CN110987633A - Hydraulic fracturing method for dry hot rock sample - Google Patents
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Abstract
The invention relates to the technical field of geothermal fracturing experiments, in particular to a hydraulic fracturing method of a dry hot rock sample. The hydraulic fracturing method comprises the following specific processes: s1: carrying out sectional type heating treatment on the hot dry rock sample (1) from normal temperature to a preset temperature until the hot dry rock sample (1) reaches the preset temperature; s2: and carrying out hydraulic fracturing treatment on the dry hot rock sample (1). According to the hydraulic fracturing method for the dry hot rock sample, sectional type heating treatment is carried out before hydraulic fracturing treatment, the dry hot rock sample can be preheated to a preset temperature and then subjected to hydraulic fracturing test, the integrity of the internal structure of the dry hot rock sample is guaranteed in a sectional type heating treatment mode, the internal structure of the dry hot rock sample is prevented from being damaged due to rapid heating in the heating process, the real situation of the dry hot rock geothermal reservoir can be reflected more accurately, and the reliability of research data is improved.
Description
Technical Field
The invention relates to the technical field of geothermal fracturing experiments, in particular to a hydraulic fracturing method of a dry hot rock sample.
Background
Geothermal resources are a novel, clean and renewable resource, and are one of green new energy sources which can effectively solve the problems of the traditional fossil fuel and the energy shortage and air pollution at present. Geothermal resources can be divided into a hydrothermal type and a dry-hot rock type according to the output conditions, wherein the dry-hot rock is a high-temperature rock body without water (or containing a small amount of water but not capable of flowing), has few pores or cracks, has extremely poor permeability, has a wide temperature range between 150 and 650 ℃, is mainly metamorphic rock or crystalline rock, and is usually commercially and effectively developed by means of various reservoir stratum modification technologies such as external hydraulic fracturing.
Taking a hydraulic fracturing method as an example, a fracturing well is injected with high-pressure fluid to fracture a dry-hot rock geothermal reservoir so as to establish an artificial geothermal reservoir underground; then, the heat exchange rate of water and surrounding rock masses is increased by accelerating the injection of water, so that the heat exchange area of the reservoir is enlarged; after hydraulic fracturing, a production well needs to be additionally drilled in a fracture transformation area to realize hot fluid circulation extraction, and the extracted low-temperature fluid can be reinjected into the fracturing well again to serve as a fracturing fluid medium again, so that the extraction cost is reduced. In order to reduce the exploitation cost of the geothermal reservoir of the dry hot rock, a numerical simulation method and an indoor test method are generally adopted to research and improve a hydraulic fracturing method. Specifically, although the numerical simulation method is low in cost and can change the condition for repeated calculation, the established numerical model still has the defect that the real condition of the reservoir is difficult to reflect; the existing indoor test method mainly uses true triaxial hydraulic fracturing as a main part, wherein the size of a rock sample is mainly a rectangular body or a cube, a fracturing fluid with colors or added with fluorescent powder is mostly adopted to analyze the fracture form and the range size after hydraulic fracturing, and three-dimensional positioning interpretation is carried out according to the visually observed fracture form.
Disclosure of Invention
The invention aims to solve the problems that the real condition of a dry hot rock geothermal reservoir is difficult to reflect and the reference significance of research is not large and the like due to the fact that the hydraulic fracturing exploitation of the dry hot rock geothermal reservoir is simulated and researched by a numerical simulation method and an indoor true triaxial hydraulic fracturing test method (under the conditions of normal temperature and high pressure) in the prior art.
In order to achieve the aim, the invention provides a hydraulic fracturing method of a dry hot rock sample, which comprises the following specific processes:
s1: carrying out sectional type heating treatment on the hot dry rock sample from normal temperature to preset temperature until the hot dry rock sample reaches the preset temperature;
s2: and carrying out hydraulic fracturing treatment on the dry hot rock sample.
Optionally, the predetermined temperature is set to 200 ℃, and the specific process of the step-wise heating treatment in step S1 is as follows:
s11, heating the hot dry rock sample to 50 ℃ from normal temperature, and then carrying out heat preservation treatment, wherein the heat preservation time is set to be T1;
s12: heating the dry hot rock sample from 50 ℃ to 100 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T2;
s13: heating the dry hot rock sample from 100 ℃ to 150 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T3;
s14: and heating the dry hot rock sample from 150 ℃ to 200 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T4.
Optionally, the hydraulic fracturing method comprises at least one of the following forms:
the first form: the holding time T1 was set to 12 hours;
the second form: the holding time T2 was set to 12 hours;
the third form: the holding time T3 was set to 12 hours;
form four: the incubation time T4 was set to 2 hours.
Optionally, in step S2, the actual temperature of the dry hot rock sample at the time of the hydraulic fracturing treatment is set to 170-.
Optionally, in step S1, the hot dry rock sample is subjected to the sectional heating process by a heating unit, and the pressurizing unit includes a plurality of heating plates surrounding the periphery of the hot dry rock sample and capable of heating the hot dry rock sample.
Optionally, in step S1, the dry hot rock sample monitors the temperature of the dry hot rock sample in real time through a temperature measurement unit, the temperature measurement unit includes a temperature sensor and a plurality of temperature detectors respectively assembled with the plurality of heating plates in a one-to-one correspondence manner, in step S1, before the heating unit performs the sectional heating process, the temperature sensor is releasably installed in a fracturing cylinder inserted in the dry hot rock sample, so that the temperature sensor monitors the internal temperature of the dry hot rock sample in real time during the sectional heating process, and the temperature of the heating plates is monitored in real time during the sectional heating process through the temperature detectors, so as to monitor the temperature of the outer peripheral wall of the dry hot rock sample in real time, until the temperature values displayed by the temperature sensor and the temperature detectors are consistent, the dry hot rock sample reaches the temperature value; after step S1 is completed, the heating unit is turned off, and then the temperature sensor is taken out.
Optionally, in step S2, the dry hot rock sample is pressurized by a pressurizing unit, wherein the pressurizing unit is capable of applying pressure to the heating plates to apply a confining pressure to the dry hot rock sample through the heating plates until the confining pressure is consistent with the ground stress applied to the dry hot rock reservoir.
Optionally, in step S2, after the confining pressure applied to the hot dry rock sample is consistent with the ground stress applied to the hot dry rock reservoir, injecting a fracturing fluid into the hot dry rock sample through the fracturing cylinder until the hot dry rock sample is fractured, and closing the pressurizing unit.
Optionally, the hydraulic fracturing method comprises a step S0 provided before the step S1, wherein:
and S0, drilling the hot dry rock to form a drill hole, and inserting the fracturing cylinder into the drill hole to obtain the hot dry rock sample.
Optionally, in step S2, monitoring the fracturing condition of the hot dry rock sample in real time by an acoustic emission method.
According to the technical scheme, the hydraulic fracturing method of the dry hot rock sample is characterized in that sectional type heating treatment is carried out before the hydraulic fracturing treatment, so that the dry hot rock sample can be preheated to a preset temperature and then subjected to the hydraulic fracturing test, the internal structure of the dry hot rock sample is ensured to be intact through the sectional type heating treatment, the internal structure of the dry hot rock sample is prevented from being damaged due to rapid temperature rise in the heating process, the real situation of the dry hot rock geothermal reservoir is favorably and accurately reflected, the reliability of research data is improved, a more accurate and reliable theoretical basis is provided for the development of the dry hot rock geothermal reservoir, and the cost for developing the dry hot rock geothermal reservoir is favorably reduced.
Drawings
FIG. 1 is a schematic structural diagram of a hot dry rock sample provided by the invention when a hydraulic fracturing test is carried out;
fig. 2 is a pressure change curve diagram of a hot dry rock sample 1 provided by the invention in a hydraulic fracturing test.
Description of the reference numerals
1. Hot dry rock samples; 2. heating plates; 3. a heating member; 4. a fracturing cylinder; 5. a temperature detector.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The invention provides a hydraulic fracturing method of a dry hot rock sample, which comprises the following specific processes as shown in figure 1:
s1: carrying out sectional type heating treatment on the hot dry rock sample 1 from normal temperature to a preset temperature until the hot dry rock sample 1 reaches the preset temperature;
s2: and carrying out hydraulic fracturing treatment on the dry hot rock sample 1.
According to the technical scheme, the hydraulic fracturing method of the dry hot rock sample is characterized in that sectional type heating treatment is carried out before the hydraulic fracturing treatment, so that the dry hot rock sample can be preheated to a preset temperature and then subjected to the hydraulic fracturing test, the internal structure of the dry hot rock sample is ensured to be intact through the sectional type heating treatment, the internal structure of the dry hot rock sample is prevented from being damaged due to rapid temperature rise in the heating process, the real situation of the dry hot rock geothermal reservoir is favorably and accurately reflected, the reliability of research data is improved, a more accurate and reliable theoretical basis is provided for the development of the dry hot rock geothermal reservoir, and the cost for developing the dry hot rock geothermal reservoir is favorably reduced.
In order to protect the internal structure of the hot dry rock sample 1 from being damaged due to too high temperature or too fast temperature rise, the predetermined temperature is set to 200 ℃, and the specific process of the segmented heating process in the step S1 is as follows:
s11, heating the hot dry rock sample 1 from normal temperature to 50 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set to be T1;
s12: heating the dry hot rock sample 1 from 50 ℃ to 100 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T2;
s13: heating the dry hot rock sample 1 from 100 ℃ to 150 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T3;
s14: and heating the dry hot rock sample 1 from 150 ℃ to 200 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T4.
In the sectional heating process, in order to ensure that the surface and internal temperatures of the hot dry rock sample 1 can be finally consistent in the heating treatment in any stage of the steps S11-S14, the hydraulic fracturing method comprises at least one of the following forms:
the first form: the holding time T1 was set to 12 hours;
the second form: the holding time T2 was set to 12 hours;
the third form: the holding time T3 was set to 12 hours;
form four: the incubation time T4 was set to 2 hours.
In order to meet the test requirement of the dry hot rock sample 1, in step S2, the actual temperature of the dry hot rock sample 1 during the hydraulic fracturing treatment is set to 170-. It is understood that, in consideration of heat dissipation, the hot dry rock sample 1 is heated to the predetermined temperature of 200 ℃ and then subjected to the hydraulic fracturing test at the actual temperature of 170 ℃ and 180 ℃ (i.e., the core internal temperature of the hot dry rock sample 1) due to partial heat dissipation.
Further, in step S1, the hot dry rock sample 1 is heated by a heating unit, the pressurizing unit includes a plurality of heating plates 2, the plurality of heating plates 2 surround the periphery of the hot dry rock sample 1 and can heat the hot dry rock sample 1, the plurality of heating plates 2 surround the periphery of the hot dry rock sample 1 to heat the hot dry rock sample 1, the periphery of the hot dry rock sample 1 is favorably heated at the same time, the temperature on the outer peripheral surface of the hot dry rock sample 1 is ensured to be consistent, the internal temperature of the core of the hot dry rock sample 1 is favorably and rapidly increased, the heat loss is reduced, the phenomenon of temperature fluctuation in the heating process caused by rapid heat loss of the hot dry rock sample 1 is avoided, the hot dry rock sample 1 can be gradually and slowly heated in the sectional heating process, and the integrity of the internal structure of the hot dry rock sample 1 is ensured, the method is favorable for more accurately reflecting the real situation of the dry-hot rock geothermal reservoir.
In order to precisely control the temperature of each stage of the above-mentioned sectional heating process in steps S11-S14, in step S1, the dry hot rock sample 1 monitors the temperature of the dry hot rock sample 1 in real time by a temperature measuring unit including a temperature sensor and a plurality of temperature detectors 5 respectively assembled in one-to-one correspondence with the plurality of heating plates 2, in step S1, before the heating unit performs the sectional heating process, the temperature sensor is releasably mounted in a fracturing cylinder 4 inserted in the dry hot rock sample 1 so that the temperature sensor monitors the internal temperature of the dry hot rock sample 1 in real time during the sectional heating process and monitors the temperature of the heating plates 2 in real time during the sectional heating process by the temperature detectors 5 to monitor the temperature of the peripheral wall of the dry hot rock sample 1 in real time, until the temperature values displayed by the temperature sensor and the temperature detector 5 are consistent, the dry hot rock sample 1 reaches the temperature value; after step S1 is completed, the heating unit is turned off, and then the temperature sensor is taken out. The temperature of each heating plate 2 is monitored in real time by adopting the temperature detector 5, so that the temperature of the outer peripheral wall of the dry hot rock sample 1 can be controlled in real time, meanwhile, the temperature sensor is adopted to monitor the internal temperature of the dry hot rock sample 1 in real time, and when the temperatures measured by the temperature detector 5 and the temperature sensor are consistent, the dry hot rock sample 1 is considered to reach the specific set temperature of each stage of the steps S11-S14 in the sectional type heating process.
During the hydraulic fracturing treatment of step S2, the hot dry rock sample 1 is no longer supplied with heat due to the shut-off of the heating unit, in which case, in order to reduce the heat loss of the hot dry rock sample 1 as much as possible, corresponding heat preservation measures can be performed on the hot dry rock sample 1. For example, in step S2, it is right to carry out pressurization through the pressure cell dry hot rock sample 1 and handle, wherein, the pressure cell can be to a plurality of the pressure is applyed to hot plate 2, in order to be through a plurality of hot plate 2 is right hot dry rock sample 1 applys the confining pressure, until the confining pressure is unanimous with the ground stress that the dry hot rock reservoir received, because hot plate 2 is in higher temperature, surrounds hot dry rock sample 1 through hot plate 2 of higher temperature, has avoided hot dry rock sample 1 direct and external (normal atmospheric temperature state) contact and rapid cooling, has played and has carried out heat retaining effect to hot dry rock sample 1, and can also make full use of hot plate 2 and surround the setting mode of hot dry rock sample 1, directly utilizes the pressure cell to carry out heating process to hot dry rock sample 1, has simplified test device, has optimized the operation flow, the cost is reduced. Specifically, the heating plate 2 may be provided in various reasonable forms, for example, the heating plate 2 may include a main plate, and a heating member 3 (e.g., a heating rod) and a temperature detector 5 embedded in the main plate, wherein the heating member 3 is connected to a heating unit, the heating unit may be provided as a heating box or the like capable of heating the heating rod to perform a sectional type heating process on the dry hot rock sample 1, the main plate is connected to a pressurizing unit, and the pressurizing unit may be provided as a hydraulic pressure or the like capable of pressurizing the main plate to apply a confining pressure to the dry hot rock sample 1. Further, the heating plate 2 comprises a heating layer for installing the heating element 3 and a heat preservation layer attached outside the heating layer, so that the hot dry rock sample is heated by the heating element 3 in the heating layer in the step S1, and the hot dry rock sample 1 is subjected to heat preservation by the heat preservation layer in the step S2, so that the hot dry rock sample 1 can reach and be kept at a reasonable temperature for hydraulic fracturing test; of course, the pressurizing unit may pressurize the insulating layer or the heating layer. On the basis, in order to accurately monitor the temperature of the outer peripheral wall of the dry hot rock sample 1, a temperature detector 5 is arranged on a heating layer; wherein the heating layers may be provided in various reasonable forms, for example, as shown in fig. 1, each heating layer includes a plurality of parallel heating members 3 (e.g., heating rods) arranged at intervals and a temperature detector 5 arranged between the plurality of heating members, thereby optimizing heating efficiency, improving heating uniformity of the dry hot rock sample 1, and improving accuracy of temperature measurement.
In order to perform the hydraulic fracturing test on the dry hot rock sample 1, a large amount of fracturing fluid needs to be injected into the dry hot rock sample 1. Specifically, in step S2, after the confining pressure applied to the dry hot rock sample 1 is consistent with the ground stress applied to the dry hot rock reservoir, the fracturing fluid is injected into the dry hot rock sample 1 through the fracturing cylinder 4 until the dry hot rock sample 1 is fractured, and the pressurizing unit is closed, so that the dry hot rock sample 1 can be subjected to sectional heating treatment and confining pressure application treatment through the plurality of heating plates 2 before the hydraulic fracturing test, which is beneficial to more accurately reflecting the real situation of the dry hot rock geothermal reservoir, improving the reliability of research data, providing a more accurate and reliable theoretical basis for the development of the dry hot rock geothermal reservoir, and reducing the cost for developing the dry hot rock geothermal reservoir.
Further, the hydraulic fracturing method includes step S0 provided before step S1, wherein:
and S0, drilling the hot dry rock to form a drill hole, and inserting the fracturing cylinder 4 into the drill hole to obtain the hot dry rock sample 1. The hot dry rock sample 1 may be set to various reasonable specifications, and for example, a core cutting machine is used to process a hot dry rock into a cube block of 300 × 300 × 300mm, a drill is used to drill a small hole in the middle of one face of the hot dry rock of the cube block, a fracturing cylinder 4 is installed (for example, a high temperature and high pressure resistant metal pipe is used to simulate a fractured wellbore used in an actual mining process), and then a sealing structure (for example, a sealing ring and a sealing glue) is used to perform a sealing treatment, so as to obtain the hot dry rock sample 1.
Of course, in step S1, it is understood that the temperature sensor is first placed in the fracturing cylinder 4; then, the respective faces of the hot dry rock sample 1 are respectively pressed by 6 heating plates to surround the outer surface of the hot dry rock sample 1, and the heating plate pressing the face of the hot dry rock sample 1 having the fracturing cylinder has a hole so that the fracturing cylinder can communicate with the outside through the hole, so as to pump the fracturing fluid to the inside of the hot dry rock sample 1 by an external high-pressure fracturing pump in step S2; operating the heating unit to perform the sectional type heating process of steps S11-S14 on the hot dry rock sample 1 through the heating plate, wherein the temperature sensor can monitor the internal temperature of the hot dry rock sample 1 in real time during the sectional type heating process, and the temperature detector 5 can monitor the temperature of the outer peripheral wall of the hot dry rock sample 1 in real time during the sectional type heating process, so as to measure whether the internal and outer peripheral walls of the hot dry rock sample 1 reach the set temperature of each stage of steps S11-S14 at the same time; after the step S11-S14 of the stepwise heating process is completed, the temperature sensor is taken out and the heating unit is turned off. It can be understood that, in order to observe the measurement result, the temperature measurement unit can be provided with a display screen such as a computer, so that the temperature values measured by the temperature detector 5 and the temperature sensor are transmitted to the display screen in real time to be displayed, and the visual observation is facilitated.
It is worth mentioning that in step S2, first, a confining pressure is applied to the dry hot rock sample 1 by a pressurizing unit, specifically, the pressurizing unit includes a hydraulic device capable of driving the heating plates 2 to move in a horizontal or vertical direction, and the hydraulic device of the pressurizing unit is controlled by a hydraulic servo control system of the true triaxial hydraulic fracturing experimental apparatus to drive the heating plates 2 to apply a three-way stress to the dry hot rock sample 1, that is, a horizontal stress and a vertical stress are applied at the same time to simulate a ground stress state; furthermore, a hydraulic servo control system of the true triaxial hydraulic fracturing experimental equipment can be set as a hydraulic servo control system adopted by conventional hydraulic fracturing experimental equipment; and then, injecting a fracturing fluid into the dry hot rock sample 1 until the dry hot rock sample 1 is fractured, and closing a pressurizing unit.
Further, in step S2, the fracturing condition of the dry hot rock sample 1 is monitored in real time by an acoustic emission method, so as to effectively simulate and record fracture initiation and propagation conditions of hydraulic fractures in the dry hot rock reservoir. When in use, in step S2, first, the high-pressure fracturing pump, the fracturing fluid storage tank and the fracturing cylinder may be connected together in sequence by using a high-pressure pipeline; then, simulating a hydraulic fracturing process in an actual exploitation process, entering a stage of applying perforation pressure, specifically, starting a high-pressure fracturing pump, pumping fracturing fluid in a fracturing fluid storage tank into a fracturing cylinder at a constant speed to gradually fracture the hot dry rock sample 1, simultaneously recording the perforation pressure and the change rule of the hot dry rock sample 1 by using a pressure gauge arranged on the fracturing cylinder, recording the initiation and expansion dynamics of the hydraulic fracture by using sound emission equipment, observing from a pressure change curve shown in fig. 2, during the whole hydraulic fracturing process, continuously increasing the perforation pressure, closing the high-pressure fracturing pump when sudden drop occurs and the amplitude is large, namely 16MPa shown in fig. 2, when the hot dry rock sample 1 is already pressed, considering that the hydraulic fracturing simulation of the whole hot dry rock is finished, simultaneously opening an air release valve and unloading the confining pressure applied by a plurality of heating plates of a pressurizing unit, and then, taking out the pressed dry hot rock sample 1, observing and photographing to record the final shape of the crack, and scanning the crack surface of the pressed rock sample, so that microscopic analysis can be performed, and a more accurate and reliable theoretical basis is provided for the development of the geothermal reservoir of the dry hot rock.
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications may be made to the technical solution of the invention, and in order to avoid unnecessary repetition, various possible combinations of the invention will not be described further. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.
Claims (10)
1. The hydraulic fracturing method of the dry hot rock sample is characterized by comprising the following specific processes:
s1: carrying out sectional type heating treatment on the hot dry rock sample (1) from normal temperature to a preset temperature until the hot dry rock sample (1) reaches the preset temperature;
s2: and carrying out hydraulic fracturing treatment on the dry hot rock sample (1).
2. The method for hydraulic fracturing of a hot dry rock sample according to claim 1, wherein the predetermined temperature is set to 200 ℃, and the sectional heating process in step S1 is performed as follows:
s11, heating the hot dry rock sample (1) from normal temperature to 50 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set to be T1;
s12: heating the dry hot rock sample (1) from 50 ℃ to 100 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T2;
s13: heating the dry hot rock sample (1) from 100 ℃ to 150 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T3;
s14: and heating the dry hot rock sample (1) from 150 ℃ to 200 ℃, and then carrying out heat preservation treatment, wherein the heat preservation time is set as T4.
3. The method of hydraulic fracturing of a hot dry rock sample of claim 2, wherein the method comprises at least one of the following:
the first form: the holding time T1 was set to 12 hours;
the second form: the holding time T2 was set to 12 hours;
the third form: the holding time T3 was set to 12 hours;
form four: the incubation time T4 was set to 2 hours.
4. The hydraulic fracturing method of the dry hot rock sample according to claim 3, wherein in step S2, the actual temperature of the dry hot rock sample (1) at the time of the hydraulic fracturing treatment is set to 170-180 ℃.
5. The method for hydraulic fracturing of a hot dry rock sample according to any one of claims 1 to 4, wherein in step S1, the hot dry rock sample (1) is subjected to the stepwise heating treatment by a heating unit comprising a plurality of heating plates (2), the plurality of heating plates (2) surrounding the periphery of the hot dry rock sample (1) and capable of heating the hot dry rock sample (1).
6. The method for hydraulic fracturing of a hot dry rock specimen according to claim 5, wherein the hot dry rock specimen (1) is monitored in real time for temperature of the hot dry rock specimen (1) by a temperature measuring unit comprising a temperature sensor and a plurality of temperature detectors (5) assembled in one-to-one correspondence with a plurality of the heating plates (2), respectively, in step S1, the temperature sensor is releasably mounted in a fracturing cylinder (4) inserted in the hot dry rock specimen (1) prior to the heating unit performing the sectional heating process in step S1 so that the temperature sensor monitors the internal temperature of the hot dry rock specimen (1) in real time during the sectional heating process and monitors the temperature of the heating plates (2) in real time during the sectional heating process by the temperature detectors (5), the temperature of the outer peripheral wall of the dry hot rock sample (1) is monitored in real time until the temperature values displayed by the temperature sensor and the temperature detector (5) are consistent, and then the dry hot rock sample (1) reaches the temperature value; after step S1 is completed, the heating unit is turned off, and then the temperature sensor is taken out.
7. The method for hydraulic fracturing of a dry hot rock sample according to claim 6, wherein in step S2, the dry hot rock sample (1) is subjected to a pressurizing treatment by a pressurizing unit, wherein the pressurizing unit is capable of applying pressure to the plurality of heating plates (2) to apply a confining pressure to the dry hot rock sample (1) through the plurality of heating plates (2) until the confining pressure is consistent with the ground stress to which the dry hot rock reservoir is subjected.
8. The method for hydraulic fracturing of the hot dry rock sample according to claim 7, wherein in step S2, after the confining pressure applied to the hot dry rock sample (1) is consistent with the ground stress applied to the hot dry rock reservoir, the fracturing fluid is injected into the hot dry rock sample (1) through the fracturing cylinder (4) until the hot dry rock sample (1) is fractured, and the pressurizing unit is closed.
9. The hydraulic fracturing method of the hot dry rock sample as claimed in claim 7, comprising a step S0 provided before step S1, wherein:
s0, drilling the hot dry rock to form a drill hole, and inserting the fracturing cylinder (4) into the drill hole to obtain the hot dry rock sample (1).
10. The method for hydraulic fracturing of a dry hot rock sample according to claim 9, wherein in step S2, the fracturing condition of the dry hot rock sample (1) is monitored in real time by an acoustic emission method.
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