66 results about "Geothermal fluid" patented technology

The invention discloses a cationic polymer scale inhibitor as well as a preparation method and application thereof, and relates to the field of scale inhibitors in geothermal pipelines, the scale inhibitor limits easy-to-scale metal from adhering and scaling on a coating through cationic groups on polymer molecule side chains, meanwhile, the surface contact angle of the coating is increased through functional components with low surface energy, and the scale inhibitor can be used for inhibiting scale formation of the coating. The cationic polymer-based scale inhibitor has the advantages that the cationic polymer-based scale inhibitor is added into the geothermal fluid, so that some granular solid components of the geothermal fluid are difficult to accumulate on the coating to form a crystallized nucleation center, the problems of scaling and accumulation are fundamentally solved, in addition, the cationic polymer-based scale inhibitor has excellent adhesive force with the geothermal pipeline, and guarantee is provided for the corrosion resistance and the long-term effect of the coating.

Various examples are provided related to airlift pumping of downhole geothermal fluids. In one example, an airlift system includes a compressor; a gas sparger head in a wellbore of a geothermal well, and a pressure head recycle assembly. The sparger head produces artificial lift of the geothermal fluids by injecting a gas resulting in a difference in density downhole. The entrained gas can be extracted by the pressure head recycle assembly, compressed, and reinjected downhole. The geothermal fluid at the well head can be used in direct use applications or in a thermodynamic cycle to make shaft power. The gas sparger head can include a venturi shaped passage extending through the gas sparger head and a bubble orifice including gas orifices radially spaced about a narrow portion of the venturi shaped passage. The gas orifices can have a corresponding resonant chamber through which the gas (e.g., air) is provided.

The invention discloses a geothermal fluid source discrimination method based on geochemical index and machine learning fusion, and relates to the technical field of geothermal resource intelligent exploration, and the method comprises the steps: firstly collecting and calculating multi-dimensional geochemical indexes, and constructing a standardized feature sequence; establishing an end member feature library by using unsupervised clustering; identifying the source type of the fluid through a discrimination model fused with an attention mechanism; aiming at the mixed source fluid, constructing an optimization model embedded with physical and chemical constraints, and quantitatively inverting the contribution proportion of each end member; and finally, on the basis of the time sequence proportion data obtained by inversion, predicting a future evolution trend by adopting a time convolutional network-long and short-term memory network model fused with an attention mechanism. According to the geothermal fluid source discrimination method based on geochemical index and machine learning fusion provided by the invention, the whole-process intelligent analysis of the geothermal fluid source from qualitative identification to quantitative prediction is realized.

The application discloses a hydrogen production system of geothermal water source and belongs to the technical field of hydrogen production. The system comprises a geothermal fluid circulation unit, an electrolyte preheating unit and an electrolytic hydrogen production unit. The geothermal fluid circulation unit realizes the recycling of geothermal water through a geothermal well, a recharge well and a geothermal heat exchanger; the electrolyte preheating unit connects an electrolyte storage tank and the second side of the geothermal heat exchanger through a second circulation pipeline to form a preheating circulation; the electrolytic hydrogen production unit comprises an electrolytic tank and a hydrogen purification device and receives the preheated electrolyte to produce hydrogen by electrolysis. In the preferred scheme, a flash evaporation pressurization and heat supplement unit is further included, the geothermal tail water is subjected to waste heat recovery through a flash tank and a steam compressor to generate high-temperature steam for auxiliary heating of the electrolytic tank. The application uses geothermal energy to replace electric heating to preheat electrolyte, significantly reduces the energy consumption of hydrogen production, has the advantages of reasonable structure, high automation degree, environmental protection and water saving and is suitable for hydrogen production application in areas rich in geothermal resources.

System, method, and apparatus for harnessing geothermal power from superhot geothermal fluid (SHGF) and magma reservoirs. An exemplary apparatus can include a well screen coupled to an end of a casing string. The well screen, which is at least partially submerged within an underground reservoir, defines a volume in the underground reservoir that can be filled with superhot geothermal fluid. A slidable casing is aligned coaxially with the well screen and configured to be repositioned relative to the well screen. A draw pipe extending through the slidable casing is configured to convey SHGF from the underground reservoir towards the surface in response to the slidable casing being repositioned to obstruct more of a set of apertures in the well screen and an increase in pressure within a cavity of the slidable casing.

The invention relates to the field of heat supply control, in particular to a terrestrial heat and solar energy coupling heat supply control method and system. The method comprises the following steps: acquiring heat supply load prediction data and solar radiation prediction data of a target area, dynamically formulating and executing pre-preparation operation of a cascade flash evaporation reactor based on the data, and generating a reactor dynamic preheating scheme set; on this basis, geothermal fluid is introduced into a fluid self-flashing chamber, geothermal fluid self-flashing triggered based on pressure drop is executed, and a primary basic flashing information set is generated; on this basis, the remaining liquid fluid is guided to an enhanced boiling flash chamber, contact type enhanced boiling flash operation triggered based on the significant temperature difference is executed, and a secondary enhanced flash information set is generated; on the basis, multi-parameter dynamic feedback of geothermal fluid flow, chamber pressure and heat storage release rate is collected, and a collaborative optimization heat supply control set is generated. In the multi-energy coupling heat supply process, the heat supply quality can be guaranteed.

The invention provides a method for determining in-situ composition of geothermal water, and belongs to the technical field of geothermal energy development. Geothermal water, geothermal gas and spring bloom or scale samples are collected, chemical composition analysis of the geothermal water, component analysis of the geothermal gas (including absolute content of CO2 and H2S) and mineral composition analysis of the spring bloom or scale are carried out, and then according to the geochemical process of mother geothermal fluid rising from a deep reservoir to the earth surface, the geothermal gas is analyzed. And determining whether cold water mixing, gas escape and mineral precipitation occur in the geothermal water, finally correcting the influence of the generated geochemical action on the chemical components of the geothermal water, and calculating the chemical components of the in-situ geothermal fluid. According to the invention, the problem that the scaling property, corrosivity and thermal storage temperature evaluation of the thermal storage fluid are inaccurate due to the fact that the chemical composition of the mother geothermal fluid cannot be represented due to the geochemical effect of changing the composition of the existing surface thermal spring water or borehole geothermal well water in the upflow process can be solved.

A geothermal power system generates electricity using a geothermal fluid. The geothermal fluid is produced from, and then injected into, fractures in a subterranean formation such that pressures inside the fractures are maintained between the corresponding closure pressures propagation pressures of the fractures. In some aspects, the fractures are devoid of proppant, and are maintained open by the pressure of the fluid within the fractures.

The invention discloses a multi-energy co-production system based on geothermal energy and LNG cold energy. The multi-energy co-production system comprises a geothermal dual-ORC power generation module and an LNG cold energy comprehensive utilization module. The geothermal dual-ORC power generation module comprises a first power generation cycle and a second power generation cycle, working medium fluid of the first power generation cycle absorbs heat of geothermal fluid for power generation, and working medium fluid of the second power generation cycle absorbs heat of the working medium fluid of the first power generation cycle for power generation. And the LNG cold energy comprehensive utilization module is used for generating power by using heat energy of the working medium fluid of the second power generation cycle, and is used for re-heating natural gas by using heat of the geothermal fluid used by the first power generation cycle for subsequent use. The method has the advantage of improving the energy utilization rate.

The invention relates to the technical field of hydrogen production, in particular to a waste organic matter hydrogen development system under deep high-temperature geothermal energy, which comprises a deep stratum heat storage and temperature control unit, the deep stratum heat storage and temperature control unit comprises a heat storage shell, a geothermal fluid circulation pipeline and an electric auxiliary heating module, and the heat storage shell is made of a high-temperature-resistant composite geological material; collected geothermal fluid is conveyed through a geothermal fluid circulation pipeline in the deep stratum heat storage and temperature control unit, and a stable high-temperature field at the temperature of 400-600 DEG C is maintained in cooperation with an electric auxiliary heating module. According to the development system and method, the stable high-temperature field at the temperature of 400-600 DEG C is maintained through the geothermal fluid circulation pipeline and the electric auxiliary heating module through the deep stratum heat storage and temperature control unit; geothermal resources serve as a main heat source, energy consumption is reduced by 30%-40% compared with a traditional process, the U-shaped reaction unit is covered with the thermal stress buffer layer, the thermal stress buffer layer is made of a memory alloy and flexible ceramic composite material, and the rigidity can be automatically adjusted along with thermal stress.

The invention relates to the technical field of geothermal fluid water-vapor separation, and discloses a geothermal well high-temperature geothermal fluid sample water-vapor separation device and method.The geothermal well high-temperature geothermal fluid sample water-vapor separation device comprises a shell and a bottom plate, the bottom plate is arranged on one side of the shell, the front side of the shell is fixedly connected with a feeding pipe, and the top of the shell is fixedly connected with a box. Through the design of the gas collecting mechanism, after geothermal fluid passing through the interior of the shell is subjected to water vapor separation, separated gas enters the detachable gas storage units, the detachable gas storage unit at the tail end can be expanded firstly, and after the detachable gas storage unit on the edge side is expanded to the maximum value, the detachable gas storage unit at the tail end can be expanded to the maximum value. After the valve, facing one end of the detachable gas storage unit, of the adjacent detachable gas storage unit can be closed, the detachable gas storage unit on the outermost side can be taken down and replaced, and in the replacement process, the whole separation work of the device does not need to be closed, and the other detachable gas storage units can continue to store gas, so that the separation efficiency is guaranteed; and the detachable gas storage units are relatively light in weight, so that more labor is saved in the carrying process of workers.

The present disclosure relates to systems and methods for geothermal energy systems utilizing underground geothermal fluid transmission and distribution pipelines. In some examples, underground geothermal fluid transmission and distribution pipelines may be installed with underground expansion loops and a central anchor block that allows for controlled thermal expansion without exceeding the strength of the pipe material used for the pipelines.

The invention relates to the technical field of comprehensive utilization of clean energy, and discloses a thermal power generation cascade heat exchange method and system based on geothermal preheating, and the method comprises the following steps: S1, extracting geothermal fluid of which the temperature is greater than or equal to 120 DEG C, and preheating boiler feed water of a thermal power generation system to 120-160 DEG C by using the geothermal fluid; s2, the terrestrial heat tail water obtained after boiler feed water preheating in the step S1 is fed into an evaporator of an organic Rankine cycle system so as to drive an organic working medium to generate electricity; s3, the cooling water side of a condenser of the organic Rankine cycle system and the cooling water side of a condenser of the thermal power generation system are connected in parallel and connected into the same cooling tower for heat dissipation; and S4, conveying heat discharged by the organic Rankine cycle system to a thermally driven absorption tower of a carbon capture system for amine liquid regeneration. The invention aims to realize the coupling of fuel saving, efficiency improvement and carbon emission reduction; efficiency loss generated in the thermal power peak regulation process is compensated through terrestrial heat, and the overall energy utilization efficiency can be guaranteed.

The invention discloses a method for calculating the total heat loss of geothermal fluid in the flowing process of a geothermal shaft. According to the method, the influence of phase change heat transfer and fouling heat resistance on the total heat loss of the geothermal fluid is considered at the same time. The result shows that the total heat loss is gradually increased along with the shallow depth of the geothermal shaft, and once the geothermal fluid is flashed, the total heat loss is rapidly increased. In addition, according to an energy conservation equation, the total heat loss of the geothermal fluid is mainly divided into three parts which are respectively caused by specific enthalpy, kinetic energy and potential energy. The calculation result can deduce that the specific enthalpy is the main reason causing the total heat loss, and the change trend of the specific enthalpy is basically consistent with the total heat loss. The calculation result is mainly used for revealing main factors causing the total heat loss of the geothermal fluid, the total heat loss of the geothermal fluid is reduced by improving a shaft structure, a geothermal exploitation mode and other measures, and finally the overall utilization efficiency of geothermal energy is improved.

The application provides a geothermal field area seismic electric fluid velocity anomaly information extraction method, comprising the following steps: a, using a seismic electric exploration instrument to measure a measurement area to obtain original seismic electric data; b, obtaining seismic electric data after input parameters; c, obtaining fluid data containing relative permeability corresponding to different depths; d, drawing a relative permeability profile curve graph and a relative permeability section graph according to the relative permeability data obtained in step c; e, obtaining a relative permeability profile curve graph, a water-bearing layer inference interpretation result graph and a relative permeability water-bearing layer inference interpretation section graph. The anomaly information extraction method of the application finds out the distribution characteristics of underground fluid, and comprehensively interprets the results of the wide frequency magnetotelluric method, so that good survey effect can be achieved for searching for geothermal fluid.

The invention provides a temperature prediction method and system for geothermal fluid at an outlet of a geothermal field, and belongs to the technical field of geothermal development. The method for predicting the temperature of the geothermal fluid at the outlet of the geothermal field comprises the following steps: dividing a development target interval to obtain a plurality of thermal storage fluid layers of the development target interval and interpretation data of each thermal storage fluid layer; according to the interpretation data of each thermal storage fluid layer in the development target interval, determining the heat obtained after geothermal fluid in each thermal storage fluid layer reaches a wellhead from the current thermal storage fluid layer in unit time; according to the heat which can be obtained after the geothermal fluid in each thermal storage fluid layer reaches the wellhead from the current thermal storage fluid layer in unit time, the heat which can be obtained after the geothermal fluid in the development target interval reaches the wellhead is determined; and according to the heat obtained after the geothermal fluid in the development target interval reaches the wellhead, the temperature of the geothermal fluid in the development target interval after the geothermal fluid reaches the wellhead is estimated.

The invention relates to the technical field of development and application of geothermal resources, and particularly discloses a geothermal resource development system and method.The geothermal resource development system comprises an evaporation assembly, an output assembly, a condensation assembly, a storage assembly, a working medium exchange assembly and a pumping assembly; the evaporation assembly comprises a first heat source pipeline, a first evaporator, a three-way valve, a second heat source pipeline and a second evaporator. The output assembly comprises a steam inlet pipeline, a screw expander and a steam exhaust pipeline; the storage assembly comprises a four-way valve, a first working medium box, a second working medium box, a working medium pipeline, a first working medium valve and a second working medium valve; the working medium exchange assembly comprises an upstream pipeline, a control valve and a downstream pipeline. By adjusting the three-way valve and the four-way valve, flexible switching of working modes and flexible selection of organic working media are achieved, so that the system can cope with exploitation of geothermal fluid with different flows and temperatures, geothermal resources with different depths can be efficiently utilized, and the heat efficiency and adaptability of the system are improved.

The present invention provides a control device, a control method, and a control program for a geothermal power plant, with which it is possible to accurately obtain the steam production amount of a well. Provided is a control device (50) for controlling a geothermal power plant that generates electricity, the geothermal power plant including a plurality of wells from which a geothermal fluid is ejected, and one separator that separates the geothermal fluid ejected from each well into steam and hot water. The control device (50) comprises an acquisition unit (51) that acquires information regarding each well, and an estimation unit (52) that estimates, for each well, a function expression indicating a correlation, from the wellhead pressure of the well, the pressure of the separator, the valve opening degree of a flow control valve of the well, and the flow rate of steam separated by the separator. The control device (50) activates a first well among the plurality of wells, the acquisition unit (51) acquires information regarding the first well, and the estimation unit (52) estimates a first function expression indicating the correlation of the first well. The control device (50) activates a second well while the first well is being activated, the acquisition unit (51) acquires information regarding the second well, and the estimation unit (52) estimates a second function expression indicating the correlation of the second well.

Various examples are provided related to airlift pumping of downhole geothermal fluids. In one example, an airlift system includes a compressor; a gas sparger head in a wellbore of a geothermal well, and a pressure head recycle assembly. The sparger head produces artificial lift of the geothermal fluids by injecting a gas resulting in a difference in density downhole. The entrained gas can be extracted by the pressure head recycle assembly, compressed, and reinjected downhole. The geothermal fluid at the well head can be used in direct use applications or in a thermodynamic cycle to make shaft power. The gas sparger head can include a venturi shaped passage extending through the gas sparger head and a bubble orifice including gas orifices radially spaced about a narrow portion of the venturi shaped passage. The gas orifices can have a corresponding resonant chamber through which the gas (e.g., air) is provided.

The application discloses a device and method for measuring non-condensable gas of high-temperature geothermal fluid, belonging to the field of high-temperature geothermal reservoir engineering testing, and comprises a water vapor separator (2) and a non-condensable gas collecting device (9) connected in sequence, wherein the non-condensable gas collecting device (9) comprises a non-condensable gas collecting tank (10) and an inlet and outlet water adjusting tank (12) which are communicated through a connecting graduated tube (11), and corresponding valves and connecting pipes are further arranged; the measuring method is to convert the collected non-condensable gas into the mass of gas, measure the mass of the discharged water in the water collecting tank, and thus calculate the mass ratio of the non-condensable gas; the application can obtain accurate and reliable mass concentration data of the non-condensable gas in the fluid, is suitable for single-well productivity testing, geothermal resource assessment, geothermal field production monitoring and other fields of high-temperature geothermal fields, and provides reliable data for high-temperature geothermal field scale prevention and scale inhibition and power plant unit design.

The invention belongs to the technical field of fractured geothermal reservoir water quality evolution, and provides a fractured geothermal reservoir water quality evolution simulation method and system based on water-rock reaction, and the method comprises the steps: obtaining a mixed dimension geometric model of a fractured geothermal reservoir; building a fissure medium seepage-heat transfer-solute reaction migration control equation based on the obtained mixed dimension geometric model; according to a chemical reaction system of geothermal fluid of the fractured thermal reservoir, the constructed fractured medium seepage-heat transfer-solute reaction migration control equation is coupled, and a seepage-heat transfer-solute reaction migration multi-field coupling model is obtained; and solving the obtained seepage-heat transfer-solute reaction migration multi-field coupling model, and simulating evolution of a temperature field, a seepage field and a chemical field in a geothermal exploitation process according to a solving result, thereby completing water quality evolution simulation of the fractured geothermal reservoir based on the water-rock reaction.

The utility model belongs to the technical field of energy engineering, concretely relates to the proportional measurement of geothermal fluid. A kind of direct condensing geothermal fluid vapor-liquid proportional measurement system, including main output pipe, condensing unit, separation unit, cooling water unit, measurement unit;Condensing unit includes the direct condensing condenser for receiving heat source fluid;Cooling water unit is used to output cooling water to direct condensing condenser;Separation unit includes gas-liquid separator;Gas-liquid separator includes the gas phase output pipe for outputting gas and the liquid phase output pipe for outputting liquid, and the liquid phase output pipe is connected with measurement tank;Heat source fluid and cooling water are directly mixed and heat exchanged in the direct condensing condenser, and the obtained mixed fluid is output to gas-liquid separator.The utility model provides the system and method using direct condensing method, and the original proportion of water, steam and incondensable gas in wellhead geothermal fluid can be accurately measured.

The invention discloses a numerical simulation method for a fracture fracture development process of a fault-reservoir combination area, and belongs to the technical field of geothermal resource development and utilization, and the method comprises the steps: constructing a heat-flow coupling model of a stratum three-dimensional model and a fault-reservoir coupling model of the fault-reservoir combination area; data exchange channels are arranged among the models, multi-physics field simulation is carried out on the stratum three-dimensional model, and meanwhile the fracture and fracture development process of the fracture and reservoir combination area is simulated through the fracture and reservoir coupling model. The method accurately simulates the heat transfer process of the terrestrial heat in the fracture and reservoir combination area, judges the terrestrial heat transfer modes, and simulates the expansion behavior of the fracture and the evolution process of the crack in different terrestrial heat transfer modes in combination with a related algorithm model. According to the method, the fracture development process can be accurately simulated, the influence of complex structures such as the fracture and reservoir combination area on geothermal heat transfer and geothermal fluid migration is obtained, a scientific basis is provided for geothermal exploitation and structure safety assessment, and the method has high practical value and popularization prospects.

The invention relates to a method for calculating the recoverable quantity of geothermal fluid under the condition of sandstone heat storage and recharge. The method comprises the steps that heat storage distribution characteristic data, physical property parameter data and vertical temperature distribution data of a recharge well, average temperature data of all water filtering sections and recharge water amount data of all the water filtering sections are obtained; constructing a hot water recharge migration distribution model based on the heat storage distribution characteristic data and the physical property parameter data; according to the vertical temperature distribution data, the average temperature data of all the water filtering sections and the recharge water amount data, all recharge horizon data are calculated; calculating the hydrothermal influence radius and the thermal breakthrough time of each recharge horizon based on the recharge migration distribution model and the data of each recharge horizon; and calculating the recoverable quantity of the geothermal fluid by adopting an average well spacing method according to the heat influence radius and the heat breakthrough time. With the adoption of the method, the precise evaluation of the sustainable resource quantity under the recharge condition is realized by coupling the dynamic process of hydrothermal migration and heat exchange.

The invention discloses a geothermal fluid potential field interpolation method, device and system and a storage medium. The method comprises the following steps: acquiring actual measurement data of a geothermal well point; constructing a physical constraint Gaussian process model; calculating a physical residual error according to the actually measured data of the geothermal well point and the physical constraint type; constructing a physical constraint item based on the physical residual error; training the physical constraint Gaussian process model including the physical constraint terms by using actual measurement data of geothermal well points; and utilizing the trained physical constraint Gaussian process model to predict the fluid potential field of the target area to obtain physically reasonable fluid potential field distribution and uncertainty quantification results. By adopting the technical scheme of the invention, a physically reasonable, high-precision and high-reliability fluid potential field prediction result can be obtained under the constraint of a small amount of measured data.

The invention discloses a heat preservation and temperature increase integrated coupling reheating device for a low-temperature geothermal well and a using method, and belongs to the technical field of geothermal resource development and utilization equipment.The heat preservation and temperature increase integrated coupling reheating device comprises an outer shell coaxially arranged outside a main pipeline in a sleeving mode, and a first-stage atomization spraying module, a second-stage turbulent flow heat exchange module and a third-stage rotational flow module which are sequentially arranged in the outer shell; low-temperature geothermal fluid flows in the main pipeline, high-temperature water is sprayed to the outer wall of the pipeline through the atomization nozzles, and rapid and efficient temperature rise is achieved through the three-stage combined action of impact heating, turbulent flow synergistic effect and rotational flow heating. The device integrates a temperature sensor and a controller to form heat preservation and temperature increasing integrated coupling arrangement, closed-loop control is formed, and the outlet temperature is accurately adjusted; the device is compact in structure, capable of being directly connected to a wellhead pipeline in series, high in heating rate, accurate in temperature control, capable of saving water and preventing scale, solves the problems that in the prior art, a system is complex, temperature control lags behind, mixing is uneven and the like, and is particularly suitable for direct heating regulation and control scenes of geothermal wellheads.

This invention concerns a geothermal software consisting of five features used to simulate geothermal fluid flow and its conditions starting from the fluid outlet or inlet zone (permeable zone) to the surface. This simulator can calculate the contribution of each fluid outlet or inlet zone, fluid flow conditions in the wellbore to the surface, fluid flow allocation between individual wells on the surface, pressure flow modeling and fluid enthalpy in the reservoir and reservoir treatment based on time, as well as thermodynamic flow conditions in the production pipe on the surface.

The application provides an LNG gasification power generation system and method coupled with geothermal and seawater, and relates to the technical field of LNG gasification. The system comprises an LNG pipeline, the LNG pipeline sequentially passes through at least two condensers; at least two organic flash cycle units, each of which is connected with a condenser, the organic flash cycle unit comprises a circulation pipeline, the circulation pipeline sequentially passes through a heat exchanger, a flash tank, an expander and a condenser, the circulation pipeline is provided with an organic working medium, the condenser is used for providing cold energy for condensation of the organic working medium, the heat exchanger exchanges heat with seawater or geothermal fluid, and the expander is used for power generation. The problems of high energy consumption and large heat loss in the LNG gasification process in the prior art are solved.

A system and method for generating hydrogen using thermal energy in a geothermal fluid are disclosed. An electrical power generation subsystem is configured to receive geothermal fluid from a geothermal fluid source and use thermal energy in the geothermal fluid to generate electrical power. A steam generation subsystem is configured to receive water and produce steam using thermal energy in the geothermal fluid and the electrical power generated by the electrical power generation subsystem. A hydrogen generation subsystem is configured to disassociate hydrogen from the steam using the electrical power generated by the electrical power generation subsystem.

The invention discloses a sample collection device for waste mine geothermal exploration, and relates to the technical field of mine geothermal exploration sample collection. Comprising an outer cylinder and an inner cylinder, a rotating cylinder is rotatably connected to the surface of the outer cylinder, a plurality of mounting tables are mounted in the rotating cylinder, downstream plates are arranged at the ends, away from the outer cylinder, of the mounting tables, adjusting plates are arranged in the downstream plates in a limited sliding mode, and an electric push rod is mounted at the top of the inner wall of the outer cylinder; a buoyancy adjusting and controlling assembly is arranged in the gap between the outer cylinder and the inner cylinder. According to the geothermal fluid sampling device, through the arranged buoyancy regulation and control assembly, when the outer cylinder extends into geothermal fluid, the resistance of the fluid to the outer cylinder can be reduced, and the situation that the sampling container cannot stably stay at the target depth due to upward lifting force generated by buoyancy, and depth positioning deviation is caused is avoided; the inner drainage port of the annular plate can be gradually overlapped with the inner drainage port of the outer cylinder, and the drainage caliber is increased.