Method for testing hydraulic fracture face reproduction and combined proppant conductivity

Abstract

The application discloses a hydraulic fracture face reproduction and combined proppant conductivity testing method, which comprises the following steps: preparing a cylindrical sample and a flow guide plate body from obtained downhole cores, pouring concrete outside the cylindrical sample to form a standard cubic sample, and performing a hydraulic fracturing experiment on the standard cubic sample; performing three-dimensional laser scanning on the fracture of the cylindrical sample to extract a hydraulic fracture face, and carving the upper flow guide plate fracture face or the lower flow guide plate fracture face according to the extracted hydraulic fracture face; installing the upper flow guide plate fracture face and the lower flow guide plate fracture face in a flow guide chamber to perform a flow guide test, and calculating a proppant embedding degree value and a proppant crushing rate according to the test result. The application extracts the fracture face after the hydraulic fracturing experiment through three-dimensional laser scanning, obtains a numerical fracture face, carves a plurality of groups of flow guide plates with the same hydraulic fracturing fracture face by using a carving machine, and can truly obtain the flow guide capacity and embedding degree of mixed proppants of different quality quartz sand and ceramsite in the well.

Description

Technical Field

[0001] This invention relates to the field of unconventional shale oil and gas development, and in particular to a method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant. Background Technology

[0002] Shale gas wells initially produce high yields, but later, due to the long-term effects of closure stress, hydraulic fractures close, leading to a sharp decline in oil and gas production. Currently, the most effective method to prevent this decline is to prop up the hydraulic fractures. In field operations, quartz sand is used as a proppant due to its low hardness, high breakage rate, and poor conductivity. Ceramsite is used as a proppant because of its high strength, good conductivity, and low breakage rate, but its cost is high. To achieve the goal of increasing production, the two proppants need to be mixed in a specific mass ratio to increase shale oil production while reducing proppant costs. Therefore, it is urgent to study the conductivity of proppant mixtures with different mass ratios.

[0003] Currently, indoor flow-conducting physical simulation experiments are the best means to reveal the flow-conducting capacity of proppant in downhole shale hydraulic fractures. However, conventional flow-conducting experiments have the following three drawbacks: 1. The flow-conducting plates used in the flow-conducting experiments have smooth surfaces or are artificially split fracture surfaces. The flow-conducting capacity tested using the surface of a smooth flow-conducting plate as the fracture surface differs greatly from that of a real hydraulic fracture surface; 2. When using artificially split fracture surfaces as the flow-conducting fracture surfaces, the roughness and morphology of the split fracture surfaces are random. When testing the flow-conducting capacity of mixed proppants of different masses, the principle of a single variable is not followed, and the results are not comparable; 3. The rock samples used for the flow-conducting plates are usually shale outcrops, whose mechanical properties and mineral composition differ greatly from those of real downhole shale. Therefore, the measured flow-conducting capacity also has certain differences. Summary of the Invention

[0004] The main objective of this invention is to provide a method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant, aiming to obtain more accurate and comparable experimental results.

[0005] To achieve the above objectives, the present invention provides a method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant, comprising the following steps:

[0006] The obtained downhole core was used to make cylindrical specimens and guide plate bodies. Concrete was poured on the outside of the cylindrical specimens to form standard cubic specimens. After drilling a hole on the top of the standard cubic specimens to form a well hole, hydraulic fracturing experiments were carried out on the standard cubic specimens.

[0007] After the hydraulic fracturing experiment, the outer layer of cement of the standard cubic specimen was broken, and the crack of the cylindrical specimen was subjected to three-dimensional laser scanning to extract the hydraulic crack surface. Based on the extracted hydraulic crack surface, multiple guide vanes were engraved into the upper guide vane crack surface or the lower guide vane crack surface.

[0008] The upper and lower guide vane crack surfaces are installed in the flow chamber for flow guidance tests. Based on the test results, the proppant embedding degree and proppant breakage rate are calculated.

[0009] Preferably, the steps of preparing a cylindrical sample and a guide plate body from the obtained downhole core, pouring concrete around the cylindrical sample to form a standard cubic sample, drilling a hole above the standard cubic sample to form a wellbore, and then conducting a hydraulic fracturing test on the standard cubic sample specifically include:

[0010] The obtained downhole core was used to make cylindrical samples and guide plate bodies. Concrete was poured on the outside of the cylindrical sample to form a standard cubic sample. A well hole was drilled on the top of the standard cubic sample to form a well hole. The bottom of the well hole was compacted and filled with edible salt. The well tube was inserted into the well hole and the well tube was coupled to the well hole with black glue.

[0011] The experimental parameters were set according to the on-site construction parameters. Hydraulic fracturing experiments were conducted on standard cubic specimens. The experiment ended when the pump pressure dropped from the fracturing peak to 0.

[0012] Preferably, the on-site construction parameters include fracturing fluid viscosity, injection rate, and ground stress magnitude, while the experimental parameters include triaxial stress magnitude, fracturing fluid viscosity, and fracturing fluid discharge rate.

[0013] Preferably, the steps of breaking the outer cement layer of the standard cubic specimen after the hydraulic fracturing experiment, performing three-dimensional laser scanning on the cracks of the cylindrical specimen to extract the hydraulic crack surface, and carving the multiple guide vane bodies into the upper guide vane crack surface or the lower guide vane crack surface based on the extracted hydraulic crack surface specifically include:

[0014] Break the outer layer of cement from the standard cubic specimen, remove the cylindrical specimen, locate the surface cracks, and use an awl to completely open the hydraulic crack surface.

[0015] Remove debris and particles from the surface of the hydraulic fracture, spray a developer evenly on the fracture surface, and use a 3D profilometer to scan the two fracture surfaces that make up a fracture. Import the point cloud data of the two fracture surfaces into the software, encapsulate and synthesize a mesh surface, delete noise and fill holes, and trim and stitch the two fracture surfaces. The two fracture surfaces are then matched and their shape and size are the same as the guide plate, thus obtaining the point cloud data of the two fracture surfaces.

[0016] Based on the point cloud data of the two crack surfaces, the deflector body is made into either the upper deflector crack surface or the lower deflector crack surface.

[0017] Preferably, the step of fabricating the guide vane body into an upper guide vane crack surface or a lower guide vane crack surface based on the processed two crack surface data specifically includes:

[0018] Import the scanned point cloud data of the two crack surfaces into the software, establish a digital crack surface and smooth the crack surface, establish a guide plate coordinate system, obtain the coordinate point position of the point cloud, install and fix the guide plate on the carving mold, and control the 3D carving and guide plate carving accuracy according to the obtained point cloud data and smoothing programming to carve multiple sets of upper guide plate crack surfaces or lower guide plate crack surfaces.

[0019] Preferably, the step of installing the upper guide plate crack surface and the lower guide plate crack surface in the guide chamber, conducting a guide test, and calculating the proppant embedding degree value and proppant breakage rate based on the test results specifically includes:

[0020] Based on the on-site construction conditions, experimental injection rate, closure stress and sand concentration were set, and proppant mass was calculated.

[0021] Quartz sand and ceramsite are mixed in a certain proportion, and the crack surfaces of the upper and lower guide plates are installed in the guide chamber.

[0022] Apply closing stress to the flow guiding chamber and inject liquid into the flow guiding chamber. Observe the liquid outlet until no more bubbles emerge from the liquid outlet. Apply the closing stress to the target value to start the experiment and record the flow guiding experimental data.

[0023] The proppant embedding degree and proppant breakage rate were calculated based on the flow diversion experiment data.

[0024] Preferably, the step of mixing quartz sand and ceramsite in a certain proportion and installing the upper and lower guide vane crack surfaces in the guide chamber specifically includes:

[0025] Mix quartz sand and ceramsite in a certain proportion;

[0026] Insert the lower guide plate with the cracked side facing upward into the guide chamber, pour in the mixed quartz sand and ceramsite, brush the quartz sand and ceramsite evenly with a brush, and then insert the upper guide plate with the cracked side facing downward into the guide chamber.

[0027] Preferably, the step of calculating the proppant embedding degree value and proppant breakage rate based on the flow-guiding experiment data specifically includes:

[0028] The crack surfaces of the upper and lower guide vanes before and after the experiment were scanned, and the proppant embedding degree was calculated based on the scanning results.

[0029] The mixed proppant is collected, dried, and weighed to obtain mass a1. The mixed proppant is then sieved using the sieve with the smallest mesh size. The broken proppant that can pass through the sieve with the smallest mesh size is weighed to obtain mass a2. The mass a2 is compared with mass a1 to obtain the proppant breakage rate.

[0030] Preferably, the step of calculating the proppant embedding value based on the scanning results specifically includes: importing the scanned crack surface into the software, using Boolean operations, subtracting the crack surface before the experiment from the crack surface of the proppant-containing guide plate after the experiment to obtain the proppant indentation surface, filling the proppant indentation surface, and using the software to calculate the volume and number of fillers of the proppant indentation surface, and calculating the average filling volume as the proppant embedding value.

[0031] The proposed method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant involves extracting the fracture surface after a hydraulic fracturing experiment using three-dimensional laser scanning to obtain a numerical fracture surface. Multiple sets of proppant plates with the same hydraulic fracturing fracture surface are then carved onto a smooth proppant plate using a 3D engraving machine. This allows for the accurate determination of the conductivity and embedding degree of proppant mixtures of different masses of quartz sand and ceramsite in the well. Furthermore, by controlling a single variable, it is also beneficial to conduct multiple sets of proppant conductivity experiments with different mass ratios, resulting in more accurate and comparable experimental results. Attached Figure Description

[0032] Figure 1 This is a hydraulic fracturing experimental sample preparation diagram for the hydraulic fracture surface reproduction and combined proppant conductivity testing method of the present invention.

[0033] Figure 2 This is a flowchart illustrating the method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant according to the present invention.

[0034] Figure 3 for Figure 2 A detailed flowchart of step S1;

[0035] Figure 4 for Figure 2 A detailed flowchart of step S2;

[0036] Figure 5 for Figure 2 A detailed flowchart of step S3.

[0037] In the figure: 1. Cylindrical sample, 2. Cement, 3. Salt, 4. Well hole, 5. Stethoscope.

[0038] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0040] In this invention, reference is made to Figure 1 and Figure 2 A method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant includes the following steps:

[0041] Step S1: Prepare cylindrical specimens and guide plate bodies from the obtained downhole core. Pour concrete on the outside of the cylindrical specimen to form a standard cubic specimen. Drill a hole on the top of the standard cubic specimen to form a wellbore. Then conduct a hydraulic fracturing test on the standard cubic specimen.

[0042] Step S2: After the hydraulic fracturing experiment, the outer layer of cement of the standard cubic sample is broken, and the crack of the cylindrical sample is subjected to three-dimensional laser scanning to extract the hydraulic crack surface. Based on the extracted hydraulic crack surface, the bodies of multiple guide plates are engraved into the upper guide plate crack surface or the lower guide plate crack surface.

[0043] Step S3: Install the upper guide plate crack surface and the lower guide plate crack surface in the guide chamber and conduct a guide test. Calculate the proppant embedding degree value and proppant breakage rate based on the test results.

[0044] Reference Figure 3 Step S1 specifically includes:

[0045] Step S11: Prepare a cylindrical sample and a guide plate body from the obtained downhole core. Pour concrete on the outside of the cylindrical sample to form a standard cube sample. Drill a hole on the top of the standard cube sample to form a well hole. Fill the bottom of the well hole with edible salt and insert the well tube into the well hole and use black glue to couple the well tube to the well hole.

[0046] Step S12: Determine the experimental parameter settings based on the on-site construction parameters, and conduct a hydraulic fracturing experiment on the standard cubic sample. The experiment ends when the pump pressure drops from the fracturing peak to 0.

[0047] In step S12, the on-site construction parameters include fracturing fluid viscosity, injection rate, and ground stress magnitude, while the experimental parameters include triaxial stress magnitude, fracturing fluid viscosity, and fracturing fluid discharge rate.

[0048] Reference Figure 4 Step S2 specifically includes:

[0049] Step S21: Break the outer layer of cement of the standard cubic sample, take out the cylindrical sample, find the surface cracks and use an awl to completely open the hydraulic crack surface.

[0050] Step S22: Remove debris and particles from the surface of the hydraulic fracture, spray developer evenly on the fracture surface, use a 3D profilometer to scan the two fracture surfaces that make up a fracture, import the point cloud data of the two fracture surfaces into Geomagic software, encapsulate and synthesize a mesh surface, delete noise and fill holes, trim and stitch the two fracture surfaces, the two fracture surfaces can match and their shape and size are the same as the guide plate, thus obtaining the point cloud data of the two fracture surfaces.

[0051] Step S23: Based on the point cloud data of the two crack surfaces, the guide vane body is made into the upper guide vane crack surface or the lower guide vane crack surface.

[0052] Step S23 specifically includes: importing the scanned point cloud data of the two crack surfaces into JDPaint software, establishing a digital crack surface and smoothing the crack surface, establishing a guide plate coordinate system, obtaining the coordinate point positions of the point cloud, installing and fixing the guide plate on the carving mold, controlling the 3D carving and guide plate carving accuracy according to the obtained point cloud data and smoothing programming, and carving multiple sets of upper guide plate crack surfaces or lower guide plate crack surfaces.

[0053] Reference Figure 5 Step S3 specifically includes:

[0054] Step S31: Based on the on-site construction conditions, set the experimental injection rate, closure stress, and sand concentration, and calculate the proppant mass;

[0055] Step S32: Mix quartz sand and ceramsite in a certain proportion, and install the upper guide plate crack surface and the lower guide plate crack surface in the guide chamber;

[0056] Step S33: Apply closing stress to the flow guiding chamber and inject liquid into the flow guiding chamber. Observe the liquid outlet until no more bubbles emerge from the liquid outlet. Apply the closing stress to the target value to start the experiment and record the flow guiding experiment data.

[0057] Step S34: Calculate the proppant embedding degree and proppant breakage rate based on the flow diversion experiment data.

[0058] Step S32 specifically includes:

[0059] Step S321: Mix the quartz sand and ceramsite in a certain proportion;

[0060] Step S322: Insert the lower guide plate with the crack side facing upward into the guide chamber, pour in the mixed quartz sand and ceramsite, brush the quartz sand and ceramsite evenly with a brush, and then insert the upper guide plate with the crack side facing downward into the guide chamber.

[0061] Step S34 specifically includes:

[0062] Step S341: Scan the crack surfaces of the upper and lower guide vanes before and after the experiment, and calculate the proppant embedding degree value based on the scanning results.

[0063] Step S342: Collect, dry, and weigh the mixed proppant to obtain mass a1. Select the sieve with the smallest mesh size of the mixed proppant to sieve it. Weigh the broken proppant that can pass through the sieve with the smallest mesh size to obtain mass a2. The mass a2 is compared with the mass a1 to obtain the proppant breakage rate.

[0064] Step S341 specifically includes: importing the scanned crack surface into Geomagic software, using Boolean operations to subtract the crack surface before the experiment from the crack surface of the proppant-containing guide plate after the experiment to obtain the proppant indentation surface, filling the proppant indentation surface, and using Geomagic software to calculate the volume and number of fillers of the proppant indentation surface, and calculating its average filling volume as the proppant embedding degree value.

[0065] The following embodiment illustrates the method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant.

[0066] S1. Sample preparation and hydraulic fracturing test of downhole core.

[0067] The obtained downhole core samples were processed using wire cutting into cylindrical samples with a diameter of 100 mm and a height of 200 mm, and a guide plate with a length of 177 mm, a width of 37 mm, and a thickness of 10 mm, with smooth semi-circular surfaces at both ends. The cylindrical samples were placed horizontally and cast into standard cubic samples of 300 mm × 300 mm × 300 mm using high-strength cement (the axis of the cylindrical sample was perpendicular to the side of the standard cubic sample and 120 mm from the bottom). A wellbore with a diameter of 22 mm and a depth of 170 mm was drilled at the center of the top surface of the standard cubic sample. The bottom of the wellbore was filled with edible salt to a thickness of 20 mm. A wellbore with a diameter of 18 mm and a length of 150 mm was inserted into the wellbore and coupled to the wellbore with black glue.

[0068] Based on the relevant on-site construction parameters (fracturing fluid viscosity, injection rate, and ground stress magnitude), the parameters such as the magnitude of the triaxial stress, fracturing fluid viscosity, and discharge rate were determined based on the similarity criterion. The hydraulic fracturing experiment was then started, and the pump pressure change was observed. The experiment ended when the pump pressure dropped from the fracturing peak to 0.

[0069] S2. Extract the hydraulic fracture surface and carve the guide plate.

[0070] Break the outer layer of cement on the standard cubic specimen, remove the cylindrical specimen, locate the surface cracks, and use an awl to completely open the hydraulic crack surface.

[0071] Debris and particles on the surface of the crack are removed, and a developer is sprayed evenly on the crack surface. A high-precision 3D profilometer is used to scan the two crack surfaces that make up a crack. The point cloud data of the two crack surfaces after scanning are imported into Geomagic software, encapsulated and synthesized into a mesh surface, and deleting noise and filling holes. Then, the two crack surfaces are trimmed and spliced. The two crack surfaces that are processed can match and their shape and size are the same as the guide plate. They are used to make the crack surface of the upper guide plate and the crack surface of the lower guide plate, respectively.

[0072] The scanned point cloud data of the two crack surfaces were imported into JDPaint software to create a digital crack surface and smooth it. The processed numerical crack surface was then converted into more refined point cloud data. A guide plate coordinate system was established to obtain the coordinate points of the point cloud. The guide plate was then installed and fixed on the engraving mold. A JD-15-0.5 tapered ball end mill was selected. Based on the obtained point cloud data and smoothing programming, the 3D engraving and guide plate engraving accuracy were controlled. The crack surfaces of the upper and lower guide plates were engraved sequentially. Multiple guide plates with the same crack surface were engraved in a similar manner.

[0073] S3. Conduct flow testing and analyze proppant embedding degree and breakage rate.

[0074] Based on the on-site construction conditions, the experimental injection rate, closure stress, and sand concentration were set, and the proppant mass was calculated. Quartz sand and ceramsite (with a particle size of 0.125-0.85mm) were mixed in a certain mass ratio. First, the lower guide plate with its crack side facing upward was placed into the API proppant chamber, and the mixed quartz sand and ceramsite were poured in. The quartz sand and ceramsite were then brushed smooth with a brush. The upper guide plate with its crack side facing downward was then placed into the API proppant chamber. After the proppant chamber was installed, a closure stress of 1-2MPa was applied to it. The proppant chamber was injected at a rate of 5ml / min, and the outlet was observed. When no more bubbles emerged from the outlet, the closure stress was applied to the target value to start the experiment. The proppant experimental data were recorded. Similarly, the proppant conductivity of mixed proppant with different mass ratios of quartz sand and ceramsite was tested.

[0075] First, the crack surfaces of the upper and lower guide vanes before and after the experiment were scanned. The scanned crack surfaces were imported into Geomagic software. Using Boolean operations, the crack surface of the guide vane with proppant indentations after the experiment was subtracted from the crack surface before the experiment to obtain the proppant indentation surface. The proppant indentation surface was filled, and the volume and number of indentations filled were calculated using Geomagic software. The average filling volume was calculated to obtain the proppant embedding degree value. The mixed proppant was collected, dried, and weighed to obtain mass a1. The mixed proppant was sieved using the sieve with the smallest mesh size. The mass of broken proppant that could pass through the sieve with the smallest mesh size was weighed to obtain mass a2. The mass a2 was compared with mass a1 to obtain the proppant breakage rate.

[0076] The proposed method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant involves extracting the fracture surface after a hydraulic fracturing experiment using three-dimensional laser scanning to obtain a numerical fracture surface. Multiple sets of proppant plates with the same hydraulic fracturing fracture surface are then carved onto a smooth proppant plate using a 3D engraving machine. This allows for the accurate determination of the conductivity and embedding degree of proppant mixtures of different masses of quartz sand and ceramsite in the wellbore. Furthermore, by controlling a single variable, it facilitates conducting multiple sets of proppant conductivity experiments with different mass ratios, resulting in more accurate and comparable experimental results.

[0077] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant, characterized in that, Includes the following steps: The obtained downhole core was used to make cylindrical specimens and guide plate bodies. Concrete was poured on the outside of the cylindrical specimens to form standard cubic specimens. After drilling a hole on the top of the standard cubic specimens to form a well hole, hydraulic fracturing experiments were carried out on the standard cubic specimens. After the hydraulic fracturing experiment, the outer layer of cement of the standard cubic specimen was broken, and the crack of the cylindrical specimen was subjected to three-dimensional laser scanning to extract the hydraulic crack surface. Based on the extracted hydraulic crack surface, multiple guide vanes were engraved into the upper guide vane crack surface or the lower guide vane crack surface. The upper and lower guide plate crack surfaces are installed in the flow chamber for flow guidance test. The proppant embedding degree and proppant breakage rate are calculated based on the test results. The steps of breaking the outer cement layer of the standard cubic specimen after the hydraulic fracturing experiment, performing three-dimensional laser scanning on the cracks of the cylindrical specimen to extract the hydraulic crack surface, and carving multiple guide vane bodies into the upper guide vane crack surface or the lower guide vane crack surface based on the extracted hydraulic crack surface specifically include: Break the outer layer of cement from the standard cubic specimen, remove the cylindrical specimen, locate the surface cracks, and use an awl to completely open the hydraulic crack surface. Remove debris and particles from the surface of the hydraulic fracture, spray a developer evenly on the fracture surface, and use a 3D profilometer to scan the two fracture surfaces that make up a fracture. Import the point cloud data of the two fracture surfaces into the software, encapsulate and synthesize a mesh surface, delete noise and fill holes, and trim and stitch the two fracture surfaces. The two fracture surfaces are then matched and their shape and size are the same as the guide plate, thus obtaining the point cloud data of the two fracture surfaces. Based on the point cloud data of the two crack surfaces, the deflector body is made into either the upper deflector crack surface or the lower deflector crack surface. The step of fabricating the guide vane body into an upper guide vane crack surface or a lower guide vane crack surface based on the point cloud data of the two crack surfaces specifically includes: Import the scanned point cloud data of the two crack surfaces into the software, establish a digital crack surface and smooth the crack surface, establish a guide plate coordinate system, obtain the coordinate point position of the point cloud, install and fix the guide plate on the carving mold, and control the 3D carving and guide plate carving accuracy according to the obtained point cloud data and smoothing programming to carve multiple sets of upper guide plate crack surfaces or lower guide plate crack surfaces.

2. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in claim 1, characterized in that, The steps of preparing cylindrical specimens and guide vanes from the obtained downhole cores, pouring concrete around the cylindrical specimens to form standard cubic specimens, drilling a borehole above the standard cubic specimens to form a wellbore, and then conducting hydraulic fracturing experiments on the standard cubic specimens specifically include: The obtained downhole core was used to make cylindrical samples and guide plate bodies. Concrete was poured on the outside of the cylindrical sample to form a standard cubic sample. A well hole was drilled on the top of the standard cubic sample to form a well hole. The bottom of the well hole was compacted and filled with edible salt. The well tube was inserted into the well hole and the well tube was coupled to the well hole with black glue. The experimental parameters were set according to the on-site construction parameters. Hydraulic fracturing experiments were conducted on standard cubic specimens. The experiment ended when the pump pressure dropped from the fracturing peak to 0.

3. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in claim 2, characterized in that, The on-site construction parameters include fracturing fluid viscosity, injection rate, and ground stress magnitude, while the experimental parameters include triaxial stress magnitude, fracturing fluid viscosity, and fracturing fluid discharge rate.

4. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in any one of claims 1 to 3, characterized in that, The steps of installing the upper and lower guide plate crack surfaces in the flow guiding chamber, conducting flow guiding tests, and calculating the proppant embedding degree and proppant breakage rate based on the test results specifically include: Based on the on-site construction conditions, experimental injection rate, closure stress and sand concentration were set, and proppant mass was calculated. Quartz sand and ceramsite are mixed in a certain proportion, and the crack surfaces of the upper and lower guide plates are installed in the guide chamber. Apply closing stress to the flow guiding chamber and inject liquid into the flow guiding chamber. Observe the liquid outlet until no more bubbles emerge from the liquid outlet. Apply the closing stress to the target value to start the experiment and record the flow guiding experimental data. The proppant embedding degree and proppant breakage rate were calculated based on the flow diversion experiment data.

5. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in claim 4, characterized in that, The steps of mixing quartz sand and ceramsite in a certain proportion and installing the upper and lower guide vane crack surfaces in the guide chamber specifically include: Mix quartz sand and ceramsite in a certain proportion; Insert the lower guide plate with the cracked side facing upward into the guide chamber, pour in the mixed quartz sand and ceramsite, brush the quartz sand and ceramsite evenly with a brush, and then insert the upper guide plate with the cracked side facing downward into the guide chamber.

6. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in claim 4, characterized in that, The steps of calculating the proppant embedding degree and proppant breakage rate based on the flow-guiding experiment data specifically include: The crack surfaces of the upper and lower guide vanes before and after the experiment were scanned, and the proppant embedding degree was calculated based on the scanning results. The mixed proppant is collected, dried, and weighed to obtain mass a1. The mixed proppant is then sieved using the sieve with the smallest mesh size. The broken proppant that can pass through the sieve with the smallest mesh size is weighed to obtain mass a2. The mass a2 is compared with mass a1 to obtain the proppant breakage rate.

7. The method for reproducing hydraulic fracture surfaces and testing the conductivity of combined proppant as described in claim 6, characterized in that, The calculation of the proppant embedding value based on the scanning results specifically includes: importing the scanned crack surface into the software, using Boolean operations, subtracting the crack surface before the experiment from the crack surface of the proppant-containing guide plate after the experiment to obtain the proppant indentation surface, filling the proppant indentation surface, and using the software to calculate the volume and number of fillers of the proppant indentation surface, and calculating the average filling volume as the proppant embedding value.

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