Underground gasification may be an alternative method of extracting energy from an underground energy source. The method may involve drilling multiple wells into an underground energy source and igniting the underground energy source. Typically, the wells may be connected within the underground energy source to form a horizontal well. The underground energy source may be ignited to produce synthetic gas, “syngas”, which may flow or be pumped out of a recovery well, connected to the underground energy source.
The ignition and re-ignition of an underground energy source may often be unreliable. Current methods of ignition may include the use of (1) pyrophoric gases, (2) chemical reactants, or (3) electrical glow plugs or resistors. The use of pyrophoric gases and chemical reactants may present safety and environmental hazards, leading to the risk of increased injuries and increased risk-mitigation costs. Additionally, current technology in igniting an underground energy source may often be impractical and not cost effective. Thus, there is needed a more cost effective and reliable system and method for the ignition and re-ignition of an underground energy source.
These drawings illustrate certain aspects of some of the examples of the present invention, and should not be used to limit or define the invention.
The present disclosure relates to a system and method for initiating and monitoring an underground gasification process. This disclosure may also describe use of a number of different ignition systems to ignite an underground energy source including, but not limited to, a piezoelectric igniter system, a fuel igniter system, a paddle igniter system, a laser ignition system, and/or a chemical igniter system.
Underground gasification may be a process used to create synthetic gas by igniting an underground energy source. Typically, two or more wells may be drilled into an underground energy source. Each well may be connected within the underground energy source, for example, to create a horizontal well. One or more wells may be used as an injection well, and one or more wells may be used as a recovery well. The injection and recovery wells may be on the same or different sides of the underground energy source.
A downhole ignition device may be inserted into the injection well and may ignite the underground energy source. Once the underground energy source is ignited, a synthetic gas, “syngas”, may be produced as the underground energy source burns. Syngas may include, but is not limited to methane, hydrogen, carbon monoxide, carbon dioxide, water vapor, air, and/or oxygen. This syngas may flow or may be pumped out through a recovery well. The downhole ignition device may typically be removed from the burning underground energy source to a location in the injection well (or at the surface) and may be utilized within the horizontal well or injection well. Additionally, the underground energy source may require re-ignition. To re-ignite the underground energy source, the downhole ignition device may be sent downhole and disposed adjacent the underground energy source. The ignition process, described above, may be repeated in an effort to re-ignite the underground energy source.
The downhole ignition device may also record and transmit bottom hole conditions such as pressure, temperature, and humidity through a communication line. These recordings may be transmitted to the ground surface in real time to control the gasification process. Temperature sensors may be used to determine when the underground energy source is sufficiently burning, allowing for removal of the downhole ignition device from the well. Water or steam may be used during underground gasification to control air temperatures within the burning underground energy source. Additionally, the downhole ignition device may detect, measure, and/or transmit data regarding gases disposed in the underground energy source, including, but not limited to, methane, hydrogen, carbon monoxide, carbon dioxide, water vapor, air, and/or oxygen. The downhole ignition device may also utilize a casing collar locator or a Gamma sensor for accurate placement of the downhole ignition device in the underground energy source for maximum efficiency.
Underground gasification system 100 may include downhole ignition device 112 that may be used to ignite underground energy source 104 and collect data that may be transmitted to the ground surface. As illustrated in
Certain examples of the present disclosure may be implemented at least in part with an information handling system 206. For purposes of this disclosure, information handling system 206 may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, information handling system 206 may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. Information handling system 206 may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of information handling system 206 may include one or more disk drives, one or more network ports for communication with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. Information handling system 206 may also include one or more buses operable to transmit communications between the various hardware components.
Certain examples of the present disclosure may be implemented at least in part with non-transitory computer-readable media. For the purposes of this disclosure, non-transitory computer-readable media may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Non-transitory computer-readable media may include, for example, without limitation, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk drive), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing.
As described above, downhole ignition device 112 may ignite underground energy source 104. Without limitation, as illustrated in
Ignition subassembly 306 may comprise a cam 310 and a piezoelectric igniter 312, which may be a rotary piezoelectric igniter. Piezoelectric igniter 312 may comprise of a suitable piezoelectric material, such as quarts, berlinite, sucrose, rochelle salt, topaz, tourmaline-group minerals, lead titanate, and/or any combination there. Without limitation there may be any number of cams 310 disposed within ignition subassembly 306. Cam 310 may be engaged and/or engage piezoelectric igniter 312. Cam 310 may be made of any suitable material, including ferrous alloy. When igniting an underground energy source 104, motor 302 may rotate cam 310 through shaft 308. Without limitation, information handling system 206 may control the operation of motor 302 through communication line 204. Frictionally engaged to piezoelectric igniter 312, cams 310 may cause piezoelectric igniter 312 material to deform. Deformation of piezo material may create a voltage charge across piezoelectric igniter 312. The charge may arc across piezoelectric igniter 312 and ignite fuel, which may be traversing the length of piezoelectric igniter 312. In examples, fuel may be supplied through supply line 114 from the surface. Additionally, the control and/or flow of fuel through piezoelectric igniter system 300 may be controlled by information handling system 206 at the surface. Without limitation, fuel may be methane, butane, propane, any combination thereof, and/or the like. Ignited, fuel may produce heat that may be used to ignite underground energy source 104. In examples, an oxygen source may be transported through supply line 114 and/or injection well 102 to downhole ignition device 112 to accelerate the ignition process. Additionally, the addition of oxygen and/or flow of oxygen may be controlled by information handling system 206 at the surface. Ignition of underground energy source 104 by downhole ignition device 112 may allow for downhole ignition device 112 to be removed to the surface and/or away from underground energy source 104. In examples, underground energy source 104 may require re-ignition. To re-ignite underground energy source 104, downhole ignition device 112 may be re-positioned adjacent underground energy source 104. The ignition process, described above, may be repeated in an effort to re-ignite underground energy source 104.
Paddle igniter system 700 may be disposed at a distal end of downhole ignition device 112. Paddle igniter system 700 may comprise paddles 702 and ignition sleeve 704. Ignition sleeve 704 may comprise magnesium and/or any ignitable pyrophoric composite material. Paddles 702 may be frictionally engaged to ignition sleeve 704 and/or separated from ignition sleeve 704. Paddles 702 may be made of any suitable material, including ferrous alloy. When igniting an underground energy source 104, motor 302 may rotate paddles 702 through shaft 308. Frictionally engaged to ignition sleeve 704, paddles 702 may initiate enough heat to ignite ignition sleeve 704. Once ignited, ignition sleeve 704 may ignite underground energy source 104. Without limitation, oxygen may be transported to downhole ignition device 112 to accelerate the ignition process. Ignition sleeve 704, once ignited, may completely burn away. In examples, underground energy source 104 may require further and/or re-ignition. To re-ignite underground energy source 104, downhole ignition device 112 may be removed to the surface and an additional ignition sleeve 704 may be placed upon lance 304. Alternatively, a plurality of ignition sleeves 704 may be positioned on lance 304 that can be used for re-ignition. Downhole ignition device 112 may then be sent downhole back to underground energy source 104 and ignition sleeve 704 may be reignited using motor 302 and paddles 702. In examples, a casing of downhole ignition device 112 may comprise fiber optic sensors, which may monitor the temperature profile in and around downhole ignition device 112.
Additionally, underground gasification system 100 may use an accelerant and/or a fuel to achieve ignition of underground energy source 104. An accelerant may be comprised of oxygen, air, nitrogen dioxide, combinations thereof, and/or the like. A fuel may be comprised of methane, butane, propane, and/or the like. An accelerant and/or a fuel may flow from the surface using supply line 114 to laser ignition system 800 and/or underground energy source 104. Additionally, an accelerant and/or fuel may be contained in canisters disposed in laser ignition system 800 and/or another subassembly of underground gasification system 100.
Chemical igniter system 900 may comprise, but is not limited to, connector 402, a first chemical container 902, a second chemical container 904, a first valve 906, a second valve 908, a third valve 910, a chemical mix chamber 912, or any combination of these subassemblies. Chemical igniter system 900 may also comprise sensors that may measure temperature, pressure, humidity, and/or the like. The first chemical container 902, second chemical container 904, first valve 906, second valve 908, and third valve 910 may each be comprised of a metal, a composite, and/or the like. The first chemical container 902 may comprise a first chemical, which may comprise fuel, methane, butane, propane, and/or the like. Additionally, second chemical container 904 may comprise a second chemical, which may comprise accelerant, oxygen, air, silane, and/or the like. Without limitation, fuel and/or accelerant may be disposed in either/or both of first chemical container 902 or second chemical container 904. Those ordinary of ordinary skill in the art, with the benefit of this disclosure, should be able to select appropriate chemicals that may react upon mixing to ignite underground energy source 104.
In examples, accelerant may flow through supply line 114 and may saturate underground energy source 104. Information handling system 206 may operate power line 202 and communication line 204 to operate a first valve 906, second valve 908, third valve 910, and/or other valves as needed. First valve 906 may be opened and/or closed using a command from information handling system 206. Opening first valve 906 may allow the first chemical container 902 to dispose a first chemical into chemical mix chamber 912 and/or to another area. Additionally, second valve 908 may be opened and/or closed using a command from information handling system 206. Opening second valve 908 and third valve 910 may allow second chemical container 904 to dispose a second chemical into chemical mix chamber 912 and/or to another area. Disposing the first chemical from the first chemical container 902 and the second chemical from second chemical container 904 into chemical mix chamber 912 and/or another area may cause a combustion reaction between the first chemical and the second chemical, which may ignite and/or burn underground energy source 104. The ignition and/or burning of underground energy source 104 may be accelerated by accelerant. In examples, mixture of the first and second chemicals may cause a combustion reaction, which may ignite and/or burn accelerant. The ignition and/or burning of accelerant may ignite and/or burn underground energy source 104.
In examples, chemical igniter system 900 may be disposed near underground energy source 104, injection well 102, and/or another location to allow for re-ignition of underground energy source 104 as needed. First chemical container 902 and second chemical container 904 may have the capacity to dispose sufficient fuel for ignition of underground energy source 104 and/or one or more re-ignitions of underground energy source 104. Additionally, first chemical container 902 and second chemical container 904 may be replaced for other chemical containers or may be refilled as needed. In an alternative example, chemical igniter system 900 may contain more than two chemicals and more than two chemical containers to allow for a combustion reaction, which may ignite and/or burn underground energy source 104.
Chemical igniter system 900 may also be configured to dispose a single chemical that may mix with accelerant to create a combustion reaction. A configuration may contain a first chemical container 902, which may contain a chemical, such as, but not limited to, silane and/or the like. The first chemical may be disposed using a first valve 906. Accelerant may flow from supply line 114 or may be disposed from second chemical container 904 using second valve 908. Accelerant 24 may mix with first chemical to cause a combustion reaction, which may ignite and/or burn underground energy source 104.
Additionally, an ignition target may be used to promote ignition of underground energy source 104. The ignition target may be placed adjacent to chemical mixing chamber 912 and may be comprised of, iron oxide, thermite, and/or the like.
Without limitation, the underground gasification systems disclosed herein may be used in a wide variety of subterranean applications for ignition of an underground energy source. Without limitation, an underground gasification system may comprise a recovery system, a supply line, a downhole ignition device operable to ignite an underground energy source. The downhole ignition device may be connected to the supply line and the supply line may be connected to the recovery system. The underground gasification system may further comprise an information handling system that may be operable to control the downhole ignition device. This system may include any of the various features of the compositions, methods, and systems disclosed herein, including one or more of the following features in any combination. A piezoelectric igniter system that may comprise a motor, a lance, a shaft, a cam, and a piezoelectric igniter. The information handling system may be operable to control the piezoelectric igniter system. The information handling system may operate the motor, and wherein the motor rotates the shaft which rotates the cam against the piezoelectric igniter. A fuel igniter system that may comprise a connector, an electronic sensor subassembly, a fuel supply subassembly, and ignition subassembly. The information handling system may be operable to control the fuel igniter system, where the information handling system may control a flow of a fuel or an accelerant through the fuel supply subassembly to the ignition subassembly, and where the information handling system may activate a resistance device disposed on the ignition subassembly to ignite the fuel or the accelerant. A paddle igniter system that may comprise a motor, a lance, a shaft, a paddle, and an ignition sleeve. The information handling system may be operable to control the paddle igniter system. The information handling system may operate the motor and the motor may rotate the shaft which may rotate the paddle against the ignition sleeve. The downhole ignition device may comprise a laser ignition system that may comprise a laser source, a lance, an optical fiber, and a circulating valve. The information handling system may be operable to control the laser ignition system and may turn the laser ignition system on and/or off. A chemical igniter system that may comprise a connector, a first chemical container, a second chemical container, a first valve, a second valve, a third valve, and a chemical mix chamber. The information handling system may be operable to control the chemical igniter system and operate the first valve, the second valve, and the third valve to mix a first chemical from the first chemical container and a second chemical from the second chemical container in the chemical mix chamber.
Without limitation, a method for igniting an underground energy source may comprise disposing a downhole ignition device into an injection well, positioning the downhole ignition device within the underground energy source, activating the downhole ignition device, igniting the underground energy source, and recovering a gas from the underground energy source. This method may include any of the various features of the compositions, methods, and systems disclosed herein, including one or more of the following features in any combination. The method may further comprise removing the downhole ignition device from the underground energy source, inserting oxygen, water, or accelerant to control burning of the underground energy source, re-positioning the downhole ignition device within the underground energy source, and re-igniting the underground energy source with the downhole ignition device. The method may further comprise operating the downhole ignition device with an information handling system. The downhole device may be a piezoelectric igniter system where the piezoelectric igniter may produce heat. The method may further comprise operating the downhole device with an information handling system. The downhole device may be a fuel igniter system, injecting a fuel and/or an accelerant from a fuel supply subassembly to an ignition subassembly, and igniting the fuel or the accelerant with a resistance device disposed on the ignition subassembly to ignite the fuel or the accelerant. The method may further comprise removing the fuel igniter system from the underground energy source, adding fuel and/or accelerant to the fuel igniter system, inserting the fuel igniter system into the underground energy source, and re-igniting the fuel igniter system. The method may further comprise operating a downhole device with the information handling system, wherein the downhole device may be a paddle igniter system and the paddle igniter system may produce heat with an ignition sleeve. The method may further comprise releasing the ignition sleeve form the paddle igniter system, removing the paddle igniter system from the underground energy source, adding a second ignition sleeve to the paddle igniter system, inserting the paddle igniter system into the underground energy source, and re-igniting the paddle igniter system. The method may further comprise powering a laser source and transmitting light from the laser source through an optical fiber into the underground energy source. The method may further comprise operating a downhole device with an information handling system and the downhole device may be a chemical igniter system, mixing a first chemical and a second chemical in a chemical mix chamber, where a chemical reaction may produce heat.
The preceding description provides various embodiments of the systems and methods of use disclosed herein which may contain different method steps and alternative combinations of components. It should be understood that, although individual embodiments may be discussed herein, the present disclosure covers all combinations of the disclosed embodiments, including, without limitation, the different component combinations, method step combinations, and properties of the system.
It should be understood that the compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.
Therefore, the present embodiments are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Although individual embodiments are discussed, the invention covers all combinations of all those embodiments. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention.
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