Temperature-pressure-controllable rough fracture supporting belt scaling simulation device and method

Abstract

The invention relates to a temperature-pressure-controllable rough fracture supporting belt scaling simulation device and method, and belongs to the technical field of oil field evaluation test devices. The simulation device comprises a rock core with a crack supporting zone penetrating through the whole and a clamping device clamped on the periphery of the rock core, and the clamping device is clamped on the periphery of the rock core to form a closed space; the clamp holder is connected with a confining pressure control assembly and a temperature control assembly; the clamp holder is communicated with a plurality of infusion apparatuses; and the holder is arranged in an inspection room of the nuclear magnetic scanner. According to the method, a real rock sample and a real crack are adopted, and the reservoir crack supporting zone condition is restored; the temperature-resistant and pressure-resistant rubber sleeve is adopted, the real reservoir temperature and pressure conditions can be simulated, nuclear magnetic on-line scanning in the displacement process can be achieved, the real-time change of a microscopic pore throat can be defined, and the rock core can be directly opened to observe the scaling condition of cracks in the rock core in the experiment process.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield evaluation test devices, and in particular relates to a temperature and pressure controllable rough fracture support belt scaling simulation device and method. Background Art

[0002] Fracturing proppants are widely used in deep wells and high-pressure oil and gas layers for fracturing and transformation, which is of great significance for crack expansion and improving reservoir transformation effects. After stopping the pump and fracturing fluid loss, the proppant can form a support belt with high-efficiency conductivity in the formation, reducing fluid resistance to achieve the purpose of increasing production and injection. However, the problem of scaling and clogging in the fracture support belt after reservoir fracturing is relatively serious. After reservoir transformation, the water-rock reaction becomes violent, the mineralization in the liquid phase increases, the incompatible scaling ions increase, and the scaling problem is aggravated; and the scale minerals in the formation are often distributed in large pores and micro-cracks with good porosity and permeability, making the support belt formed after fracturing the main area of ​​scale. As early as 1996, Shu Gan proposed in "Several Understandings of Scaling in Oil and Gas Fields" that the sudden change in the shape of the rock or pipe surface, the rough inner surface, and the formation fractures are the most prone to scaling. In 2014, Hongyu Luo proposed in the article "Scaling from an Unexpected Source" that scale may be the main source of damage to the conductivity of fractures in hydraulic fracturing wells.

[0003] In recent years, there are many devices and methods for dynamically evaluating core scaling. In the prior art, an oilfield scale inhibition evaluation method has been published, which is equipped with a core displacement dynamic evaluation system, which can judge the scaling situation inside the core by the changes in pressure difference and permeability. However, the scaling results obtained by calculating the pressure difference and permeability changes are relatively general, and there is no intuitive understanding and analysis of the scaling problem of the internal microscopic pores. Moreover, the scaling simulation using the core cannot truly reflect the scaling situation of the reservoir support belt. For example, a scaling measurement method used in a paper entitled "Experimental Study on the Scaling Law of Proppant and Its Effect on Seepage" is to evaluate the scale inhibitor by placing gravel, reaction solution and scale inhibitor in a glass tube and observing the scaling situation and scale distribution in the glass tube. Although this device simulates the reservoir support belt formed after pressure, the disadvantage is that the temperature and pressure conditions during the experiment are normal temperature and pressure, which cannot reflect the scaling situation of the support belt under formation conditions, and the pressure difference and permeability are still used as standards for quantitative evaluation of scaling, which cannot clearly define the pore changes in the support belt before and after scaling and the scale distribution in the microscopic pore throats.

[0004] At present, some scholars have used many advanced technical means to analyze and study the characteristics of fractures (pore size changes, permeability, water saturation, etc.) to clarify the microscopic scaling in the support zone. In contrast, nuclear magnetic resonance technology is considered to be a relatively accurate means of describing pore characteristics and determining fluid distribution, and has been maturely applied in the oil and gas industry. Nuclear magnetic resonance can be used to scan the core T2 spectrum, analyze the changes in hydrocarbons and pore size before and after scaling in the fracture support zone, and clarify the degree of internal scaling damage. For example, in 2007, Zhong Ping et al. used nuclear magnetic resonance technology to study the changes in porosity and pore structure before and after scaling in the core pores. At the same time, core flow experiments were used to study the degree of damage to the formation caused by scaling in the oil layer. The results show that scaling in the oil layer will block the pores, resulting in a decreasing number of large pores and deterioration of reservoir properties. Therefore, it is necessary to provide a device and method that can simulate the temperature and pressure conditions of the reservoir, dynamically detect the scaling of the fracture support zone using nuclear magnetic resonance technology, and clarify the microscopic changes of the fracture. Summary of the invention

[0005] In response to the above problems, the present invention provides a device and method for simulating scaling of a rough fracture support belt with controllable temperature and pressure, which can observe the scaling condition in the core support belt from macroscopic and microscopic perspectives while scaling and scale inhibition experiments are being carried out, so that the analysis of scale inhibition results and the evaluation of scale inhibitors are more accurate and reliable when conducting proppant scale inhibition evaluation experiments. Secondly, under the condition of determining the temperature and pressure of the reservoir, the temperature and pressure of the core can be changed by injecting fluid to simulate the temperature and pressure conditions inside the formation, thereby more realistically and accurately simulating the scaling condition of the rough fracture support belt under the temperature and pressure conditions of the reservoir.

[0006] The first object of the present invention is to provide a temperature and pressure controllable rough fracture support belt scaling simulation device, the simulation device comprising a core with a fracture support belt running through the whole and a clamp clamped on the periphery of the core, the clamp clamped on the periphery of the core to form a closed space;

[0007] The clamp is connected to a confining pressure control component and a temperature control component, wherein the confining pressure control component is used to set a preset pressure on the core, and the temperature control component is used to set a preset temperature on the core;

[0008] The clamp is connected to a plurality of infusion devices, and the infusion devices are used to inject scaling liquid into the core;

[0009] The holder is placed in an inspection room of a nuclear magnetic resonance scanner, and the nuclear magnetic resonance scanner is used to detect the distribution and intensity of hydrogen signals in the core and cracks at a preset pressure and a preset temperature.

[0010] Furthermore, the outer surface of the core is wrapped with a rubber sleeve.

[0011] Furthermore, the rubber sleeve is made of temperature-resistant and pressure-resistant material.

[0012] Furthermore, the clamp is connected to the infusion set via a pipeline, and a displacement pressure pump is provided on the pipeline.

[0013] Furthermore, the number of the infusion pumps is at least two.

[0014] Furthermore, the infusion pump is connected to an oil barrel, and the oil barrel is connected to a pressure pump.

[0015] Furthermore, the clamp is connected to a plurality of waste liquid barrels.

[0016] Furthermore, a flow meter is provided on the connecting pipeline between the clamp and the waste liquid barrel.

[0017] Furthermore, a plurality of valves are provided on the connecting pipeline between the clamp and the infusion set, and on the connecting pipeline between the clamp and the waste liquid bucket.

[0018] Furthermore, it also includes a computing system, which is connected to the nuclear magnetic resonance scanner signal.

[0019] The second object of the present invention is to provide a temperature and pressure controllable rough fracture support belt scaling simulation method, the simulation method comprising:

[0020] The core with the fracture support band running through the core is mounted in a holder to form a closed space;

[0021] Connecting a clamp holding the core to a confining pressure control assembly and a temperature control assembly;

[0022] Connecting a holder holding a core to a plurality of infusion devices;

[0023] Place the holder holding the core into the inspection room of the nuclear magnetic resonance scanner;

[0024] Setting a preset pressure on the core through a confining pressure control assembly;

[0025] Setting a preset temperature to the core via a temperature control assembly;

[0026] Injecting scaling liquid into the core held by the holder through an infusion device;

[0027] The distribution and intensity of hydrogen signals in the core and fractures at preset pressure and temperature are detected by a nuclear magnetic resonance scanner.

[0028] Furthermore, the simulation method further includes:

[0029] The hydrogen signal distribution and intensity data in the core and fractures at the preset pressure and preset temperature obtained by the nuclear magnetic resonance scanner are processed.

[0030] Beneficial effects of the present invention:

[0031] The device and method for simulating scaling of rough fracture support belts with controllable temperature and pressure provided by the present invention adopts real rock samples and real fractures to restore the conditions of reservoir fracture support belts; and adopts a temperature-resistant and pressure-resistant rubber sleeve to simulate the temperature and pressure conditions of real reservoirs;

[0032] It can realize online NMR scanning during the displacement process to clarify the real-time changes of microscopic pore throats, and the core can be directly opened during the experiment to observe the scaling of fractures inside the core;

[0033] This is to avoid the shortcomings of the prior art in testing the hazards of scaling of the support belt.

[0034] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic structural diagram of a temperature and pressure controllable rough fracture support belt scaling simulation device according to an embodiment of the present invention is shown;

[0037] Figure 2 A schematic diagram of a core according to an embodiment of the present invention is shown;

[0038] Figure 3 A diagram showing the change of pore radius at a core fracture under the simulated constant pressure and temperature change according to an embodiment of the present invention is shown;

[0039] Figure 4 A diagram showing the change of pore radius at a core fracture under the simulated constant temperature and changing pressure according to an embodiment of the present invention is shown;

[0040] In the figure: 1. Oil drum; 2. Pressure pump; 3. Infusion pump; 4. Displacement pressure pump; 5. Temperature control component; 6. Confining pressure control component; 7. MRI scanner; 8. Clamp; 9. Core; 10. Rubber sleeve; 11. Waste liquid barrel; 12. Calculation system; 13. Flow meter. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] like Figure 1 As shown, a temperature and pressure controllable rough fracture support belt scaling simulation device according to an embodiment of the present invention comprises a core 9 with a fracture support belt running through the whole, and a clamp 8 clamped on the periphery of the core 9, wherein the clamp 8 is clamped on the periphery of the core 9 to form a closed space;

[0043] The clamp 8 is connected to a confining pressure control component 6 and a temperature control component 5, wherein the confining pressure control component 6 is used to set a preset pressure on the core 9, and the temperature control component 5 is used to set a preset temperature on the core 9;

[0044] The clamp 8 is connected to a plurality of infusion devices 3, and the infusion devices 3 are used to inject scaling liquid into the core 9;

[0045] The holder 8 is placed in the inspection room of the nuclear magnetic resonance scanner 7, and the nuclear magnetic resonance scanner 7 is used to detect the distribution and intensity of hydrogen signals in the core 9 and cracks at a preset pressure and a preset temperature.

[0046] In the embodiment of the present invention, the core 9 with the fracture support belt running through the whole is used to simulate the core 9 with the actual fracture on the one hand, and to simulate the support belt formed by the fracturing proppant in the formation on the other hand. In the specific actual operation, the core 9 is split from the middle by the wire cutting method, and a layer of quartz sand is evenly laid on the splitting surface of the core 9 after the splitting, and a porous gauze without hydrogen signal is pasted on the upper and lower end surfaces in accordance with the rock slice to prevent the quartz sand in the crack from sliding out of the crack, wherein the splitting simulates the crack, and the quartz sand plays the role of a proppant;

[0047] The particle size of the quartz sand is 40-70 mesh. Specifically, the specific value of the particle size of the quartz sand can be one of 40 mesh, 45 mesh, 50 mesh, 55 mesh, 50 mesh, 55 mesh, 60 mesh, 65 mesh, and 70 mesh.

[0048] In the embodiment of the present invention, and in order to improve the simulation accuracy, the outer surface of the core 9 with the fracture support band running through the whole is wrapped with a rubber sleeve 10, so that the cleavage surfaces in the core 9 overlap, so as to ensure the integrity of the core 9 and prevent the core 9 with the fracture support band running through the whole from being broken during the simulation process;

[0049] The rubber sleeve 10 is made of a temperature-resistant and pressure-resistant material; for example, the rubber sleeve 10 is a thermoplastic tube. Figure 2 shown.

[0050] In the embodiment of the present invention, the clamp 8 is connected to the infusion device 3 through a pipeline, and a displacement pressure pump 4 is provided on the pipeline. The displacement pressure pump 4 provides pressure for the scaling liquid in the infusion device 3 so that it can enter the clamp 8 and provide scaling liquid for the core 9;

[0051] The scaling liquid is used to scale the fracture support zone of the core 9, and includes a scaling anion solution and a scaling cation solution. For example, the scaling anion solution is formed by configuring NaCl, Na2SO4, NaHCO3 and water, and the scaling cation solution is formed by configuring CaCl2, MgCl2·2H2O, KCl and water. The scaling anion solution and the scaling cation solution are anions and cations in scaling of the fracture support zone of the simulated formation, which are familiar to those skilled in the art. The present invention does not limit the ion types and concentrations of the scaling anion solution and the scaling cation solution.

[0052] The infusion device 3 is used to inject scaling liquid into the core 9. Therefore, the number of the infusion devices 3 is at least two, so as to simultaneously inject the scaling anion solution and the scaling cation solution into the core 9.

[0053] If the scaling anion solution and the scaling cation solution are directly mixed in the infusion pump 3 and then input into the core 9, the solution in the infusion pump 3 will precipitate, making it difficult to displace the solution in the infusion pump 3, which may easily cause damage to the displacement pressure pump 4.

[0054] In certain embodiments of the present invention, the infusion pump 3 is connected to an oil barrel 1, and the oil barrel 1 is connected to a pressure pump 2. The pressure pump 2 uses the oil in the oil barrel 1 as a pressure source to drive the liquid in the infusion pump 3 into the displacement pressure pump 4.

[0055] In the embodiment of the present invention, the clamp 8 is connected to a plurality of waste liquid barrels 11 to facilitate the outflow and storage of the scaling liquid entering the core 9.

[0056] In certain embodiments of the present invention, a flow meter 13 is provided on the connecting pipeline between the clamper 8 and the waste liquid barrel 11 to facilitate the flow control and monitoring of the waste liquid.

[0057] In the embodiment of the present invention, a plurality of valves are provided on the connecting pipeline between the clamp 8 and the infusion set 3 and on the connecting pipeline between the clamp 8 and the waste liquid bucket 11;

[0058] Exemplarily, the connecting pipeline between the clamp 8 and the infusion device 3 includes the connecting pipeline between the clamp 8 and the displacement pressure pump 4, and the connecting pipeline between the displacement pressure pump 4 and the infusion device 3, wherein a valve is provided on the connecting pipeline between the clamp 8 and the displacement pressure pump 4, and when the scaling liquid is not input into the clamp 8, the valve is closed to ensure the closed environment in the clamp 8 and the stability of the pressure simulation and the temperature simulation; a valve is provided on the connecting pipeline between the displacement pressure pump 4 and the infusion device 3 to facilitate the input control of the scaling liquid in the infusion device 3;

[0059] A valve is provided on the connecting pipe between the clamp 8 and the waste liquid bucket 11 to ensure a closed environment in the clamp 8;

[0060] In certain embodiments of the present invention, a valve is provided on the connecting pipeline between the infusion pump 3 and the oil barrel 1 .

[0061] In certain embodiments of the present invention, the simulation device also includes a computing system 12, and the computing system 12 is connected to the signal of the nuclear magnetic resonance scanner 7, so that the T2 spectrum related data obtained by the nuclear magnetic resonance scanner 7 is acquired by the computing system 12. The computing system 12 can process the T2 spectrum related data to analyze the changes in pores in the support zone before and after scaling, and the distribution of scale in the microscopic pore throats.

[0062] In the embodiment of the present invention, the confining pressure control component 6 and the temperature control component 5 are both well known to those skilled in the art and will not be described in detail herein.

[0063] In some embodiments of the present invention, a method for simulating scaling of a rough fracture support belt with controllable temperature and pressure is also provided, the simulation method comprising:

[0064] Step 1: Install the core 9 with the fracture support band running through the core 9 in the holder 8 to form a closed space;

[0065] Step 2: Connect the clamp 8 holding the core 9 to the confining pressure control assembly 6 and the temperature control assembly 5;

[0066] Step 3, connecting the clamp 8 holding the core 9 to a plurality of infusion devices 3;

[0067] Step 4: Place the holder 8 holding the core 9 into the inspection room of the nuclear magnetic resonance scanner 7;

[0068] Step 5: setting a preset pressure on the core 9 through the confining pressure control assembly 6;

[0069] Step 6: Setting a preset temperature to the core 9 through the temperature control component 5;

[0070] Step 7: inject the scaling liquid into the core 9 held by the holder 8 through the infusion device 3;

[0071] Step eight: using the nuclear magnetic resonance scanner 7 to detect the distribution and intensity of hydrogen signals in the core 9 and the fractures at a preset pressure and a preset temperature.

[0072] Specifically, exemplarily, the scaling solution includes the following solution:

[0073] Prepare scaling cation solution; prepare 500ml solution: 0.01268mol / L CaCl2, 3.72733mol / LMgCl2·2H2O, 8.1747mol / L KCl;

[0074] Prepare scaling anion solution: Prepare 500ml solution: 0.25mol / LNaCl, 0.0233mol / LNa2SO4, 2.31*10-3mol / LNaHCO3;

[0075] The two scaling liquids are loaded into the two input liquids, and the simulation device is assembled according to the above steps 1, 2, 3, and 4, and then the steps 5, 6, 7, and 8 are performed in sequence;

[0076] In step five, step six and step seven, illustratively:

[0077] The preset pressure of the core 9 is set to 5MP as the confining pressure of the displacement pressure pump through the confining pressure control component 6, and the preset temperature of the core 9 is set to 60°C through the temperature control component 5;

[0078] The infusion speed of the infusion device 3 is set to a constant flow rate of 0.1 mL / min.

[0079] In step eight, the nuclear magnetic resonance scanner 7 is used to detect the distribution and intensity of hydrogen signals in the core 9 and the fractures at a preset pressure and a preset temperature. Specifically,

[0080] After the flow meter 13 shows stable readings, the first T2 spectrum scan is performed using the nuclear magnetic resonance scanner 7;

[0081] The preset pressure and the preset temperature, as well as the infusion speed of the liquid device are maintained unchanged. When the total input volume reaches a preset value, illustratively, 0.5 PV, the infusion to the clamp 8 is stopped, and a scan is performed once every 1 hour using the nuclear magnetic resonance scanner 7 (using the CPMG sequence). When the T2 spectrum curve is stable, the scanning is stopped and the currently stable T2 spectrum is recorded;

[0082] Keep the pressure constant, change the preset temperature of the core 9 through the temperature control component 5, illustratively to 50°C, and then use the nuclear magnetic resonance scanner 7 (using the CPMG sequence) to scan once every 1 hour, and record the T2 spectrum when the T2 spectrum curve is stable;

[0083] Keep the pressure constant, change the preset temperature of the core 9 through the temperature control component 5, illustratively to 40°C, repeat the above scanning steps of the nuclear magnetic resonance scanner 7, and record the T2 spectrum when the T2 spectrum curve is stable;

[0084] As described above, the pressure is kept constant, and the preset temperature is changed again to the core 9 through the temperature control component 5. The preset temperature changed each time is a decrease or increase of the initial preset temperature. In this embodiment, the preset temperature is set by 10° C. as an example.

[0085] Each time the nuclear magnetic resonance scanner 7 scans at a preset temperature, the operation is as described above, and a scan is performed once at a certain interval. When the T2 spectrum curve is stable, the T2 spectrum is recorded. In the embodiment of the present invention, the interval is 1 hour for example;

[0086] And in the embodiment of the present invention, the final preset temperature is 30°C.

[0087] In an embodiment of the present invention, the simulation method further includes:

[0088] The hydrogen signal distribution and intensity data in the core and fractures at the preset pressure and preset temperature detected by the nuclear magnetic scanner 7 are processed, specifically:

[0089] The pore radius after saturation of the water phase in the core is calculated by the calculation system using the T2 spectrum obtained by the nuclear magnetic scanner 7 (the T2 spectrum of the first scan, the stable T2 spectrum at 50°C, the stable T2 spectrum at 40°C, and the stable T2 spectrum at 30°C);

[0090] The specific calculation formula is as follows:

[0091]

[0092] In formula (1): T 2s is the transverse relaxation time; S / V is the ratio of the internal surface pore volume to the sample volume; ρ2 is the transverse relaxivity, which is the relaxation strength that characterizes the solid interaction.

[0093] The pore volume S can be regarded as the spherical volume, and the formula can be simplified to formula (2):

[0094] r=a*3*T2 (2)

[0095] In formula (2), r is the pore radius; a is the core property characteristic number, which is generally 3.3 for sandstone; T2 is the transverse relaxation time.

[0096] The final analysis results are as follows Figure 3 As shown, the T2 spectrum of the first scan is the T2 spectrum of the original core, and the obtained pore radius is the pore radius of the original core;

[0097] from Figure 3 It can be seen that at 60℃, the amount of scaling in the core is less, and the difference with the curve at room temperature is not big. When the pore radius is between 10nm-100nm and 1000nm-10000nm, the strength of the original core is slightly higher than that at 60℃, indicating that a small number of large pores and small pores are reduced due to scaling blockage, but the impact is small. When the temperature is 50℃, the intensity of the curve is greatly reduced for both large pores and small pores, indicating that after the temperature drops from 60℃ to 50℃, both large pores and small pores have serious scaling problems, and the scale blocks part of the pores, affecting the reservoir properties. After the temperature drops from 50℃ to 40℃, the intensity of the large pores exceeding 10000nm decreases slightly, and the intensity of the small pores 10nm increases, indicating that compared with 50℃, after the temperature drops to 40℃, the amount of scaling increases, and scaling in large pores causes the pore size to decrease to small pores, thereby increasing the number of small pores. When the temperature drops to 30°C, there is a phenomenon that large pores become fewer and small pores become more. However, after the temperature drops to 40°C, the intensity variation at the same relaxation time becomes smaller. Even after it drops to 30°C, the curve intensity is not much different, indicating that the degree of scaling has been relatively stable. After dropping from 60°C to 50°C, the temperature point with the highest degree of scaling is reached, so 50°C is the temperature at which scaling is most likely to occur.

[0098] In some other embodiments of the present invention, the simulation method is specifically:

[0099] Exemplarily, the scaling solution includes the following solution:

[0100] Prepare scaling cation solution; prepare 500ml solution: 0.01268mol / L CaCl2, 3.72733mol / LMgCl2·2H2O, 8.1747mol / L KCl;

[0101] Prepare scaling anion solution: Prepare 500ml solution: 0.25mol / LNaCl, 0.0233mol / LNa2SO4, 2.31*10 -3 mol / L NaHCO3;

[0102] The two scaling liquids are loaded into the two input liquids, and the simulation device is assembled according to the above steps 1, 2, 3, and 4, and then the steps 5, 6, 7, and 8 are performed in sequence;

[0103] In step five, step six and step seven, illustratively:

[0104] The confining pressure control component 6 sets a preset confining pressure of 30 MPa to the core, and the temperature control component 5 sets a preset temperature of the core to normal temperature;

[0105] The infusion rate of the infusion device was set to a constant flow rate of 0.1 mL / min.

[0106] In step eight, the nuclear magnetic resonance scanner 7 is used to detect the distribution and intensity of hydrogen signals in the core and fractures at a preset pressure and a preset temperature. Specifically, after the flow rate indication number is stabilized, the nuclear magnetic resonance scanner is used to perform the first T2 spectrum scan;

[0107] The preset pressure and the preset temperature, as well as the infusion speed of the liquid device are maintained unchanged. When the total input volume reaches a preset value, illustratively, 0.5 PV, the infusion to the holder is stopped, and a nuclear magnetic resonance scanner (using a CPMG sequence) is used to perform a scan once every 1 hour. When the T2 spectrum curve is stable, the scanning is stopped and the currently stable T2 spectrum is recorded;

[0108] Keep the temperature constant, change the preset pressure to the core through the confining pressure control assembly 6, illustratively to 25 MPa, repeat the above scanning steps of the nuclear magnetic resonance scanner 7, and record the T2 spectrum when the T2 spectrum curve is stable;

[0109] As described above, the temperature is kept constant, and the preset pressure is changed to the core again through the confining pressure control assembly 6. The preset pressure changed each time is a decrease or increase of the initial preset pressure. In this embodiment, the preset pressure is changed by decreasing by 5 MPa as an example.

[0110] Each time the nuclear magnetic resonance scanner 7 scans under the preset pressure, the operation is as described above, and the scanning is performed once at a certain interval. When the T2 spectrum curve is stable, the T2 spectrum is recorded. In the embodiment of the present invention, the interval is 1 hour for example;

[0111] And in the embodiment of the present invention, the final preset pressure is 10 MPa.

[0112] Then, the pore radius is calculated repeatedly according to formula (1) and formula (2) for the T2 spectrum of the first scan, the stable T2 spectrum at 30 MPa, the stable T2 spectrum at 25 MPa, the stable T2 spectrum at 20 MPa, the stable T2 spectrum at 15 MPa, the stable T2 spectrum at 10 MPa and the stable T2 spectrum at 5 MPa. The results are as follows: Figure 4As shown;

[0113] from Figure 4 It can be seen that as the pressure decreases, the scaling of large and small pores becomes more serious. As the pressure decreases, the curve shows an overall downward trend. When the pressure decreases from 25MPa to 15MPa, the pore size changes of both large and small pores are small. When the pressure decreases from 15MPa to 10MPa, the 10nm small pore size and the 1000nm large pore size both show a large decrease, indicating that after the pressure drops to 10MPa, the scaling of large and small pores is more severe, and 15MPa-10MPa is a jump point for scaling; similar situations occur at 10MPa and 5MPa. Although the confining pressure drops from 10MPa to 5MPa, the curve changes slightly. However, when the confining pressure drops to 1MPa, the 10nm small pore size and the 1000nm large pore size on the curve once again show a large decrease, indicating that 5MPa-1MPa is another jump point for scaling.

[0114] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature and pressure controllable rough fracture support belt scaling simulation device, characterized in that: It comprises a rock core (9) with a fracture support band running through the whole rock core and a clamp (8) clamped on the outer periphery of the rock core (9), wherein the clamp (8) is clamped on the outer periphery of the rock core (9) to form a closed space; The clamp (8) is connected to a confining pressure control component (6) and a temperature control component (5), wherein the confining pressure control component (6) is used to set a preset pressure on the core (9), and the temperature control component (5) is used to set a preset temperature on the core (9); The clamp (8) is connected to a plurality of infusion devices (3), and the infusion devices (3) are used to inject scaling liquid into the core (9); The holder (8) is placed in an inspection room of a nuclear magnetic resonance scanner (7), and the nuclear magnetic resonance scanner (7) is used to detect the distribution and intensity of hydrogen signals in the core (9) and cracks at a preset pressure and a preset temperature.

2. A temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 1, characterized in that: The outer surface of the core (9) is wrapped with a rubber sleeve (10).

3. A temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 2, characterized in that: The rubber sleeve (10) is made of a temperature-resistant and pressure-resistant material.

4. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 1, characterized in that: The clamp (8) is connected to the infusion set (3) via a pipeline, and a displacement pressure pump (4) is provided on the pipeline.

5. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 4, characterized in that: The number of the infusion devices (3) is at least two.

6. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 4, characterized in that: The infusion device (3) is connected to an oil barrel (1), and the oil barrel (1) is connected to a pressure pump (2).

7. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 1, characterized in that: The clamp (8) is connected to a plurality of waste liquid barrels (11).

8. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 7, characterized in that: A flow meter (13) is provided on the connecting pipeline between the clamp (8) and the waste liquid bucket (11).

9. The temperature and pressure controllable rough fracture support belt scaling simulation device according to claim 7, characterized in that: A plurality of valves are provided on the connecting pipeline between the clamp (8) and the infusion device (3), and on the connecting pipeline between the clamp (8) and the waste liquid bucket (11).

10. A temperature and pressure controllable rough fracture support belt scaling simulation device according to any one of claims 1 to 8, characterized in that: It also includes a computing system (12), which is connected to the nuclear magnetic resonance scanner (7) by signals.

11. A temperature and pressure controllable rough fracture support belt scaling simulation method, characterized in that: include: The core (9) with the fracture support band running through the core (9) is installed in a holder (8) to form a closed space; Connecting a clamp (8) holding a core (9) to a confining pressure control assembly (6) and a temperature control assembly (5); Connecting a clamp (8) holding a core (9) to a plurality of infusion devices (3); Place a holder (8) holding a rock core (9) into an inspection room of a nuclear magnetic resonance scanner (7); Setting a preset pressure on the core (9) through a confining pressure control assembly (6); Setting a preset temperature to the core (9) through a temperature control assembly (5); Injecting the scaling liquid into the core (9) held by the holder (8) through the infusion device (3); The nuclear magnetic resonance scanner (7) is used to detect the distribution and intensity of hydrogen signals in the core (9) and the cracks at a preset pressure and a preset temperature.

12. A temperature and pressure controllable rough fracture support belt scaling simulation method according to claim 11, characterized in that: Also includes: The hydrogen signal distribution and intensity data in the core (9) and the cracks at the preset pressure and preset temperature detected by the nuclear magnetic resonance scanner (7) are processed.

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