TW202204759A - Method for configuring wellbores in a geologic formation - Google Patents

Abstract

Closed loop wellbore configurations with unrestricted geometry for accommodating irregular or challenging thermal gradients within a thermally productive formation are disclosed. A working fluid is utilized in the loop for extraction of thermal energy there from. The loop and the unrestricted geometry are achieved using magnetic ranging of independent drilling operations which intersect from an inlet well and outlet well to form an interconnecting segment. In conjunction with the directional drilling, conditioning operations are incorporated to condition the rock face, cool the entire system, activate the wellbore for treatment to optimize thermal transfer inter alia. The significant degree of freedom in wellbore configuration is further optimized by the absence of mechanical impediments such as casing or liners in the heat transfer areas.

Description

Method for assembling a wellbore in a geological formation

The present invention pertains to wells assembled within thermally generating geological formations, and more particularly, the invention pertains to optimizing formation drilling that facilitates well positioning to maximize thermal energy recovery from specific formation thermal gradients.

With the advent of improved drilling techniques for drilling formations to greater depths and tolerant of higher temperatures, many advances have been made that allow for the formation of specific well configurations.

In order to improve the efficiency of well positioning, the unification of drilling techniques, working fluid chemistry, wellbore dressing unit operations and flow rates, in particular, must be combined with sequencing to achieve efficient heat recovery in the most complex and diverse thermal gradients of a given formation.

The present invention facilitates the ability to recover thermal energy regardless of thermal gradient anomalies and complexity.

As far as the evolution of the art is concerned, Moe, US Patent No. 6,247,313, issued June 19, 2001, implemented one of the earlier developments. There is a disclosure about a wellbore assembly structure, which includes a plurality of heat absorption holes in a geothermal area. The disclosure makes no mention of casing or lining, however, it is limited to the use of crushing belts, the angular placement of heat sink holes parallel to each other, and further limitations. The teaching specifically states: "The magnitude of the inclination angle will depend on several factors, such as the temperature gradient in the rock, the length of the heat sink, and the water flow rate. Calculating the angle is within the skill of the artisan and is therefore not detailed here. The angle will typically fall between 20° and 50°, preferably about 40°. Furthermore, in order to maximize heat extraction from a given volume of rock, at least substantial portions of the heat sink holes extend parallel to each other. More preferably, the endothermic holes are arranged in one layer, or, if necessary, in a plurality of vertically spaced layers. Providing an array of vertically spaced layers with a plurality of heat sink holes in each layer allows the capacity of the plant to be increased without spreading the holes over a wide area. This is very important if the volume of land available for extraction is not large.

The supply and return holes 3, 4 are interconnected by four heat-absorbing holes 5 each having a diameter of 10 cm and a length of about 2000 meters. The spacing of these holes 5 may be 100-150 meters. They start drilling from supply hole 3 and end at or near return hole 4 . A fracture zone 6 has been established in this area to provide flow communication between the holes 4 and 5, as it is difficult to hit the return holes 4 directly when drilling the heat sink holes 5. "

As it emphasizes, the teaching also teaches about the difficulty of connecting the inlet to the outlet. As a disadvantage, Moe's configuration does not provide sufficient teaching about unrestricted access to gradients regardless of their anomalies, so this disclosure is limited to specific situations.

In Shulman, US Patent No. 5,515,679, issued May 14, 1996. This document teaches a closed loop heat recovery arrangement at various rock types at elevated temperature, one of which is solid rock, which is distinguished in Shulman's disclosure: "This invention relates to a novel method and apparatus that utilizes liquid circulation in a closed pipe loop system whereby thermal energy is extracted from subterranean hot rock, that is, mined, and brought to the surface for utilization. The hot rock may be in a solid state , cracked or broken and dry or wet but substantially devoid of active fluid. By this invention, thermal energy is transferred from hot rock to relatively cool liquid in one or more of a plurality of remotely separated heat transfer pipe loops The remotely separated loops of heat transfer tubing descend from the manifold at the surface into the hot rock and then join together with the bottom of the riser through which the heated fluid can return to the surface.” .

These wellbore configurations do not discuss any details of heat recovery piping with intricate patterns or arrangements. This configuration relies on the tubing in the wellbore assembly for transporting fluids through the configuration for heat recovery from the formation. Another disadvantage is the positioning of the manifold on the surface rather than inherently within the lower network of wellbore.

US Patent No. 6,668,554, issued to Brown on December 30, 2003, teaches a failure process for forming fractured zones in hot dry rock. Supercritical carbon dioxide is used as a working fluid to deliver absorbed energy from geothermal formations. The fluid communication is not in a closed loop, where there is an interconnecting segment between the inlet and outlet wells in fluid communication, where the working fluid is isolated from the formation. In Brown's configuration, the formation itself communicates indiscriminately with the inlet and outlet wells. This is further evidenced by the facts taught by Brown below: "Finally, the hot dry rock circulation system is accomplished by drilling two or more production wells to meet the reservoir near each end of the elongated reservoir zone as defined by: the fractured hot dry rock reservoir defined by A "cloud" of the locations of microseismic events in the shape of . All wells are properly casingd to the surface, and then gaseous carbon dioxide is used again to remove drilling fluids and other water-based materials.”

This segment using casing is identified as a well-to-well intersection, but does not intersect with each other when in a closed loop, but rather with artificial reservoirs within the formation.

US Patent No. 10,260,778, issued April 16, 2019 by Sonju, discloses a geothermal plant. This patent teaches the special requirements of assembling the production section to be in a particular setting relative to the concentric inlet/outlet well configuration. This disclosure does not provide remedial indications as to the possible orientation of the wellbore during or after drilling or interconnecting segments to exploit the heat generating zone without limitation.

US Patent No. 10,527,026, issued Jan. 7, 2020 to Muir et al., teaches a closed loop heat recovery arrangement for heat transfer from a well casing into a fluid. The article states: "Embodiments disclosed herein are directed to methods and apparatus for generating electricity from impermeable geological resources using a closed loop design where the fluid is completely isolated from the formation in a closed loop well and heat is transferred into the fluid through the well casing ". "As described in the background paragraph above, typical hydrothermal systems as well as closed-loop systems have focused on extracting heat from permeable geological resources, where fractures or porosity occur either naturally or through stimulation. In contrast, the specifics disclosed here Embodiments can effectively and efficiently extract heat from low permeability rock, such as rock in a plastic zone. Advantageous use of fluids through resources including higher temperatures without direct contact of the fluid with the rock A geological formation of low permeable rock whereby heat is transferred from the rock directly into the fluid through the well casing". "Then, based on the measured temperature profile and the measured heat supplementation profile of the subterranean formation, a closed loop geothermal heat exchange system may be disposed within the subterranean formation. The placement of the closed loop geothermal heat exchange system may include drilling, casing, drilling , cement grouting, expanding a fractured uncased borehole wall, sealing an uncased borehole wall, and other steps known to those skilled in the art associated with the drilling process and placement of a well circuit. In some embodiments, the placement The step may include arranging the closed loop well system in a heat exchange zone within a plastic zone or a brittle-ductile transition zone of the formation. In some embodiments, the locating step may include or additionally include arranging the closed loop well system within the brittle zone of the formation heat-exchange zone, and stimulate the brittle zone immediately adjacent to the heat-exchange zone.”

This document provides general teaching on sealing, but including casing in the heat recovery portion of a wellbore assembly. The article states: "According to some embodiments, the methods described herein for producing geothermal energy may include portions of the well that are not jacketed with metal tubing, instead the walls of those portions may be formation rock sealed with hardened sealant and The walls in these sections are bounded by hardened sealant which, in some embodiments, results in a larger well in these sections than in the metal casing section of the well diameter, and in some cases, larger."

The citation reflects Shulman's teachings above and does not provide an indication of well-to-well intersection, no casing and/or lining or geometric variation in the setting of the heat recovery section of the wellbore configuration to accommodate any thermal gradient patterns.

It would be desirable to have a method of forming a wellbore configuration that can be used to accommodate gradient pattern anomalies, as opposed to specific wellbore designs that are limited to the limitations of existing equipment and methods for recovering thermal energy.

The methods of the present invention disclosed herein below can improve upon the above limitations and provide unprecedented degrees of freedom for efficiently harvesting thermal energy within a heat generating formation.

An object of one embodiment of the present invention is to provide an improved method for assembling wells and well systems in a heat generating formation for recovering thermal energy therefrom for subsequent use.

Another object of an embodiment of the present invention is to provide a method for assembling a wellbore in a thermally generated geological formation comprising: independently drilling a well of an inlet well and an outlet well in the formation; Communication between the inlet well and the outlet well is communicated between the inlet well and the outlet well during intersection drilling to form a continuous well with an interconnecting segment between the inlet well and the outlet well, the interconnecting segment relative to the formation in the formation the inlet well and the outlet well have a predetermined angular configuration; At least the interconnected segment is trimmed to facilitate heat recovery by working fluid flowing through the interconnected segment in the absence of a sleeve or liner material in the interconnected segment.

The trimming step is accomplished by at least one of: drilling in combination with drilling of at least one of the inlet well and the outlet well, consecutively, discontinuously, during, after, and in sequence.

In more detail, the trimming may include introducing at least one of: a component and a unit operation that are not native to the formation, and combinations thereof.

To increase the effectiveness of the method, the dressing operations may be dynamically modified in response to communication data from at least one of the drilling operations of the inlet well and the outlet well.

Depending on the particular situation, the unit operations may include: controlling the temperature of the drilling fluid, pre-cooling a wall of the formation being drilled, cooling the drilling equipment, and modifying the porosity of the wellbore formed by drilling the formation ( pore space).

Modification of the pore may include: activating the pore for subsequent processing to render the pore impermeable to both: formation fluids invading the interconnected segment or the working fluid escaping into the formation; A continuous operation to seal the aperture; a discontinuous operation to seal the aperture during drilling; and combinations thereof.

Operational dressing modifications may also be based on communication data from the communication of the inlet well and the outlet well.

Optionally, another unit operation includes forming a plurality of conduits in the formation relative to and in fluid communication with a longitudinal axis of an interconnected segment for augmenting heat recovery of the working fluid. The tubing may have a terminal end and the tubing of an interconnecting segment may be positioned to be in thermal contact with adjacent tubing of an adjacent interconnecting segment of another well. The conduits may incorporate natural buoyancy-driven convection, which increases the effective radius of the heat-collecting interconnecting segments and increases the overall heat transfer from the rock volume.

The conduits may be fissures, single holes, auxiliary sections, or radial bores extending radially from an interconnected section.

When provided with a vertical assembly, the conduits act as convection cells where natural buoyancy drives convection to increase the effective radius of the collector interconnect segments. The diameter of these conduits is typically 0.5 inches (12.7 mm) or greater, and may be 8.5 inches (215.9 mm) or equal to the diameter of the interconnecting segment itself.

As another option, several conduits of an interconnecting section may be connected in fluid communication with adjacent conduits of an adjacent interconnecting section of another well.

It is a further object of an embodiment of the present invention to provide a well configuration suitable for recovering thermal energy of a fluid of a thermally generating geological formation by circulating through it, comprising: an entrance well; an exit well; an interconnected segment in fluid communication with the inlet well and the outlet well and disposed within a heat generating region of the formation; a selectively operable auxiliary section in selective fluid communication with the interconnecting section for storing heated fluid; a cuttings section in fluid communication with at least one of the inlet well, the outlet well, and the interconnecting section for collecting well cuttings; The outlet well is at least one of: concentric with the inlet well and 5° to 175° relative to the inlet well, and the interconnecting segment is 5° to 355° relative to the inlet well; and A conversion device connected to the wells to form a closed loop and recover thermal energy from the fluid collection for conversion.

In one embodiment, the auxiliary section includes a selectively operable valve for circulating stored heated fluid into and out of the interconnecting section and may further include: a selectable valve in fluid communication with at least one of the following: Selective Operational Export: The conversion device and an adjacent well assembly structure.

The assembly structures may be a plurality of well assembly structures in a concentric and spaced relationship, a plurality of well assembly structures in a spaced laterally offset parallel plane relationship, and may further include at least one of the following: a A common inlet well and a common outlet well.

To collect thermal energy, the interconnected segments are utilized, and the assembled structures may provide a plurality of interconnected segments in fluid communication with the inlet well and the outlet well and a plurality of interconnected segments in a predetermined pattern Consists of a plurality of spaced arrays.

It is a further object of an embodiment of the present invention to provide a method of forming a well assembly suitable for recovering thermal energy of a fluid circulating through a thermally generating geological formation, the method comprising: independently drilling an inlet well and an outlet well at a predetermined location in the formation; Intersecting drills from the inlet well and the outlet well, the outlet well having the following At least one of: concentric with the inlet well and 5° to 175° relative to the inlet well, the interconnecting segment 5° to 355° relative to the inlet well; forming a selectively operative auxiliary section in selective fluid communication with the interconnecting section for storing heated fluid; forming a cuttings section in fluid communication with at least one of the inlet well, the outlet well, and the interconnecting section for collecting well cuttings; and A conversion device is provided which is connected to the wells to form a closed loop and recover thermal energy from the fluid collection for conversion.

Regarding the intersecting drilling step, independent drilling from the inlet well and the outlet well to form an interconnected segment between the inlet well and the outlet is performed using electromagnetic communication.

A number of electromagnetic communication devices will be used for the communication and will be selectively positioned in a predetermined combination of locations of the entry well, the exit well, the cuttings segment and the interconnecting segment.

The devices may operate in a predetermined sequence.

Additionally, the method includes coordinating a call from a well under construction with a call from a previously formed offset well.

This method is very suitable for recovering thermal energy from a geothermal formation with a temperature of not less than 40°C.

With regard to the efficiency and resiliency of deployment in the formation, the circulation of fluids within the interconnected segments can be performed without casing and lining.

A plurality of interconnected segments in several embodiments may be in fluid communication with the inlet well and the outlet well, wherein the assembled structure has a plurality of spaced arrays of interconnected segments in a predetermined pattern .

Optionally, there may be the step of selectively circulating the fluid as a slipstream from one array to an entry point separating a second array prior to discharge from the outlet well common to all arrays. In this way, the slipstream preheats fluid from the inlet well prior to circulating in the spaced second array.

The slipstream can also be distributed to an offset well assembly for thermally amplifying the offset well.

Having thus broadly described the invention, several preferred embodiments will now be illustrated with reference to the accompanying drawings.

Please refer to FIG. 1 , which schematically illustrates a closed loop well system 10 disposed within a heat generating formation 12 . The system 10 includes an inlet well 14, an interconnecting well section 16, and an outlet well 18, which are in a closed loop in fluid communication with an energy treatment device 20 located at the surface S. The outlet well may be co-located with the inlet well at device 20, or located distally as indicated by dashed line 22 for backup connections. Working fluid is circulated through system 10 in order to absorb thermal energy from within formation 12 .

In terms of efficiency, the interconnecting well section 16 is not cased or lined and does not include any other tubing or related mechanical arrangements. Outlet well 18 and inlet well 16 may be cased or otherwise fabricated to comply with conventions known to those skilled in the art. Any cuttings progressively formed from the used configuration may be collected in section 19 .

The energy processing device 20 may process the energy for other purposes, which is stored at 26 at a storage location generally designated by the reference numeral 24, or delivered to a power grid 28, which may include solar energy installations 30 and/or wind installations 32 in any suitable combination as desired. .

Reference may be made to FIG. 2 regarding the spatial orientation of wells within the heat generating formation. In this illustration, elements may be removed for clarity of illustration, however, it should be understood that this figure is meant to convey that the arrangement of interconnecting segments 16 may be relative to at least one of the planes of the inlet well 14 and outlet well 18 .

In the figures, interconnect well segments 16 may be positioned at any angle in any of the following planes: (XY), (X-(-Y))((-X)-Y)(( -X)–(-Y)), (XZ), (X-(-Z)), (Z-(-X)), ((-X)-(-Z)), (ZY), (Z -(-Y)), ((-Z)-(-Y)), and ((-Z)-Y) and can also be set with X, Y and Z coordinates for cross plane settings. For purposes of explanation, the positive x-axis represents the inlet well 14 . The well can be positioned at any angle α or β within a range that does not interfere with the operation of the well 14 . This is also true at outlet well 18 . The inlet well 14 and the outlet well 18 communicate with the surface S, as shown in FIG. 1 .

Any number of interconnected segments 16 may be provided within the space. Other well configurations are discussed in subsequent figures. The number and spatial orientation will depend on the thermal gradient of the formation 12 .

Advantageously, it was observed that the inlet well 14 and the outlet well were formed by independent drilling operations without liners, casings, etc. within the interconnecting segment to form the interconnecting segment 18 and trimming the drilling operation. The intersecting drilling of 16 results in assembly degrees of freedom for maximum heat recovery.

One embodiment of the steps shown in FIG. 3 involves sensor ranging of entry and exit wells in the formation in order to intersect by shaped interconnect segments. Although this embodiment refers to interconnected segments, it should be understood that the method pertains to forming a plurality of interconnected segments in any pattern as described in the description of FIG. 2 . All of the individual interconnecting segments may be used to have sensor communication therebetween to direct drilling by a given well system for subsequent interconnecting segments or those formed in adjacent systems within the formation. By providing cross communication between wells, inlets, outlets and interconnecting segments, trajectory drift is minimized to facilitate accurate intersection of wells being drilled. Sensors may also be used in the cuttings capture section 19, not shown and described in more detail below.

The cross-section of FIG. 4 illustrates interconnected segments 16 disposed within formation 12 . Extending from section 16 is conduit 34 extending into formation 12 . Line 34 may be a cavity in fluid communication with interior 36 of segment 16 or may be closed from fluid communication with interior 36 . It has been found that conduit 34 is beneficial for enhancing the heat recovery capacity of the interconnected segments when the working fluid is also circulated therethrough during the quiescent period. The location and number of radial extensions will be determined by formation properties to maximize heat recovery without compromising the structure/mechanics of segment 16 . If pre-existing cracks, fissures, fissures or embedded permeable zones are encountered, these may be used as conduits where appropriate. These may also occur during drilling of segment 16 .

The embodiment of FIG. 5 illustrates the conduits 34 arranged in a generally helical pattern, where the dotted dots indicate that they extend outward from the plane and the cross points indicate extensions that extend out of the plane on the opposite side. This is a demonstration; among other parameters, the pattern can be detected from gradient data.

FIG. 6 illustrates yet another embodiment in which a plurality of segments 16 are disposed within the formation 12 . In this embodiment, adjacent segmented extensions 34 may be arranged in close proximity to fill a given area 38 with extensions to effectively increase the gradient volume from which thermal energy can be recovered. Conduit 34 acts as a convective cell for buoyancy-driven flow directing thermal energy into interior 34 of segment 16 . The extensions may be configured to adjoin or intersect other conduits 34 .

As yet another specific example, the individual segments 16 may be connected by conduits 34 , the connections generally designated by the reference numeral 40 . In this way, the configuration has a stepped appearance when viewed in perspective.

Turning now to the possibilities of well packs, FIG. 7 illustrates a generally annular well pack, generally designated by the reference numeral 42 , disposed within the formation 12 .

In this configuration, the inlet well 14 is in fluid communication with the main inlet hub well 44 connected to each of the interconnecting segments 16 . A suitable valve arrangement (not shown, but generally designated by the reference numeral 46) may be incorporated into some or all of the looped segments 16 for fluid flow redirection and other control. Configuration 42 also includes a main outlet hub well 48 that is connected in a manner similar to the main inlet hub well 46 shown with similar valving features (not shown).

Within this configuration, each looped segment 16 can operate as a single unit to recover thermal energy.

As an operational alternative, the flow of working fluid within configuration 42 may circulate through the entire configuration in a generally helical pattern with a sequence of quiescent periods to allow for maximum heat recovery. Such flexibility allows for connections to, for example, the energy treatment device 20 . This facilitates on demand power when energy is converted to electricity and overcomes limitations associated with baseload generation spike delivery issues.

FIG. 8 illustrates yet another embodiment of a well assembly, designated by the reference numeral 50 . The general shape is a saddle, where the interconnected loop segments are adjacent to each other and arcuate. The inlet wells 14 may be connected to various looped segments 16 in a hub or manifold arrangement 52, or valved at 54 for selective operation. In a similar manner, outlets 18 may be connected in the same manner.

Figure 9 illustrates a further possible variation in the form of a generally inverted parabola.

Figure 10 illustrates another well system assembly where the inlets 14 may be singular or joined at 56 from the far point of the assembly. Likewise, outlet 18 may be joined at 58 . For co-location, outlet 58 and inlet 56 may extend in close proximity geographically.

Figure 11 illustrates a generally tapered package where the exit well 18 may be at the bottom of the package or at the top as shown in phantom. The lower halves of the loop segments 16 may be joined together or independently.

Figure 12 illustrates another configuration in the form of a general stirrer. In this particular embodiment, the segmented circuit 16 may have concentric inlets 14 and outlets 18 , with fluid flowing from the inlets in the direction of arrows 62 and out at 64 . This configuration allows for "production" of a large volume of the formation for heating the formation 12 outside the package as well as the formation volume 66 within the package. One of the advantages of this configuration is that all intersections take place under a single borehole or "mother hole" and can simplify electromagnetic communication, either with permanent devices placed in the female hole or passively. Another advantage is that only a single vertical bore is required to accommodate the inlet and outlet streams.

Turning to FIG. 13, a schematic illustration of a wellbore system section designated by reference numeral 68 is shown. Zones 68 are within the heat generating formation 12 and place different wellbore configurations in predetermined areas to maximize gradient coverage. In this embodiment, partitions 68 provide a stacked spaced configuration of looped segments 16 that share a common inlet well 14 and a common outlet well 18 .

Depending on these parameters, the fluid circulation may follow a pattern denoted by reference numerals A to F. In this manner, at least a portion of the heated fluid from the upper looping section 70 may preheat the fluid entering the lower looping section 72 . Alternatively, looping segments 70 and 72 may each operate independently.

With regard to the rest of the pack, the annular pack 80 may receive heated fluid from the outlets 18 of the stacked arrangements 70 , 72 , as shown by dashed line 74 , or only have a separate inlet well 14 as indicated by dashed line 76 .

The agitator package may have separate inlet wells 14 and outlet wells 18 at the bottom or the inlet wells may be shared with those in the annular package, as indicated by element 78 .

Finally, the saddle assembly may include an exit well shared with the annular assembly at 80 .

It will be appreciated that all inlet wells 14 and outlet wells 18 will extend to the surface or to the conversion device 20 (FIG. 1) for operation. In Figure 13, the wells 14, 18 are truncated for clarity of illustration.

Zone 68 is merely an example of wellbore configuration and common and independent combinations. With directional intersecting drilling, trimming operations, and sensor-guided drilling, any pattern or configuration can be synthesized to mine even the most irregular, multi-regional gradient profiles. In the fact that the present technology does not include piping liners or other mechanical arrangements within the heat recovery interconnecting section, all of these features, upon integration, immediately remove the geometric constraints of the assembled structure allowing the production of any rock formation with any gradient .

FIG. 14 illustrates another embodiment of a well configuration 82 for recovering thermal energy from a formation 12 having a specific volume. In this embodiment, the cuttings segment 19 may include a sensor 84 that transmits information about the accumulation of cuttings. In this way, the composition of the working fluid can be altered to include chemical additives to mitigate/repair any compromised areas with the well system. The configuration of the interconnecting segments 16 may be arranged in a spaced array as shown to recover thermal energy.

Additionally, as shown in FIG. 15, the auxiliary segment 86 may be in fluid communication with each segment 16 to which it is attached and incorporate a valve mechanism 88 to allow selective operation. In the configuration of the well system of this embodiment, the auxiliary section 88 may be used to store heated working fluid for selective use as a thermal driver, or via suitable interconnection for use in another well system (not shown in this figure). As illustrated, the auxiliary segment 86 may be disposed coplanar with the segment to which it is attached, or in an orthogonal plane as shown in phantom in the figure. Depending on the gradient characteristics, suitable variants of that are conceivable.

16 and 16A illustrate clustered well systems 82 positioned at different angles in the formation. In a cluster configuration, the system 82 is modularized within the formation 12 having a specific volume to allow for the small footprint and convenient general co-location of the inlet wells 14 and the outlet wells 18 . Within this module, inlet wells 14 and outlet wells may be common to individual well systems or common to all modules of system 82 .

Figure 17 provides the possibility of interconnecting auxiliary sections 86 of adjacent two wells at 90 or thermally supplemented from an outlet 18 to the inlet 14 of an adjacent well.

In FIG. 18, a network is depicted and intended to express the characteristics of generating energy within any well system 82 that can be taken directly for other uses through the energy generating device 20 associated with the system 82, as indicated by the combination shown at element 96 One system 82 is clustered with another system 82, or further as indicated by reference numeral 98, for eventual use on the grid 28 to provide on-demand power regardless of quantitative demand.

3: Supply hole 4: Reflow hole 5: Endothermic hole 6: Rift Zone 10: Closed Loop Well System 12: Thermally generated formations 14: Entrance Well 16: Interconnect Well Segmentation 18: Exit Well 19: (Debris Capture) Segmentation 20: Energy treatment device 22: Dotted line 24: Other uses 26: Storage 28: Grid 30: Solar installation 32: Wind installations 34: Extensions/Pipes 36: Inside Section 16 38: Given area 40: Connection of segment 16 to line 34 42: Well assembly structure 44: Main entrance hub well 46: Valve device 48: Main exit hub well 50: Well assembly structure 52: Hub or Manifold Configuration 54: Set the valve 56: Entrance 58: Export 62: Arrow 64: Fluid outflow 66: Formation volume 68: Partition 70: Upper circle segment 72: Lower circle segment 74: Dotted line 76: Dotted line 78: Ring assembly structure 80: Ring assembly structure 82: Well Configuration 84: Sensor 86: Auxiliary Segmentation 88: Valve mechanism 96: Combination of system 82 with another system 82 98: System groups S: ground A-F: Pattern

Figure 1 schematically illustrates a closed loop energy recovery configuration;

The coordinate system of Figure 2 illustrates possible locations of interconnected segments or groups of segments within the volume of the formation such that thermal energy can be recovered therefrom;

Figure 3 is a flow diagram illustrating steps involved in forming a wellbore assembly by intersecting drilling at least two points;

Figure 4 is a cross section of a wellbore variant;

Fig. 5 is the side view of Fig. 4;

Fig. 6 is the alternative embodiment of Fig. 5;

Fig. 7 is a specific embodiment of the wellbore assembly structure;

8 is an alternative specific embodiment of the wellbore assembly structure;

Fig. 9 is another alternative specific embodiment of the wellbore assembly structure;

Figure 10 is another alternative specific embodiment of the wellbore assembly structure;

Figure 11 is yet another alternative specific embodiment of the wellbore assembly structure;

Figure 12 is yet another alternative specific embodiment of the wellbore assembly structure;

Figure 13 schematically illustrates a system of wellbore assemblies within the formation;

Fig. 14 is a schematic diagram showing a network of fan-shaped wellbore assembly structures;

15 is a schematic diagram illustrating a well system of cuttings segmentation;

16 schematically illustrates stacked wells in a modular format;

Figure 16A is an alternative embodiment of Figure 16;

Figure 17 schematically illustrates a well system with interconnections between auxiliary sections; and

Figure 18 schematically illustrates a network consisting of a well system integrated with the grid.

Similar elements in the figures are denoted by the same reference numerals.

10: Closed Loop Well System

12: Thermally generated formations

14: Entrance Well

16: Interconnect Well Segmentation

18: Exit Well

19: (Debris Capture) Segmentation

20: Energy treatment device

22: Dotted line

24: Other uses

26: Storage

28: Grid

30: Solar installation

32: Wind installations

Claims (38)

A method for assembling a wellbore in a thermally generated geological formation, comprising: independently drilling a well of an inlet well and an outlet well in the formation; Communication between the inlet well and the outlet well is communicated between the inlet well and the outlet well during intersection drilling to form a continuous well with an interconnecting segment between the inlet well and the outlet well, the interconnecting segment relative to the formation in the formation the inlet well and the outlet well have a predetermined angular configuration; At least the interconnected segment is trimmed to facilitate heat recovery by working fluid flowing through the interconnected segment in the absence of a sleeve or liner material in the interconnected segment. The method of claim 1, wherein the trimming is accomplished in at least one of: continuously, discontinuously, in between, after, and in combination with drilling at least one of the inlet well and the outlet well of drilling. The method of claim 1 or 2, wherein the trimming includes introducing at least one of: a component and a unit operation not native to the formation, and combinations thereof. The method of any one of claims 1 to 3, further comprising the step of dynamically modifying the trim in response to communications from at least one of the drilling operations of the entry well and the exit well. 3. The method of claim 3 wherein the unit operations include controlling the temperature of the drilling fluid, pre-cooling a rock wall of the formation being drilled, and modifying the porosity of the wellbore formed by drilling the formation. 5. The method of claim 5, wherein the modification of the pore comprises at least one of: activating the pore for subsequent processing such that the pore is impermeable to both: formation fluids invading the interconnected segment or overflow the working fluid into the formation; sealing the aperture in a continuous operation during drilling; sealing the aperture in a discontinuous operation during drilling; and combinations thereof. The method of claim 5, further comprising the step of: selecting a modification based on the communication data from the communication from the inlet well and the outlet well. 6. The method of claim 5, wherein the unit operation includes forming a plurality of conduits in the formation relative to a longitudinal axis of the interconnecting section, the conduits being in fluid communication with the interconnecting section for use The working fluid amplifies heat recovery. The method of claim 8, wherein the conduits have a terminal. The method of claim 9, wherein the conduits comprise radial borehole segments, induced fractures, induced fractures, induced fractures, and combinations thereof. 10. The method of claim 9, further comprising the step of using the tubes to amplify heat recovery by including a plurality of buoyantly driven convection cells. 10. The method of claim 10, further comprising the step of disposing a plurality of radial borehole segments of an interconnecting segment, the radial borehole segments and a number of adjacent interconnecting segments of the other well Two adjacent radial borehole segments are in thermal contact. 10. The method of claim 10, further comprising the step of connecting radial borehole segments of an interconnecting segment to adjacent radial borehole segments of an adjacent interconnecting segment of another well segment in fluid communication. 13. The method of any one of claims 1 to 13, further comprising: positioning the interconnecting segment within the formation relative to a plane of the entry well and a plane of the exit well, wherein the interconnecting segment The plane of the segment is in a plane selected from the group consisting of: an orthogonal plane, an acute-angled plane, an obtuse-angled plane, coplanar, and a parallel plane. A well configuration suitable for recovering thermal energy of fluids circulating through a thermally generating geological formation, comprising: an entrance well; an exit well; an interconnected segment in fluid communication with the inlet well and the outlet well and disposed within a heat generating region of the formation; a selectively operable auxiliary section in fluid circulatory communication with the interconnecting section for storing heated fluid; a cuttings section in fluid communication with at least one of the inlet well, the outlet well, and the interconnecting section for collecting well cuttings; The outlet well is at least one of: concentric with the inlet well and 5° to 175° relative to the inlet well; The interconnecting segment is 5° to 355° relative to the inlet well; and A conversion device connected to the wells to form a closed loop and to collect recovered thermal energy from the fluid for conversion. The well configuration of claim 15 wherein the auxiliary section includes a selectively operable valve for circulating stored heated fluid in and out of the interconnecting section. The well assembly of claim 15 or 16, wherein the auxiliary section includes a selectively operable outlet in fluid communication with at least one of the conversion device and an offset well assembly. The well configuration of any one of claims 15 to 17, wherein the auxiliary segment augments heat recovery by including buoyancy-driven convection cells. The well assembly structure of any one of claims 15 to 18, wherein the well assembly structure comprises a plurality of the well assembly structure. The well assembly of claim 19, wherein the assembly includes a plurality of the well assembly that have at least one of the following relationships: a concentric and spaced relationship, a spaced laterally offset parallel plane Relationships, including a common inlet well and a common outlet well, and combinations of them. The well assembly of claim 14, wherein the assembly includes a plurality of interconnected segments in fluid communication with the inlet well and the outlet well, the assembly having a predetermined pattern of the interconnected segments Consists of a plurality of spaced arrays. The well assembly of claim 21, wherein the plurality of interconnected segments includes at least one of a common inlet well and a common outlet well. The well configuration of claim 21, wherein the plurality of interconnected segments each have an inlet well and are collectively connected to a common outlet well. The well assembly of claim 15, wherein the cuttings segment includes a sensor for sensing collected cuttings of the segment. A method of forming a well arrangement suitable for recovering thermal energy of a fluid circulating through a thermally generating geological formation, the method comprising: independently drilling an inlet well and an outlet well at a predetermined location in the formation; Drilled from the intersection of the inlet and outlet wells to form an interconnected section between the inlet and outlet wells in a predetermined heat generating zone at the formation location of the formation, the outlet well having the following At least one of: concentric with the inlet well and 5° to 175° relative to the inlet well, the interconnecting segment 5° to 355° relative to the inlet well; forming a selectively operable auxiliary section in selective fluid circulatory communication with the interconnecting section for storing heated fluid; forming a cuttings section in fluid communication with at least one of the inlet well, the outlet well and the interconnecting section for collecting well cuttings; and A conversion device is provided in connection with the wells to form a closed loop and recover thermal energy from the fluid collection for conversion. 26. The method of claim 25, wherein the step of intersecting drilling from the inlet and outlet wells to form an interconnecting segment between the inlet and outlet wells is performed using electromagnetic communication. The method of claim 26, further comprising: selectively disposing a plurality of electromagnetic communication devices in a predetermined combination of the entry well, the exit well, the cuttings segment, and the interconnect segment. The method of claim 27, further comprising the step of: operating the electromagnetic communication devices in a predetermined sequence. 28. The method of claim 28, further comprising the step of coordinating a call from a well under construction with a call from a previously formed offset well. The method of claim 25, further comprising the step of disposing a sensor in the cuttings segment. The method of claim 30, further comprising the step of changing the chemical composition of the working fluid in response to a sensed signal from the cuttings segment. The method of any one of claims 25 to 31, wherein the formation is a geothermal formation. The method of any one of claims 25 to 32, further comprising the step of circulating fluid within the interconnected segment without a casing and a liner. The method of claim 32, wherein the geothermal formation has a temperature of not less than 40°C. The method of any one of claims 25 to 35, further comprising the step of: providing a plurality of interconnected segments in fluid communication with the inlet well and the outlet well, the assembled structure having the interconnected segments The segments are formed in a plurality of spaced arrays in a predetermined pattern. 35. The method of claim 35, further comprising the step of selectively circulating the fluid as a slipstream from one array to a second, spaced-apart array prior to discharge from the outlet well common to all arrays an entry point. The method of claim 36, wherein the slip flow preheats fluid from the inlet well prior to circulation in the second array of spaced apart. 36. The method of claim 36, further comprising the step of distributing the slip flow to an offset well assembly for thermally augmenting the offset well.

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