, a positioning system, a sensor 170, and a controller 165.

The ignition system comprises ignition means and a fixture 155 for igniting an underground coal seam 151 in a well channel 154 (or a casing liner enclosed in a well channel 154).

The positioning system comprises a flexible tubing 156 connected to the ignition device 155 and passing through the wellhead 153 in the well channel 154 to place the ignition device 155 at a desired location within the well channel 154. The positioning system further comprises a flex drum 157 for transporting and dispensing flexible tubing 156.

The flexible tubing 156 of the positioning system may comprise one pipe (“single flexible tubing”) or concentrically arranged inner and outer pipes (“concentric winding of the tubing”), and the end of each pipe is connected to the end of the fixture 155 for ignition directly or by means of an adapter welded to the end of each pipe, and usually either welded or screwed to the end of the device 155 for ignition. A preferred diameter of the outer tube is two inches, while the preferred diameter of the inner pipe is _^3/4 inches.

The flexible tubing 156 is also in fluid communication with the controller system piping system 171 via hoses 172 and is additionally in fluid communication with the fluid source 162, 163 (chemical reagent for ignition, fuel for ignition, and oxidizing agent, depending from a possible situation).

A single or external pipe from a flexible tubing 156 is used to transfer electric cables and / or sensor cables (for example, from a sensor / thermocouple 170) from the ignition device 155 to the controller 165 using electric lines 173 that extend from the flexible drum 157 the pipeline.

The ignition means can directly ignite the coal seam 151 itself, or ignite a combustible fluid (gas, liquid), either constantly located in the borehole / casing liner, or entering the borehole / casing liner in the form of gas, liquid, or in the solid state.

In one embodiment of a concentric flexible tubing, the ignition means comprise an electric spark generator 160 (e.g., a spark plug) connected by electrical connection to a power source (generator - not shown) to generate a spark. In another embodiment of a concentric flexible tubing, the ignition means comprise an electric heat thermistor 160 (for example, a glow plug) connected by electrical connection with an electric cable to a power source (not shown) to supply power to the resistor. A resistor can, for example, generate about 180 kW of heat. For both embodiments, the ignition means further comprise an ignition fuel source (compressed gas or water cylinders 162 containing, for example, hydrocarbons, such as methane) and a source oxidizer (e.g., air compressor 163) for burning refueling. The ignition fuel is supplied to the ignition device 155 through the inner pipe of the flexible tubing 156, and the oxidizer is fed to the ignition device 155 through the outer pipe of the flexible tubing 156. An electric spark generator / heat heat resistor 160 is located inside the 155 ignition (or, possibly, outside the ignition device 155), and in the way of a mixture of combustible gases (fuel for ignition and an oxidizing agent) that passes through the ignition device 155. In an embodiment of a single flexible tubing, only the ignition fuel can flow through the pipe to the ignition fixture 155.

In yet another embodiment, the concentric flexible tubing of the ignition means comprises at least one type of chemical reagent for ignition and a source of chemical reagent for ignition (for example, compressed gas or water cylinders 162). The firing agent may be a self-igniting substance — for example, a liquid such as triethyl borane, a gas such as silane, a solid such as phosphorus or an alkali metal, a self-igniting chemical and a hydrocarbon mixture such as triethyl borane vaporizing in methane, or self-igniting chemical reagent and inert gas such as triethyl borane and nitrogen. The flow of hydrocarbon or inert gas may aid in transporting / vaporizing the self-igniting material or cork / piston flow of the self-igniting chemical reagent to the ignition tool 155. The ignition means may further comprise an oxidizing agent source (for example, an air compressor 163) for igniting charged fuel and combustion. The chemical reagent for ignition specifically interacts with the oxidizing agent (air or oxygen) inside the channel of the well or coal seam, for igniting the coal seam. The ignition chemical can be specially released when the ignition tool 155 is turned on at a desired location in the well / channel of the well. The firing agent may be supplied to the firing device 155 from the cylinders 162 through the inner pipe, while the oxidizing agent may be supplied to the firing device 155 from the air compressor 163 through the outer pipe. In an embodiment of a single flexible tubing, the ignition chemical itself can flow through the pipe into the ignition fixture 155.

In an embodiment of a single flexible tubing, the ignition means may comprise pure oxygen or substantially pure oxygen (cylinders 162) supplied through a pipe from the flexible tubing and ignition device 155. Oxygen directly ignites a coal seam. The ignition means may further comprise an oxidizing agent source (air compressor 163) for burning refueling.

Summarizing, for an ignition device containing a single flexible tubing, the oxidizing agent injected into the borehole can pass from the outside of the tubing of the flexible tubing. However, for an ignition device containing one flexible tubing, the ignition fuel and / or the ignition chemical injected into the well bore may extend inside the pipe. For an ignition device containing concentric pipes, the oxidizing agent injected into the borehole channel can pass inside the outer pipe (preferably, just like in the borehole channel, outside the outer pipe) and the ignition fuel / ignition chemical can flow inside the inner pipes.

When using a single flexible tubing (having one pipe) or a concentric flexible tubing (having an inner and outer pipe), the (outer) pipe can be made of stainless steel or carbon steel. If air is used as an oxidizing agent, the outer pipe can be made of carbon steel and the inner pipe can be made of copper. If air or oxygen is used as an oxidizing agent, the outer pipe may be made of stainless steel and the inner pipe may be made of copper or stainless steel.

The fixture 155 for ignition can be made mainly of stainless steel or carbon steel. The protective part of the ignition device, such as the core extrusion device (as described above), may be made of non-heat resistant materials such as aluminum, plastic or rubber. The ignition tool or device body may have any suitable outer diameter and length. For example, the ignition fixture or fixture body may have an outer diameter, for example, about 2 inches, 3 inches, or 4 inches. Preferably, the ignition tool or device body has a diameter of about 2 inches.

The controller 165 (slide) acts to initiate ignition, including providing electric energy or fuel for ignition, an oxidizing agent, or for releasing a combustible chemical reagent for ignition. The controller 165 comprises a control cabinet 169. The controller 165 comprises a piping system 171 fluidly coupled to a flexible tubing 156 and an ignition chemical, an ignition fuel, and an oxidizer source 162, 163.

The controller 165 further comprises control, non-return and shut-off valves, a device for measuring flow and a device for relieving pressure. Such control devices make it possible to respectively measure and control the volume during injection of the oxidizing agent and gaseous fuel for ignition. They also allow purging of fuel for ignition using inert gases such as nitrogen. The oxidizer / fuel mixture for ignition can be controlled using a device for measuring flow, such devices are powered by a pneumatic drive, manually shut off, turned 90 degrees, or powered by an electric drive. The controller 165 may include overpressure protection devices, filtering, flow measuring devices, in addition to an isolation valve. The logic control device may allow the oxidizer / ignition fuel to flow according to the required parameters. In the event of a power failure or oxidizer loss, the logic control device can stop the flow of gaseous fuel for ignition. Controller 165 allows the use of volatile chemicals such as triethylborane, silane, or mixtures of any type.

The controller can maintain the ratio of gaseous oxidizer and fuel for ignition within predetermined limits, which are preferably the upper limit of flammability and the lower limit of flammability for fuel, for ignition and act on the basis of the stoichiometric ratio of oxidizer to fuel for ignition.

The controller is configured to supply power to the electric incendiary device when the fuel coefficient is between the lower flammability limit and the upper flammability limit. The thermocouple on the ignition device indicates that there is no ignition and that ignition is necessary either to maintain or to initiate combustion at the ignition site.

The power supply and temperature measurement for the monitoring system can be controlled through a multi-core electrical cable passing inside the pipe to the ignition device. The temperature monitoring system displays by means of a thermocouple fixed on the ignition device whether the ignition is successful, and further confirms the presence of ignition inside the combustion zone of the coal seam.

The ignition is supported by the supply of fuel for ignition and an oxidizing agent, while the coefficient of gaseous fuel is regulated above ground. The corresponding regulation of the oxidizer to the fuel coefficient is performed depending on the confirmation of the ignition of coal in the coal seam. Preferably, the ratio is maintained near the lower flammability limit of the gaseous fuel to provide a sufficient amount of oxidizing agent provided for initiating combustion within the combustion zone. After ignition has occurred, combustible gases, as well as the volatile gases emitted by the coal seam, are pushed out of the end of the well (i.e., the production well) and sent to the flare for combustion. The quality of the gaseous product (synthesis gas) is monitored, and as soon as the ignition of coal in the combustion zone is confirmed, combustion is maintained, the ignition fuel entering the ignition device is gradually reduced until only the oxidizer is injected into the combustion zone. The flexible tubing can then be removed from the borehole / well and the injection rate of the oxidizing agent can be increased up to the volume necessary for the complete gasification of coal under operating conditions.

Coal seam ignition can occur at any ignition temperature. This allows you to further re-ignite the coal seam, simply removing the device for ignition along the coal seam, and re-initiate the ignition process. This can be done either when the combustion process in the previous combustion zone is already completed, or while the underground gasification of coal occurs in other places along the coal seam. The ability to remove and re-ignite a coal seam is advantageous in that it has the ability to reduce the cost of underground gasification, allowing a longer extension of the horizontal borehole / borehole channel inside the ignition layer. This allows you to maintain combustion in the coal seam for a longer time, thereby increasing the production period of the well and amortizing costs over a longer production period.

In order to install the ignition device, the ignition device along with the flexible tubing is introduced into the borehole / well, which is aligned with the protective casing. A protective casing extends to at least a portion of the borehole / borehole that is substantially horizontal, inclined, or vertical within the coal seam. The ignition device, firstly, corresponds to the tip of the flexible tubing along with the cables operating inside the pipe / tubes. The ignition tool, together with the flexible tubing, is lowered into the borehole / well and installed at a predetermined or ignition location within the coal seam. The ignition fuel and oxidizing agent are supplied through a flexible tubing, and the space / interval of the well between the tubing and the protective bore of the borehole is a predetermined size. This size is determined using the ratio of the required oxidizing agent to the fuel for ignition and the heat needed to ignite the coal seam. As soon as the ignition fuel and oxidizer reach the ignition device, the electric ignition device activates the ignition of the fuel, and the oxidizer in the ignition device.

The device allows the ignition of a coal seam at any predetermined ignition temperature. This allows you to further re-ignite the coal seam, simply removing the device for ignition along the coal seam, and re-initiate the ignition process. This can be done either when the combustion process in the previous combustion zone is already completed, or while the underground gasification of coal occurs in other places along the coal seam.

Embodiments of various single flexible tubing are further illustrated in FIG. 2.

Figure 2, in General, shows the parts of the device 110 (110a, b, c) for ignition for ignition of an underground coal seam 111 from within the channel 112 of the well (shown enclosed in a casing shank) passing through the formation 111. Each device 110 for ignition contains an ignition system comprising ignition means and an ignition device 113 (113a, b, c) for igniting an underground coal seam 111 from within the well channel 112. Each ignition device 110 further comprises a positioning system comprising a flexible tubing 114 (114a, b, c) connected to the ignition device 113 and extends inside the well channel 112 to install the ignition device 113 at a desired location within the channel 112 wells. Other components of each device 110, not shown in FIG. 2, may be clarified from FIG. 1.

The positioning system comprises a flexible tubing 114 containing one pipe 114, and the end of the pipe 114 is connected to the end of the ignition device 113, either directly or via an adapter. For a flexible tubing 114 containing one pipe 114, the oxidizing agent will typically be injected into the well and flow outside the flexible tubing / pipe 114, but inside the bore 112 of the well.

As previously explained, the ignition device 110 may have various ignition means.

In FIG. 2 (a), the ignition means comprise an electric heater (glow plug) 116 and an electric cable 117 extending from the heater 116 through the pipe 114a to the surface, to the energy controller. Ignition fuel (e.g., hydrocarbon such as methane) is supplied from an above-ground source through a pipe 114a and through an ignition device 113a to an electric ignition heater 116 and to further burn an oxidizer inside a bore 112 to ignite a coal seam 111.

In FIG. 2 (b), the ignition means comprise an ignition chemical 117 (for example, a self-igniting gas) that is supplied from an above-ground source through a pipe 114b and completely through an ignition device 113b, where, when mixed with an oxidizing agent, it ignites a coal seam 111.

In FIG. 2 (c), the ignition means comprise an electric heater 118, and an electric cable 119 passes from the heater 118 through a pipe 114c to the surface of the energy controller. When the heater 118 is driven, it ignites the oxidizer and the coal seam 111. In this embodiment, no gas flows through the pipe 114c. More specifically, pipe 114c only accommodates electrical cable 119.

Figure 3, in General, shows the parts of the devices 120 for ignition (120a, b, c) for igniting an underground coal seam 121 from within the channel 122 of the well (shown enclosed in a casing shank), which passes through the formation 121. Each device 120 for The ignition system comprises an ignition system comprising ignition means and an ignition device 123 (123a, b, c) for igniting an underground coal seam 121 from within the well channel 122. Each ignition device 120 further comprises a positioning system comprising a flexible tubing 124 (124a, b, c) connected to the ignition device 123 and extending inside the well channel 122 to install the ignition device 123 at a desired location within the channel 122 wells. Other components of each device 120 may be understood from FIG.

The positioning system comprises a flexible tubing 124 containing double concentrically arranged pipes, and the end of each pipe is connected to the end of the ignition device 123, either directly or via an adapter. The inner pipe 125 (125a, b, c) extends inside the outer pipe 126 (126a, b, c).

For a concentric flexible tubing 124, ignition fuel (such as hydrocarbon, gas, methane) and / or an ignition chemical (such as self-igniting gas) is usually supplied from an aboveground source through an inner pipe 125 and through an ignition device 123. An oxidizing agent (such as air or oxygen) is typically supplied from an elevated source through an external pipe 126 and through an ignition tool 123. The oxidizing agent may also be supplied from an above-ground source outside the outer pipe 126, but inside the bore 122.

As previously explained, the ignition device 120 may have various ignition means.

In FIG. 3 (a), the ignition means comprise an incendiary device 130a in the form of an electric heater (glow plug) or a spark generator (spark plug), and the electric cable 131 passes from the device 130 through an external pipe 126a to the energy controller. Ignition fuel is supplied from an above-ground source through an inner pipe 125a and into an inlet pipe 133 of an incendiary device 130. An oxidizing agent is supplied from an above-ground source through an external pipe 126a to an incendiary device 130, where it is mixed with the ignition fuel. After mixing, ignition, and passage through the diffuser plate 132 of the ignition tool 123a, the ignition ignites the coal seam 121.

In FIG. 3 (b), the ignition means comprise an ignition chemical 135 (for example, a self-igniting gas) that is supplied from an aboveground source through an inner pipe 125b to the inlet pipe 135 of the ignition device 123b. The oxidizing agent is supplied from an overhead source through an external pipe 126b (as well as inside a well outside the external pipe 126b) to an ignition tool 123b. After stopping the tool 123b, the oxidizing agent is mixed with the chemical reagent for ignition and ignites the coal seam 121.

In FIG. 3 (c), the ignition means comprise a fixture 140 in the form of an electric heater (glow plug) or a spark generator (spark plug), and the electric cable 141 passes from fixture 140 through an external pipe 126c to the energy controller. Ignition fuel is supplied from the above-ground source through the inner pipe 125c and from the spray nozzle 141 to the ignition device 140. The oxidizer is supplied from the above-ground source through the external pipe 126c to the ignition device 140. Before ignition using the ignition device 140, the gases pass through the mixing chamber 142, containing venturi device 143, and are thoroughly mixed. After mixing, ignition, and passage through the diffuser plate 147 of the ignition tool 123 s, the ignition is exposed to an additional oxidizing agent source and ignites the coal seam 121.

Still further examples of ignition devices 200 (200a, b, c, d) containing concentrically arranged pipes / flexible tubing 201 (201a, b, c, d) connected to fixtures 202 (202a, b, c, d) for ignition, shown in Fig.4. In each case, the ignition means contain an electric incendiary device 203 (203a, b, c, d) in the form of an electric heater (glow plug) or a spark generator (spark plug) and an electric cable 204 (204a, b, c, d) passing from fixtures 203 through the outer pipe 205 (205a, b, c, d) to the surface of the energy controller. The ignition fuel or ignition chemical (gas) is supplied from an above-ground source through an internal pipe 206 (206a, b, c, d) to the incendiary device 203 through the inlet pipes 218 (218a, b, c, d) of the ignition device 202. The oxidizing agent (gas) is supplied from an above-ground source through an external pipe 205 to an incendiary device 203.

Each ignition device 200 also has a sensor / thermocouple 210 (210a, b, c, d), and a cable that passes through the outer pipe 205. Also not completely marked, each ignition device 202 contains different parts of the device housing that are screwed on one to another and additionally welded to the flexible tubing 201. Part 219 (219a, b, c, d) of the housing is an adapter of the flexible tubing.

Before ignition, using incendiary device 203, gases pass through various types of mixing chambers 211 (211a, b, c, d). The ignition device 202a of FIG. 4 (a) has a mixing chamber 211a containing a spiral baffle or partitions 213. The ignition device 202a of FIG. 4 (b) has a mixing chamber 211b containing a diffuser plate 214. The ignition device 202c of FIG. 4 (c) has a mixing chamber 211c comprising a venturi device 216. The ignition fixture 202d of FIG. 4 (d) has a mixing chamber 211d containing a diffuser plate 217, and mixing also contributes to the fact that the inlet pipes 218 of the ignition fixture 202d end with a spray nozzle.

After mixing, ignition, and exiting the ignition tool 202, the ignition is exposed to an additional oxidizing agent source and ignites the coal seam.

However, further examples of ignition devices comprising single pipes / single flexible tubing connected to the ignition device are shown in FIGS. 5-7.

Referring now to FIG. 5, an ignition device 301 for igniting an underground coal seam 302 is depicted. An ignition device 301 includes an ignition system comprising ignition means and an ignition tool 304 for igniting an underground coal seam 302 from within a well channel 303. The ignition device 301 further comprises a positioning system comprising a flexible tubing 305 connected to the ignition device 304 and extending inside the well channel 303 to install the ignition device 304 at a desired location within the well channel 303. The ignition device 301 may have various components, shown generally in FIG.

Flexible tubing 305 comprises a single pipe 306 (stainless steel or carbon steel) and the end 307 of pipe 306 is threaded. The flexible tubing 305 further comprises heat exchange plates 310 extending from the pipe 306. These plates 310 maintain cold inside the pipe 306 (to protect the ignition means electrical cables 311 that pass through the pipe 306). These plates 310 also help center the ignition tool 304 within the borehole 303.

The ignition device 304 comprises a device body 308 having an inlet end 309 which is threaded and which is connected to the threaded end 307 of the pipe 306. This connection must be threaded. Alternatively, pipe 306 and housing 308 may be welded to each other. Housing 308 is made of high melting point metal and resistant to oxidation, such as stainless steel, inconel, monel, or Hastelloy.

The ignition means comprise an electric incendiary device 312 electrically connected to an above-ground power source (not shown) using a cable 311. The device 312 contains an electric heating element 313 wound around a non-conductive (ceramic) core 314. The device 312 contains two non-conductive (ceramic) partitions 315 , 316, which regulate the electric heating element 313 inside the housing 308. The wires (not marked) of the electric heating element 313 pass through partitions 315 and tanavlivayut connection cable 311.

The ignition device 304 includes a flow opening 317 that diverts an oxidizing stream from the end of the electric heating element 313 of the housing 308, as shown by arrows. The partition walls 313 of the casings and the electric cable 311 prevent the device from melting and damage.

The ignition device 301 further comprises a thermocouple 319, which extends from the inside of the pipe 306 and downstream into the fixture body 308. Thermocouple 319 is used to determine if the electric heating element 313 reaches its intended temperature, as well as to monitor the temperature of the cable 311 so that it does not collapse.

The state of the automatic shutdown mechanism (power supply to the electric heating element 313) can be configured on the surface as soon as the thermocouple 319 on the electric cable 311 indicates that the electric cable 311 is controlled at the calculated temperature. The electric cable 311 is protected by the air flow around the pipe 306. The protection is further enhanced by heat exchanger plates 310, which provide a large surface area for cooling with the addition of conductive paste to improve the connection between the pipe 306 and the electric cable 311.

In use, the electric heating element 313 heats the housing 308 and radiates this heat 320 to the surface 302 of the coal seam until the coal reaches its spontaneous combustion temperature with the participation of an oxidizing agent, which leads to the burning of coal. The exhaust stream 317 diverts the oxidizing stream from the electric heating element 313 containing the end of the housing 308, as shown by arrows, thereby preventing excessive cooling of the electric heating element 313 containing the end of the housing 308.

Referring now to FIG. 6, another type of ignition device 331 is shown. The ignition device 331 comprises an ignition system comprising ignition means and an ignition device 334 for igniting an underground coal seam 332. The ignition device 331 further comprises a positioning system comprising a flexible tubing 335 connected to the ignition device 334 and extending inside channel 333 wells for installing fixtures 334 for ignition in the desired location inside the channel 33 of the well. The ignition device 331 may have various components, shown generally in FIG.

Flexible tubing 335 comprises a single pipe 336 (stainless steel or carbon steel), and the end 337 of pipe 336 is threaded. The flexible tubing 335 further comprises adjusting plates 340 to help center the ignition tool 334 within the well bore 333.

The flexible tubing 336 further comprises a non-return / return valve 345 (ball and spring, spring-loaded damper, etc.) mounted inside the pipe 336 to prevent back flow of fuel for ignition and the gaseous product / synthesis gas up the flexible tubing 336 when the flexible tubing 335 is removed from the well bore 333.

The ignition device 334 includes a housing 338 having an inlet end 339 (having an inlet 339), which is threaded and attached to the threaded end 337 of the pipe 336 in a hermetic manner. This inlet end 339 may be threaded. Alternatively, pipe 336 and housing 338 may be sealed to each other.

The device body 338 further has an outlet end 341 (has an outlet 341). The outlet 341 has a reduced diameter relative to the inlet 339. The outlet end 341 of the body 338 is in the form of a core extrusion device 342 that is connected to the rest of the body 338. The core extrusion device 342 has a barrel around which an O-ring 343 and the friction of the O-ring 343 abuts against the outlet 341. The core extrusion device 342 may be made of aluminum, or may alternatively be made of duralumin rubber, or plastic. This material of core extrusion device 342 will be consumed inside the gas generator due to the presence of high temperature. Case 338 is made of high melting point metal and resistant to oxidation, such as stainless steel, Inconel, Monel, or Hastelloy.

Pipe 336 may transfer the ignition chemical to the inlet 339 of the ignition device 334, and the fixture body 338 provides a flushing channel 344 for transferring the ignition chemical from the pipe 336 to the outlet 341.

The ignition device 331 may further comprise a thermocouple connected to the pipe 336 and / or the fixture body 338 (not shown). However, it is not shown that the ignition device 331 may further comprise an oxidizing agent source, as mentioned in relation to FIG.

However, it is not shown that the ignition device 331 may further comprise an ignition chemical source connected in a sealed manner to the pipe 336. The ignition chemical may be a self-igniting chemical (e.g., a liquid such as triethyl borane, a gas such as silane, a solid such as phosphorus or an alkali metal), or a self-igniting chemical and a mixture of hydrocarbons (e.g. triethyl borane, vaporized into methane ), or a self-igniting chemical and an inert gas (e.g. triethyl borane and nitrogen). A hydrocarbon or inert gas stream 347 helps transport / vaporize a self-igniting chemical reagent or plug / piston stream 346 of a self-igniting chemical reagent to an ignition tool 334.

However, an ignition device 331 is not shown comprising a controller operable to initiate an ignition. The controller controls the injection of a chemical reagent for ignition, etc. into the pipe 335 and the well, and by injecting the oxidizing agent into the well — as generally described for FIG. 1.

When used, a self-igniting chemical reagent provides heat for ignition, or alternatively initiates ignition for the hydrocarbon material mixed with it, or follows it into the piston stream 346 to maintain ignition until coal is ignited. Inert gas 347 can be used either to transport the self-igniting chemical reagent 346 through the pipe 336, or can be used to purge the pipe 336 with inert gas before starting the ignition process and after ignition before the flexible tubing 335 is removed from the well bore 333 .

The injection oxidizer around the ignition tool 334 provides the oxidizer with the ability to maintain ignition when the oxidizer and the mixture of self-igniting chemical reagent come into contact with each other at the output end 341 of the device 338. The heat generated by the oxidizing agent and the self-igniting chemical reagent / reaction of the exothermic mixture of the chemical reagent provides heat to the coal surface 332 to heat the coal until the coal ignites at temperatures higher than the spontaneous combustion temperature of the coal.

The reduced diameter of the outlet 341 provides a higher flow rate of the self-igniting chemical reagent / mixture to reflect ignition from the flexible tubing 335 and to prevent excessive heat from reaching the outlet end 341 of the housing.

The ignition tool 334 may be designed with a plate profile of the outer circumference of the housing 338 in order to provide a large heat transfer surface to increase cooling of the housing 338 from introducing an oxidizer flow down to the annulus of the injection well around the ignition device 334.

The core extrusion device 342 prevents coal dust, drilling mud or water from entering the ignition device 334 when the bottom of the well is lowered past the protective cover 348 of the well. The core extrusion device 342 is pushed out of the connection to the outlet 341 by a stream under pressure of a self-igniting chemical reagent / mixture or an inert gas.

Referring now to FIG. 7, there is shown an ignition device 351 for igniting an underground coal seam 352 from within a well channel 353 that passes through the reservoir 352. The ignition device 351 includes an ignition system comprising ignition means and an ignition device 354 for igniting an underground coal seam 352. The ignition device 351 further comprises a positioning system comprising a flexible tubing 355 connected to the ignition device 354 and extending inside the channel 353 of the well for the fixture 354 for ignition at a desired location within the channel 353 of the well. The ignition device 351 may have various components, shown generally in FIG. 1.

The positioning system comprises a flexible tubing 355 containing a single pipe 356 (stainless steel or carbon steel) and the end 357 of the pipe 356 is threaded.

The ignition device 354 includes a housing 358 having an inlet end 359 (having an inlet 359), which is threaded and attached to the threaded end 357 of the pipe 356 in a hermetic manner. This inlet end may not be threaded.

The fixture body 358 further has an outlet end 361 (has an outlet 361) that extends through the inlet 359 via a flushing channel 364. The outlet end 361 of the housing 358 is in the form of a core extrusion device 362 connected to the rest of the housing 358. The fixture 362 for extrusion, the core has a barrel around which an O-ring 363 extends, and an O-ring 363 is frictionally seated on the outlet 361, as described for FIG. 6.

The pipe 356 can transfer ignition fuel 372, such as methane, to the inlet 359 of the ignition device 354, and the flushing channel 364 transmits the ignition fuel 372 from the inlet 359 to the outlet 361.

The ignition device 354 comprises a gas mixing (swirl) chamber 370 located inside the housing 358, within which the oxidizing agent and the ignition fuel are mixed. The housing 358 provides a chamber wall 370 and a diffuser plate 371 extending across the housing 358 defining the lower end of the chamber 370. The mixing chamber 370 comprises a venturi device 372 located in front of the device. The ignition device 354 contains oxidizer intakes 373 in a housing 358 through which the oxidizer can be introduced by means of the differential pressure caused by the venturi device 372.

The ignition device 354 further comprises a non-return / return valve 365 (ball and spring, spring-loaded valve flap, etc.) mounted inside the flushing channel 364 to prevent back flow of fuel for ignition and the gaseous product (synthesis gas) up the pipe 356.

The housing 358 comprises four housing parts that are connected in a continuous chain so that the ignition tool 354 can be easily assembled from its components. The three body parts are threaded and the fourth part is a core extrusion device 362 inserted in a sliding fit.

The ignition means comprise an electric incendiary device 366, electrically connected to an above-ground power source (not shown) with a cable 367, which, when electrified, heats up or sparks. Incendiary fixture 366 may include double glow plugs, each having an electric heating element located at the corresponding end of the ceramic body. Alternatively, incendiary device 366 may be a spark generator (spark plug) that generates sparks when electrified. However, an advantage of a device such as a glow plug is that a lower voltage value is required, with a significant voltage drop occurring at a distance from the earth to the coal seam.

An electric incendiary device 366 is connected to the outer surface of the device body 358. An electric cable 367 extends from an electric incendiary device 366 along the housing 358, through a sealed port 374 to a flushing channel 364, and additionally through a pipe 356 to a power source.

The ignition device 351 has a thermocouple 369 connected to the outer surface of the housing 358 for measuring the temperature in the outlet 361. The signal cable (not marked) of the thermocouple 369 passes through port 374 and optionally through the pipe 356. A thermocouple 369 is used to determine whether the device 354 reaches to ignite the correct temperature. Compression fittings (not shown) around cable 367 and cable thermocouples seal electrical cables 367 and provide port 374 with a sealed seal.

The ignition tool 354 further comprises adjusting plates 360 extending from the housing 358. These plates 360 protect the electrical / signal cables 367 and the ignition device 366 from damage when using the bottom hole tool 354. These plates 360 help center the body of the fixture 358 within the well channel 353.

However, it is not shown that the ignition device may further comprise an oxidizing agent source, as described for FIG. 1. However, it is not shown that the ignition device 351 comprises a controller operable to initiate ignition, as is generally described for FIG.

In use, the ignition fuel (gaseous hydrocarbon, preferably methane) is supplied through a pipe 356 to the inlet 359 of the fixture, followed by gas flowing through a non-return valve 365 and optionally through a Venturi device 372. The venturi device 372 is configured to provide the differential pressure necessary for the oxidizing agent surrounding the ignition device 354 to be drawn into the flushing channel 364 of the housing for mixing with the ignition fuel in the mixing chamber 370 at the outlet of the venturi 372. The higher the flow of fuel for ignition, the greater the pressure drop across the Venturi device 372, the more the oxidizer is drawn in to achieve a stoichiometric ratio of oxidizer to fuel for ignition (in the range from 5: 1 to 20: 1). From here, the ignition fuel and oxidizer mixture flow through the diffuser plate 371, where they are ignited by incendiary device 366 to produce ignition for burning the coal seam 352.

Referring now to FIG. 8, an ignition device 381 is shown for igniting an underground coal seam 382 from within a well channel 383 that passes through the formation 382. The ignition device 381 includes an ignition system comprising ignition means and an ignition device 384 for igniting an underground coal seam 382 from within the channel 383 of the well. The ignition device 381 further comprises a positioning system comprising a flexible tubing 385 connected to the ignition device 384 and extending inside the well channel 383 to install the ignition device 384 at a desired location within the well channel 383. The ignition device 381 may have various components, shown generally in FIG.

The positioning system includes a flexible tubing 385 containing a single pipe 386 (stainless steel or carbon steel) and the end 387 of the pipe 386 is threaded. The ignition device 384 includes a housing 388 having an inlet end 389 (having an inlet 389) that is threaded and attached to the threaded end 387 of the pipe 386 in a hermetic manner. The connection of this input end 339 may not be threaded.

The device body 388 further has an outlet end 391 (outlet opening 391). The output end 391 of the casing 388 is in the form of a core extrusion device 392, which is connected to the rest of the casing 388, as described for earlier figures.

The pipe 386 can transfer generator gas, such as air 393, to the inlet 389 of the ignition fixture 384, and the fixture body 388 has a flushing channel 394 for transmitting the generator gas 393 from the pipe 386 to the outlet 391.

The ignition means comprise a turbine connected to a transformer 397 located inside the housing 388 through which the generator gas flows. The ignition means further comprises a compressed air supply, such as an air compressor connected to the pipe 386. The ignition means also comprise an electric incendiary device 400 connected by electrical connection to a transformer 397. When electrified by a transformer 397, the device 400 heats up.

The electric heating device 400 comprises an electric electric heating element 401 wound around a non-conductive part of the device body 388. The ignition fixture 384 includes protective mounting plates 402, 403 that extend from the housing 338.

The ignition device 384 further comprises a non-return / return valve 395 (ball and spring type, conical and spring type, shield with spring type or the like) installed inside the flushing channel 394 located in front of the turbine and transformer 384 to prevent back flow of fuel for ignition and gaseous product (synthesis gas) up the pipe 386.

The housing 388 comprises housing parts that are connected in a continuous chain so that the ignition fixture 384 can be easily assembled from its components. The body parts are threaded, in contrast to the core extrusion device 392 inserted in a sliding fit.

However, it is not shown that the ignition device 381 may include a thermocouple for controlling the temperature near the outlet 391. However, it is not shown that the ignition device may further comprise an oxidizing agent.

In use, generator gas 393, such as air, is supplied through a pipe 386, and a check valve 395, and a turbine, and a transformer 384 for generating power in order to electrify the electric heating element 400, in order to ignite the coal seam 382. The air displaces a turbine 384 for generating an electric current, which can be changed for a higher voltage value using a transformer 387.

The remaining part of the air flows from the outlet 391 of the housing into the channel of the well 383 and cools the outlet 391.

The electric heating element 401 is installed outside the fixture housing 388 and can be separated by a threaded portion if it is considered disposable, since the electric heating element 401 is installed outside the fixture housing 388.

Protective plates 402, 403 protect the electric heating element 401 from damage. The electric heating element 401 may be coated with a wax layer to protect it from moisture when used in the bottom of a well. Alternatively, a protective combustion tube may be installed to protect against moisture.

The electric heating element 401 will heat the coal seam 382 to approximately the auto-ignition temperature and, as a result, kindle the coal with the participation of the oxidizing stream around the fixture 384.

Referring now to FIG. 9, a fixture 22 for igniting an ignition device similar to that shown in FIG. 5 is shown.

The ignition device 22 comprises a device body 23 having an input end 24 (for a power cable 29) welded to the end of a single flexible tubing pipe 21.

The ignition means of the ignition device comprise an electric incendiary device 25 connected by electrical connection to an above-ground power source (not shown) using a power cable 29. The device 25 comprises a group of electric electric heating elements 26 located around a non-conductive core 27. Partitions 30, 31 are located at each end of the core 27.

In use, the electric heating element 26 heats the housing 23, and the housing radiates this heat to the surface of the coal seam until the coal reaches a spontaneous combustion temperature involving an oxidizing agent, which leads to the burning of coal.

Referring now to FIG. 10, a part of an ignition device 1 for igniting an underground coal seam is shown. The ignition device 1 has an ignition device 2 and a concentric flexible tubing 3, which are very similar to those shown in FIG. 3 (c). Other components of the ignition device 1 not shown are generally described for FIG. 1.

The ignition device 2 comprises a housing 4, an incendiary device 5, a support 6 of the incendiary device and a mixing chamber 7.

The ignition device 2 has separate inlets for the oxidizer 8 and fuel 9 for ignition from one end of the housing 4, which is connected to the concentric pipes 10, 11 of the flexible tubing 3 and to the outlet 12 for igniting the fuel at the opposite end of the housing 4.

The housing 4 consists of various parts of the housing (not marked), which are connected by a continuous chain, so that the ignition device 2 can be easily assembled from its components.

The output end 12 of the casing is conical and made in the form of a core extrusion device 25 (essentially as described previously). The output end 8, 9 of the housing 4 is welded to a flexible tubing 3.

Incendiary device 5 is an electric thermistor connected via an electrical connection through a cable 26 to a power source, which, when electrified, heats up due to its electrical resistance. Incendiary device 5 contains double glow plugs 13, each of which has an electric heating element located in accordance with the end of the ceramic body. A glow plug can, for example, generate about 180 kW of heat. Alternatively, the incendiary device 5 may equally be a spark generator that generates sparks when electrified. The electric cable 26 passes from the power source to the incendiary device 5 through the outer pipe 10.

The support 6 of the incendiary device comprises a spacer sleeve. This support 6 fits snugly inside the housing 4. The ceramic housing of the incendiary device 5 is supported and passes from the inside of the sleeve 6 and additionally through the hole in the diffuser plate 15, which extends across the housing 4, such electric heating elements of the end of the glow plug are located directly near the outlet 12 of the housing 4.

The ignition device 2 contains a gas mixing (creating a turbulence) chamber 7 located inside the housing 4, inside of which the oxidizing agent and the ignition fuel are mixed. The housing 4 provides the wall of the chamber 7 and the diffuser plate 15 defining the lower end of the chamber 7. The mixing chamber 7 comprises a venturi device 17 located in front of the device to generate back pressure. The venturi device 17 is made in the form of a cylindrical insert, which fits snugly inside the housing 4.

The ignition device 1 further comprises a temperature sensor / thermocouple 18 located inside the housing 4 near the incendiary device 5. The electric cable of the thermocouple 18 passes inside the outer pipe 10.

The inner pipe 11 supplies fuel for ignition, such as methane, propane, butane, or mixtures thereof (or another type of volatile gaseous hydrocarbon) to the mixing chamber 7. The outer pipe 10 delivers an oxidizing agent, such as air or oxygenated air, or substantially pure oxygen (from 20 to about 100% oxygen) also into the mixing chamber 7.

Oxygen and fuel for ignition are first connected inside the mixing chamber 7. Venturi device 17 ensures that these gases are mixed before moving through the spacer sleeve 6 and the diffuser plate 15 to the electric heating element of the glow plugs. Being electrified, the electric heating element causes the gas mixture to be ignited and the ignited gas mixture leaves the housing 4 through the outlet 12.

Referring now to FIG. 11, a part of an ignition device for igniting an underground coal seam is shown. The ignition device has an ignition device 30 and a concentric flexible tubing (not shown) similar to those shown in FIG. 3 (b). Other non-illustrated ignition device components are generally described for FIGS. 1 and 3 (b).

The ignition device comprises an ignition system comprising ignition means and an ignition device 30 for igniting an underground coal seam from within the well channel. The ignition device comprises a thermocouple 42 for temperature control. However, it is not shown that the ignition device may further comprise an oxidizing agent source and an ignition chemical.

The flexible tubing contains double concentrically arranged pipes, and the end of each pipe is connected to the inlet end of the ignition device 30 either directly or via an adapter (but usually by welding). The inner pipe passes inside the outer pipe.

The thermocouple cable 42, together with the electric cable 41 (but inoperative in this embodiment), passes through the outer pipe.

The ignition device 31 has a housing 32 having an inlet end 33 and an outlet end 34. The inlet end 33 has an inlet pipe 35 for receiving an ignition chemical and a second inlet 36 near the inlet pipe 35 for producing an oxidizing agent. The output end 34 of the housing 32 is located in the purge cap 37, which, when removed, opens the pipe 35 for the borehole.

The ignition means contain a chemical reagent for ignition, for example, a self-igniting gas (and possibly fuel for ignition, for example methane), which is supplied from an aboveground source through an inner pipe, which is additionally fed into a pipe 35. The oxidizing agent is fed from an aboveground source through an external pipe ( as well as inside the well, outside the outer pipe 33) and further into the inlet 36 of the ignition device 30.

The ignition device includes a sealing ring / sleeve 43, which extends between the housing 32 and the pipe 35 and supports the pipe 35 in a centered position.

The oxidizing agent injected inside the housing 32 from the inlet 36 exits through the outlet 50 created when the purge cap 34 is removed. The ignition chemical flowing inside the pipe 35 exits through an outlet 51 created when the purge cap 34 is removed. At this stage, the oxidizing agent is mixed with the chemical reagent for ignition and ignites the coal seam.

After the cap 34 is removed from the rest of the housing 32, the ignition device 30 resembles the device shown in FIG. 3 (b).

It should be understood that the invention disclosed and defined in this description extends to all alternative combinations of two or more features mentioned or obvious from the description and graphic materials. All of the various combinations constitute various alternative aspects of the invention.

As used in this document, except where the context requires otherwise, the term “contain” and variations of the term such as “comprising”, “contains” and “contain” are not intended to exclude additional additions, components, numbers or steps .

References to any prior art in the present description are not and should not be considered confirmed, or any form of proposals that are prior art forms a part that is publicly available in Australia or any other jurisdiction.

Claims (15)

1. A device for firing an underground coal seam from within the well channel, which passes through the coal seam, comprising:
a) a pipe body adapted to be inserted into a well channel, comprising an end having at least one inlet, an opposite end having an outlet, and a channel extending between the inlet and the outlet;
b) a mixing chamber located inside the channel passing between the inlet and the outlet of the pipe body, inside which the ignition fuel and the oxidizing agent are mixed; and
c) electric incendiary device for ignition of fuel for ignition and oxidizing mixture. 2. The ignition device according to claim 1, characterized in that at least one inlet opening comprises a first inlet opening supplying fuel for ignition to a channel passing between the inlet and the outlet of the pipe body. 3. The ignition device according to claim 2, characterized in that the first inlet is connected to an inner pipe containing a spray nozzle that extends inside the pipe body and supplies ignition fuel to a channel passing between the inlet and the outlet of the pipe body. 4. The ignition device according to claim 1, characterized in that it further comprises one or more oxidizer intakes passing through the pipe body for drawing the oxidizer from the well channel into the channel passing between the inlet and the outlet of the pipe body. 5. The ignition device according to claim 1, characterized in that at least one inlet contains a second inlet that feeds an oxidizing agent into a channel extending between the inlet and the outlet of the pipe body. 6. The ignition device according to claim 1, characterized in that the mixing chamber comprises one or more mixing devices selected from the group consisting of a venturi device, a partition, a spiral partition, a diffuser sheet, and combinations thereof. 7. The ignition device according to claim 1, characterized in that the power source of the electric incendiary device comprises a reservoir turbine and a transformer connected by electrical connection to the electric incendiary device. 8. The ignition device according to claim 7, characterized in that the turbine and transformer are located inside the channel passing between the inlet and the outlet of the pipe body. 9. The ignition device according to claim 1, characterized in that it further comprises one or more thermocouples for determining and reporting temperature in the pipe body, next to the pipe body, well channel, and / or coal seam. 10. The ignition device according to any one of claims 1 to 9, characterized in that the pipe body further comprises ribs or guide ribs. 11. A device for firing an underground coal seam from within the well channel passing through the coal seam, comprising:
a) a pipe body configured to be inserted into a well channel, comprising:
(i) an end having first and second threaded inlets;
(ii) an opposite end having a conical outlet; and
(iii) a channel extending between the inlet and the outlet,
wherein the first inlet is connected to an inner pipe containing a spray nozzle extending inside the pipe body and supplying fuel for ignition to the channel, and the second inlet feeds the oxidizing agent into the channel;
b) a mixing chamber located inside a channel extending between the inlets and the outlet of the pipe body, inside which the ignition fuel and oxidizer are mixed, the mixing chamber comprising a venturi device, a baffle and / or a diffuser plate;
c) an electric incendiary device for igniting a mixture of fuel and an oxidizing agent, wherein the electric incendiary device comprises an electric spark generator or an electric thermistor; and
d) one or more thermocouples for determining and reporting temperature in the pipe body, next to the pipe body, well channel and / or coal seam. 12. The ignition device according to claim 11, characterized in that it further comprises a positioning system comprising a flexible tubing connected to the ignition device and extending inside the well channel to install the ignition device in a desired location inside the well channel, the flexible tubing contains an inner pipe extending inside the outer pipe, wherein both the inner and outer pipes are connected to the pipe body, and the first inlet opening of the pipe body ditsya in fluid communication with the inner tube of flexible tubing, and a second inlet pipe body is in fluid communication with the flexible outer tube of the tubing. 13. A device for firing an underground coal seam from within the well channel passing through the coal seam, comprising:
a) a pipe body adapted to be inserted into a well channel, comprising an end having a threaded inlet, an opposite end having a conical outlet, and a channel extending between the inlet and the outlet, the inlet supplying fuel for ignition into the channel ;
b) one or more oxidizer intakes passing through the pipe body to draw the oxidizing agent from the well channel into the channel passing between the inlet and the outlet of the pipe body;
c) a mixing chamber located inside a channel extending between the inlet and the outlet of the pipe body, inside which the ignition fuel and oxidizing agent are mixed, the mixing chamber comprising a venturi device, a baffle and / or a diffuser plate;
d) an electric incendiary device for igniting a mixture of fuel for ignition and an oxidizing agent, wherein the electric incendiary device comprises an electric spark generator or an electric thermistor; and
e) one or more thermocouples for determining and reporting temperature in the pipe body, next to the pipe body, well channel and / or coal seam. 14. The ignition device according to item 13, wherein the power source of the electric incendiary device is a turbine and a transformer located inside the channel passing between the inlet and the outlet of the pipe body, connected by electrical connection to an electric incendiary device. 15. The ignition device according to item 13 or 14, characterized in that it further comprises a positioning system comprising a flexible tubing connected to the ignition device and extending inside the well channel for installing the ignition device in a desired location inside the well channel, however, the flexible tubing contains a single pipe connected to the pipe body, and the inlet of the pipe body is fluidly connected to the single pipe of the flexible tubing ompressornoy pipe.

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