The present disclosure relates to a system and method of initially extracting underground coal-bed methane (CBM) and subsequently storing CO2 in its place.
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.
Extraction wells are used to extract coalbed methane (CBM) CH4 from coalbeds and the CH4 can be used in the production of electricity, hydrogen, and/or sustainable aviation fuel (SAF). Injection wells can be used to enhance extraction of CH4 from a neighboring well of a common coalbed. Class VI certified wells are approved by the Environmental Protection Agency (EPA) for the safe geologic sequestration and permanent storage of CO2 in a CBM chamber within a coalbed.
According to aspects of the disclosed subject matter, a carbon-based gas extraction and CO2 (i.e., CO2, carbon dioxide) storage system is described that includes a coalbed methane (CBM) energy production facility. A first well includes a first pump (submersible) configured operate in an extraction mode in which methane (CH4, also referred to as CH4) from the CBM chamber is pumped from the CBM chamber. The first well is also convertible to operate in an insertion mode in which CO2 is injected into the CBM chamber for enhancing CH4 extraction and also CO2 geologic sequestration. The second well extracts CBM from the CBM chamber. A controller controls the first pump to operate in the extraction mode and controllably switches to operate a different pump to inject CO2 to the coalbed in the insertion mode. The CO2 may be a byproduct of a conversion process performed on the extracted CH4. A computer-based system allocates credits to users that elect to use CH4 converted into sustainable sources of energy such as H2 or aviation fuel.
The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not necessarily intended to represent the only embodiment(s). In certain instances, the description includes specific details for the purpose of providing an understanding of the disclosed subject matter. However, it will be apparent to those skilled in the art that embodiments may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form in order to avoid obscuring the concepts of the disclosed subject matter.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, characteristic, operation, or function described in connection with an embodiment is included in at least one embodiment of the disclosed subject matter. Thus, any appearance of the phrases “in one embodiment” or “in an embodiment” in the specification is not necessarily referring to the same embodiment. Further, the particular features, structures, characteristics, operations, or functions may be combined in any suitable manner in one or more embodiments. Further, it is intended that embodiments of the disclosed subject matter can and do cover modifications and variations of the described embodiments.
It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. That is, unless clearly specified otherwise, as used herein the words “a” and “an” and the like carry the meaning of “one or more.” Additionally, it is to be understood that terms such as “left,” “right,” “top,” “bottom,” “front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,” “interior,” “exterior,” “inner,” “outer,” and the like that may be used herein, merely describe points of reference and do not necessarily limit embodiments of the disclosed subject matter to any particular orientation or configuration. Furthermore, terms such as “first,” “second,” “third,” etc., merely identify one of a number of portions, components, points of reference, operations and/or functions as described herein, and likewise do not necessarily limit embodiments of the disclosed subject matter to any particular configuration or orientation.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views:
The first well 13 communicates gases via a vertical casing 15A from an optional horizontal well casing 15B that is positioned in the coalbed 7. Likewise, the second well 17 includes a vertical casing 21A to an optional horizontal well casing 21B that is positioned in the coalbed 7. The vertical wall casings 15A and 21A may be referred to herein as vertical wall conduits, vertical conduits, and/or well conduits. Submersible pumps 22A and 22B at the bottom of the first well 13 and the second well 17 pump fluid upward, which in turn draws CH4 from the coalbed 7 into the horizontal well casings 15B and 21B. In this example, the horizontal well casings 15B and 21B include perforations that allow the CH4 to be drawn into the horizontal well casings 15B and 21B through the perforations, as well as through open ends thereof. The CH4 that is drawn into the horizontal well casings 15B and 21B is conveyed to the first well 13 and second well 17 via the vertical well casings 15A and 21A respectively. This “upward” flow of CH4 is indicated by the upward pointed arrows in
Step 1: Steam-methane reforming reaction CH4+H2O (+heat)→CO+3H2
Step 2: Water-gas shift reaction CO+H2O→CO2+H2 (+small amount of heat)
Partial Oxidation is another process that may be used for CH4 to H2 conversion. In partial oxidation, the methane and other hydrocarbons in natural gas react with a limited amount of oxygen (typically from air) that is not enough to completely oxidize the hydrocarbons to carbon dioxide and water. With less than the stoichiometric amount of oxygen available, the reaction products contain primarily hydrogen and carbon monoxide (and nitrogen, if the reaction is carried out with air rather than pure oxygen), and a relatively small amount of carbon dioxide and other compounds. Subsequently, in a water-gas shift reaction the carbon monoxide reacts with water to form carbon dioxide and more hydrogen. This two-step process may be summarized as follows:
Step 1: Partial oxidation of methane reaction: CH4+½O2→CO+2H2 (+heat)
Step 2: Water-gas shift reaction: CO+H2O→CO2+H2 (+small amount of heat)
One example of a CH4 to sustainable jet fuel (sustainable aviation fuel, SAF) process is called a Fischer-Tropsch process in which compressed steam reformed CH4 is combined with CO2 and supplied to a Fisher Tropsch Wax Cracking reactor before passing the gas through a heat exchanger and gas/liquid separator to produce the liquid jet fuel. The jet fuel distills at a temperature of between 150 degrees Celsius to 280 degrees Celsius. This process consumes CO2 to make a SAF.
Returning to
The first well 25 operates in an injection mode. The first well 25 includes a compressor that compresses the CO2 and injects the CO2 down the vertical wall casing 15A to the horizontal wall casing 15B which is disposed in the coalbed 7. Once in the coalbed 7, the CO2 expands and displaces the resident CH4 disposed in the coalbed 7, and thus urges the CH4 into the horizontal well casing 21B that is communicatively connected to the second well 17 via the vertical well casing 21A. Moreover, the negative pressure provided by the pumping action of the second submersible pump 22B at the bottom of the second well 17, in combination with the positive pressure on the CH4 applied by the injected CO2 enhances the movement of CH4 into the horizontal well casing 21B, and thus enhances the extraction of the CH4 from the coalbed 7 by the second well 17.
In an alternative embodiment, the first well 25 may by a Class II well (enhanced gas recovery). Class II may be used since the coal is a hydrocarbon reservoir previously degassed and dewatered and this CO2 injection would be sequestering CO2 and enhancing Methane production.
As recognized by the present inventors, the Class VI well certification is a lengthy process, often taking 5 years or more. Part of the approval process is comprehensive monitoring of CO2 injection and storage, as well as ground water inspection. However, rather than having a single well dedicated to CO2 injection, the present disclosure switches the operation of one of the wells from extraction to injection. From a system perspective, having both wells 13 and 17 operate in extraction during Phase 1 allows for rapid extraction during Phase 1. The production of CH4 during Phase 1 may be used for traditional energy production applications. However, by careful construction of the first well 13 and the surface pipe 19A, the existing infrastructure may be repurposed for more sustainable efforts to support end-users who may wish to exploit the benefits the CH4 converter 23 by producing electricity applied to an electrical line 29, and/or by H2 production, and/or aviation fuel production. Moreover, use of CO2 provided by the CH4 converter 23 may be captured and used for displacing CH4 in the coalbed 7 during Phase 2; however, simultaneous with Phase 2 operations, the application for converting the first well 13 into a Class VI well 27 may be submitted and thus “short cut” the process for geological sequestration of CO2 because some of the CO2 will remain trapped in the coalbed 7 during Phase 2. Thus, CO2 produced by the CH4 converter 23 in Phase 2 and Phase 3 is captured and permanently stored in the coalbed 7.
The present inventors recognized that the rate and volume of CO2 injected into the coalbed 7 during Phases 2 and 3 may be different. Thus, the first well 27 is equipped with a controllable compressor 24A and a variable rate pump 26A that variably adjusts the pressure at which CO2 is injected during Phase 2 so as to displace CH4 at a controlled rate without raising the pressures beyond the capability of the coalbed 7 to retain the CO2. Furthermore, although the first well 13 will initially be used in Phase 1 for extraction of CH4, it will ultimately be switched from extraction to insertion (for CO2 permanent storage). Thus, first well 13 is constructed (as will be discussed in more detail with respect to
Methane gas extraction wells are constructed by using a drill rig to install boreholes, typically at least 24 inches in diameter, into layers (layers 1, 3, and 5 in
In an openhole cavity configuration, an intermediate casing is disposed on an inner periphery of the surface casing, but the intermediate casing is not perforated and does not extend into the coalbed 7 by any appreciable amount. Extending from an inner surface of the intermediate casing is a perforated production liner that extends into the coalbed 7 and allows for CH4 to permeate into the void between the casings and the central pipe.
Class VI wells have different structural demands than extraction wells due mainly to higher injection rates and pressures for geologic sequestration (GS). Higher injection rates are also of concern because CO2 is less dense than most subsurface fluids and will tend to migrate to the top of an injection zone. A description of materials is provided below, and an arrangement of the structure is shown in
An injection well has one or more successively smaller concentric pipes (essentially thick-walled pipes within pipes) placed in the well bore. All but the innermost pipe (called the tubing, or exchange tubing) serve as well casings. Leaks in the casing can allow fluid to escape into unintended zones or allow fluid movement between zones. Thus, the outermost material of the casing is cement that is used to support and seal the well casing to rock formations exposed in the borehole. Cement also protects the casing from corrosion and prevents movement of injectate up the borehole. The composition of the cement may contain latex, mineral blends, or epoxy. Cement additives may be used to ensure chemical compatibility, reduce cement loss, improve resistance to cyclic stress, or increase strength.
Carbon dioxide in combination with water forms carbonic acid, which is corrosive to many well components. Native fluids can also contain corrosive elements such as brines and hydrogen sulfide. Therefore, the casing is manufactured of materials that are compatible with fluids with which the casing might come into contact. The surface casing is the largest in diameter. It extends from the ground surface through the base of the lowermost portion of the underground sources of drinking water (USDW). This casing is emplaced and cemented into the bore hole from the base of the lowermost USDW up to the ground surface, serving to both prevent fluids from entering USDWs and prevent migration of fluids between USDWs and other formations, as the casing isolates the injection fluid. If the lowermost USDW is particularly deep, multiple strings of casing may be used as surface casing. Each string of casing is to be cemented to the surface. The smallest diameter casing extends into the injection zone and is referred to as the long-string casing. The long-string casing is routinely perforated in the injection zone to allow fluid to flow out of the injection well and into the injection formation. Spaces between the long-string casing and the surface casing, the long-string casing and the geologic formation, and the surface casing and the geologic formation are called annuli. These annuli are filled with cement in Class VI injection wells, along both the surface and the long-string casing. The long-string casing extends from the ground surface down to an injection zone. If the well is very deep, there may be one or more intermediate casings of intermediate diameter between the surface casing and the long-string casing. These casings are cemented in place as well.
The tubing (or exchange tube) is a smaller pipe which runs inside the long-string casing from the ground surface down to the injection zone. The CO2 (during injection) moves down the tubing, out through the perforations in the long-string casing, and into the injection zone. The tubing ends at a point just below a well packer 49. The space between the long-string casing and tubing is referred to as the annulus and is filled with a noncorrosive fluid. The tubing forms another barrier between the injected fluid and the long-string casing. The tubing and long-string casing act in concert to form two levels of protection between the carbon dioxide stream and the geologic formations above the injection zone.
Cement is important for providing structural support of the casing, preventing contact of the casing with corrosive formation fluids, and preventing vertical movement of fluids and gases, including carbon dioxide. Down-hole pressures, fluids, and drilling mud can be managed when drilling so that down-hole conditions are suitable for well construction, cementing, and subsequent injection of carbon dioxide. Failing to cement the entire length of the casing, failure of the cement to bond with the casing or formation, not centralizing the casing during cementing, cracking, and alteration of the cement can all allow migration of fluids along the well bore. If carbon dioxide escapes the injection zone through the well bore because of a failed cement job, the well would be out of compliance with Class VI Rules and required to cease injection. CO2 can react with typical Portland cements commonly used in extraction well construction. As such, Class VI wells may be constructed using cements that are enhanced with additives that make the cement non-reactive to CO2, carbonated brine, and other corrosive fluids.
A well packer 49 is a sealing device at the lower end of the tubing and keeps fluid from migrating from the injection zone into the annulus between the long-string casing and tubing. It must also be made of materials that are compatible with fluids with which it will come into contact, and thus are non-corrosive such as a nickel-plated assembly.
A Class VI Rule requires the well be constructed to withstand anticipated stresses (e.g., 1500 to 3000 psi), to last the lifetime of the project, and to be compatible with fluids and materials that flow through the well. The cements are Portland based with various additives to alter cure time, strength, and sulfate resistance. American Petroleum Institute O, M, or H cements are used.
The surface casing must extend through the base of the lowermost USDW and be cemented to the surface through the use of single or multiple strings of casing and single or multiple stages of cement. A long-string casing extends at least to the injection zone and be cemented to the surface. The surface casing provides stability to the well bore by preventing unconsolidated soils and aggregates from falling into the borehole. It also typically decreases the amount of drilling mud used in the deeper portions of the well. By extending through the base of the lowermost USDW, the surface casing also seals off USDWs and other permeable zones from deeper intervals of the well bore. Thus, it provides an additional barrier to fluid or injectate migration into a USDW if the tubing and long-string casing should fail. Cementing of the long string casing serves to seal off the well bore and may prevent fluid or injectate leaks through the casing from entering a permeable zone, such as a USDW. If the cement was absent or improperly emplaced, and there was a tubing and casing failure, carbon dioxide could enter a permeable zone and then potentially migrate into USDWs through an annulus, or faults. Cementing the casing also protects it from exposure to carbonated brine and other corrosive fluids. Creation of a tight interface between the cement, casing, and the formation is the key to hydraulic isolation. Duguid and Crow, 2007, “CO2 Well Integrity and Wellbore Monitoring” describes more detail about cementing, and the entire contents of this document is incorporated herein by reference. The well of
Two-stage cementing is performed similarly to single stage cementing, except that a cement collar with cement ports is installed at an appropriate point in the well. The cement collar allows cement to be injected into the annulus between the casing and formation at some point in the column under construction other than the bottom of the well.
In Phase 2, converter box 23 is installed along the first surface pipe segment 19A. Converter box 23 is configured to convert CBM (e.g., methane CH4) to CO2/zero carbon product. Well A is converted to a CO2 injection well and the surface pipe (pipe C) is converted to a CO2 pipeline. The CO2 injection well (Well A) may also be referred to herein as a CO2 injector. Pipe C is converted into a CO2 pipeline. In some embodiments, the same pipe (pipe C) may be used in Phase 1 and Phase 2 provided the pipe is lined with a material (e.g., cement) to prevent CO2 from reacting with, and thus degrading over time, the pipe material (which in this example is steel). As such, the CO2 generated by the converter box 23 can be delivered to Well A over pipe C. By using a surface pump at Well A to inject compressed CO2 at a high pressure (e.g., above 500 psi), the pressure of the CO2 in the coalbed 7 displaces CH4 from the coalbed 7 and into the extraction well (Well B). Well B continues to operate in CBM extraction operations. The CH4 extracted from the coalbed 7 is divided at Well B with a controllable amount sent to the market via the second surface pipe segment 19B, and the remaining amount of CH4 feeds a process controlled by the converter box 23 that generates CO2 that is used for enhanced recovery operations by injection in Well A. Monetary, or carbon, credit is attributed to the entity that provides the CO2 via the CH4 conversion device (e.g., Converter Box 23 in
In Phase 3, Well A is approved for use as a Class VI well for permanent geologic sequestration of CO2 produced by the CH4 conversion device 23. Well A continues to inject CO2, generated by the converter box 23 and delivered via pipe C, into the coalbed 7 for permanent storage of the CO2 and for the enhanced CBM extraction of CH4 at Well B. During Phase 3 operation, zero carbon market products (e.g., hydrogen, gas-to-liquids, GTL, jet fuel, SAF, and/or the like) may be generated by the converter box 23. Further credits are provided to the entity for the CO2 that is stored permanently in the coalbed 7. For example, the additional credits may be generated by an entity during Phase 3 operations of the wells at a 45Q “Permanent Storage Rate” (e.g., $55/ton to $85/ton). Phase 3 operation may be referred to herein as CO2 storage, CO2 permanent storage, and/or CO2 storage operation. By following the phased approach summarized in
However, a byproduct of H2 production from CH4 is CO2, which, as discussed in references to
Turning now to
Although Well A is initially used as an extraction well, it is easily configurable to support Class VI operations. Moreover, although an extraction well places a long string casing 43 in a borehole 51 and perhaps attaches at least a portion of the outer surface of the casing to the geologic material via concrete, the demands placed on an extraction well are much less than those placed on a Class VI injection well. Moreover, the extraction well normally only provides a water-based fluid that is pumped up through a central pipe (e.g., exchange tube 35) via a submersible pump 22A (see
As shown in
The perforations 45 at the bottom portion of the long string casing 43 communicate gases in and out of the borehole 51 and the coalbed 7. Thus during extraction, CH4 enters the long string casing 43 via the perforations 45, and during injection, the CO2 is emitted via the perforations 45.
At the upper end of the vertical well casing 15A, the outermost portion is a surface casing 39 having an outer surface cemented 37 to the surrounding geologic material. The surface casing 39 extends below the base layer 31. An intermediate casing 41 extends deeper, and it too is cemented 37 to geologic material around its outer periphery.
At the confining layer 33, for the conversion of the first well casing 15A from extraction operation during Phase 1 to injection operation during Phase 2, an injection well packer 49 is disposed about the exchange tube 35 to isolate an injection zone. In some embodiments, the injection well packer 49 is made from non-corrosive material (e.g., a nickel-plated steel). An annulus 47 may be filled with a non-corrosive fluid during Phase 1 extraction. However, during injection of CO2 (at least during Phase 3, and optionally during Phase 2) the annulus 47 is filled with cement 37 to firmly hold and seal the exchange tube 35 in place; see
In some embodiments, a new Well B may be formed a second distance D2 from the old Well B and operate in Phase 1 as an extraction well separate from the old Well B. In such embodiments, the old Well B may be converted at a later time to an injection well and operate as a new Well A in Phase 2 for the enhanced CBM extraction at new Well B. New Well A may be further converted to operate in Phase 3 as a Class VI injection well for the sequestration of CO2 in the coalbed 7 and for the enhanced CBM extraction at new Well B. At a still later time, new Well A may be capped by filling the exchange tube 35 with cement 37 for the permanent storage of CO2 in the coalbed 7. This process may continue along the coalbed 7 by adding a new Well B at a third distance D3 from the old Well B. The new Well B being constructed as an extraction well and the old Well B being converted to an injection well as a new Well A to assist in the extraction of at the new Well B. Although three pairs of Wells A and B are illustrated, any suitable number of wells may be utilized. Furthermore, the first distance D1, the second distance D2, and the third distance D3 may be different distances or they may be the same. The distances D1, D2, and D3 may be determined by the geology of the coalbed 7, the terrain at the surface of the wells, and/or the property rights of the land owners.
According to one or more aspects of the disclosed subject matter, a carbon-based gas extraction and storage system includes: a coal bed methane (CBM) energy production facility; a first well at a first location having a first pump and a first well conduit within a first borehole, the first well conduit extending from above ground to a subterranean coalbed methane (CBM) chamber, the first pump configured to operate in an extraction mode in which methane from the CBM chamber is pumped up from the CBM chamber, the first well being convertible to operate in insertion mode in which CO2 is injected into the CBM chamber for enhanced CH4 recovery and also for permanent CO2 geologic sequestration; a second well at a second location having a second pump and a second well conduit within a second borehole, the second well conduit extending from above ground to the subterranean coal bed methane chamber; an above-ground conduit that interconnects the first well conduit, the CBM energy production facility and the second well conduit; a controller configured to control the first pump to selectably operate in the extraction mode and provide CBM from the CBM chamber to the above-ground conduit, and configured to switch control of the first pump to a different pump that injects into the coalbed CO2 produced from CBM processed by the CBM energy production facility, wherein the different pump injects the CO2 emissions into the CBM chamber to assist in extraction of CBM by the second pump, and subsequently operates as a Class VI well that permanently stores the CO2 in the CBM chamber. In some embodiments, the first well conduit further includes an exchange tube including a cement lining. According to some aspects, the first well conduit further includes a string casing surrounding the exchange tube with an annulus disposed between sidewalls of the string casing and the exchange tube, wherein at least a portion of the outer surface of the string casing is attached to geologic material of the first bore hole via concrete. In one or more embodiments, the first well conduit further includes an intermediate casing surrounding the string casing and at least a portion of the outer surface of the string casing is attached to the intermediate casing via concrete. According to some aspects, the first well conduit further includes a surface casing surrounding the intermediate casing and at least a portion of the outer surface of the intermediate casing is attached to the surface casing via concrete. In accordance with some embodiments, at least a portion of the outer surface of the intermediate casing is attached to geologic material of the first bore hole via concrete, and at least a portion of the outer surface of the surface casing is attached to geologic material of the first bore hole via concrete. According to some embodiments, the carbon-based gas extraction and storage system further includes an injection packer disposed within the annulus above perforations in the string casing to prevent fluid from migrating from an injection zone of the first well into the annulus. In some embodiments, the injection packer includes a nickel-plated assembly. In accordance with some aspects of the carbon-based gas extraction and storage system, the system further includes a cement plug adjacent to the injection packer and filling the annulus. According to some embodiments, at least one of hydrogen and sustainable aviation fuel is produced from the CBM production facility.
In accordance with one or more aspects of the disclosed subject matter, a method of converting a well operable in an extraction mode to operate in insertion mode for enhanced CH4 recovery and also for permanent CO2 geologic sequestration, the method includes: forming a borehole from a first surface location to a subterranean coalbed methane (CBM) chamber; inserting a string casing in the borehole; cementing at least a portion of the string casing to geologic material of the borehole via concrete; inserting an exchange tube in the string casing such that a hollow annulus is formed between the outer sidewall of the exchange tube and the inner sidewall of the string casing; lining the inner sidewall of the exchange tube with a cement lining; operating a well pump in an extraction mode to pump CBM through the exchange tube from the CBM chamber to the first surface location; after operating the well pump in the extraction mode, inserting an injection packer in the annulus of the well; receiving a flow of CO2 from a surface pipe; and operating another well pump in an injection mode to inject the CO2 through the exchange tube and into the CBM chamber. In some embodiments, the method further includes forming a cement plug adjacent to the injection packer by filling the section of the annulus over the injection packer with the concrete. According to one or more embodiments, a composition of the concrete contains a cement additive including at least one of: latex, mineral blends, and epoxy. In accordance with one or more aspects of the method, the injection packer includes a nickel-plated assembly. In some embodiments, the method further includes inserting an intermediate casing in the borehole, wherein the intermediate casing surrounds the string casing; cementing at least a portion of the intermediate casing to geologic material of the borehole via concrete; and cementing at least another portion of the string casing to the intermediate casing via the concrete. According to one or more embodiments, the method further includes inserting a surface casing in the borehole, wherein the surface casing surrounds the intermediate casing; cementing at least a portion of the surface casing to geologic material of the borehole via concrete; and cementing at least another portion of the intermediate casing to the surface casing via the concrete.
In accordance with one or more aspects of the disclosed subject matter, a carbon-based gas extraction and storage well includes a well including a first pump and a well conduit within a borehole, the well conduit extending from above ground to a subterranean coalbed methane (CBM) chamber, the first pump being configured to operate in an extraction mode in which methane from the CBM chamber is pumped up from the CBM chamber, wherein the well is convertible to operate in insertion mode in which CO2 is injected into the CBM chamber for enhanced CH4 recovery and also for permanent CO2 geologic sequestration; and a controller configured to control the first pump to selectably operate in the extraction mode and provide CBM from the CBM chamber to the above-ground conduit, and configured to switch control of the first pump to a different pump that injects into the coalbed CO2 emissions produced from a CBM energy production facility, wherein the different pump injects the CO2 emissions into the CBM chamber to assist in extraction of CBM from the coalbed by another well, and subsequently operates as a Class VI well that permanently stores the CO2 in the CBM chamber. In some embodiments, the carbon-based gas extraction and storage well further includes an exchange tube including a cement lining; and a string casing surrounding the exchange tube such that a hollow annulus is disposed between the outer sidewall of the exchange tube and the inner sidewall of the string casing, wherein at least a portion of the string casing is attached to geologic material of the borehole via concrete. According to one or more embodiments, a composition of the concrete contains a cement additive including at least one of: latex, mineral blends, and epoxy. In some embodiments, the carbon-based gas extraction and storage well further includes an injection packer in the hollow annulus of the well to prevent leakage into the hollow annulus during injection of the CO2 emissions into the CBM chamber.
The present application contains subject matter related to that disclosed in U.S. provisional patent application No. 63/303,280, filed in the USPTO on Jan. 26, 2022, the entire contents of which is incorporated herein by reference.
Number | Date | Country | |
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63303280 | Jan 2022 | US |