WO2014089603A1

WO2014089603A1 - Apparatus for igniting an underground coal seam

Info

Publication number: WO2014089603A1
Application number: PCT/AU2013/001419
Authority: WO
Inventors: Fazal Uddin SHAIKH; Casper Jan Hendrik BURGER
Original assignee: Linc Energy Ltd
Priority date: 2012-12-14
Filing date: 2013-12-06
Publication date: 2014-06-19

Abstract

The invention provides a device for igniting an underground coal seam.

Description

APPARATUS FOR IGNITING AN UNDERGROUND COAL SEAM

TECHNICAL FIELD

[0001] This invention relates to underground coal gasification (UCG). In particular, a device for igniting an underground coal seam is disclosed.

BACKGROUND ART

[0002] Underground coal gasification is a process by which product gas is produced from a coal seam by combusting and gasifying the coal in situ in the presence of an oxidant. The product gas is typically referred to as synthesis gas or syngas and can be used as a feedstock for various applications, including clean fuels production, chemical production, and electricity generation.

[0003] Wells are drilled into the coal seam to allow for oxidant injection and product gas extraction. The wells are linked or extended to form an in-seam well channel (also referred to as a "linkage channel") to facilitate oxidant injection, cavity development, and product gas flow. The well allowing the injection of oxidant is called an injection well. The well from which product gas emerges is called a production well. Both horizontal and vertical well regions can be used for injection and production. Underground coal gasification can also utilise one or more vertical wells (service wells) located between the injection and production wells.

[0004] A coal seam having an injection well and a production well, with a well channel linking the two wells, is typically referred to as an underground coal gasifier. The gasifier will have a combustion zone within which coal is combusted in the presence of an oxidant, a gasification zone located downstream of the combustion zone in which coal is gasified and partially oxidized to produce product gas, and a downstream pyrolysis zone in which pyrolysis of coal occurs. Hot product gas flows downstream from the gasification zone and exits the ground from a well head of the production well. As coal is consumed or gasified, a gasifier (gasification) cavity within the coal seam develops and grows in size. [0005] The product gas (raw syngas) generated by UCG typically comprises syngas as well as other components, and the constituency will depend on various factors including the type of oxidant used for UCG (air or other oxidant, such as oxygen or oxygen-enriched air), water presence (both ground water and exogenous water), coal quality, and UCG operating temperature and pressure.

[0006] Major challenges of UCG include ignition of the coal seam, controlled combustion and gasification of the coal following ignition, controlling the composition of the product gas, and reigniting the coal seam when necessary.

SUMMARY OF INVENTION

[0007] An object of the present invention is to provide a device for UCG that minimises one or more of the problems of the prior art.

[0008] Throughout this specification, unless the context requires otherwise, the words "comprise", "comprises" and "comprising" will be understood to mean the inclusion of a stated integer, group of integers, step, or steps, but not the exclusion of any other integer, group of integers, step, or steps.

[0009] In one aspect, the invention provides an ignition tool for igniting an underground coal seam from within the seam (e.g., from within a well channel that extends through the coal seam), including: a) a tube body that is insertable into the seam (e.g., insertable into the well channel that extends through the coal seam), including an end having at least one inlet, an opposing end having an outlet, and a passage extending between the inlet and the outlet, b) a mixing chamber located within the passage extending between the inlet and the outlet of the tube body within which an ignition fuel and an oxidant mix, c) an electrical ignition device for igniting the ignition fuel and oxidant mixture, d) a side-ported burner nozzle connected to the outlet, and e) a combustible burner nozzle tip, wherein the burner nozzle port is angled about 45° to the axial centreline of the tube body.

[0010] The ignition tool tube body can be of unitary construction or can include two or more connectable body segments/pieces. Where the tube body includes multiple connectable body segments/pieces, these segments/pieces can be screwed and/or welded together to form a complete tube body.

[0011] The ignition tool tube body can have any suitable outside diameter and length. For example, the tube body can have an outside diameter of about two to four inches, including, for example, 3.00 inches, 3.25 inches, 3.50 inches, and 3.75 inches. Preferably, the tube body has an outside diameter of about 3.25 inches. As will be understood by one of ordinary skill in the art, the outside diameter of the tube body will not exceed the inside diameter of a well channel (including a lined well channel) into which the ignition tool is to be inserted for igniting an underground coal seam.

[0012] The ignition tool tube body includes an end having at least one inlet, an opposing end having an outlet, and a passage extending between the inlet and the outlet. As will be understood by one of ordinary skill in the art, the internal passage of the tube body can extend to (or be connected to) similar internal passages in other components of the ignition tool (e.g., internal passages in a coiled tubing adapter, spacer tube, and burner nozzle).

[0013] The inlet can be of any suitable size and shape. The inlet can be provided by a simple opening or openings in the tube body, or an inner tube that extends within the tube body. Ignition fuel and/or an oxidant can be fed through the inlet. Additionally, an electrical cable, sensor or other component can extend through the inlet. The inlet/inlet end of the tube body can be adapted to be connected to coiled tubing.

[0014] The outlet/outlet end of the tube body can be tapered or otherwise shaped so as to reduce resistance when moving the ignition tool to its intended location within a well channel within an underground coal seam.

[0015] The ignition tool includes a mixing chamber located within the tube body within which an ignition fuel and an oxidant mix. Mixing can be achieved in any suitable way. Typically, this will involve providing turbulence and/or resistance to flow of the ignition fuel and oxidant through the mixing chamber. To that end, in one embodiment, the mixing chamber includes at least one mixing structure or device, such as a Venturi device, one or more baffles (e.g., a spiral baffle), a diffuser plate, and/or other turbulence-creators (and combinations thereof) located within the mixing chamber (to create a pressure differential for the ignition fuel and oxidant streams to mix) or that define walls of the mixing chamber.

[0016] The mixing structure or device can be, for example, integrally formed with the ignition tool tube body or can be a separate component insertable into the tube body. In one embodiment, the mixing chamber is defined by the tube body and a diffuser plate extending transversely across the tube body adjacent the outlet from the tube body. In another embodiment, the mixing structure or device is in the form of a Venturi device positioned within the mixing chamber of the tube body.

[0017] Suitable ignition fuels include, but are not limited to, hydrocarbon gases, for example, methane, propane, butane, and mixtures thereof. The ignition fuel source can include a tank/cylinder of compressed hydrocarbon gas or liquefied hydrocarbon gas.

[0018] The oxidant is preferably a gas such as air (approximately 20% oxygen), oxygen-enriched air (greater than 20% oxygen), or a gas/gas mixture (e.g., CO₂ and/or nitrogen in any desired ratio) enriched with oxygen (greater than 20% oxygen), or substantially pure oxygen. The oxidant source can include an air compressor, a tank/cylinder of compressed air or oxygen, an air separation unit, or a tank/cylinder of liquid oxygen.

[0019] The ignition tool also includes an electrical ignition device for igniting the ignition fuel and oxidant mixture. In one embodiment, the electrical ignition device includes an electrical spark generator (e.g., a spark plug) and a power supply for generating the spark.

[0020] In another embodiment, the electrical ignition device includes an electrical heat resistor (e.g., a glow plug) and a power supply for electrifying the resistor.

Suitably, the resistor generates about 150 to 200 kW of heat, such as 160 kW, 170 kW, 180 kW, or 190 kW of heat. [0021] In some embodiments, the electrical spark generator or electrical heat resistor is located within the passage extending between the inlet and the outlet of the ignition tool tube body (or an internal passage in an optional spacer tube or the burner nozzle). In other embodiments, the electrical spark generator or electrical heat resistor is attached to an external surface of the ignition tool.

[0022] The ignition tool can include a support for supporting the electrical ignition device (or other component of the tool) within the tube body or externally of the tube body. Any suitable type of support can be used. For example, the support can be integrally formed with the tube body or can be a separate component insertable into the tube body. In one embodiment, the support is in the form of a spacer sleeve or stay that snugly fits within the tube body and supports the electrical ignition device within an interior region of the tube body (e.g., within the passage extending between the inlet and the outlet of the ignition tool tube body).

[0023] The power supply for the electrical ignition device can be located above ground, or the electrical ignition device can be powered by an in-seam turbine and transformer located within the passage extending between the inlet and the outlet of the ignition tool tube body and electrically connected to the electrical ignition device.

[0024] Dispersion of the ignited fuel and oxidant mixture in the form of a flame is accomplished by way of a side-ported burner nozzle connected to the ignition tool tube body outlet, which allows for contact between the flame and an underground coal seam (e.g., from within a well channel that extends through the coal seam). Suitably, the burner nozzle port is angled about 15° to 45° to the axial centreline of the tube body, including, for example, 20°, 25°, 30°, 35°, and 40°. Preferably, the burner nozzle port is angled about 45° to the axial centreline of the tube body.

[0025] In one embodiment, the burner nozzle includes a diffuser plate designed to improve the dispersion characteristics of an ignited fuel and oxidant mixture leaving the burner nozzle in the form of a flame. As will be known to one of ordinary skill in the art, any suitable type of diffuser plate, such as a perforated and/or slotted plate, can be used. [0026] According to an important aspect of the present invention, the ignition tool further includes a combustible burner nozzle tip, which facilitates ignition (including re-ignition) of an underground coal seam, particularly in instances where the coal seam has a high moisture content. Such a burner nozzle tip can be made of any suitable combustible material, including plastic or fibreglass, and acts as an aid and/or accelerant during ignition of the coal seam. Preferably, the combustible burner nozzle tip is made of high density polyethylene (HDPE).

[0027] In some embodiments, the combustible burner nozzle tip further includes thermite. As will be understood by one of ordinary skill in the art, thermite includes metallic fuel/metal oxide mixtures that produce exothermic oxidation-reduction reactions known as a thermite reactions. Exemplary metallic fuels for a thermite composition include aluminium, magnesium, titanium, zinc, silicon, and boron, while exemplary metal oxidizes include Iron(lll) Oxide [Fe2O₃], lron(ll, III) Oxide [Fe3O₄], Copper(ll) Oxide [CuO], Copper(l) Oxide [Cu₂O], Tin(IV) Oxide [SnO₂],

Manganese(IV) Oxide [MnO2], Manganese(lll) Oxide [Mn₂O3], Chromium(lll) Oxide [Cr₂O₃], Cobalt(ll) Oxide [CoO], and Nickel(ll) Oxide [NiO]. Preferably, thermite including finely powdered aluminium and Fe2O3/Fe3O₄ is used.

[0028] In one embodiment, the at least one inlet of the ignition tool tube body includes a first inlet that feeds ignition fuel to the passage extending between the inlet and the outlet of the tube body. In another embodiment, the first inlet is connected to an inner tube that extends within the tube body and feeds ignition fuel to the passage extending between the inlet and the outlet of the tube body. In a further embodiment, the ignition tool also includes a spray nozzle connected to the end of the inner tube through which ignition fuel is fed to the passage extending between the inlet and the outlet of the tube body. That is, the spray nozzle is connected to the end of the inner tube that terminates within the tube body.

[0029] In another embodiment, the at least one inlet of the ignition tool tube body includes a second inlet that feeds oxidant to the passage extending between the inlet and the outlet of the tube body. [0030] As discussed herein, the inlet/inlet end of the ignition tool tube body can be adapted to be connected to coiled tubing. Thus, the ignition tool can include at least one inlet in the tube body that is in fluid communication with at least one tube of the coiled tubing.

[0031] The ignition tool tube body can be connected to the coiled tubing in any suitable way. The tube body can be releasably connected or permanently connected to the coiled tubing. Preferably, the tube body is connected to an end of the coiled tubing by way of a screw thread or weld.

[0032] The coiled tubing can be of any suitable size, shape and construction, and can be made of any suitable material or materials. More particularly, the coiled tubing can be of any suitable length and diameter. Preferably, the coiled tubing is made of metal, such as stainless steel, carbon steel, or copper. The coiled tubing can be of unitary construction or can include two or more connectable tube segments/pieces. A preferred outside diameter for the coiled tubing is two inches.

[0033] The coiled tubing can include a single tube (i.e., line) connected to the ignition tool tube body. The coiled tubing can alternatively include at least one inner tube (i.e., inner line) extending within an outer tube (i.e., outer line), wherein one or both of the inner and outer tubes are connected to the ignition tool tube body. That is, the coiled tubing can include at least one inner tube and an outer tube that extend concentrically relative to one another. More than one inner tube can extend within the same outer tube. A preferred diameter for the outer tube is two inches, whereas a preferred diameter for the inner tube is 0.75 inches.

[0034] In some embodiments, the coiled tubing includes a single tube connected to the ignition tool tube body, and a first inlet of the tube body is in fluid

communication with the single tube of the coiled tubing, as discussed herein. In other embodiments, the coiled tubing includes an inner tube extending within an outer tube, and both the inner and outer tubes are connected to the tube body, with the first inlet of the tube body in fluid communication with the inner tube of the coiled tubing and a second inlet of the tube body in fluid communication with the outer tube of the coiled tubing, as discussed herein. [0035] In a preferred embodiment, the inlet end of the ignition tool tube body includes a first inlet connected to an inner tube of the coiled tubing that feeds ignition fuel to the tube body and a second inlet connected to an outer tube of the coiled tubing that feeds oxidant to the tube body. The source of the ignition fuel/oxidant can be connected directly or indirectly to the coiled tubing associated with the ignition tool in a fluid-tight manner, for introduction of the ignition fuel/oxidant into the tube body via the coiled tubing.

[0036] In addition to feeding ignition fuel and/or oxidant to the ignition tool, the coiled tubing can also convey electrical (e.g., power and/or data) cables of the ignition tool, and act as a positioning system that is extendible within a well channel to position the ignition tool at a desired location within the well channel.

[0037] In one embodiment, the ignition tool further includes a non-return/check valve (e.g., ball and spring, spring loaded flapper valve, or the like) fitted within the passage extending between the inlet and the outlet of the tube body. As will be understood by one of skill in the art, a check valve can prevent ignition fuel, oxidant, and/or product gas reverse flow in the passage extending between the inlet and the outlet of the tube body. More than one check valve can be included. For example, dual check valves can be included in the ignition tool.

[0038] According to an important aspect of the present invention, in one embodiment, the combustible burner nozzle tip includes a flow deflector, which facilitates dispersion of an ignited fuel and oxidant mixture once the combustible burner nozzle tip has been consumed. The flow deflector can be integrated with and support the combustible material of the burner nozzle tip, such that the flow deflector is not exposed until the combustible material has been consumed in the

ignition/combustion process.

[0039] In another embodiment, the ignition tool further includes one or more spacer tubes connected to the outlet of the tube body and the inlet end of the burner nozzle. That is, the one or more spacer tubes lie between the tube body and the burner nozzle of the ignition tool. As will be understood by one of ordinary skill in the art, the one or more spacer tubes can be used to enhance the mixing of an ignition fuel and oxidant prior to the mixture being ignited.

[0040] In a further embodiment, the ignition tool further includes fins or vanes (i.e., centralizers) that extend from the tube body (and/or one or more optional spacer tubes) and help position the ignition tool within a well channel that extends through an underground coal seam. The centralizers can be spring-loaded. In addition to helping position the ignition tool within the well channel, the fins or vanes can act as heat-exchange formations, for cooling the ignition tool.

[0041] The ignition tool can include a detachable cap or plug (e.g., blow-out plug) covering the burner nozzle port, which can be detached from the port prior to ignition. The cap or plug can be bull nose, long nose, or conical in shape. Detachment can be achieved in any suitable way. For example, an increase in gas pressure due to ignition fuel and/or oxidant flow through the tube body can be used to detach the cap or plug. The cap or plug can friction fit to the burner nozzle port. If in the form of a plug, a stem of the plug can friction fit to the burner nozzle port using an O-ring that extends around the stem of the plug.

[0042] As will be understood by one of ordinary skill in the art, one or more components of the ignition tool can be made of material that is resistant to high temperatures and corrosion, and/or undergoes controlled expansion at elevated temperatures, such as those found in an active underground coal gasifier.

[0043] Exemplary metal, metal alloys, and ceramics suitable for one or more components of the ignition tool include, but are not limited to, stainless steel (and alloys thereof), chromium-nickel alloys (including those containing silicon, cobalt, tungsten, molybdenum, and microalloying elements such as nitrogen, and rare earth metals such as cesium), the Inconel ® (predominantly nickel-chromium alloys), Monel ® (predominantly nickel-copper alloys), and Hastelloy ® (predominantly nickel- containing alloys) families of high-performance alloys, zirconia toughened alumina, yttrium stabilised zirconia, zirconia di-oxide, and silicon carbide. [0044] Additionally, one or more components of the ignition tool can be coated (e.g., via plasma coating) with a protective coating, including, for example, ceramic coatings, zirconia (zirconium oxide) coatings, alumina-zirconia coatings, and carbon composite coatings.

[0045] In one embodiment, the ignition tool further includes one or more sensors for sensing and reporting conditions in the tube body, adjacent the tube body, the well channel, and/or the underground coal seam. Any suitable type of sensor can be used. For example, the sensor can be a thermocouple for sensing the temperature, a gas sensor for sensing the nature of the product gas, a pressure sensor for sensing pressure, an optical sensor for viewing the linkage channel, or a position sensor for reporting the location of the ignition tool within the well channel.

[0046] Suitably, the ignition tool includes one or more thermocouples so that temperature information/data can be collected from the ignition tool. This temperature information/data can be used to control the operating parameters of the ignition tool.

[0047] As will be understood by one of ordinary skill in the art, the one or more sensors can be located within the ignition tool (e.g., within the tube body) and/or attached to an external surface of the ignition tool, including the tube body.

[0048] An electrical cable of the one or more sensors can extend within the coiled tubing and internally or externally of the ignition tool tube body.

[0049] The ignition tool can include a controller operable to trigger ignition, including the provision of electrical energy and/or the release of ignition fuel/oxidant. The controller can include a pipe manifold in fluid communication with the coiled tubing and ignition fuel and oxidant sources.

[0050] The controller can be operable remotely from the ignition tool to control the ignition fuel and oxidant ratio of the mixture, monitor combustion of the mixture, and control the supply of electrical energy to the ignition tool. The controller can include a voltage and current measuring and controlling device connected to an electrical ignition device by means of an electrical cable extending through the coiled tubing. [0051] The controller can include trim, non-return, and isolation valves, flow measuring devices, and pressure relief devices. Such operating devices allow for injection rate measurement and control for ignition fuel and oxidant, and purging of the ignition fuel with inert gases, such as nitrogen. Ignition fuel/oxidant mixture can be adjusted using flow controlling devices, such devices being either pneumatically actuated, manually choked, quarter-turn types, or electrically actuated.

[0052] The controller can include pressure safety devices, filtration devices, and flow metering devices, in addition to isolation valves. Control logic can allow the ignition fuel/oxidant to flow as per the required settings. In case of power failure or loss of oxidant, the control logic can stop the flow of the ignition fuel.

[0053] The source of ignition fuel and oxidant can be connected to a pipe manifold of the controller and further to the coiled tubing and a well head of an injection well. A power supply (e.g., generator) can be electrically connected to the controller and further to an electrical cable and sensor cable extending through the coiled tubing.

[0054] The controller can supply electrical energy to the ignition tool to ignite the ignition fuel/oxidant mixture, monitor the condition of the ignited mixture, and ramp the ignition fuel/oxidant flow up or down until combustion has been established in the underground coal seam.

[0055] In order to continue the UCG process through the coal seam, it may be necessary to reposition the ignition tool to a new ignition site where the coal in the vicinity of the new ignition site can be ignited and a new combustion zone created to progress the combustion along the coal seam and have optimum consumption of the underground coal resource.

[0056] Thus, to support particularly the movement of the combustion zone, the coiled tubing and ignition tool can be drawn along the well channel that extends through the underground coal seam and re-ignited periodically as needed to not only maintain the combustion in the combustion zone, but also to initiate subsequent combustion zones in the coal seam. A preferred method is utilising the controlled retracting injection point (CRIP) concept, as will be understood by one of ordinary skill in the art.

[0057] In order that the invention may be more readily understood and put into practice, one or more preferred embodiments thereof will now be described, by way of example only, with reference to the accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a cutaway view of an ignition tool according to an embodiment of the present invention.

[0059] Figure 2 is a cutaway view of a part of the ignition tool illustrated in Figure 1.

[0060] Figure 3 is a perspective view of another part of the ignition tool illustrated in Figure 1.

DESCRIPTION OF EMBODIMENTS

[0061] The present invention relates to a device for igniting an underground coal seam.

[0062] In the figures, like reference numerals refer to like features.

[0063] Referring first to figure 1 , there is generally depicted an ignition tool 10 according to an embodiment of the present invention. The ignition tool 10 has a 3.25" outside diameter tube body 12 that includes an inlet 15, outlet 17, and a passage 20 extending between inlet 15 and outlet 17. A coiled tubing adapter 22 connects to the inlet 15 of the tube body 12, while a 3.25" outside diameter optional spacer tube 25 connects to the outlet 17 of the tube body 12. A 3.25" outside diameter burner nozzle 27 connects to the forward end of the spacer tube 25 and includes an internal electrical ignition device 30 (glow plug) and nozzle port 32. A combustible burner nozzle tip 35 connects to the burner nozzle 27, and includes a flow deflector 37.

[0064] In use, the flow deflector 37 is not exposed until the combustible portion of the combustible burner nozzle tip 35 is consumed.

[0065] The tube body 12 includes a mixing chamber 40, a Venturi device 42, and an inner tube 45 located within passage 20.

[0066] In use, ignition fuel (e.g., methane) transported via the inner tube 45 mixes with oxidant transported via the passage 20 in the mixing chamber 40, with Venturi device 42 creating a pressure differential to facilitate the mixing of the ignition fuel and oxidant. Additional mixing can occur in the spacer tube 25. The ignition fuel and oxidant mixture is ignited by the electrical ignition device 30 in the burner nozzle 27, and dispersion of the ignited fuel and oxidant mixture in the form of a flame is accomplished by way of nozzle port 32, which allows for contact between the flame, the combustible burner nozzle tip 35, and an underground coal seam (not shown) from within a well channel that extends through the coal seam.

[0067] A cutaway view of burner nozzle 27 of the ignition tool 10 is shown in Figure 2, and illustrates that, in a preferred embodiment, nozzle port 32 is angled 45° to the axial centreline of the tube body 12.

[0068] A perspective view of combustible burner nozzle tip 35 of the ignition tool 10 is shown in Figure 3, and illustrates how the flow deflector 37 is integrated with and supports combustible material 47 (e.g., HDPE) of the burner nozzle tip 35. A series of supports 49 integrate and also support the combustible material 47 with the flow deflector 37 in the combustible burner nozzle tip 35. Although only one support 49 is illustrated, the combustible burner nozzle tip 35 generally includes four such supports. In some embodiments, the combustible material 47 contains a thermite core (not shown).

[0069] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more

combinations.

[0070] Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. It will therefore be appreciated by those of skill in the art that, in light of the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention.

Claims

1. An ignition tool for igniting an underground coal seam from within a well channel that extends through the coal seam, comprising:

a. a tube body that is insertable into the well channel, comprising an end having at least one inlet, an opposing end having an outlet, and a passage extending between the inlet and the outlet;

b. a mixing chamber located within the passage extending between the inlet and the outlet of the tube body within which an ignition fuel and an oxidant mix;

c. an electrical ignition device for igniting the ignition fuel and oxidant mixture; d. a side-ported burner nozzle connected to the outlet; and

e. a combustible burner nozzle tip,

wherein the burner nozzle port is angled about 45° to the axial centreline of the tube body.

2. The ignition tool of claim 1 , wherein the at least one inlet comprises a first inlet that feeds ignition fuel to the passage extending between the inlet and the outlet of the tube body.

3. The ignition tool of claim 2, wherein the first inlet is connected to an inner tube that extends within the tube body and feeds ignition fuel to the passage extending between the inlet and the outlet of the tube body.

4. The ignition tool of claim 3, further comprising a spray nozzle connected to the end of the inner tube through which ignition fuel is fed to the passage extending between the inlet and the outlet of the tube body.

5. The ignition tool of any one of claims 1 to 4, wherein the at least one inlet comprises a second inlet that feeds oxidant to the passage extending between the inlet and the outlet of the tube body.

6. The ignition tool of any one of claims 1 to 5, wherein the inlet of the tube body is adapted to be connected to coiled tubing.

7. The ignition tool of any one of claims 1 to 6, wherein the mixing chamber comprises one or more mixing devices.

8. The ignition tool of claim 7, wherein the one or more mixing devices are selected from the group consisting of a Venturi device, a baffle, a diffuser plate, and combinations thereof.

9. The ignition tool of claim 8, wherein the baffle is a spiral baffle.

10. The ignition tool of any one of claims 1 to 9, wherein the electrical ignition device comprises an electrical spark generator or an electrical heat resistor.

11. The ignition tool of claim 10, wherein the electrical spark generator or electrical heat resistor is located within the passage extending between the inlet and the outlet of the tube body.

12. The ignition tool of claim 10, wherein the electrical spark generator or electrical heat resistor is attached to an external surface of the tube body. 3. The ignition tool of claim 10, wherein a power supply for the electrical ignition device comprises a turbine and transformer located within the passage extending between the inlet and the outlet of the tube body and electrically connected to the electrical ignition device.

14. The ignition tool of any one of claims 1 to 13, wherein the combustible burner nozzle tip comprises HDPE.

15. The ignition tool of claim 14, wherein the combustible burner nozzle tip further comprises thermite.

16. The ignition tool of any one of claims 1 to 5, wherein the combustible burner nozzle tip comprises a flow deflector.

17. The ignition tool of any one of claims 1 to 16, further comprising a nonreturn/check valve fitted within the passage extending between the inlet and the outlet of the tube body.

18. The ignition tool of any one of claims 1 to 17, wherein the tube body further comprises fins or vanes.

19. The ignition tool of any one of claims 1 to 18, further comprising one or more sensors for sensing and reporting conditions in the tube body, adjacent the tube body, the well channel, and/or the coal seam.

20. The ignition tool of claim 19, wherein the one or more sensors comprise one or more thermocouples for sensing and reporting the temperature in the tube body, adjacent the tube body, the well channel, and/or the coal seam.

21. The ignition tool of claim 20, wherein the one or more thermocouples are located within the tube body.

22. The ignition tool of claim 20, wherein the one or more thermocouples are attached to an external surface of the tube body.

23. The ignition tool of any one of claims 1 to 22, further comprising a positioning system comprising coiled tubing connected to the ignition tool and extendible within the well channel to position the ignition tool at a desired location within the well channel.

24. The ignition tool of claim 23, wherein the coiled tubing comprises a single tube connected to the tube body and wherein the first inlet of the tube body is in fluid communication with the single tube of the coiled tubing.

25. The ignition tool of claim 23, wherein the coiled tubing comprises an inner tube extending within an outer tube and both the inner and outer tubes are connected to the tube body and wherein the first inlet of the tube body is in fluid communication with the inner tube of the coiled tubing and the second inlet of the tube body is in fluid communication with the outer tube of the coiled tubing.