41 results about "Enhanced geothermal system" patented technology

The invention discloses a heat flow curing multi-field coupling modeling method based on an enhanced geothermal system, which belongs to the technical field of oil and gas field exploitation, and comprises the following steps: generating two groups of random numbers as crack center positions, and determining random crack end point coordinates according to the crack center positions, trace lengths and directions; forming an initial smooth fracture grid according to the determined random fracture endpoint coordinates; according to the initial smooth fracture grid, roughness continuity of each fracture path is controlled through a Hurst index, and a random fracture path containing roughness is generated; according to the generated random crack path containing the roughness, a hot dry rock one-injection and two-production random crack model is established; setting material parameters of the random fracture model according to logging data, and adding a stress field, a seepage field, a temperature field and a chemical field to the random fracture model; initial conditions and boundary conditions are set for a stress field, a seepage field, a temperature field and a chemical field of the random fracture model, and multi-physics field coupling setting is carried out.

The invention belongs to the technical field of dual-carbon strategy and peak regulation and supply guarantee, and particularly discloses an enhanced geothermal system and method for power grid energy storage and peak regulation, and the enhanced geothermal system comprises a drilling unit, a reservoir and an organic Rankine cycle system. The reservoir is communicated with the injection well through the first high-pressure water pump, the liquid pumping end of the first high-pressure water pump is connected with the reservoir, and the liquid injection end of the first high-pressure water pump is connected with the injection well; when a power grid system is in a power generation peak, a first high-pressure water pump is driven by electric power to inject water in a reservoir into a first rock crack and a second rock crack through an injection well so as to press the first rock crack and the second rock crack to open and accumulate elastic potential energy; and when the power grid system is in a load peak, the accumulated elastic potential energy is utilized to drive high-pressure fluid in the production well to be reversely discharged to the organic Rankine cycle system so as to provide electric energy for the power grid system. According to the method, the limitation of low energy storage density of a single well is overcome, and risks caused by complex regulation and control and high technical requirements of multi-branch wells are avoided.

The invention discloses a hot dry rock reservoir transformation mutual feedback multi-stage dynamic earthquake control method based on comprehensive prediction, and relates to the field of enhanced geothermal system development, and the method comprises the following steps: S1, dividing a limited earthquake magnitude into four stages according to a site earthquake control demand; s2, establishing an induced earthquake real-time monitoring system, and providing a real-time induced earthquake catalog; s3, comprehensively predicting and evaluating an induced earthquake risk; s4, according to the different limited earthquake magnitudes determined in the step S1 and the induced earthquake risk comprehensive analysis provided in the step S3, dynamically adjusting hierarchical management and control early warning conditions; s5, performing dynamic limitation on injection parameters by utilizing the earthquake risk analysis in the step S3; and S6, taking corresponding countermeasures according to different dynamic early warning conditions in the step S4 to realize prospective active earthquake control. And S7, through induced earthquake real-time monitoring in S2, mutual feedback type analysis in S3 and S5, dynamic injection limiting parameters are provided, dynamic early warning conditions are provided for S4 in combination with S3, prospective active earthquake control adjustment measures in S6 are realized, a real-time earthquake risk analysis and dynamic parameter adjustment mutual feedback type multi-stage earthquake control system is formed, and finally the purpose of safe earthquake control is achieved.

The present application relates to a kind of acid liquid fingering quantitative evaluation method for carbonate rock geothermal reservoir preflush acid fracturing, belong to the technical field of enhanced geothermal system reservoir stimulation.Establish three-dimensional model and multi-field coupling numerical model considering fingering effect, using numerical simulation method can obtain the three-dimensional morphological change of fracture surface, by calculating etching front fingering coefficient, the acid liquid fingering effect in the process of carbonate rock heat reservoir preflush acid fracturing is quantitatively evaluated, and the sensitivity of rock plate temperature, preflush viscosity, acid injection displacement and other parameters to fingering effect is also analyzed, which provides theoretical basis and technical support for geothermal reservoir depth acid fracturing technology.

The invention discloses an artificial heat reservoir construction device and method based on ultra-high-temperature thermal fracture dry hot rock mass, and belongs to the technical field of enhanced geothermal systems. The artificial heat storage building device comprises an inner-layer pipeline and an outer-layer annular space pipeline which are coaxially nested, and an annular oxidizing agent channel is formed in an annular space area between the outer wall of the inner-layer pipeline and the inner wall of the outer-layer annular space pipeline. A plurality of groups of inner nozzles are formed in the pipe wall of the inner-layer pipeline, a plurality of groups of outer nozzles are formed in the pipe wall of the outer-layer annular space pipeline, and the inner nozzles and the outer nozzles are in butt joint through magnetic attraction; through non-equal-length nozzle layout, magnetic attraction positioning and runner separation technologies, the risk that fuel and an oxidizing agent are mixed in advance and react in a non-designated area is avoided, efficient and controllable injection and thermal cracking regulation and control of the fuel and the oxidizing agent are achieved, and the reservoir transformation efficiency and engineering safety are remarkably improved; the method is suitable for dry hot rock reservoir artificial transformation and enhanced geothermal system development.

The invention relates to the technical field of new energy development and energy storage, and discloses a coupling system based on deep ground dry hot rock stratum hydrogen storage and geothermal energy development and a working method thereof.The coupling system comprises a ground surface subsystem, a shaft subsystem and a dry hot rock reservoir; the earth surface subsystem comprises a hydrogen production unit, a hydrogen compression and injection module, a power generation combined heat and power supply unit, a gas separation and purification module and a central control system; the gas separation and purification module is connected with a power grid; the shaft subsystem comprises underground extraction equipment, a shaft conveying system and a ground wellhead device; the shaft conveying system comprises an injection well and a production well, the hot dry rock reservoir comprises a plurality of artificial fracture networks which are communicated with one another, and monitoring modules are installed in the artificial fracture networks. Large-scale hydrogen storage and hot dry rock development are combined, hydrogen storage and efficient geothermal extraction and conversion are synchronously achieved by means of the space, the high-temperature environment and the sealing performance of a hot dry rock reservoir, and the development problem of a hydrogen storage and enhanced geothermal system is solved.

The invention relates to a method of designing an enhanced geothermal system and characterising at least one fracture in an enhanced geothermal system. The enhanced geothermal system comprises at least one well combination of at least one injector well and at least one production well. The method comprises forming at least one stage fracture from at least one well of the well combination according to a fracture treatment design and injecting at least one tracer into the at least one stage fracture. The method comprising circulating fluid from at least a first well to at least a second well of well combination via the at least one stage fracture; wherein the circulated fluid carries at least one circulation tracer and collecting samples of fluid from at least one well and analysing tracer concentrations with respect to sampling time. The method comprises calculating at least one fracture characteristic from the analysis of the tracer concentrations.

The application provides a dry hot rock enhanced geothermal system completion pipe column and method, and belongs to the technical field of dry hot rock development. The completion pipe column comprises a main wellbore pipe column, an injection branch wellbore pipe column and a production branch wellbore pipe column which are respectively connected with the main wellbore pipe column, and the production branch wellbore pipe column is located above the injection branch wellbore pipe column. The application connects a bridging sub between two packers, realizes that the annular injection water (liquid) is injected into the lower injection branch wellbore through the bridging sub, flows into the production branch wellbore through the reformed fracture, and is produced to the wellhead through the center oil pipe, which is beneficial to maintaining the maximum temperature of the produced water. The water flow enters the production branch wellbore from the injection branch wellbore, the water flow overcomes the influence of gravity, and heat exchange is more sufficient.

Methods and systems for geothermal energy production wherein multiple horizontal or vertical wells may be used to pass fluids through the Earth from an injector well to a producer well through induced cracks, splits, fractures, conduits, or channels in the rock. Such methods and systems may include controlling tensile-split conduits in a subterranean geothermal formation by providing an injection well, providing a production well, configuring the injection well for injection of a tensile-splitting fluid into a production zone, configuring the production well to produce a heated fluid from the production zone, applying pressure to the production well, creating a plurality of tensile-split conduits, raising or lowering the pressure in the production well, establishing fluid communication between the injection well and the production well, and producing the heated fluid to the surface.

The invention relates to an enhanced geothermal system U-shaped well heat exchange method based on multi-stage fracturing permeation enhancement, and relates to the technical field of geothermal development. Optimizing a heat exchange medium; and heat exchange control. An oil and gas reservoir fracturing technology is innovatively transplanted to the field of geothermal development, and the core lies in that multi-stage directional hydraulic fracturing is carried out on a horizontal heat exchange section of a U-shaped well, a high-density branch fracture network is constructed, and a capillary type heat exchange structure is formed. Compared with a traditional geothermal development technology, the heat exchange area is increased in an exponential level mode, and the effective heat exchange area is increased to be more than 10 times that of a traditional smooth well wall through a crack network; the heat extraction efficiency is improved by 40-70%, and the temperature of tail water is increased by 15-25 DEG C; the fracture network delays the thermal breakthrough phenomenon, and the economic exploitation period is prolonged; the cost advantage is that the mature fracturing process is utilized, and the cost is reduced by more than 30% compared with drilling of an ultra-long horizontal well.

Methods for forming wellbore systems include drilling a helical injection portion of the wellbore system through a formation, the helical injection portion defining a helix centerline, drilling a production portion of the wellbore system through the formation along the helix centerline, and performing a fracturing operation to form a fracture network within the formation and define a fluid connection between the injection portion and the production portion through the fracture network.

The invention discloses a distributed enhanced mining test platform and method for deep geothermal resources, and relates to the technical field of mine safety engineering and disaster prevention and control. Wherein the test platform comprises an outer shell, an inner shell, a three-way pressurizing device, a counter-force frame, a multifunctional injection well and a production well; a three-way pressurizing device is arranged between the outer shell and the inner shell, a hot rock test piece is placed in the inner shell, and a multifunctional injection well, a production well and a sensor hole are formed in a groove of the reaction frame; the test method comprises the following steps of: loading a test piece, simulating a field environment by zone heating and stress application, constructing an artificial heat reservoir by step-by-step zone fracturing, circularly collecting heat in modes of an integral area, a combined area, an independent area and the like, and changing parameters to compare and evaluate the mining efficiency. According to the method, the whole deep geothermal exploitation process can be truly reproduced, the fracturing and exploitation scheme is accurately optimized, and scientific test support is provided for safe and efficient development of an enhanced geothermal system.

Methods and systems for managing enhanced geothermal system fields are provided. The fields may be managed by monitoring the fields using both point and distributed sensors. Measurements from the sensors may be used to model the fields, and potential scenarios for the fields. The measurements may also be used to revise the models for the fields, such as corrections of incorrect assumptions regarding the fields. The models may also be used to proactively alert and / or take automated actions to address occurrence of undesired events in the fields.

The invention discloses an EGS surrounding rock thermal efficiency estimation method and system based on a dynamic strength criterion, and relates to the technical field of dry hot rock geothermal resource development, and the method comprises the steps: introducing a temperature correction term and a bedding direction coefficient based on a Nova-Zaninetti criterion, and building a dynamic strength equation; establishing a three-dimensional roadway model of the enhanced geothermal system based on excavation; constructing a heat transfer model of the enhanced geothermal system based on the unsteady heat conduction equation; based on the dynamic strength equation, a solid mechanical field model of the enhanced geothermal system is constructed; the heat transfer model and the solid mechanical field model are coupled into the three-dimensional roadway model, and a surrounding rock heat efficiency numerical model of the enhanced geothermal system is constructed; and estimating the thermal efficiency of the enhanced geothermal system based on the surrounding rock thermal efficiency numerical model. According to the invention, the technical problem of large deviation between the thermal efficiency estimation result and the actual thermal efficiency estimation result in the prior art is relieved.

The application provides a compounded scale inhibitor, a preparation method and application thereof, and relates to the fields of water treatment and energy. The compounded scale inhibitor provided by the application is obtained by compounding ester fatty alcohol polyoxyethylene ether maleic acid monoester-methyl methacrylate sulfonic acid sodium salt-maleic acid ternary polymer and sodium gluconate; wherein the mass content ratio of the added sodium gluconate and the ternary polymer in the compounding system is (0.8-1.0):1. The compounded scale inhibitor provided by the application has good Ca 2+ compatibility, can adapt to working environments with different Ca 2+ concentrations, has high scale inhibition efficiency, can well solve the CaCO3 scaling problem in the exploitation process of the enhanced geothermal system, guarantees the safe and stable operation of the system, and ensures the sustainable exploitation of heat energy.

The application relates to the technical field of enhanced geothermal system, and discloses a wellbore thermal coupling simulation method, device and equipment based on a fractional order model; the method comprises the following steps: assigning values to a geological geometry model of a thermal reservoir work area, setting initial conditions and boundary conditions of the geological geometry model, and constructing a thermal coupling model of the thermal reservoir work area; based on the thermal coupling model of the thermal reservoir work area, extracting a temperature field and a stress field around a target wellbore; setting outer boundary conditions for a geometry model of the target wellbore based on the temperature field and the stress field around the target wellbore, setting initial conditions and inner boundary conditions, and constructing a wellbore thermal coupling model; introducing a fractional order heat transfer model and a fractional order plasticity model into the wellbore thermal coupling model, performing wellbore thermal coupling simulation, and obtaining a temperature field and a stress field of the target wellbore evolving over time. The application realizes cross-scale thermal coupling analysis from a thermal reservoir well group to a single wellbore, and more accurately depicts temperature and stress responses of the wellbore under complex working conditions.

A method of designing an enhanced geothermal system and characterising at least one fracture in an enhanced geothermal system. The enhanced geothermal system comprises at least one well combination of

The application discloses a kind of based on enhanced geothermal system heat fluidization multi-field coupling modeling method, belong to oil and gas field exploitation technical field, including generating two groups of random numbers as fracture center position, and according to fracture center position, trace length and direction determine random fracture endpoint coordinate, according to the random fracture endpoint coordinate determined, form initial smooth fracture grid;According to the initial smooth fracture grid, the roughness persistence of each fracture path is controlled by Hurst index, to generate random fracture path containing roughness;According to the random fracture path containing roughness generated, establish dry hot rock one injection two mining random fracture model;According to well logging data, set the material parameters of random fracture model, add stress field, seepage field, temperature field, chemical field to random fracture model;The initial conditions and boundary conditions of stress field, seepage field, temperature field and chemical field of random fracture model are set respectively, and multi-physical field coupling is set.

The present disclosure relates generally to systems and processes for enhancing connectivity and / or permeability between injector and producer wells in enhanced geothermal systems using sequenced stimulation. The system comprises an injector well (cemented or uncemented) extending from a surface to a subterranean geologic formation and configured to be perforated; a pump configured to produce a thermal lattice in the subterranean geologic formation; and a measurement sub-system configured to measure enhanced connectivity and / or permeability of the subterranean geologic formation after creation of the thermal lattice.

Systems and techniques may be used to operate an enhanced geothermal system (EGS). An example technique may include applying a stimulation treatment including a proppant to generate a distributed network of fractures along wellbores between a horizontal geothermal injection well and a horizontal geothermal production well. The horizontal geothermal injection well and the horizontal geothermal production well may be positioned within a mixed metasedimentary and igneous formation.

The application discloses a device and method for constructing an artificial thermal reservoir based on super-high-temperature thermal cracking of hot dry rock, and belongs to the technical field of enhanced geothermal systems. The device for constructing an artificial thermal reservoir comprises coaxially nested inner-layer pipelines and outer-layer annular gap pipelines. An annular space between the outer wall of the inner-layer pipelines and the inner wall of the outer-layer annular gap pipelines forms an annular oxidant channel. A plurality of inner nozzles are arranged on the wall of the inner-layer pipelines, and a plurality of outer nozzles are arranged on the wall of the outer-layer annular gap pipelines. The inner and outer nozzles are connected through magnetic attraction. The device avoids the risk of the fuel and the oxidant reacting in a non-designated area due to early mixing through non-equal-length nozzle arrangement, magnetic attraction positioning and flow channel separation technology, realizes efficient and controllable injection of the fuel and the oxidant and thermal cracking regulation, and significantly improves the reservoir reconstruction efficiency and engineering safety. The device is suitable for artificial reconstruction of hot dry rock reservoirs and development of enhanced geothermal systems.

The invention discloses a dry hot rock reservoir transformation method for controlling induced earthquakes, and relates to the field of enhanced geothermal system development, and the method comprises the following steps: S1, setting a regional induced earthquake threshold value through local induced earthquake environment bearing capacity evaluation or local management department requirements; s2, determining a known fault and fracture instability disturbance pressure by using the three-dimensional stress field, determining a fault of an upper limit magnitude of an induced area according to a fitting relationship between the magnitude and the fault length, determining an upper limit value of wellhead injection pressure, and adjusting the wellhead pressure in real time according to a relationship between the maximum injection magnitude and the injection pressure; s3, the maximum injection volume limit value is calculated, and the maximum injection volume limit value is adjusted in real time; s4, carrying out real-time comprehensive monitoring and analysis on the induced earthquake, the injection pressure and the injection volume, feeding back the relationship between the wellhead pressure and the maximum magnitude to S2, and feeding back the ratio of the earthquake b value, the accumulated earthquake moment and the injection volume to S3; and S5, controlling the wellhead pressure and the injection volume within the limit values calculated in real time in the S2 and S3 through measures of reducing the displacement, stopping the pump and reversely discharging.

The invention may provide a method and system of characterising at least one fracture in an enhanced geothermal system. The method comprises arranging two or more tracer sources with distinct tracer materials in known levels of a production well of the enhanced geothermal system. The method comprises injecting at least one tracer into the at least one fracture in the injection well, producing fluid in the production well, collecting samples of produced fluid and analysing the samples for the presence and / or concentration of tracers. Based on the presence and / or concentration of tracers in the samples estimating at least one characteristic of the at least one fracture.

The invention discloses an enhanced geothermal system heat flow coupling effect simulation device and an optimization design method, and relates to the technical field of geothermal energy, the enhanced geothermal system heat flow coupling effect simulation device comprises a supporting frame, a sliding rail is arranged on one side of the supporting frame, a sliding supporting arm is slidably mounted at the top end of the sliding rail, and a winding motor is mounted at the top end of the sliding supporting arm; a rolling motor is arranged on the outer side of the sliding rod, a rolling disc is connected to the transmission end of the rolling motor, a rolling steel cable is rolled on the outer side of the rolling disc, a fixing plate is connected to one end of the rolling steel cable, and a mounting ring plate is welded to the bottom end of the fixing plate. When the two rocks accurately move to a position where a test needs to be carried out, an operator can stop moving the sliding block, and at the moment, the driving screw rod can play a limiting role to fix the two rocks, so that the accuracy of experimental data is ensured.

Disclosed are various approaches for using controlled fractures in geothermal systems. In some examples, a method includes drilling at least one injection well bore. The method can also include cutting at least a first slot at an angle to the injection well bore, where the first slot has a first end connected to the injection well bore and a distal end. The method can include cutting at least a second slot at an angle to the injection well bore, where the second slot has a first end connected to the distal end of the first slot and a distal end. The method can also include drilling at least one production well bore, where the production well bore is connected to the distal end of the second slot.

An enhanced geothermal system includes a first well and a second well drilled through a subterranean formation. The first well includes a lateral section extending through a heat zone in the subterranean formation. The second well is a U-shaped well having a first lateral section extending through the heat zone on a first side of the lateral section of the first well, and a second lateral section extending through the heat zone on a second side of the lateral section of the first well.

This invention discloses a method for constructing an enhanced geothermal system for abandoned oil and gas wells, characterized by the following steps: logging and testing the target abandoned oil and gas well to assess wellbore integrity, reservoir parameters, and the type, content, and spatial distribution of residual alkyl compounds; injecting an igniter and oxygen-containing gas into the reservoir, followed by the injection of high-pressure nitrogen for ignition, thereby igniting the residual alkyl compounds to establish an initial combustion zone; injecting an oxidizer into the combustible gas enrichment zone, mixing it with the combustible gas therein to form an explosive mixture and detonating it; periodically or continuously injecting an oxidizer and water vapor alternately into the reservoir through the fracture network, continuously heating the reservoir through combustion and gasification reactions; stopping the injection of oxidizer, injecting a low-temperature working fluid into the artificial geothermal reservoir space through injection wells, and subsequently extracting it from production wells for thermal energy utilization; thus, this invention achieves in-situ energy upgrading and enrichment of abandoned resources.

The invention relates to the technical field of enhanced geothermal systems, and discloses a shaft thermal-mechanical coupling simulation method, device and equipment based on a fractional order model. Comprising the following steps: assigning a value to a geological geometric model of the heat storage work area, and setting initial conditions and boundary conditions of the geological geometric model to construct a thermal-mechanical coupling model of the heat storage work area; based on the thermal-mechanical coupling model of the thermal storage work area, extracting a temperature field and a stress field around the target shaft; setting an outer boundary condition for the geometric model of the target shaft based on a temperature field and a stress field around the target shaft, setting an initial condition and an inner boundary condition, and constructing a shaft thermal coupling model; and a fractional order heat transfer model and a fractional order plastic model are introduced into the wellbore thermal coupling model, wellbore thermal coupling simulation is conducted, and a temperature field and a stress field, evolving along with time, of the target wellbore are obtained. According to the method, cross-scale thermal coupling analysis from a thermal storage well group to a single shaft is realized, and the temperature and stress response of the shaft under complex working conditions is described more accurately.

Methods and systems for managing enhanced geothermal system fields are provided. The fields may be managed by monitoring the fields using both point and distributed sensors. Measurements from the sensors may be used to model the fields, and potential scenarios for the fields. The measurements may also be used to revise the models for the fields, such as corrections of incorrect assumptions regarding the fields. The models may also be used to proactively alert and / or take automated actions to address occurrence of undesired events in the fields.