Patent Application
20250067481
Embodiments of the subject matter disclosed herein generally relate to a system and method for extracting energy and/or valuable resources from a coal or similar reservoir, and more particularly, to a process and associated system for exploiting an underground coal reservoir without mining the coal and bringing it to the surface for being burned in a power facility, which reduces pollution.
Use of hydrogen gas and geothermal heat are two important components of the transition to green energy. In addition to being an essential resource used in the chemical industry, hydrogen, when burnt for power only, produces fresh water as a by-product. Geothermal energy use (either naturally generated by the Earth or humanly induced by, for example, burning coal at its underground location) is wide-ranging, from power generation to a multitude of localized, direct uses, such as district heating, industrial processing, agricultural and aquacultural heating, and recreational bathing.
Since the 1960s, global energy consumption has followed a linear growth trend (approximately 2,200 additional TWh per year) and coal remains one of the three main energy resources along with oil and gas, as illustrated in
Underground coal gasification (UCG) has been investigated since the beginning of the 20th century and several successful long-term production cases were developed. It is considered a promising option for advanced clean coal exploitation. UCG is an in-situ gasification process of naturally existing coal. The gasification process includes the controlled burning of coal strata or seam to produce a mixture of gases, called syngas, including methane and hydrogen, but carbon dioxide and carbon monoxide are also produced. Note that the coal strata is not extracted from the underground, but is burned in a controlled manner at its underground location.
Different development methods for the in-situ gasification of coal resources already exist. They all involve the introduction of steam and air or oxygen into a coal seam via an injection well, the ignition of the coal, and transport of the resulting gases to the surface via a production well. Regarding the exploitation design, there are various methods that involve injection and production wells linked by a range of processes including linked vertical well (LVW), controlled retractable injection point (CRIP), single well integrated flow tubing (SWIFT), and steeply dipping seams (SDS). The suitability of these UCG methods is dependent on parameters such as natural permeability of the coal seam, geochemistry of the coal, seam thickness, depth and inclination.
The proportions of the various component gases in the syngas are mainly a function of the quality and rank of the coal, the seam depth, and the gasifying agent (oxygen or air).
For example, H2, which is primarily used to produce chemical products, is now a promising energy source. Several trials have been implemented for enhanced hydrogen output in UCG [1-4]. Depending on the coal properties, depth, operating parameters, hydrogeological setting and the combustion process, hydrogen can be a main syngas product of UCG, and CO2 and CO gas can be relatively minor components, as illustrated in
The last two decades of research dedicated to UCG focused on the reinjection and sequestration of CO2 directly in the cavity formed by UCG [5]. Numerical simulations performed by [5] and dealing with the long-term sequestration of CO2 at about 1 km depth in a commercial-scale post-UCG multi-cavity have demonstrated that injecting and sequestrating CO2 in the UCG cavities is a feasible and viable concept. Other projects have considered coupled CCS but not within the cavity itself.
Another component of the syngas, the CO, can be used for the production of additional commercial products such as methanol, or fertilizer.
Because these components of the syngas can efficiently be used to provide fuel or raw materials for the chemical industry, the UCG process is attractive for the decarbonization of the coal industry.
Another important factor to be considered when implementing the decarbonization of the UCG process is the high temperatures associated with this process. The temperatures of above ground coal gasification typically exceed 1,000° C. Underground combustion temperatures are usually cooler due to groundwater influx but still reach above 600° C. Research on subsurface heat generated in the coal seam and surrounding strata has largely concentrated on the thermodynamic processes and impacts on syngas quality and thermo-mechanics, rather than on utilizing the heat as an energy source. Nevertheless, few studies have forecasted high temperature in the coal seam and in the surrounding strata lasting for a long period of time, as schematically illustrated in the temperature graph shown in
The heat produced by the combustion of the coal represents a huge amount of energy, with temperatures around 600° C. in the cavity. For example, for a medium-volatile bituminous coal with a heating value of 32 MJ/kg, with a seam thickness of 4 m and an area of 1 km2, it is estimated that 5.4 megatonnes of coal are available with a potential total thermal energy of 174.1 Petajoules (assuming a continuous coal seam with a density of 1350 kg/m3). After applying a reduction of 50% for unburnt coal (inaccessible and left for roof support), and a thermal energy to electrical energy capture efficiency even of only 2%, this is equivalent to ˜48 GWh or 28,235 Barrels of Oil Equivalent. This amount of energy is sufficient for significant industrial applications.
Considering that this example reflects only a very small portion of the available coal seams that can be targeted for clean, green underground coal gasification, it is evident that a huge amount of energy could be harnessed with minimal emissions. Several technological solutions have been proposed to harvest a part of the heat produced by the combustion process. In this regard, [7] has proposed water circulation in a cooling tube in the production well, with a double end-use: cooling the production well to mitigate the damage due to extreme conditions and harvesting the waste heat. The authors in [8] have proposed to use two sleeve pipe heat-exchange, or a complex heat-gas coproduction equipment [9-10] to extract the heat from the productor well. The authors in [11] have proposed to circulate a fluid between the injection and the production wells to directly harvest the heat through a heat exchanger inserted in the production well. The authors in [12] have proposed a specific device including a coolant conveying pipe to be inserted in the production well to harvest the heat and cool the well. The authors in [13] have proposed a system based on heat conduction pipelines inserted in vertical drillings and connected to a thermoelectric generation system to produce electricity from heat. The authors in [14] rely on an integrated system that is inserted in horizontal wells to ignite the coal, extract the heat and store carbon dioxide.
Others have proposed to use shafts and tunnels in UCG. For example, the authors in [15] have proposed to dig channels for pipelines in the overburden, prior to UCG involving shafts. The authors in [16] have proposed to use solenoids in spirally wound pipe walls. Both methods are adapted to shafted exploitation. Other coal exploitation methods, such as the deep coal in-situ fluidization mining method, or surface coal combustion using a reaction, have been associated with heat extraction. Inter alia, some previous research has focused on extraction of heat from the UCG produced syngas using a heat exchanger system at the surface, as discussed in [17]. Similarly, harnessing waste heat in coking plants has been researched and developed by the authors in [18].
Devices for extracting heat in shallow fired-coal zones (natural or man-made, usually shallow) have been disclosed in [19, 20], and are based on horizontal steel pipes located in the fire area of the coalfield and these pipes introduce a heat carrier for the purpose of extracting thermal energy, or they are based on large vertical casing-type borehole thermal exchanger (up to 30 m diameter) which includes a high thermal conductivity cylindrical housing.
When installed in production wells, the quantity of harvested heat is limited, and the remaining heat in the UCG cavity remains largely unexploited. In addition, devices directly inserted in the coal will encounter extreme conditions that may jeopardize their life length. Other technologies, based on the heat extraction from the overburden by using horizontal wells [21], may breach the confinement of the coal and represent a pollution risk (gas leakage).
Thus, the existing methods are either prone to damaging the used equipment due to the direct heat experienced by the various parts designed to extract the heat or are dangerous for the environment due to the pollution risk. Therefore, there is a need for complementary and adaptable solutions, suitable even for deep coal seams, designed to harvest larger amounts of heat and to limit the risk of damaging the heat extraction devices. In addition, these new methods and systems need to achieve a minimum disturbance to the overburden and to monitor the environment to mitigate the potential environmental impact due to uncontrolled gas leakage and ground movements.
According to an embodiment, there is a heat extraction system for extracting heat from a reservoir, and the system includes a co-axial tool configured to be placed underground, the co-axial tool having an outer pipe and an inner pipe located within the outer pipe, each of the outer pipe and the inner pipe being connected to a shoe so that a fluid flows through an annulus defined by the inner and outer pipes, reaches the shoe, and flows through a bore of the inner pipe. The system also includes a power generator fluidly connected to a chemical processing unit to receive a fluid, and also fluidly connected with a first port to the inner pipe and with a second port to the outer pipe of the co-axial tool. A temperature difference of the fluid at the power generator and at the co-axial tool drives the power generator to generate energy.
According to another embodiment, there is a method for extracting heat from a reservoir, and the method includes placing one or more co-axial tools underground, the co-axial tool having an outer pipe and an inner pipe located within the outer pipe, each of the outer pipe and the inner pipe being connected to a shoe so that a fluid flows through an annulus of the inner and outer pipes, reaches the shoe, and also flows through a bore of the inner pipe, wherein only the shoe is in contact with a coal seam located underground, fluidly connecting a power generator to a chemical processing unit to receive a fluid, and also fluidly connecting a first port of the power generator to the inner pipe and connecting a second port of the power generator to the outer pipe of the co-axial tool, and generating energy with the power generator based exclusively on a temperature difference of the fluid at the power generator and at the co-axial tool.
According to yet another embodiment, there is a heat extraction system for extracting heat from a reservoir, and the system includes a co-axial tool configured to be placed underground, the co-axial tool having an outer pipe and an inner pipe located within the outer pipe and configured so that a fluid flows through an annulus of the inner and outer pipes, reaches a closed end of the outer pipe, and also flows through a bore of the inner pipe, and a power generator fluidly connected to a chemical processing unit to receive the fluid, and also fluidly connected with a first port to the inner pipe and with a second port to the outer pipe of the co-axial tool. A temperature difference of the fluid at the power generator and at the co-axial tool drives the power generator to generate energy.
According to still another embodiment, there is a method for extracting heat from a reservoir, and the method includes placing one or more co-axial tools underground, the co-axial tool having an outer pipe and an inner pipe located within the outer pipe, and configured so that a fluid flows through an annulus of the inner and outer pipes, reaches a closed end of the outer pipe, and also flows through a bore of the inner pipe, fluidly connecting a power generator to a chemical processing unit to receive the fluid, and also fluidly connecting a first port of the power generator to the inner pipe and connecting a second port of the power generator to the outer pipe of the co-axial tool, and generating energy with the power generator based exclusively on a temperature difference of the fluid at the power generator and at the co-axial tool.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to a heat harvesting system that includes a co-axial tool provided with an end shoe for entering a high temperature reservoir for harvesting energy. The system can also be configured to extract and/or generate one or more raw materials for chemical plants. However, the embodiments to be discussed next are not limited to the co-axial tool with the end shoe, but may be applied with other tools for extracting the heat, for example, a tool with no end shoe.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
According to an embodiment, a novel system for heat and raw material extraction from an underground coal oxidation process is introduced and this system is configured to reduce the amount of pollution associated with traditional coal exploitation. The system is configured to capture the heat generated during the UCG process with the use of one or more co-axial tools, each having a shoe end, also to capture the syngas generated by the UCG process and to separate from it various raw materials for industrial use, and to incorporate reinjection, recycling and underground sequestration of the Green House Gases (GHGs) in the syngas not used for industrial purposes.
In one application, the system uses complementary and adaptable solutions to produce power from the heat extracted from underground using the co-axial tools (for example, steel shoes of co-axial wells in the cavity, co-axial deviated wells in the underburden or serpentine wells in the underburden). The final products of this system, in one embodiment, are power from the underground heat, and hydrogen from the syngas. Depending on the commercial needs, other raw materials for the chemical industry, such as methanol, can also be extracted. The other syngas constituents will be reinjected into the ground. No GHGs are released to the atmosphere.
The system may be implemented with different configurations. Techno-economic modelling based on thermo-hydraulic simulations allow the definition of the best designs for the system for a given geological context. The designs can be “tuned” to the technology used for the UCG: shaft or shaftless methods, controlled retracting injection point, linked vertical wells, single well integrated flow tubing and methods associated with steeply dipping seams.
The system may include plural co-axial tools that are deployed in wells drilled into the reservoir. In one application, some or all the co-axial tools are driven into the ground without the need of drilling wells. Different patterns may be used for the plural wells/tools to extract the heat, i.e., the number and geographical distribution of the tools over the reservoir may be calculated based on the parameters of the reservoir. Each co-axial tool in the well uses a closed loop working fluid flow (where there is no contact between (1) the rock mass and its components and the coal and (2) the working fluid circulating in the wells). The heat is extracted from the medium by thermal conduction through the wellbore liner/outer pipe or along the stainless-steel shoes at the bottom of the tool. Convection may occur in high permeability zones (cavities, permeable strata and fractures); this enhances the rate of transfer of the extractable heat, and gives better performance of the system.
A range of working fluids can be used in the closed loops of the co-axial tools. However, in one application, supercritical CO2 (S—CO2) is used as the working fluid as it presents several advantages. CO2 is one of the components of the syngas and appears to be a low-cost and a local solution. Supercriticality of the CO2 can be reached above its critical temperature (31° C.) and its critical pressure (7.4 MPa). In addition, S—CO2 is chemically stable and non-flammable. S—CO2 is a promising candidate for high-temperature plant topping cycle to improve thermal efficiency. Indeed, high temperature S—CO2 (>500° C.) presents an excellent system performance (>50% thermal efficiency), in particular when used in Brayton cycles, but also in Rankin cycles, combined gas turbine (CCGT) and super-critical CO2 direct and indirect cycles.
Various scenarios for extracting the heat and/or raw material from an underground coal deposit are now discussed with regard to the figures.
The chemical processing unit 410 separates the syngas 407 into its various components, for example, CO2, H2, CO, CH4, etc. As noted above, the CO2 may be used as the fluid 422 that flows into the co-axial tool 420. The fluid 422 may be CO2, which is first turned into supercritical CO2, for example, with the help of a compressor 412, and then injected into the piping 440. One way valves 442 may be present in the piping 440 for ensuring that the S—CO2 flows along a desired path, i.e., from the power generator 430 to the inner pipe of the co-axial tools 420, and back to the power generator through the annulus formed by the inner and outer pipes of the tools 420. The direction of this flow can be reversed, i.e., it enters first the annulus, goes all the way into the coal seam, and then goes up through the bore of the inner pipe. In this way, the flow of S—CO2 powers continuously the power generator as long as heat is extracted from the coal seam 401. After the compressor 412 starts the S—CO2 flow, the flow is self-sustained even if the compressor is shut down (valve 412A is closed), as the temperature difference T2−T1 maintains the flow, where T1 is the temperature of the S—CO2 flow at the power generator 430 and T2 is the temperature of the S—CO2 flow at the bottom of the co-axial tool 420. Note that the temperature difference T2−T1 may be about 500° C. or larger.
The produced CO in the chemical processing unit 410 may be treated with oxygen from an oxygen supply 414 to increase the amount of available CO2, such that enough CO2 is pumped through the piping 440 for filing the one or more co-axial tools 420. At the end of the process, i.e., when the coal seam 401 has been all burned, the used CO2 may be injected back into the cavity 405 so that no CO2 is released into the atmosphere. Note that
In one application, the co-axial tools 420 are installed prior to the coal combustion and remain in place during the combustion. The shoe of the tool is inserted in the to-be-combusted coal seam as shown in
In one application, the wellbore is fully cased and insulated from the overburden rock mass. Cementation is not essential, and depending on the site-specific operational characteristics, the system could be removed after the process, if placed in a proper outer casing (in that case, the outer-casing shoe has to be above the coal seam, as discussed later). The shoe is directly in contact with the to-be-burnt coal. It makes the system more resilient to potential damage due to the ultra-high temperature and to corrosion processes occurring during the burning. The shoe is designed to resist thermo-mechanical strains due to thermal stress, ground movements during the linkage process and when roof spalling occurs. The shoe is made of alloys that must be resistant to high temperature (up to 1,000° C.), corrosive environments, thermal stress, burst strength, and with a sufficient thermal conductivity at the relevant temperatures. At very high temperature, thermal stability is the first factor considered, as this may set limits to a particular type of alloy from the standpoint of softening or, more commonly, embrittlement, and may induce a change in the thermal properties (thermal conductivity in particular). Note that the shoe is allowed to accommodate large deformations as it is not a supporting element but only the heat-transfer tool. Hence, the creep rupture strength at high temperature is the basis for alloy selection.
The co-axial tool 420 is now discussed with regard to
Note that for achieving the connection with the outer pipe 520, in one embodiment, the shoe 530 has threads 610 on an external surface 532, next to the top surface 536, as shown in
Returning to
In the embodiment shown in
In another embodiment, as illustrated in
In yet another embodiment, as illustrated in
In still another embodiment, as illustrated in
With regard to the shape of the shoe 530, the previous embodiments illustrated it as being shaped like a bullet, for example, a largest external diameter matching the external diameter of the outer pipe and then the body having a vertex 538, as shown in
In one application, as shown in
When the tool 420 is desired to be used (as illustrated in
The high thermal conductivity of the alloys at high temperature allows the heat transfer from the metal shoe 530 to the co-axial pipes 510/520. Thermo-hydraulic numerical simulations are run to optimize the design of the tool and the corresponding well (shoe length and diameter, well diameter, number and position of co-axial-well-with-shoe systems).
After the heat from the coal seam has been extracted in step 1206, which can take months if not years, just prior to removing the casing 1110 and associated tool 420 from the well in step 1208, it is possible to store CO2 in the cavity 405, and then the well 1102 is sealed with cement plugs 1120 in step 1210, as illustrated in
Smart and safe implementation of this technology may be matched with monitoring methods, for example, focusing in particular on the temperature, the pressure, and the mechanical behaviour of the tool and of the hosting rock-mass. Additional specific monitoring may be required depending on the nature of the coal seam or of the UCG. For example, distributed acoustic sensing (DAS) systems 1103 cemented behind the sacrificial casing 1106 would allow monitoring of the temperature and the pressure at the interface between the rock-mass and the tool, while DAS fibres inserted in the coaxial tool 420 and fixed to the inner or outer tube give temperature and pressure evolution with the depth in the co-axial loop. In one application, seismic sensors network 1130 at the surface (or buried in noisy environments), as schematically illustrated in
By using the novel combination of technologies disclosed here, it is possible to harvest significant quantities of hydrogen from the syngas 407 and heat generated by underground oxidation of coal without releasing harmful emissions to the atmosphere. This opens the door to a greener use of the world's abundant coal resources. The technologies discussed herein can be configured to optimize the capture of heat generated, and then hosted in the rock or in the fluids, during oxidation of coal in the subsurface, for example, by determining how many wells 1102 are necessary for a given coal seam 401, and also the distribution of the wells, and implicit of the tools 420, over the coal seam 401. The amount of captured heat can deliver all the electrical power needed to supply onsite operational needs, including drilling, pumping, measurement, monitoring and validation, plus processing of the hydrogen. This means that these technologies can be applied on a standalone basis and there is no parasitic use of hydrogen for on-site energy needs. The excess power can be used locally for industrial activity or supplied to the grid.
Hydrogen delivery can be optimized to local market conditions, for example, to be delivered by pipeline, compression and cooling for export as liquid, or conversion to ammonia for export as fuel or fertilizer. One or more benefits of one or more embodiments discussed herein for the industries that currently burn coal is that these existing facilities do not need to be closed down, since rapid advances in technology are showing that coal-fired power stations can be converted to burn hydrogen, whilst cement manufacture and steel production can utilize hydrogen and green power.
While the embodiments of
In one application, the well 1302 is drilled prior to gasification. The upper part of the well 1302 may be insulated from the overburden rock using a thermally insulated grout 1304. The bottom of the well 1302, under the future cavity 405, may be cemented using thermally enhanced grout 1306. The working fluid 422, which can be, as discussed above, supercritical CO2 coming from the syngas 407, is injected through the inner pipe 510 and pumped out through the annulus formed between the inner pipe 510 and the outer pipe 520. The trajectory of the lower part of the well (which will harvest the heat) depends on the UCG method. When the gasification involves methods based on vertical wells 450 and 454, deviated co-axial tools 1320 are used for heat extraction as schematically illustrated in
If the gasification is realized using the CRIP method, another design may be used, for harvesting the heat from a well 1402. In this case, a system 1400 is based on a serpentine trajectory drilled in the underburden 404, in a plane 1410 parallel to the coal seam 401's bottom wall 1412, as shown in
Wells 450 and 454 are shown in
Clean and safe implementation of these technologies requires proper risk assessment and mitigation. The following risks in particular must be closely monitored: ground water pollution, gas leakage, and ground movement. Regarding the groundwater pollution, depending on the geological and hydrogeological context, pollutant elements trapped in the combustion ash 406 may be leached by underground water after cavity flooding by groundwater ingress. In one application, risk mitigation is based on keeping the cavity pressure below the surrounding hydrostatic pressure, to help retain contaminated fluid within the cavity. Regarding gas leakage, during and after the coal oxidation, there is a risk of gas release into the overlying strata and into the atmosphere if the cavity is not confined by impermeable overburden, or if discontinuities provide permeable connectivity from the cavity to the overburden and/or to the surface. Thus, these factors should be monitored. Regarding ground movement, depending on the geological context, including the depth and the thickness of the targeted coal seams, subsidence can be encountered. To mitigate this risk, a system of pillars and cavities may be used.
In addition to properly designing the operation to prevent these risks, it is desired to monitor these sites for risk prevention. In one application, it is possible to implement DAS systems, discussed above with regard to
Further, it is possible to use a seismic sensors network (see network 1130 in
A methodology to optimize the design of the heat extraction and monitoring systems is now discussed. The optimization of the heat extraction design is based on hydrothermal numerical simulations including site-specific data and using generic designs to be adjusted to the context in order to fast-track the workflow. A monitoring design is included in the workflow illustrated in
The simulations noted above may be run using a hydrothermal fully coupled software multiphase (liquid and gaseous phases) flow model as very high temperatures are involved. Fluid can flow in the rock matrix, in the faults/fractures if any, and in the cavity. The predefined generic models received in step 1504 may involve a generic geology (both horizontal and dipping coal seams) at an appropriate depth (such as 1 km) and generic petrophysical and thermal properties based on the data ranges available in the associated database.
The technologies discussed above may be implemented as various methods in the field. For simplicity, only two such methods are discussed herein, but one skilled in the art would understand that variations of these methods are possible. The configuration shown in
More specifically, a method for extracting heat from a reservoir 401 includes, as schematically illustrated in
In step 1602, which is optional, the production well 454 is fluidly connected to a chemical processing unit 410, which is configured to receive syngas 407 from burning the coal seam located underground and is also configured to extract CO2 from the syngas 407. Note that the chemical processing unit may be refinery, a chemical plant, etc. In step 1604, a power generator 430 is fluidly connected to the chemical processing unit 410 to receive the fluid 422. The power generator is also fluidly connected, with a first port, to the inner pipe 510 and with a second port 430B to the outer pipe 520 of the co-axial tool 420. In step 1606, the power generator generates electrical energy, based exclusively on a temperature difference of the fluid 422 at the power generator 430 and at the co-axial tool 420.
The method may also include a step of separating CO2 from the syngas in the chemical processing unit, and a step of compressing the CO2 to make supercritical CO2 to be used as the fluid. The method may further include a step of circulating the supercritical CO2 through the annulus and the bore of the co-axial tool to reach the shoe and extract heat from the burning coal seam, and a step of circulating the heated supercritical CO2 through the power generator to produce electrical energy. Optionally, the method may include a step of injecting air or oxygen into the coal seam for sustaining the burning, and/or a step of extracting H2 from the syngas with the chemical processing unit. When the process is considered to not be any more economically viable, the method may include the step of injecting the supercritical CO2 into a cavity formed in place of the burned coal seam, and sealing wells connected to the cavity for storing the CO2 underground.
The configurations shown in
In step 1702, a production well 454 is fluidly connected to a chemical processing unit 410, which is configured to receive syngas 407 from burning the coal seam located underground, and configured to extract CO2 from the syngas 407. Note that this step is optional. In step 1704, a power generator 430 is fluidly connected to the chemical processing unit 410 to receive the fluid 422, and is also fluidly connected, with a first port of the power generator, to the inner pipe 510, and fluidly connected, with a second port of the power generator, to the outer pipe 520 of the co-axial tool 1320. In step 1706, energy is generated with the power generator based exclusively on a temperature difference of the fluid 422 at the power generator and at the co-axial tool.
The method may further include a step of deploying the co-axial tool in a plane below a bottom of the coal seam, and the plane is making a non zero angle with a horizontal plane, and/or a step of deploying the co-axial tool to follow a serpentine in the plane.
The term “about” is used in this application to mean a variation of up to 20% of the parameter characterized by this term. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first object or step could be termed a second object or step, and, similarly, a second object or step could be termed a first object or step, without departing from the scope of the present disclosure. The first object or step, and the second object or step, are both, objects or steps, respectively, but they are not to be considered the same object or step.
The terminology used in the description herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used in this description and the appended claims, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, as used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context.
The disclosed embodiments provide various methods for placing one or more co-axial tools with or without a shoe in a reservoir, for extracting heat, when the reservoir exhibits one or more extreme parameters, like high temperature. It should be understood that this description is not intended to limit the invention. On the contrary, the embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.
Although the features and elements of the present embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein.
This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.
The entire content of all the publications listed herein is incorporated by reference in this patent application.
| Number | Date | Country | Kind |
|---|---|---|---|
| FR2308350 | Aug 2023 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/087689 | 12/22/2023 | WO |
