Deployment of geothermal system technology

Abstract

The present disclosure relates to systems and methods for geothermal energy systems utilizing multi-well pads to target multiple formation benches. In some examples, a geothermal energy system utilizes a multi-well pad (904) at a surface location to drill a set of horizontal wells (916,918,920,922,924,926,928,930) that extend from the surface location into a basement formation, targeting different formation benches in the basement formation. By targeting different formation benches of the basement formation from the same multi-well pad (904), the geothermal energy system achieves and maintains high production temperatures without thermal decline and reduces the environmental footprint of the geothermal energy system.

Description

DEPLOYMENT OF GEOTHERMAL SYSTEM TECHNOLOGYCLAIM OF PRIORITY

[0001] This patent application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 692,595, filed on September 9, 2024, titled “DEPLOYMENT OF GEOTHERMAL SYSTEM TECHNOLOGY,” the contents of which are incorporated by reference herein in its entirety.FIELD OF INVENTION

[0001] The present disclosure relates to geothermal energy production and, in some examples, to deployment of geothermal energy production techniques, including horizontal well drilling, multistage completion, and reservoir stimulation.BACKGROUND

[0002] The increasing demand for sustainable and renewable energy has spurred recognition of geothermal energy as a unique and important resource due to its consistent and predictable output. Historically, geothermal applications have relied on expensive and visible aboveground piping systems to harness and distribute thermal energy from the geothermal well source to the power generation plant. Aboveground piping has been utilized due to the elevated operating temperatures typical of geothermal applications.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Some examples are shown for purposes of illustration and not limitation in the figures of the accompanying drawings. In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views or examples. It should be understood that additional and alternative examples are possible without departing from the principles of the subject matter described herein.

[0004] FIG. 1 illustrates an example of a natural resource system, in accordance with examples described herein.

[0005] FIG. 2 illustrates an example of an enhanced geothermal system, in accordance with examples described herein.

[0006] FIG. 3 illustrates an example of an enhanced geothermal system, in accordance with examples described herein.

[0007] FIG. 4 illustrates an example of an enhanced geothermal system, in accordance with examples described herein.

[0008] FIG. 5 illustrates an example of production data from a well of an enhanced geothermal system, in accordance with examples described herein.

[0009] FIG. 6 illustrates an example of power output data associated with a well of an enhanced geothermal system, in accordance with examples described herein.

[0010] FIG. 7 illustrates an example of fluid temperature data associated with an enhanced geothermal system, in accordance with examples described herein.

[0011] FIG. 8 illustrates an example of power output data associated with an enhanced geothermal system, in accordance with examples described herein.

[0012] FIG. 9 illustrates an example of an enhanced geothermal system, in accordance with examples described herein.

[0013] FIG. 10 illustrates an example technique for developing an enhanced geothermal system, in accordance with examples described herein.

[0014] FIG. 11 illustrates an example of a machine upon which any one or more of the techniques discussed herein may be performed, in accordance with examples described herein.DETAILED DESCRIPTION

[0015] The systems and techniques described herein relate to geothermal energy systems utilizing multi-well pads to target multiple formation benches, which increases power density and reduces surface disturbance. In some examples, a geothermal energy system utilizes a multi-well pad at asurface location to drill a set of horizontal wells that extend from the surface location into a basement formation. The set of horizontal wells includes a first subset of horizontal wells drilled to target a first formation bench of the basement formation and a second subset of horizontal wells drilled to target a second formation bench of the basement formation. By targeting multiple formation benches of the basement formation from the same multi-well pad, the geothermal energy system achieves and maintains high production temperatures without thermal decline and reduces the environmental footprint of the geothermal energy system.

[0016] For example, a geothermal energy system includes a multi-well pad (e.g., an 8-well pad, a 14-well pad) with a set of horizontal wells that target two benches of a granitic basement formation. The set of horizontal wells targets the granitic basement formation for the production of geothermal fluid at approximately 390 to 395°F, which provides efficient power conversion for Organic Rankine Cycle (ORC) geothermal power plant technology. To achieve these temperatures, a first subset of horizontal wells targets a first formation bench at a true vertical depth of approximately 8,000 to 9,000 feet within the granitic basement formation. A second subset of horizontal wells targets a second formation bench at a true vertical depth of approximately 9,000 to 10,000 feet within the granitic basement formation. The first subset of horizontal wells and the second subset of horizontal wells may be designed with lateral lengths of approximately 3,000 to 4,700 feet. In the example, the multi-well, multi-bench development strategy for the geothermal energy system provides an estimated power capacity density of 9.1MW per km3, which is larger (e.g., 5 to 10 times larger) than prior developments for geothermal systems.

[0017] As illustrated in this example, the geothermal energy system provides various improvements and advantages in the field of geothermal energy systems. For example, with its multi-well, multi-bench development strategy, the geothermal energy system achieves improved power capacity density, which improves the economics of geothermal energy, while reducing the environmental footprint of the geothermal energy system.Furthermore, the geothermal energy system achieves and maintains high production temperatures without thermal decline, which provides for long-term, clean, reliable, and sustainable energy. Therefore, the geothermal energy system provides for always-on, weather-independent energy generation while supporting global decarbonization efforts.

[0018] In some examples, a geothermal energy system includes an enhanced geothermal system. An enhanced geothermal system targets hot rocks that may lack sufficient permeability or fluid saturation to facilitate heat extraction. The enhanced geothermal system artificially creates or improves underground conditions around the hot rocks by, for example, drilling into and around the hot rocks and by, for example, injecting fluid or gas to fracture the hot rocks. Through drilling and fracturing, the enhanced geothermal system creates a geothermal reservoir that facilitates heat extraction.

[0019] In some examples, a geothermal energy system includes horizontal wells. Each horizontal well may extend vertically from a surface location and then transition to a horizontal trajectory that penetrates a target formation. For example, a horizontal well may extend vertically from a surface location to a true vertical depth of 8,000 to 10,000 feet and then extend horizontally for a lateral length of 3,000 to 4,700 feet through a formation bench.

[0020] In some examples, a geothermal energy system includes horizontal wells drilled from a multi-well pad that are stimulated by pumping fluid in alternating sequential stages between wells (e.g., zipper operations). For example, a first stage of a first horizontal well is stimulated by pumping fluid into the first stage of the first horizontal well. Then, a first stage of a second horizontal well is stimulated by pumping fluid into the first stage of the second horizontal well. In this example, preparations (e.g., wireline, perforation operations) for stimulating the second horizontal well may be performed while the first horizontal well is being stimulated, and likewise, preparations for stimulating the first horizontal well may be performed while the second horizontal well is being stimulated. By stimulating horizontal wells in alternating sequential stages, the geothermal energy system achieves operational efficiency improvements during development. In some examples, the geothermal energy system developed three wells stimulatedfrom the same well pad using an alternating sequential stage approach, with a total of eighty stages completed across the three wells.

[0021] During well stimulation operations, a completion technique may be utilized to achieve zonal isolation. In some examples, internal stimulation plugs are installed to complete and isolate stages during well stimulation operations. The internal stimulation plugs may be composite stimulation plugs with aluminum mandrels, or the internal stimulation plugs may be fully composite stimulation plugs that do not include metal. In some examples, a combination of composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs is installed. In some examples, stimulation plugs are installed sequentially, consistent with the completion of stages in sequential well stimulation operations (e.g., plug- and-perforate). The sequential installation provides precise control over stimulation placement and contributes to zonal isolation. In some examples, zonal isolation is achieved through external cement sheaths, such as cement casing (e.g., 7-inch cement casing). In some examples, a combination of external cement sheaths and internal stimulation plugs is utilized to complete a well.

[0022] In some examples, a geothermal energy system includes a multiwell pad from which a set of horizontal wells targets a first formation bench with a first subset of horizontal wells including a first injection well and two first production wells and targets a second formation bench with a second subset of horizontal wells including a second injection well and two second production wells. By targeting multiple formation benches, the geothermal energy system facilitates simultaneous injection operations and production operations from a multi-well pad while targeting different formation benches. For example, the geothermal energy system may operate to inject fluid into the first injection well and the second injection well at injection pressures of 2,000 to 2,300 psi with fluid produced from the two first production wells and the two second production wells at 300 to 350 psi. In this example, the geothermal energy system utilizes two closed-loop circulation systems where fluid is injected through an injection well and produced through production wells to efficiently extract thermal energy.

[0023] In some examples, a geothermal energy system includes a vertical observation well for monitoring conditions and acquiring data. For example, the vertical observation well may be drilled to monitor and confirm temperature gradients at a surface location and to identify lithologic structures of subsurface formations. The vertical observation well may be drilled to, for example, a depth of 9,000 to 10,000 feet. The vertical observation well includes distributed fiber optic sensing equipment (e.g., distributed acoustic sensing (DAS) fibers) and distributed temperature sensing equipment (e.g., distributed temperature sensing (DTS) fibers) that provide real-time monitoring of temperature conditions and seismic conditions. In some examples, the vertical observation well includes one or more downhole pressure and temperature gauges to continuously monitor temperature conditions and pressure conditions and to continuously acquire temperature data and pressure data at various depths.

[0024] In some examples, a geothermal energy system targets certain formations to leverage the geological characteristics of the formations during development and production. For example, a granitic basement formation may present characteristics that make the granitic basement formation suitable for enhanced geothermal development, such as suitable temperature gradients and suitable rock properties. A suitable temperature gradient may support the production of fluid at temperatures that adequately power an ORC turbine for power generation.

[0025] In some examples, a geothermal energy system achieves significant drilling performance improvements through systematic optimization techniques. For example, the successful implementation of drill bit optimizations, drilling fluids optimizations, and well construction design optimizations results in reduced drilling times, with wells being drilled in under 20 days. The reduction in drilling days, along with supply chain and engineering improvements, results in significant well -over- well drilling cost reductions. In some examples, the geothermal energy system demonstrates successful drilling capabilities in extremely high-temperature environments. For example, successful drilling results are achieved while drilling at temperatures up to 434°F along the lateral sections of horizontal wells. In some examples, the geothermal energy system achieves exceptionalcompletion success rates through multistage stimulation treatments. For example, a stimulation success rate of 95% to 100% is achieved based on screenout rate, achieved proppant loading, and treating pressures. In some examples, 95% of stimulation stages are completed with designed proppant loading volumes, with average treatment pressures for 80% of stages maintained between 7,000 psi and 9,000 psi. All stages are successfully initiated and propagated with no screenouts, confirming the effectiveness of the plug-and-perforate stimulation treatment design in high-temperature geothermal environments.

[0026] FIG. 1 illustrates an example 100 of a natural resource system 102, in accordance with examples described herein. For example, the natural resource system 102 may pump fluid or gas from one or more geothermal energy sources. Typically, in the production of natural resources from formations within the earth, a well or borehole is drilled into the earth to the location where the natural resource is believed to be located. These natural resources may be a heat source for geothermal energy, a hydrocarbon reservoir containing natural gas, crude oil, and combinations of these; the natural resource may be fresh water, or it may be some other natural resource that is located within the ground.

[0027] Generally, when a well is drilled into these formations, the natural resources rarely flow into and out of the formations and into the well at rates, durations, and amounts that are economically viable. This problem can relate to the viscosity of the natural resource, the porosity of the formation, the geology of the formation, the formation pressures, and the perforations that place the production tubing in the well in fluid communication with the formation, to name a few.

[0028] In drilling a well, an initial borehole is made into the earth, and then, subsequent and smaller diameter boreholes are drilled to extend the overall depth of the borehole. In this manner, as the overall borehole gets deeper, its diameter becomes smaller, resulting in what can be envisioned as a telescoping assembly of holes with the largest diameter hole being at the top of the borehole, closest to the surface of the earth.

[0029] Typically, when completing a well, it is necessary to perform a perforation operation. In general, when a well has been drilled and casing (e.g., a metal pipe) is run to the prescribed depth, the casing is typically cemented in place by pumping cement down and into the annular space between the casing and the earth. The casing, among other things, prevents the hole from collapsing and fluids from flowing between permeable zones in the annulus. Thus, this casing forms a structural support for the well and a barrier to the earth.

[0030] Boreholes are generally formed and advanced by using mechanical drilling equipment having a rotating drilling tool (e.g., a bit). For example, when creating a borehole in the earth, a drilling bit is extending to and into the earth and rotated to create a hole in the earth. In general, to perform the drilling operation, the bit must be forced against the material to be removed with a sufficient force to exceed the shear strength, compressive strength, or combinations thereof of that material.

[0031] As illustrated in FIG. 1, the natural resource system 102 can inject a fluid or a gas through a subsurface 104 via an injection well 108 to fractures 110a, 110b, 110c. The fractures 110a, 110b, 110c can be part of an enhanced geothermal system, which can be a man-made reservoir created where there is hot rock but insufficient or little natural permeability or fluid saturation. In some instances, fluid or gas can be injected through the injection well 108 to cause the fractures 110a, 110b, 110c to open or re-open to create permeability. In some instances, fluid or gas can be injected through the injection well 108 as part of a flow through the fractures 110a, 110b, 110c. The flow through the fractures 110a, 110b, 110c can be enhanced through reservoir stimulation. Here, stimulation of multiple fractures, such as the fractures 110a, 110b, 110c, allows for an area to be stimulated in a series of smaller stimulations, minimizing local stress perturbations. The stimulation of multiple fractures provides for access to significantly more of the reservoir and provides additional flow opportunities, increasing overall flow rate. For example, through multizone stimulation, flow rates of 40-80 kg / s for commercial production may be achieved, where stimulation of a single fracture may fail to achieve a flow greater than 25 kg / s.

[0032] As illustrated in FIG. 1, fluid or gas can flow from the fractures 110a, 110b, 110c to the natural resource system 102 through the subsurface 104 via a production well 106. The natural resource system 102 can extract energy (e.g., heat, thermal energy) from the fluid or the gas from the fractures 110a, 110b, 110c. As illustrated in FIG. 1, the injection well 108 and the production well 106 can be horizontal wells. The injection well 108 and the production well 106 can have limited-entry completion designs to maximize thermal sustainability. In general, limited-entry completion designs refer to well stimulation techniques that effectively treat multiple zones simultaneously. Through limited entry completion designs, even stimulation and uniform flow can be achieved.

[0033] FIG. 2 illustrates a topographical map 200 including an example of an enhanced geothermal system, in accordance with examples described herein. As illustrated in the topographical map 200, the enhanced geothermal system includes horizontal wells 202, 204 with lateral well paths 206, 208. The enhanced geothermal system includes a vertical observation well 210.

[0034] The horizontal wells 202, 204 include injection wells and production wells to form a geothermal circulation system. The injection wells penetrate subsurface formations along the lateral well paths 206, 208 to facilitate fluid injection into the subsurface formations, while the production wells extract heated fluid from the subsurface formations for thermal energy recovery. In some examples, the vertical observation includes equipment (e.g., DAS fibers, DTS fibers, pressure gauges, temperature gauges) to monitor conditions around the enhanced geothermal system and collect data.

[0035] In FIG. 2, the enhanced geothermal system illustrates the long-term thermal longevity and long-term thermal sustainability of the enhanced geothermal system development techniques described herein. The enhanced geothermal system has operated commercially for over 6,200 hours, producing fluid at approximately 341 to 347°F. This sustained thermal performance indicates that the enhanced geothermal system development techniques described herein, including drilling horizontal wells in high-temperature, hard rock formations, stimulating the reservoir to enhance permeability, and creating high-conductivity hydraulic connections between injection wells and production wells, provides sufficient heat transfer surface area to support long-term thermal longevity and long-term thermal sustainability of the enhanced geothermal system.

[0036] FIG. 3 illustrates a topographical map 300 including an example of an enhanced geothermal system, in accordance with examples described herein. As illustrated in the topographical map 300, the enhanced geothermal system includes a first multi-well pad 302, a second multi-well pad 304, and a vertical observation well 306.

[0037] In FIG. 3, the first multi-well pad 302 is an 8-well pad with eight horizontal wells targeting two different formation benches within a granitic basement formation. For example, the first multi -well pad 302 includes five horizontal wells targeting a first formation bench at a vertical depth of 8,000 to 9,000 feet and three horizontal wells targeting a second formation bench at a vertical depth of 9,000 to 10,000 feet. The eight horizontal wells are drilled with lateral lengths of 3,000 to 4,700 feet.

[0038] The second multi-well pad 304 is a 3-well triplet system with a central production well offset by two injection wells. The horizontal wells of the second multi-well pad target a formation bench at a vertical depth of 8,000 to 9,000 feet with lateral lengths of 3,000 to 4,700 feet.

[0039] The vertical observation well 306 extends to a depth of 9,000 to 10,000 feet (e.g., 9,824 feet) and includes equipment to monitor conditions around the enhanced geothermal system and acquire data. For example, the vertical observation well 306 includes distributed fiber optic sensing equipment, such as DAS fibers and DTS fibers, to monitor real-time temperature conditions and real-time seismic conditions. A downhole pressure and temperature gauge in the vertical observation well 306 monitors fluid pressure and fluid temperature. Using the equipment in the vertical observation well 306, the temperature gradient at the enhanced geothermal system and the lithologic structure of the subsurface at the enhanced geothermal system may be monitored and confirmed.

[0040] FIG. 4 illustrates a geological cross-section diagram 400 including an example of an enhanced geothermal system, in accordance with examples described herein. As illustrated in the geological cross-section diagram 400, the enhanced geothermal system includes a set of horizontal wells 402 and a vertical observation well 404.

[0041] In FIG. 4, the set of horizontal wells 402 extends vertically from the surface to a true vertical depth of approximately 8,000 to 9,000 feet. The set of horizontal wells 402 targets a formation bench in a granitic basement formation. Here, the granitic basement formation exhibits temperatures of approximately 347 to 437°F. In some examples, the enhanced geothermal system targets formation benches at depths of 8,000 to 9,000 feet to achieve geothermal fluid temperatures of 390 to 395°F, which facilitates efficient power conversion with ORC geothermal power plant technology.

[0042] The vertical observation well 404 extends vertically from the surface to a vertical depth of approximately 10,000 to 11,000 feet to facilitate condition monitoring and data acquisition for the area around the enhanced geothermal system. For example, the vertical observation well 404 may be developed before developing the set of horizontal wells 402, and distributed fiber optic sensing equipment, such as DAS fibers and DTS fibers, in the vertical observation well 404 may be used to confirm the subsurface temperature gradient. Based on the subsurface temperature gradient, the set of horizontal wells 402 is developed to target the formation benches at depths of 8,000 to 9,000 feet to achieve the appropriate temperatures for geothermal energy extraction.

[0043] In some examples, the set of horizontal wells 402 is stimulated from the same multi-well pad, which provides for improved operational efficiencies. In some examples, the set of horizontal wells 402 is stimulated using zipper operations. Sequential stages of the set of horizontal wells 402 are pumped and stimulated in alternating fashion. For example, a first stage of a first well of the set of horizontal wells 402 is pumped and stimulated while a second well of the set of horizontal wells 402 is prepared for stimulation. After the first stage of the first well is pumped and stimulated, a first stage of the second well is pumped and stimulated. During this time,a second stage of the first well is prepared for stimulation. The second stage of the first well is pumped and stimulated after the first stage of the second well is pumped and stimulated. In some examples, all the horizontal wells of the set of horizontal wells 402 are stimulated and pumped in sequential stages in alternating fashion. For example, each well is pumped and stimulated in eighty stages with average treatment pressures of 7,000 to 9,000 psi.

[0044] In some examples, completion of the set of horizontal wells 402 includes external cement sheaths around the set of horizontal wells 402 and sequentially installed internal stimulation plugs. For example, a combination of composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs, which do not include metal, is used during stimulation treatment to prevent leaks. Additionally, the use of sequentially installed internal stimulation plugs and external cement sheaths contributes to zonal isolation, improving the efficiency of the enhanced geothermal system.

[0045] FIG. 5 illustrates a graph diagram 500 of production data from a well of an enhanced geothermal system, in accordance with examples described herein. The graph diagram 500 shows measurements of mass flow rate 502 with measurements of wellhead pressure 504 over a period of time. In some examples, the graph diagram 500 shows the measurements of the mass flow rate 502 with the measurements of the wellhead pressure 504 over a 24-hour period of time.

[0046] In FIG. 5, the measurements of the mass flow rate 502 show initial transient effects leading to an initial production rate of approximately 120 kg / s, which is indicative of the production capacity of the well. The measurements of the mass flow rate 502 stabilize at approximately 93 kg / s over the period of time. Based on the 93 kg / s mass flow rate and a brine effectiveness of 94 kWe per kg / s, an electric power output of 9.5 MWe may be estimated for the well while flowing at 93 kg / s. Assuming the production capacity of the well, which is approximately 120 kg / s, the electric power output is estimated to be 12.0 MWe.

[0047] The measurements of the wellhead pressure 504 over the same period of time show an initial pressure of approximately 800 to 1,000 psi and a drop to approximately 300 to 400 psi as the measurements of the mass flow rate 502 stabilize. The stable pressure measurements of the wellhead pressure 504 demonstrate the sustainability of the mass flow rate of 90 to 120 kg / s in the well.

[0048] FIG. 6 illustrates a graph diagram 600 of power output data associated with a well of an enhanced geothermal system, in accordance with examples described herein. The graph diagram 600 shows measurements of power output 602 over a period of time. In some examples, the measurements of the power output 602 correspond with the measurements of mass flow rate 502 of FIG. 5 over the period of time (e.g., 24-hour period of time).

[0049] In FIG. 6, the measurements of the power output 602 show an initial transition period after which the measurements of the power output 602 peak at approximately 12.0 MW. This may correspond, for example, with a mass flow rate of 120 kg / s and a brine effectiveness of 94 kWe per kg / s. The measurements of the power output 602 stabilize at approximately 9.5 MW, which corresponds with a mass flow rate of 93 kg / s and a brine effectiveness of 94 kWe per kg / s.

[0050] In some examples, the measurements of the power output 602 account for fluid temperatures of approximately 369 to 382.9°F, which are within the normal operating ranges of an ORC power plant. With relatively stable temperatures and mass flow rates, the measurements of the power output 602 demonstrate the sustainability of the enhanced geothermal system at generating consistent, stable power.

[0051] FIG. 7 illustrates a graph diagram 700 of fluid temperature data associated with an enhanced geothermal system, in accordance with examples described herein. The graph diagram 700 shows measurements of production fluid temperature 702 over a period of time. The graph diagram 700 shows a region 704 of 375 to 390°F that corresponds with production fluid temperatures that are conducive to efficient geothermal power plant operations.

[0052] In FIG. 7, the measurements of the production fluid temperature 702 correspond with wellhead temperatures captured over a 30-day well test. After an initial warm-up period, the measurements of the production fluid temperature 702 maintain a relatively stable curve within the region 704. The increases in the measurements of the production fluid temperature 702 may be attributed to wellbore warmup effects during the production of the fluid. As illustrated in FIG. 7, the measurements of the production fluid temperature 702 show a lack of thermal decline or thermal short-circuiting. The lack of thermal decline and the lack of thermal short-circuiting indicate the sustained thermal efficiency of the enhanced geothermal system.

[0053] FIG. 8 illustrates a graph diagram 800 of power output data associated with an enhanced geothermal system, in accordance with examples described herein. The graph diagram 800 shows measurements of power output 802 over a period of time.

[0054] In FIG. 8, the measurements of the power output 802 correspond with a cycle in which the enhanced geothermal system operates in a flexible, dispatchable mode. As illustrated by the measurements of the power output 802, the enhanced geothermal system may modulate power output from 2 to 10 MW. The enhanced geothermal system is capable of maintaining these power outputs, such as between 2 and 4 MW and between 8 and 10 MW, over time.

[0055] The flexible operation of the enhanced geothermal system, as illustrated by the measurements of the power output 802, allows the enhanced geothermal system to modulate power output based on operational conditions. For example, the power output of the enhanced geothermal system may be reduced or increased based on power demands or grid requirements. The power output of the enhanced geothermal system may be reduced during periods of low power demands and may be increased during periods of high power demands. Therefore, the enhanced geothermal system may be developed as a dispatchable power generation resource that supplements a baseload power generation system.

[0056] FIG. 9 illustrates a geological cross-section diagram 900 of an enhanced geothermal system, in accordance with examples described herein.The geological cross-section diagram 900 illustrates a first multi-well pad 902 and a second multi-well pad 904. The first multi-well pad 902 includes a first set of horizontal wells 908, 910, 912, 914 and a vertical observation well 906. The second multi -well pad 904 includes a second set of horizontal wells 916, 918, 920, 922, 924, 926, 928, 930.

[0057] In FIG. 9, the first multi-well pad 902 includes the first set of horizontal wells 908, 910, 912, 914 targeting a formation bench in the granitic basement formation. The first set of horizontal wells 908, 910, 912, 914, targets vertical depths of 8,000 to 9,000 feet. In some examples, the first set of horizontal wells 908, 910, 912, 914 has lateral lengths of 3,000 to 4,700 feet. The first multi-well pad 902 includes the vertical observation well 906, which extends vertically to approximately 9,824 feet. The vertical observation well 906 includes equipment (e.g., distributed fiber optic sensing equipment, downhole pressure and temperature gauges) for monitoring conditions and acquiring data around the enhanced geothermal system.

[0058] The second multi -well pad 904 includes the second set of horizontal wells 916, 918, 920, 922, 924, 926, 928, 930 targeting two formation benches in the granitic basement formation. A first subset of the second set of horizontal wells 916, 918, 920, 922, 924 targets a first formation bench of vertical depth 8,000 to 9,000 feet. A second subset of the second set of horizontal wells 926, 928, 930 targets a second formation bench of vertical depth 9,000 to 10,000 feet. In some examples, the second set of horizontal wells has lateral lengths of 3,000 to 4,700 feet. In some examples, the second set of horizontal wells includes triplet well systems in which a central production well is offset by two injection wells. For example, the first subset of the second set of horizontal wells 916, 918, 920, 922, 924 may include two triplet well systems with two production wells offset by four injection wells. The second subset of the second set of horizontal wells 926, 928, 930 may include one triplet well system with one production well offset by two injection wells.

[0059] In some examples, an electric power capacity of a geothermal resource, such as the geothermal resource illustrated in the geological crosssection diagram 900, may be estimated by a geologic model tailored togeothermal energy applications. For example, the electric power capacity of the geothermal resource may be evaluated based on an estimation of total heat in place at recoverable temperature and depth conditions. A thermal recovery factor may be applied to the estimated total heat in place. An estimation of electric power converted from thermal energy production may be based on a geothermal power plant efficiency factor. In some examples, the geologic model may be developed using offset well review, resourcespecific geologic modeling, and physics-based reservoir simulation production forecasts. In some examples, an integrated Monte Carlo method is applied to account for uncertainties and risk factors.

[0060] For example, a geologic model may be constrained with available offset well data and geophysical data. The geologic model may be populated with geologic properties, such as lithology, temperature, heat capacity, fluid saturation, and rock density. In some examples, deep well data for an area may be sparse, and geostatistical methods may be used to extrapolate properties for the area. In some examples, a database of deep wells with conductive temperature gradients provides an empirical distribution of geothermal gradients that may be applied to the geologic model.

[0061] For example, a formula for heat in place may be:where V is a total reservoir volume, pris a density of rock, cris a heat capacity of the rock, (Tr- Tinj) is a temperature difference between a reservoir temperature (Tr) and a reinjection temperature (Tinj) of the fluid after going through a geothermal power plant, and Htot is a total heat in place. The total heat in place may represent the energy in place that may be used for energy and represent the maximum amount of thermal energy that may be recovered for energy production.

[0062] Based on the total heat in place, an electric power capacity for a resource may be:where r| is a thermal-to-electric power conversion efficiency of a geothermal power plant, r is a thermal recovery factor, At is a total project life, Htot is a total heat in place, and P is an electric power capacity. The electric power capacity represents the gross electric power capacity of a resource divided over a total project life, providing an average electric power capacity that may be sustained over the total project life.

[0063] FIG. 10 illustrates a flow diagram of an example technique 1000 for developing an enhanced geothermal system, in accordance with examples described herein. One or more of the functions described in the example technique 1000 may be implemented by, for example, the enhanced geothermal system of FIGS. 1-9 or a similar enhanced geothermal system. One or more of the functions described in the example technique 1000 may utilize, for example, the enhanced geothermal system of FIGS. 1-9 or a similar enhanced geothermal system. Although the flowchart depicts a particular sequence of operations, the sequence may be altered without departing from the scope of the subject matter disclosed herein. For example, some of the operations depicted may be performed in parallel or in a different sequence without materially affecting the functions described in the example technique 1000.

[0064] At operation 1002, an enhanced geothermal system establishes a multi-well pad at a surface location, the multi-well pad comprising a set of horizontal wells. For example, the set of horizontal wells is configured for the development of the enhanced geothermal system. In some examples, the multi-well pad may be an 8-well pad configuration that facilitates simultaneous drilling operations and production operations from multiple formation benches. Surface location data and geological survey data may be utilized to position the multi-well pad for access to basement formation resources. The establishment process may include site preparation, equipment positioning, and infrastructure development to support horizontal drilling operations targeting depths of approximately 8,000 to 10,000 feet.

[0065] At operation 1004, the enhanced geothermal system drills a first subset of horizontal wells of the set of horizontal wells from the multi-well pad to target a first formation bench of a basement formation. For example,drilling equipment may be utilized to drill vertically from the surface location and transition to horizontal trajectories that penetrate the first formation bench. In some examples, the first subset of horizontal wells targets a granitic basement formation at a true vertical depth of approximately 8,000 to 9,000 feet. The enhanced geothermal system may incorporate drill bit optimizations, drilling fluids optimizations, and well construction design optimizations to achieve lateral lengths of approximately 3,000 to 4,700 feet. Geological data from vertical observation wells may be utilized during drilling operations to confirm temperature gradients and lithologic structures of subsurface formations.

[0066] At operation 1006, the enhanced geothermal system drills a second subset of horizontal wells of the set of horizontal wells from the multi-well pad to target a second formation bench of the basement formation. For example, the second subset of horizontal wells extends development to access a different thermal zone at a different vertical depth within the same formation as the first subset of horizontal wells. In some examples, the second subset of horizontal wells targets the granitic basement formation at a true vertical depth of approximately 9,000 to 10,000 feet. The same drilling equipment and optimization techniques utilized to drill the first subset of horizontal wells may be utilized to drill the second subset of horizontal wells while targeting different geological strata, facilitating recovery of thermal energy from multiple formation levels, which increases power density while minimizing surface disturbance.EXAMPLE MACHINE

[0067] FIG. 11 illustrates generally an example of a block diagram of a machine 1100 upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform in accordance with some examples. In alternative examples, the machine 1100 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 1100 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 1100 may act as a peer machinein a peer-to-peer (P2P) (or other distributed) network environment. The machine 1100 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0068] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In an example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer-readable medium containing instructions, where the instructions configure the execution units to carry out a specific operation when in operation. The configuration may occur under the direction of the execution units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer-readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module.

[0069] Machine (e.g., computer system) 1100 may include a hardware processor 1102 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 1104 and a static memory 1106, some or all of which may communicate with each other via an interlink (e.g., bus) 1108. The machine 1100 may further include a display unit 1110, an alphanumeric input device1112 (e.g., a keyboard), and a user interface (UI) navigation device 1114 (e.g., a mouse). In an example, the display unit 1110, alphanumeric input device 1112, and UI navigation device 1114 may be a touch screen display. The machine 1100 may additionally include a storage device (e.g., drive unit) 1116, a signal generation device 1118 (e.g., a speaker), a network interface device 1120, and one or more sensors 1121, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine 1100 may include an output controller 1128, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0070] The storage device 1116 may include a machine-readable medium 1122 that is non-transitory on which is stored one or more sets of data structures or one or more instructions 1124 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The one or more instructions 1124 may also reside, completely or at least partially, within the main memory 1104, within static memory 1106, or within the hardware processor 1102 during execution thereof by the machine 1100. In an example, one or any combination of the hardware processor 1102, the main memory 1104, the static memory 1106, or the storage device 1116 may constitute machine-readable media.

[0071] While the machine-readable medium 1122 is illustrated as a single medium, the term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, or associated caches and servers) configured to store the one or more instructions 1124.

[0072] The term “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 1100 and that cause the machine 1100 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories, optical media, and magnetic media. Specific examplesof machine-readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

[0073] The one or more instructions 1124 may further be transmitted or received over a communications network 1126 using a transmission medium via the network interface device 1120 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 1120 may include one or more physical jacks (e.g., Ethernet, coaxial, or phonejacks) or one or more antennas to connect to the communications network 1126. In an example, the network interface device 1120 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multipleoutput (MIMO), or multiple-input single-output (MISO) techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine 1100, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.GLOSSARY

[0074] Generally, the term “about”, “approximately”, and the symbolas used herein, unless stated otherwise, is meant to encompass a variance orrange of ±10%, the experimental or instrument error associated with obtaining the stated value, and preferably the larger of these.

[0075] As used herein, unless specified otherwise, the terms “formation”, “reservoir”, “pay zone”, and similar terms are to be given their broadest possible meanings, and include all locations, areas, and geological features within the earth that contain, may contain, or are believed to contain, a desired resource (e.g., geothermal heat, hydrocarbons, etc.).

[0076] As used herein, unless specified otherwise, the terms “field”, “oil field”, “geothermal field”, and similar terms are to be given their broadest possible meanings, and include any area of land, sea floor, or water that is loosely or directly associated with a formation, and more particularly, with a resource containing formation. Thus, a field may have one or more exploratory and producing wells associated with it. A field may have one or more governmental bodies or private resource leases associated with it. A field may be directly associated with a resource containing formation.

[0077] As used herein, unless specified otherwise, the terms “geothermal”, “geothermal well”, “geothermal resource”, “geothermal energy”, and similar terms are to be given their broadest possible meanings, and include systems and operations, including wells, that recover or utilize the heat energy that is contained within the earth. Such systems and operations include enhanced geothermal wells, engineered geothermal wells, binary cycle power plants, dry steam power plants, flash steam power plants, open-loop systems, and closed-loop systems.

[0078] As used herein, unless specified otherwise, the term “earth” should be given its broadest possible meaning, and includes, the ground, all natural materials, such as rocks, and artificial materials, such as concrete, that are or may be found in the ground, including without limitation rock layer formations, such as, granite, basalt, sandstone, dolomite, sand, salt, limestone, rhyolite, quartzite and shale rock.

[0079] As used herein, unless specified otherwise, the term “borehole” should be given it broadest possible meaning and includes any opening that is created in a material, a work piece, a surface, the earth, a structure (e.g., building, protected military installation, nuclear plant, offshore platform, orship), or in a structure in the ground, (e.g., foundation, roadway, airstrip, cave or subterranean structure) that is substantially longer than it is wide, such as a well, a well bore, a well hole, a micro hole, a slimhole, a perforation, or other term commonly used to define these types of long narrow passages. Wells would further include exploratory, production, abandoned, reentered, reworked, and injection wells. Although boreholes are generally oriented substantially vertically, they may also be oriented on an angle from vertical, to and including horizontal. Thus, using a vertical line, based upon a level as a reference point, a borehole can have orientations ranging from 0° i.e., vertical, to 90°, i.e., horizontal and greater than 90° e.g., such as a heel and toe and combinations of these such as for example “U” and “Y” shapes. Boreholes may further have segments or sections that have different orientations, they may have straight sections, arcuate sections, and combinations thereof; and for example, may be of the shapes commonly found when directional drilling is employed. Thus, as used herein unless expressly provided otherwise, the “bottom” of a borehole, the “bottom surface” of the borehole and similar terms refer to the end of the borehole, i.e., that portion of the borehole furthest along the path of the borehole from the borehole's opening, the surface of the earth, or the borehole's beginning. The terms “side” and “wall” of a borehole should be given their broadest possible meaning and include the longitudinal surfaces of the borehole, whether or not casing or a liner is present, as such, these terms would include the sides of an open borehole or the sides of the casing that has been positioned within a borehole. Boreholes may be made up of a single passage, multiple passages, connected passages, and combinations thereof. In a situation where multiple boreholes are connected or interconnected, each borehole would have a borehole bottom. Boreholes may be formed in the sea floor, under bodies of water, on land, in ice formations, or in other locations and settings.

[0080] As used herein, phrases of the form “at least one of an A, a B, or a C”, “at least one of A, B, or C”, “at least one of A, B, and C”, and similar phrases, should be interpreted to select at least one from the group that comprises A, B, and C. Unless explicitly stated otherwise in connection with a particular instance, this manner of phrasing does not mean “at leastone of A, at least one of B, and at least one of C.” As used herein, the example “at least one of an A, a B, or a C” would cover any of the following selections: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, and {A, B, C}.

[0081] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense, i.e., in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words using the singular or plural number may also include the plural or singular number, respectively. The word “or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. Likewise, the term “and / or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list.EXAMPLES

[0082] In view of the above-described implementations of subject matter this application discloses the following list of examples, wherein one feature of an example in isolation or more than one feature of an example, taken in combination and, optionally, in combination with one or more features of one or more further examples are further examples also falling within the disclosure of this application.

[0083] Example l is a method comprising: establishing a multi-well pad at a surface location, the multi-well pad comprising a set of horizontal wells; drilling a first subset of horizontal wells of the set of horizontal wells fromthe multi-well pad to target a first formation bench of a basement formation; and drilling a second subset of horizontal wells of the set of horizontal wells from the multi-well pad to target a second formation bench of the basement formation.

[0084] In Example 2, the subject matter of Example 1 comprises stimulating the first subset of horizontal wells from the multi-well pad by pumping fluid in the first subset of horizontal wells in alternating sequential stages.

[0085] In Example 3, the subject matter of Example 2 comprises wherein pumping fluid in the first subset of horizontal wells comprises: pumping first fluid in a first stage of a first horizontal well in the first subset of horizontal wells; subsequent to pumping the first fluid in the first stage of the first horizontal well, pumping second fluid in a first stage of a second horizontal well in the first subset of horizontal wells; and subsequent to pumping the second fluid in the first stage of the second horizontal well, pumping the first fluid in a second stage of the first horizontal well.

[0086] In Example 4, the subject matter of Examples 1 - 3 comprises sequentially installing internal stimulation plugs in the first subset of horizontal wells.

[0087] In Example 5, the subject matter of Example 4 comprises wherein the internal stimulation plugs comprise composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs without metals.

[0088] In Example 6, the subject matter of Examples 1 - 5 comprises wherein the first subset of horizontal wells comprises a first injection well and two first production wells and the second subset of horizontal wells comprises a second injection well and two second production wells.

[0089] In Example 7, the subject matter of Example 6 comprises simultaneously injecting fluid into the first injection well and the second injection well while producing the fluid from the two first production wells and the two second production wells.

[0090] In Example 8, the subject matter of Example 7 comprises wherein the fluid is injected into the first injection well and the second injection well at an injection pressure of 2000 psi to 2300 psi, and the fluid is producedfrom the two first production wells and the two second production wells at 300 psi to 350 psi.

[0091] In Example 9, the subject matter of Examples 1 - 8 comprises wherein at least one horizontal well of the set of horizontal wells has a lateral length of 3,000 ft to 4,700 ft.

[0092] In Example 10, the subject matter of Examples 1 - 9 comprises wherein the basement formation comprises a granitic basement formation, the first formation bench has a first vertical depth of 8,000 ft to 9,000 ft, and the second formation bench has a second vertical depth of 9,000ft to 10,000 ft.

[0093] Example 11 is an enhanced geothermal system comprising: a multiwell pad at a surface location, the multi-well pad comprising a set of horizontal wells; a first subset of horizontal wells of the set of horizontal wells, the first subset of horizontal wells targeting a first formation bench of a basement formation from the multi-well pad; and a second subset of horizontal wells of the set of horizontal wells, the second subset of horizontal wells targeting a second formation bench of a basement formation from the multi-well pad.

[0094] In Example 12, the subject matter of Example 11 comprises wherein the first subset of horizontal wells is stimulated by pumping fluid in the first subset of horizontal wells in alternating sequential stages.

[0095] In Example 13, the subject matter of Examples 11 - 12 comprises wherein the first subset of horizontal wells comprises sequentially installed internal stimulation plugs.

[0096] In Example 14, the subject matter of Example 13 comprises wherein the sequentially installed internal stimulation plugs comprise composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs without metals.

[0097] In Example 15, the subject matter of Examples 11 - 14 comprises wherein the first subset of horizontal wells comprises a first injection well and two first production wells and the second subset of horizontal wells comprises a second injection well and two second production wells.

[0098] In Example 16, the subject matter of Example 15 comprises wherein fluid is simultaneously injected into the first injection well and the second injection well while the fluid is produced from the two first production wells and the two second production wells.

[0099] In Example 17, the subject matter of Example 16 comprises wherein the fluid is injected into the first injection well and the second injection well at an injection pressure of 2000 psi to 2300 psi, and the fluid is produced from the two first production wells and the two second production wells at 300 psi to 350 psi.

[0100] In Example 18, the subject matter of Examples 11 - 17 comprises at least one vertical observation well comprised by the multi-well pad, the at least one vertical observation well comprising distributed fiber optic sensing equipment and distributed temperature sensing equipment.

[0101] In Example 19, the subject matter of Examples 11 - 18 comprises at least one horizontal well of the set of horizontal wells has a lateral length of 3,000 ft to 4,700 ft.

[0102] In Example 20, the subject matter of Examples 11 - 19 comprises wherein the basement formation comprises a granitic basement formation, the first formation bench has a first vertical depth of 8,000 ft to 9,000 ft, and the second formation bench has a second vertical depth of 9,000ft to 10,000 ft.

[0103] Example 21 is a system to implement any of Examples 1 - 20.

[0104] Example 22 is a device or an apparatus to implement any of Examples 1 - 20.

[0105] Example 23 is a non-transitory, computer-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement any of Examples 1 - 20.

[0106] Example 24 is a method to implement any of Examples 1 - 20.

[0107] The present invention may be embodied in other forms than those specifically disclosed herein without departing from the essential characteristics of the present invention. The described examples are to be considered in all respects only as illustrative and not restrictive.

[0108] The various examples of systems, compositions, articles, uses, applications, equipment, methods, activities, and operations set forth in this specification may be used for various other fields and for various other activities, uses, and examples. Additionally, these examples may be used with: existing systems, compositions, articles, uses, applications, equipment, methods, activities, and operations; may be used with systems, compositions, articles, uses, applications, equipment, methods, activities, and operations that may be developed in the future; and with such systems, compositions, articles, uses, applications, equipment, methods, activities, and operations that may be modified, in-part, based on the teachings of this specification. Further, the various examples set forth in this specification may be used with each other, in whole or in part, and in different and various combinations. Thus, for example, the configurations provided in the various examples of this specification may be used with each other; and the scope of protection afforded the present inventions should not be limited to a particular example, configuration or arrangement that is set forth in a particular example, or in an example in a particular figure.

Claims

CLAIMSWhat is claimed is:

1. A method comprising: establishing a multi-well pad at a surface location, the multi-well pad comprising a set of horizontal wells; drilling a first subset of horizontal wells of the set of horizontal wells from the multi-well pad to target a first formation bench of a basement formation; and drilling a second subset of horizontal wells of the set of horizontal wells from the multi-well pad to target a second formation bench of the basement formation.

2. The method of claim 1, further comprising: stimulating the first subset of horizontal wells from the multi-well pad by pumping fluid in the first subset of horizontal wells in alternating sequential stages.

3. The method of claim 2, wherein pumping fluid in the first subset of horizontal wells comprises: pumping first fluid in a first stage of a first horizontal well in the first subset of horizontal wells; subsequent to pumping the first fluid in the first stage of the first horizontal well, pumping second fluid in a first stage of a second horizontal well in the first subset of horizontal wells; and subsequent to pumping the second fluid in the first stage of the second horizontal well, pumping the first fluid in a second stage of the first horizontal well.

4. The method of claim 1, further comprising: sequentially installing internal stimulation plugs in the first subset of horizontal wells.

5. The method of claim 4, wherein the internal stimulation plugs comprise composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs without metals.

6. The method of claim 1, wherein the first subset of horizontal wells comprises a first injection well and two first production wells and the second subset of horizontal wells comprises a second injection well and two second production wells.

7. The method of claim 6, further comprising: simultaneously injecting fluid into the first injection well and the second injection well while producing the fluid from the two first production wells and the two second production wells.

8. The method of claim 7, wherein the fluid is injected into the first injection well and the second injection well at an injection pressure of 2000 psi to 2300 psi, and the fluid is produced from the two first production wells and the two second production wells at 300 psi to 350 psi.

9. The method of claim 1, wherein at least one horizontal well of the set of horizontal wells has a lateral length of 3,000 ft to 4,700 ft.

10. The method of claim 1, wherein the basement formation comprises a granitic basement formation, the first formation bench has a first vertical depth of 8,000 ft to 9,000 ft, and the second formation bench has a second vertical depth of 9,000ft to 10,000 ft.

11. An enhanced geothermal system comprising: a multi-well pad at a surface location, the multi-well pad comprising a set of horizontal wells; a first subset of horizontal wells of the set of horizontal wells, the first subset of horizontal wells targeting a first formation bench of a basement formation from the multi-well pad; and a second subset of horizontal wells of the set of horizontal wells, the second subset of horizontal wells targeting a second formation bench of a basement formation from the multi-well pad.

12. The enhanced geothermal system of claim 11, wherein the first subset of horizontal wells is stimulated by pumping fluid in the first subset of horizontal wells in alternating sequential stages.

13. The enhanced geothermal system of claim 11, wherein the first subset of horizontal wells comprises sequentially installed internal stimulation plugs.

14. The enhanced geothermal system of claim 13, wherein the sequentially installed internal stimulation plugs comprise composite stimulation plugs with aluminum mandrels and fully composite stimulation plugs without metals.

15. The enhanced geothermal system of claim 11, wherein the first subset of horizontal wells comprises a first injection well and two first production wells and the second subset of horizontal wells comprises a second injection well and two second production wells.

Images