45 results about "Enhanced geothermal system" patented technology

The invention relates to a hydraulic fracturing simulation experimental device and method of a hot dry rock enhanced type geothermal system. A hot dry rock high-pressure and high-temperature generating environment is simulated, precise stress is applied to a rock core by designing a multistage piston, the permeability of hot dry rock fluid is maintained by adopting a pressureproof and temperature-resistant perforated plate, the hot dry rock fluid is externally connected to a fluid collection chamber through a flow guiding groove, and meanwhile an adjustable sound emission probe is embedded into a true-triaxial high-pressure axe to monitor a sound emission event happening when a fracture expands in the hydraulic fracturing process, integrated collection of information of rock hydraulic fracturing, sound emission, heat energy recovery efficiency and the like under the triaxial confining pressure condition can be achieved by utilizing the device, and therefore the fracture initiation andexpanding situations of the hot dry rock hydraulic fracture can be studied. The hydraulic fracturing simulation experimental device and method have the beneficial effects that warming and heat preservation effects are good, a sealed part is simple to replace and convenient to maintain, a sound emission embedded part can be adjusted according to the requirements for the probe sizes, in addition, the whole device further has the characteristics that operation is convenient, and the protection and maintenance period is short, and the device is an important technological innovation at the aspect of dry hot rock enhanced type geothermal system hydraulic fracturing testing device detection.

The invention discloses a simulation experiment device used for an enhanced geothermal system and a method for evaluating porous sandstone geothermal reconstruction by means of the simulation experiment device. The simulation experiment device comprises a heat exchanger chamber, a prefabricated rock, an electric heating panel, a constant-temperature liquid supply groove, two liquid colleting grooves and horizontal geostress simulation units, wherein an inlet and two outlets corresponding to the inlet are formed in the heat exchange chamber, and the inlet and the outlets all communicate with a cavity; and the prefabricated rock is arranged in the cavity, a first injection shaft, a first production shaft and a second production shaft are further arranged in the prefabricated rock, the injection shaft is located between the first production shaft and the second production shaft, the injection shaft communicates with the inlet, the first production shaft and the second production shaft communicate with the two outlets correspondingly, and preset seams, micro pressure sensors and micro temperature sensors are arranged in the prefabricated rock.

The invention relates to a method and system for extracting heat energy of hot dry rocks. The method includes that an injection well system, a horizontal well system and an output well system are arranged in a heat reservoir stratum of the dry hot rocks, a circulation channel is formed by connecting the injection well system, the horizontal well system and the output well system in sequence, heat-carrying agent fluid is adjusted to reach appropriate flow through an adjustment valve of the injection well system, the heat-carrying agent fluid is injected into different injection well pipes, the fluid flows through the injection well system, the horizontal well system and the output well system in sequence, and the heat of the hot dry rocks is absorbed, high-efficiency extracting of the heat energy of the hot dry rocks is achieved, and meanwhile the purposes of keeping relative purity of an heat-carrying agent, not running the heat-carrying agent off and not polluting the heat reservoir stratum of the dry hot rocks are achieved. The system for extracting the heat energy of the hot dry rocks comprises the injection well system, the horizontal well system and the output well system. By means of the method and system for extracting the heat energy of the hot dry rocks, self-sustaining cycle of the heat-carrying agent fluid can be achieved without consuming pump power, and pressure loss of the heat-carrying agent fluid in an energy conversion system and in a flow channel can be provided on the ground. The method and system for extracting the heat energy of the hot dry rocks are widely applied to an enhancement type geothermal system of geothermal exploitation of the hot dry rocks.

The invention relates to a completion method of an enhanced geothermal system through communication and circulation of two wells. The completion method is characterized in that when being injected into a water injection well, water is subjected to low-efficiency heat exchange in a straight well section of the water injection and then enters a geothermal reservoir along a horizontal heat collection well, and the water is subjected to sufficient and high-efficiency heat exchange with the geothermal reservoir through a high-temperature-resistant casing pipe and then enters a heat extracting well; high-temperature hot water passes through a heat-insulating protective layer formed by an intermediate casing with the interior and exterior coated with a thermal insulation material in the heat extracting well and then extracted out of the ground, and the extracted hot water is used for generating electricity.

The invention discloses an enhanced geothermal system development test device. The enhanced geothermal system development test device comprises a carbon dioxide steel cylinder, a carbon dioxide supercritical transportation device, a simulation hot dry rock reactor, a carbon dioxide turbine, a high-pressure frequency conversion type plunger pump, and a PLC data acquisition system. Carbon dioxide in the carbon dioxide steel cylinder passes through a carbon dioxide flow regulating valve and a pressure regulating valve, enters the carbon dioxide supercritical transportation device for being pressurized to a high pressure, and then enters the simulation hot dry rock reactor for temperature rise. The high-temperature high-pressure carbon dioxide CO2 after temperature rise enters the carbon dioxide turbine. The carbon dioxide turbine is used to drive a generator or a power machine for energy conversion. The low-grade carbon dioxide coming out from the carbon dioxide turbine enters the heat exchanger. The carbon dioxide after heat exchange is sent back to the simulation hot dry rock reactor through the high-pressure frequency conversion type plunger pump for cyclic utilization.

The invention relates to the field of geothermal development, and provides a pressure crack network design and completion method for an enhanced geothermal system. The method comprises the steps thatthe upper portion of an igneous rock type hot dry rock is reached through drilling, a horizontal well section is drilled by using a guiding well drilling technology, multi-stage segmented hydraulic fracturing is utilized, a horizontal crack network is produced by utilizing layer-shaped brittle components in an igneous rock body, two horizontal branch wells located on the same horizontal plane witha water injecting well section are drilled at the end of the horizontal well section of a water injection well, the rear end of a crack of the horizontal well section of the water injection well after fracturing is conducted is penetrated to complete docking, a horizontal crack network passage with high seepage is constructed, fluid can enter in a well tube along the crack on which fracturing isconducted, and energy utilization can be conducted after the fluid is exploited to the ground surface. By adopting a branch well, a micro vibration detection and processing system and a hydraulic fracturing technology, a hot dry rock storage layer is effectively recognized, the storage layer is opened to the maximum extent, geothermal energy of the hot dry rock storage layer is fully utilized, andthe exploiting efficiency of the geothermal energy is significantly improved.

The invention discloses a method for constructing a hot dry rock artificial geothermal reservoir through cooperation of hydraulic fracturing and millisecond millisecond blasting and belongs to the field of construction of a hot dry rock artificial geothermal reservoir of EGS (enhanced geothermal systems). The method comprises steps as follows: firstly, determining the depth and range of a target layer of hot dry rock; constructing a water injection well and a production well to the target layer of hot dry rock; constructing multiple parallel horizontal drilling holes in the target layer to communicate the water injection well and the production well; producing cracks to a certain degree on the periphery of hole walls in group holes with a sectional hydraulic fracturing technology; later, mounting cartridges in the group holes, and the drilling holes are blasted with a millisecond millisecond blasting technology; and finally, injecting a large amount of normal-temperature water into thetarget layer from the water injection well, performing heat exchange sufficiently through the artificial geothermal reservoir, converting solid heat into liquid heat, and exploiting high-temperaturewater and overheating steam from the production well. The hydraulic fracturing and millisecond millisecond blasting technologies are organically combined, the hot dry rock artificial geothermal reservoir can be constructed to the utmost extent, and the application prospects are broad.

An apparatus 300 for simulating a pulsed pressure induced cavitation technique (PPCT) from a pressurized working fluid (F) provides laboratory research and development for enhanced geothermal systems (EGS), oil, and gas wells. A pump 304 is configured to deliver a pressurized working fluid (F) to a control valve 306, which produces a pulsed pressure wave in a test chamber 308. The pulsed pressure wave parameters are defined by the pump 304 pressure and control valve 306 cycle rate. When a working fluid (F) and a rock specimen 312 are included in the apparatus, the pulsed pressure wave causes cavitation to occur at the surface of the specimen 312, thus initiating an extensive network of fracturing surfaces and micro fissures, which are examined by researchers.

An apparatus 300 for simulating a pulsed pressure induced cavitation technique (PPCT) from a pressurized working fluid (F) provides laboratory research and development for enhanced geothermal systems (EGS), oil, and gas wells. A pump 304 is configured to deliver a pressurized working fluid (F) to a control valve 306, which produces a pulsed pressure wave in a test chamber 308. The pulsed pressure wave parameters are defined by the pump 304 pressure and control valve 306 cycle rate. When a working fluid (F) and a rock specimen 312 are included in the apparatus, the pulsed pressure wave causes cavitation to occur at the surface of the specimen 312, thus initiating an extensive network of fracturing surfaces and micro fissures, which are examined by researchers.

The invention discloses a simulation experiment device for an enhanced geothermal system and a method for testing a reservoir stratum heat energy extracting rate of the enhanced geothermal system by utilizing the simulation experiment device. The simulation experiment device comprises a heat exchange chamber, a rock sample group, a propping agent, a waterproof sealing plug, an electric heating plate and a liquid collection groove, wherein the heat exchange chamber forms a sealed chamber; an inlet communicated with the chamber is formed in one side of the heat exchange chamber and an outlet, which is communicated with the chamber, is formed in the other side of the heat exchange chamber; the rock sample group is composed of n*n*2 rock blocks and the n*n*2 rock blocks are arrayed and arranged in the chamber according to an n*n*2 arrangement manner; each rock block is of a cubic structure with the edge length of 295nm to 300nm. By adopting the simulation experiment device for the enhanced geothermal system and the method for testing the reservoir stratum heat energy extracting rate of the enhanced geothermal system by utilizing the simulation experiment device, the technical problem of how to test the heat extracting rate and stable production time of the enhanced geothermal system under different reservoir stratum reconstruction manners is solved.

The invention relates to a well completion method for a standing column well enhanced geothermal system. The method is characterized in that a surface casing, an ordinary technical casing, a high temperature resistant technical casing, an oil tube, perforated holes and a high temperature resistant centralizer are included. By adoption of the well completion method for the standing column well enhanced geothermal system, deep-stratum geothermal energy can be effectively transmitted to the ground, and the specific achieving process is as follows: water is injected into an annulus space formed by the ordinary technical casing and the oil tube from the ground, the water in the annulus space flows from the upper portion to the lower portion, when flowing into the bottom of the annulus space, water flows from the perforated holes into the oil tube, and then the water in the oil tube flows from the lower portion to the upper portion and finally flows into a ground receiving device. The temperature of a geothermal reservoir is 200 DEG C or above, reservoir heat is transmitted to the annulus space formed by the high temperature resistant casing and the oil tube through the high temperature resistant technical casing, water flowing through the annulus space absorbs heat in the annulus space formed by the high temperature resistant technical casing and the oil tube, the temperature of the water is increased after the water absorbs the heat, and then high-temperature water flows through the oil tube to the ground receiving device for electric generation.

The invention discloses an enhanced geothermal system designing method capable of preventing an earthquake from being induced, and a using method of an enhanced geothermal system. Through the enhancedgeothermal system designing method capable of preventing the earthquake from being induced, and the using method of the enhanced geothermal system, the technical problem that in the prior art, suddenshearing slip of initial fissures is caused by injection of high-pressure water, and consequently, the earthquake is induced is solved. The enhanced geothermal system designing method comprises the steps that a single large-hole-diameter production well is drilled in the center of a hot dry rock target area through a medium-radius well drilling technology, and a plurality of equidistant small-hole-diameter water injection wells are arranged around the production well; inside a hot dry rock reservoir, all the water injection wells horizontally extend to the production well and pass through theproduction well through a horizontal direction drilling technology, and thus an artificial heat exchange space is formed; and the production well is reinforced through rigid segmented sleeves, and the junctions of the water injection wells and the production well are reinforced through concrete slurry. According to the enhanced geothermal system designing method, earthquake activities can be effectively prevented, the leakage problem of injected water can be solved, and possibility is provided for operation of scale and commercial hot dry rock development.

A system and method for determining the most favorable locations for enhanced geothermal system applications are disclosed. According to one embodiment, a computer implemented method comprises receiving input data comprising characteristics of a subsurface geothermal resource and spatial parameters associated with extracting the subsurface geothermal resource, generating formulas and look-up tables based upon the input data, wherein the formulas and look-up tables relate a cost per rate to spatial attributes associated with the subsurface geothermal resource. Geographic information is combined with the formulas and look-up tables to create a map of the cost of each component of a plurality of components. A map is output of a total cost of electricity generation capability associated with the subsurface geothermal resource, wherein the total cost is calculated by summing the cost of each component of the plurality of components.

The invention discloses a water injection fracturing shear test system and method for simulating hot dry rock of a geothermal system, and belongs to the technical field of water injection fracturing shear tests of the dry hot rock of an enhanced geothermal system (EGS). The water injection fracturing shear test method comprises the steps that firstly, a double-opening stainless steel mold is utilized to manufacture a paraffin reverse mold containing water injection drilling holes and cracking cracks; secondly, gypsum, water and a standard mold are utilized to manufacture large-sized rock-like test pieces containing the paraffin reverse mold and different forms of primary cracks; then, the test pieces are placed in an upper heating sleeve and a lower heating sleeve and placed in a direct shear test machine, and paraffin liquid is poured out after the power is turned on and heating is performed; and finally, an acoustic emission sensor, a water injection pipe and a sliding clamp are installed, the test machine is operated to apply axial stress and shear stress, and appropriate water injection parameters, temperature parameters and loading prestress parameters are selected for testing. The water injection fracturing shear test system and method truly reflect the excitation process of a hot dry rock reservoir, and provide an effective indoor test means for studying the propagation mechanism of water injection fracturing shear cracks of the hot dry rock.

The invention relates to the technical field of hot dry rock thermal energy development, in particular to a system for collecting thermal energy of hot dry rock with a U-shaped well. The overall system for collecting the thermal energy of the hot dry rock with the U-shaped well is in a U-shaped channel and comprises an injection sleeve and heat preservation system of the injection sleeve, a rock heat utilization cascade heating system, a long-lead cyclone type self-flushing underground heat exchange system and a collecting well sleeve and heat preservation system of the collecting well sleeve.The rock heat utilization cascade heating system and the long-lead cyclone type self-flushing underground heat exchange system are each formed in the manner that a plurality of groups of cyclone typeself-flushing underground heat exchangers are connected. Each cyclone self-flushing underground heat exchanger is a spiral grooved tube. The system for collecting the thermal energy of the hot dry rock with the U-shaped well can be widely applied to enhancement type geothermal systems for hot dry rock thermal energy development and is low in cost, high in heat exchange efficiency and simple in system heat exchange cycle channel.

The invention discloses a test method for crack communication evaluation and heat extraction test of an enhanced geothermal system. According to the method, a rock sample to be tested is placed into aclosed cavity with a fracturing fluid inlet, a triaxial fracturing test is carried out on a rock sample by adopting different fracturing modes, and fracturing transformation is carried out on the rock sample. The test method can be used to analyze communication conditions of cracks or crack networks formed under different fracturing modes to the injection well and the production well, and carry out thermal extraction test experiments, including the liquid production rate, the liquid production temperature and the heat collection rate of the enhanced geothermal system, on the fractured rock sample after fracturing transformation. In addition, influence of different crustal stress conditions, rock temperature, fracturing fluid, fracturing displacement, rock sample lithology and the like onfracturing transformation effect and influence of communication and heat extraction performance of cracks on an injection-production system can be discussed.

The invention relates to the technical field of geothermal systems, in particular to a gradient utilization enhanced geothermal system which can conduct gradient comprehensive utilization on geothermal energy, improves the geothermal utilization rate and saves energy. The gradient utilization enhanced geothermal system comprises a geothermal collecting device, a first-grade heat exchange device, afirst-grade utilization device, a second-grade heat exchange device, a second-grade utilization device, a third-grade heat exchange device, a third-grade utilization device, a capillary network system, a temperature control device, a water collecting tank and a geothermal recharging device. The gradient utilization enhanced geothermal system utilizes the geothermal energy as the heat source, andthe geothermal energy is clean and reproducible; gradient comprehensive utilization of the geothermal energy can be achieved, the geothermal utilization rate is improved, and energy is saved; screw pumps are arranged in the heat exchange devices, so that the heat exchange efficiency is improved; fixed trays and movable trays in bins can fix vegetables and fruits, under the driven of rotating rods,the drying process is accelerated; and the layered capillary network system is arranged in the bins, and uniform heating and drying of crops are facilitated.

This invention provides a novel system and method for Electrical Reservoir Stimulation (ERS) that increases reservoir permeability for petroleum and geothermal applications without requiring pumping of material into the subsurface. This system and method can provide an inexpensive, reliable and more-environmentally friendly increase in reservoir productivity by releasing hydrocarbons from traps and captives, increasing fluid mobility due to viscosity reduction from electrical heating of the reservoir (extremely important for the extraction of highly viscous hydrocarbons), and providing increased reservoir permeability in the direction of interest from the vibrational removal of particles within sediment pores and initiating micro-fractures. The ERS system and method can also be applied in non-petroleum producing applications, such as for use in Enhanced Geothermal Systems (EGS), and generally avoids pumping high-pH chemicals and proppant material into the subsurface, a problem that has generally challenged operators in the geothermal and petroleum industries.

The invention provides a method for determining a heat removal working medium of an enhanced geothermal system, which comprises the following steps of: establishing a hot dry rock thermal-hydraulic coupling model on the basis of physical property parameters of deep hot dry rock thermal storage obtained by a rock physical experiment; constructing a cubic domain of a rock matrix, constructing a fracture channel with sinusoidal fluctuation morphology in the middle of the rock matrix by adopting a parameterized surface method, determining the height of the fracture channel, and enabling fluid to flow into the fracture channel along the horizontal direction for heat exchange; and carrying out analogue simulation by utilizing Comsol Multiphysics to obtain different production temperatures of different working media under the same recharge flow and temperature. According to the method, it is determined that the heat removal working medium capable of obtaining the high production temperature is the mixed working medium obtained by mixing supercritical carbon dioxide and helium according to the mass fraction of 9: 1.

The invention relate to a deep well system used for an enhanced geothermal system (EGS). The system comprises a first deep well which is formed with a first bottom hole, a second deep well which drills at a distance from the first deep well and is provided with a second bottom hole and a third bottom hole, a first artificial retention layer, a second artificial retention layer, and a third artificial retention layer. The first bottom hole is disposed between the second bottom hole and the third bottom hole. The first artificial retention layer is formed on the first bottom hole through hydraulic stimulation. The second artificial retention layer is formed on the second bottom hole through hydraulic stimulation. The third artificial retention layer is formed on the third bottom hole through hydraulic stimulation, and the third artificial retention layer is connected with the first artificial retention layer and the second artificial retention layer.

The invention discloses a solar-energy-combined dual-well closed enhanced type geothermal heating system. The system comprises a first heat supply system, a second heat supply system and a heat storage system. The first heat supply system comprises a circulating pump, a heat pump and a dual-well closed enhanced type geothermal system body. The dual-well closed enhanced type geothermal system bodycomprises an injection well and a production well. The injection well is connected with the circulating pump and a first inlet of the heat pump in sequence. The production well is connected with a first outlet of the heat pump. Both a second inlet and a second outlet of the heat pump are connected with a target building. The second heat supply system comprises a solar thermal collector, a heat storage water tank and a hot water pump. An outlet of the solar thermal collector is connected with the heat storage water tank, the hot water pump and the target building in sequence. An inlet of the solar thermal collector is connected with the target building. According to the solar-energy-combined dual-well closed enhanced type geothermal heating system, solar energy and the dual-well closed enhanced type geothermal system body are combined to carry out heating during heating seasons, and the problem that solar energy is unstable is solved by utilizing the adjustment capacity of the geothermal system body; and heat of solar energy is stored into the geothermal system body during non-heating seasons.

The invention discloses a numerical simulation method and application of an enhanced geothermal system considering a working medium storage process, and the method comprises the following solving steps at any moment: solving a continuity equation and a momentum equation by taking an unsteady-state item in the continuity equation as a known value, and calculating a speed field and a pressure fieldof a working medium in a thermal reservoir at the moment; calculating a speed field, a pressure field and a temperature field of the working medium in the injection well shaft at the moment; calculating the temperature field of the thermal reservoir at the moment, and estimating the temperature field of the thermal reservoir at the next moment; calculating a speed field, a pressure field and a temperature field of the working medium in the production well shaft at the moment; calculating the average total stress field of the thermal reservoir at the moment, and estimating the average total stress field at the next moment; calculating the porosity and permeability distribution of the thermal reservoir at the moment, and estimating the porosity distribution at the next moment; and judging whether each physical field is converged or not, if not, repeating the steps, and if so, stopping. According to the invention, the thermal recovery performance and the working medium storage capacity inthe thermal reservoir can be simulated at the same time.

The invention discloses a hot dry rock heat production prediction method based on heat-fluid-solid-damage coupling, and the method comprises the steps: building a hot dry rock enhanced geothermal system heat-fluid-solid coupling model, carrying out the grid adaptive division of the hot dry rock enhanced geothermal system model, carrying out the heat-fluid-solid multi-physics field coupling calculation, and carrying out the heat-fluid-solid multi-physics field coupling calculation. Obtaining heat, flow and solid physical field solutions; performing damage analysis on the hot dry rock reservoir area according to the stress solution to obtain a local damage area of the hot dry rock reservoir; and obtaining the heat energy of the hot dry rock based on the heat-fluid-solid coupling solution. According to the method, the engineering scale hot dry rock reservoir model considering heat-fluid-solid multi-physics field coupling is established, the hot dry rock exploitation heat diffusion process is simulated, reservoir damage analysis and model grid optimization are achieved, and therefore the heat energy exploited by the hot dry rock can be reliably evaluated.

The invention provides an enhanced geothermal system construction method and device based on magnetic guidance. The enhanced geothermal system construction method comprises the steps that after an injection well is drilled and an artificial thermal storage crack is formed, a magnetic proppant is controlled to be injected into the artificial thermal storage crack; a geomagnetic field signal affected by the magnetic proppant is obtained; the well drilling trajectory of a production well is determined according to the geomagnetic field signal; and well drilling operation of the production well iscontrolled to be completed according to the well drilling trajectory of the production well. According to the enhanced geothermal system construction method and device based on magnetic guidance, thethermal storage crack position of hot dry rock is positioned through magnetic guidance, thus the problem that a crack and a production well cannot communicate accurately in the construction process of an enhanced geothermal system can be effectively solved, and the off-target risk and cost of the production well are reduced to a great extent.