A simulation experimental apparatus and method for proppant placement in horizontal well fractures

Abstract

This invention provides a simulation experimental device and method for proppant placement in horizontal well fractures, comprising a mixing tank, a horizontal pipe, a fracture system, and a collection tank. The mixing tank has a proppant-carrying fluid outlet connected to the inlet of the horizontal pipe, and the proppant-carrying fluid outlet of the horizontal pipe is connected to the collection tank. The fracture system is mounted on the horizontal pipe and is a transparent cylindrical structure including a main body. The main body has a cavity structure, and the cavity is divided circumferentially into four non-interconnected sub-chambers. The horizontal pipe has four perforations evenly distributed circumferentially, each of which corresponds to and communicates with one of the four sub-chambers. This device can more accurately simulate the proppant placement within fractures, thus providing a more reliable reference for actual operations.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, specifically relating to a simulation experimental device and method for proppant placement in horizontal well fractures. Background Technology

[0002] Perforation cluster efficiency refers to the proportion of perforation clusters in an oil well that successfully complete oil and gas extraction operations. According to industry rules of thumb, perforation cluster efficiency is approximately 70%, meaning that only about two-thirds of all perforation clusters contribute to production.

[0003] When the perforation holes are open normally, the main reason why perforation clusters fail to open and increase production is the density difference between the proppant and the fluid. The fluid and proppant do not move as a homogeneous mixture. This often results in non-uniform distribution of proppant in hydraulic fractures, producing unsupported or poorly conductive fractures, leading to low perforation cluster efficiency and significantly impacting oil and gas well productivity.

[0004] Non-uniform proppant distribution is the result of the combined forces of gravity, viscous drag, and forward thrust acting on the proppant. How the proppant is laid out and its distribution within the fracture (top, middle, bottom) depends on which force on the proppant is dominant, the fracturing operation parameters, and the well completion design. The influencing factors are complex, making laboratory simulations essential to guide the optimization of field operation parameters based on the required proppant distribution (top, middle, bottom) within the fracture for this specific well.

[0005] After hydraulic fracturing in a horizontal well, the fracture initiates at a certain angle to the wellbore. The fracture propagation direction rotates and twists, eventually extending along a direction perpendicular to the minimum principal stress. The rotation and twisting of the fracture surface can reduce the local width of the fracture, creating several non-connected sections within the fracture.

[0006] Traditional simulations of proppant placement within fractures typically involve simple, continuous fractures with two flat plates. Perforations are linearly distributed longitudinally along the fracture surface, and proppant is deposited at the bottom of the flat fracture plate. This fracture model fails to accurately reflect the actual distribution of perforations, neglects the discontinuities that occur within the fracture, and cannot simulate the specific distribution patterns and influencing factors of proppant in different parts of the fracture (top, middle, and bottom). Applying these experimental results to actual mining practices will hinder the optimization of fracturing parameters and scheme design in real-world mining environments, impacting reservoir stimulation effectiveness; for example: CN114061660A, Experimental apparatus and method for proppant delivery in simulated horizontal well multi-cluster double-wing hydraulic fractures, wherein the fracture simulation model in the apparatus is a flat plate structure.

[0007] CN112253072A, Rock fracture model and proppant transport and placement device and method within rock fracture, wherein the rock fracture model in the device includes a model body, the model body includes a first part and a second part, at least one surface of the first part is rough, at least one surface of the second part is rough, the rough surface of the first part and the rough surface of the second part can fit together and form a crack between the two surfaces. Summary of the Invention

[0008] The purpose of this invention is to provide a simulation experimental device and method for horizontal well fracture proppant placement, which solves the problem that the results of traditional fracture proppant placement simulation experiments are inaccurate, leading to a decrease in reservoir stimulation effect when applied in mining practice.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a simulation experimental device for proppant placement in horizontal well fractures, comprising a mixing tank, a horizontal pipe, a fracture system, and a collection tank, wherein: The mixing tank is provided with a sand-carrying liquid outlet, which is connected to the inlet of a horizontal pipe, and the sand-carrying liquid outlet of the horizontal pipe is connected to a collection tank. The crack system is mounted on a horizontal pipe. The crack system is a transparent cylindrical structure, including a main body. The main body is a cavity structure, and the cavity of the main body is divided into four non-interconnected sub-cavities along the circumference. The horizontal tube has four perforations evenly distributed along its circumference, and each of the four perforations is connected to one of the four sub-chambers.

[0010] Preferably, four sand-carrying liquid cleaning holes are evenly distributed circumferentially on the outer wall of the main body, and the four sand-carrying liquid cleaning holes are respectively connected to the four sub-chambers one by one.

[0011] Preferably, multiple crack systems are provided, and the multiple crack systems are arranged at equal intervals along the axial direction of the horizontal pipe.

[0012] Preferably, the spacing between two adjacent crack systems is 10.0~15.0 cm.

[0013] Preferably, the inner wall of the cavity of the body has a rough structure.

[0014] Preferably, the inner wall of the hollow body is evenly distributed with protrusions, the distance between two protrusions is 3.0~5.0mm, and the height of each protrusion is 0.5~1.5mm.

[0015] Preferably, a centrifugal pump is installed on the connecting pipe between the mixing tank and the horizontal pipe.

[0016] Preferably, a first valve is provided on the connecting pipe between the centrifugal pump and the mixing tank; a flow meter and a camera are sequentially provided on the connecting pipe between the centrifugal pump and the horizontal pipe.

[0017] Preferably, two pressure sensors are installed on the horizontal pipe, with the two pressure sensors located upstream and downstream of the crack system, respectively.

[0018] A method for simulating proppant placement in horizontal well fractures includes the following steps: Step 1: Based on the mine conditions, confirm the number of fracture systems and whether the inner wall of the fracture system is a smooth structure. Install the experimental device and check the integrity of the device and the reliability of the fracture system. Step 2: Weigh the required volume concentration of proppant; Step 3: Prepare the sand-carrying solution in the mixing tank; Step 4: Pump the sand-carrying liquid into the horizontal pipe until the experiment is completed; Step 5: Measure the proppant in the four sub-chambers of the fracture system to quantify the distribution of proppant at different locations within the fracture system.

[0019] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a simulation experimental device for proppant placement within horizontal well fractures. Because the fracture system is made of a transparent material, it allows observation of how the size and concentration of the proppant affect its distribution at different locations (top, middle, and bottom) within the fracture system, thus clarifying the specific settlement location of the proppant within the fracture system. The fracture system's interior is divided into four independent, non-communicating sub-chambers. By setting perforations on the horizontal pipe corresponding to each sub-chamber, it is ensured that the proppant can uniformly enter each sub-chamber, thereby simulating the uniform distribution of proppant in an actual horizontal well. After the experiment, By measuring the proppant in each sub-chamber, the distribution of proppant in the fracture system can be quantified. By simulating the environment of an actual horizontal well, this device can more accurately simulate the proppant placement within the fracture, thus providing a more reliable reference for actual operations. The device is simple in design, easy to operate, and easy to control experimental conditions and parameters, which is conducive to comparative experiments under different conditions and improves experimental efficiency. At the same time, by adjusting the properties of the proppant-carrying fluid in the mixing tank, the length and diameter of the horizontal pipe, and the parameters of the fracture system, the device can adapt to various experimental needs and simulate different geological conditions and engineering application scenarios.

[0020] This invention provides a simulation experiment method for proppant placement within horizontal well fractures. By simulating actual proppant placement within horizontal well fractures, this method specifically addresses potential problems encountered in field operations and enhances the guidance of experimental results for practical operations. This invention can precisely control parameters such as the properties of the proppant-carrying fluid, the type and concentration of the proppant, and the characteristics of the fracture system, thereby enabling a systematic study of the influence of various factors on the proppant placement effect. By measuring the proppant distribution in the four sub-chambers, the proppant placement within the fracture system can be quantitatively analyzed, providing a scientific basis for optimizing proppant use. Furthermore, this method provides a standardized experimental procedure, which helps improve the repeatability and comparability of experimental results, which is crucial for both scientific research and industrial applications. Attached Figure Description

[0021] Figure 1 This invention illustrates the distribution of 20-40 mesh proppant at different concentrations in a fracture system. Figure 2 This invention illustrates the distribution of 40-70 mesh proppant at different concentrations in a fracture system. Figure 3 This is a schematic diagram of the experimental apparatus described in an embodiment of the present invention; Figure 4 This is a schematic diagram of the crack system described in an embodiment of the present invention; Among them, 1-mixing tank; 2-first valve; 3-centrifugal pump; 4-flow meter; 5-first pressure sensor; 6-crack system 1; 7-horizontal pipe; 8-second pressure sensor; 9-collection tank; 10-second valve; 11-camera; 12-data acquisition unit; 13-computer; 14-sand-carrying fluid cleaning hole; 15-perforation hole. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0024] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0025] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0026] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0028] Example 1 This embodiment provides a simulation experimental device for proppant placement within horizontal well fractures. It allows observation of how proppant size and concentration affect proppant distribution at different locations (top, middle, and bottom) within the fracture, quantifying proppant distribution at different locations and clarifying the specific settlement location of the proppant within the fracture. The device's perforation distribution, fracture model, and proppant placement within the fracture more closely resemble real-world conditions, offering significant value for understanding and visualizing proppant movement dynamics. It can be used to optimize proppant placement methods and fracturing parameters, thereby improving fracturing effectiveness and success rates, and is an important tool for fracturing technology research.

[0029] The proppant transport dynamics can be decomposed into three stages: the horizontal tube, the perforation orifice, and the fracture system. This embodiment focuses on the proppant placement through the perforation orifice at different locations (top, middle, and bottom) within the fracture during hydraulic fracturing operations. Specifically: This embodiment provides a simulation experimental device for horizontal well fracture proppant placement. The device is a horizontal pipe loop with a fracture system, including a mixing tank 1, a horizontal pipe 7, a fracture system 6, and a collection tank 9, wherein: The mixing tank 1 is provided with a sand-carrying liquid outlet, which is connected to the inlet of the horizontal pipe 7, and the sand-carrying liquid outlet of the horizontal pipe 7 is connected to the collection tank 9. The crack system 6 is mounted on the horizontal pipe 7. The crack system 6 is a transparent cylindrical structure, including a body. The body is a cavity structure, and the cavity of the body is divided into four non-connected sub-cavities along the circumference. The horizontal tube 7 has four perforations evenly distributed along its circumference, and each of the four perforations is connected to one of the four sub-chambers.

[0030] In this embodiment, because the fracture system is made of a transparent material, it is possible to observe how the size and concentration of the proppant affect its distribution in different parts (top, middle, and bottom) within the fracture system, thus clarifying the specific settling location of the proppant within the fracture system. The inner cavity of the fracture system is divided into four independent, non-interconnected sub-chambers, and by setting perforations on the horizontal pipe corresponding to each sub-chamber, it is ensured that the proppant can uniformly enter each sub-chamber, thereby simulating the uniform distribution of proppant in an actual horizontal well. After the experiment, by measuring the proppant in each sub-chamber, the distribution of proppant in the fracture system can be quantified. By simulating the environment of an actual horizontal well, this device can more accurately simulate the proppant placement within the fracture, thus providing a more reliable reference for actual operations. The device has a simple design, is easy to operate, and allows for easy control of experimental conditions and parameters, which is beneficial for comparative experiments under different conditions and improves experimental efficiency. At the same time, by adjusting the properties of the sand-carrying fluid in the mixing tank, the length and diameter of the horizontal pipe, and the parameters of the fracture system, the device can adapt to various experimental needs and simulate different geological conditions and engineering application scenarios.

[0031] Example 2 This embodiment provides a simulation experimental device for proppant placement in horizontal well fractures, including a mixing tank 1, a centrifugal pump 3, a flow meter 4, a first pressure sensor 5, a fracture system 6, a horizontal pipe 7, a second pressure sensor 8, a data acquisition unit 9, a computer 10, and a collection tank 11, wherein: The sand-carrying liquid outlet is provided on the mixing tank 1. The sand-carrying liquid outlet is connected to the horizontal pipe 7 via the centrifugal pump 3. The sand-carrying liquid outlet of the horizontal pipe 7 is connected to the collection tank 9.

[0032] The outlet of the collection tank 9 is connected to the sand-carrying liquid inlet of the mixing tank 1, and a second valve 10 is provided on the connecting pipe between the collection tank 9 and the mixing tank 1.

[0033] A first valve 2 is installed on the connecting pipe between the mixing tank 1 and the centrifugal pump 3.

[0034] A flow meter 4 and a camera 11 are sequentially installed on the connecting pipe between the centrifugal pump 3 and the horizontal pipe 7.

[0035] The horizontal pipe 7 is fitted with a crack system 6.

[0036] Two pressure sensors (5, 8) are installed on the horizontal pipe 7. The two pressure sensors (5, 8) are located upstream and downstream of the crack system 6, respectively.

[0037] The crack system 6 is a cylindrical structure made of transparent material, including a body with a central through hole, which is then fitted onto a horizontal tube 7.

[0038] The main body has a hollow structure, and the cavity of the main body is divided into four non-connected sub-chambers along the circumference. The four sub-chambers are of equal size.

[0039] The horizontal pipe 7 has four perforations 15 evenly distributed along its circumference, and each of the four perforations 15 is connected to one of the four sub-chambers. Each sub-chamber represents the crack area that each perforation 15 can cover.

[0040] The outer wall of the main body has four sand-carrying liquid cleaning holes 14 evenly distributed along the circumference. The four sand-carrying liquid cleaning holes 14 are respectively connected to the four sub-chambers and are used to clean the sand-carrying liquid in the crack system 6.

[0041] In this embodiment, since the crack system 6 is made of a transparent material, it is possible to observe how the size and concentration of the proppant affect the distribution of the proppant in different parts (top, middle, and bottom) within the crack system 6, thereby clarifying the specific settlement location of the proppant within the crack system 6.

[0042] The device described in this embodiment more closely resembles real-world working conditions in terms of perforation distribution, fracture model, and proppant placement within the fracture. This is of great value for understanding and visualizing the dynamic movement of proppant. It can be used to optimize proppant placement methods and fracturing parameters, thereby improving fracturing effectiveness and success rates, and is an important tool for fracturing technology research.

[0043] Example 3 Based on Example 2, this example provides a simulation experimental device for proppant placement in horizontal well fractures. Two pressure sensors (5, 8), a camera 11, and a flow meter 4 are all connected to a data acquisition unit 12, and the output of the data acquisition unit 12 is connected to a computer 13.

[0044] Two pressure sensors are used to collect the pressure of the horizontal pipe 7 upstream and downstream of the crack system, respectively; The flow meter 4 is used to collect the discharge volume of the sand-carrying liquid entering the horizontal pipe 7; The camera 11 is used to capture the flow of sand-carrying fluid in the horizontal pipe 7.

[0045] In this embodiment, the centrifugal pump 3 and the flow meter 4 work together to effectively monitor the flow distribution and pressure changes, in order to meet different experimental requirements.

[0046] Example 4 Based on Example 1, this example provides a simulation experimental device for proppant placement in horizontal well fractures, wherein the fracture system 6 is a cylindrical structure with a diameter of 40~50cm and a height of 0.5~0.7cm.

[0047] The diameter of the perforation hole is 0.5~0.7cm.

[0048] Example 5 Based on Example 1, this example provides a simulation experimental device for proppant placement in horizontal well fractures. The inner wall of the cavity of the fracture system 6 is a rough structure, and the roughness of the inner wall is determined according to the lithology corresponding to the horizontal well reservoir.

[0049] Specifically: the inner wall of the hollow body is evenly distributed with protrusions, and the distance between two protrusions is 3.0~5.0mm.

[0050] The height of each bump is 0.5~1.5mm.

[0051] In this embodiment, the inner walls with different structures can be used to simulate crack walls with different roughness. At the same time, a disk with a suitable roughness can be selected according to different mine rock conditions.

[0052] Both the mixing tank 1 and the collecting tank 9 have a capacity of 1.0~2.0 m³. 3 .

[0053] The horizontal pipe 7 is used to simulate the wellbore of a horizontal well, and its diameter is 3.0~7.0cm and its length is 15.0~25.0cm.

[0054] Example 6 This embodiment provides a simulation experimental device for proppant placement in horizontal well fractures, comprising a mixing tank 1, a horizontal pipe 7, a fracture system 6, and a collection tank 9, wherein: The mixing tank 1 is provided with a sand-carrying liquid outlet, which is connected to the inlet of the horizontal pipe 7, and the sand-carrying liquid outlet of the horizontal pipe 7 is connected to the collection tank 9. Multiple crack systems 6 are provided, and the multiple crack systems are equidistantly mounted on the horizontal pipe 7 along the axial direction of the horizontal pipe 7.

[0055] The crack system 6 is a transparent cylindrical structure, including a main body. The main body is a cavity structure, and the cavity of the main body is divided into four non-interconnected sub-cavities along the circumference.

[0056] The horizontal pipe 7 is provided with multiple sets of perforations at equal intervals along its axial direction, and each set of perforations corresponds to a crack system 6.

[0057] Each group of perforations includes four perforation holes evenly distributed around the circumference of the horizontal pipe 7, and the four perforation holes are connected to the four sub-chambers of the fracture system 6 in a one-to-one correspondence.

[0058] In this embodiment, multiple crack systems 6 are set up to simulate multiple crack clusters, as required. Meanwhile, because the fracture system is made of a transparent material, it is possible to observe how the size and concentration of the proppant affect its distribution in different parts (top, middle, and bottom) within the fracture system, thus clarifying the specific settlement location of the proppant within the fracture system. The internal cavity of the fracture system is divided into four independent, non-interconnected sub-chambers, and by setting perforations on the horizontal pipe corresponding to each sub-chamber, it is ensured that the proppant can enter each sub-chamber uniformly, thereby simulating the uniform distribution of proppant in an actual horizontal well. After the experiment, by measuring the proppant in each sub-chamber, the distribution of proppant in the fracture system can be quantified. By simulating the environment of an actual horizontal well, this device can more accurately simulate the proppant placement within the fracture, thus providing a more reliable reference for actual operations. The device has a simple design, is easy to operate, and allows for easy control of experimental conditions and parameters, which is conducive to comparative experiments under different conditions and improves experimental efficiency. Furthermore, by adjusting the properties of the proppant-carrying fluid in the mixing tank, the length and diameter of the horizontal pipe, and the parameters of the fracture system, this device can adapt to various experimental needs and simulate different geological conditions and engineering application scenarios.

[0059] Example 7 Based on Example 6, this example provides a simulation experimental device for proppant placement in horizontal well fractures, wherein the distance between two adjacent fracture systems 6 is 10.0~15.0cm.

[0060] Example 8 This embodiment provides a simulation experiment method for proppant placement in horizontal well fractures, including the following steps: Step 1: Install the test device and connect the horizontal pipe 7 and the crack system 6 with appropriate roughness to the circuit according to the mine conditions; Step 2: Before the proppant is injected, the system integrity and crack system reliability need to be checked by circulating tap water to avoid any leaks in the circuit. Step 3: Perform a screening test on the proppant to be used in the test to ensure that the test proppant complies with the relevant API specifications; Step 4: Fill a certain amount of tap water into mixing tank 1, wherein the temperature of the tap water is 20-23°C; Step 5: Weigh the proppant to obtain the required proppant concentration; Step 6: Centrifugal pump 3 is on standby; turn on flow meter 4. Step 7: Camera 11 is turned on to record and capture the flow of sand-carrying fluid in the horizontal pipe 7; Step 8: Add the proppant obtained in step 5 to mixing tank 1; Step 9: Stir the proppant and water evenly before pumping; Step 10: When conducting the slick water test, the required concentration of drag-reducing agent needs to be added to mixing tank 1. Step 11: Mix and stir for 5 minutes to ensure that the water and proppant in mixing tank 1 are fully mixed to obtain the sand-carrying liquid; Step 12: Adjust centrifugal pump 3 to the required displacement and pump the sand-carrying liquid through horizontal pipe 7; depending on the tank capacity, the injection for high displacement test needs to last for 60 seconds, and for low displacement test it needs to last for 120 seconds. Step 13: Record the observation results of the proppant in the horizontal tube 7, the perforation hole 15, and the four sub-chambers of the fracture system using camera 11; Step 14: Record the readings of the pressure sensors (5, 8) before and after the crack system 6 through the data acquisition unit 12; Step 15: Stop pumping when the test time is completed; Step 16: Wait for all liquid to be completely drained from horizontal tube 7; Step 17: Record the volume of the sand-carrying liquid in collection tank 9; Step 18: Drain the liquid from collection tank 9; Step 19: Measure and record the amount of proppant that has settled in horizontal tube 7; Step 20: Record the volume of the sand-carrying fluid in the fracture system 6; Step 21: Drain the liquid from the crack system 6; Step 22: Measure and record the proppant entering the top, bottom, left, and right sub-chambers of the fracture system 6; this is to achieve quantitative distribution of proppant at different locations within the fracture system, clarify the specific settlement location of the proppant within the fracture, and determine the proppant size, concentration, and key liquid parameters that affect the sand-carrying and sand-suspending capacity of the slipway.

[0061] Step 23: Preheat oven to 120°C to dry the support agent; Step 24: Pump clean water to clean the device for future use; Step 25: If you need to test again, repeat steps 3 through 24.

[0062] In this embodiment, tap water carries proppant in two ways. The first way is to simulate pure water carrying sand. In this case, the mixing tank is filled with only pure water to the required volume, and then proppant is added to the tank at different concentrations. The second way is to add different concentrations of drag-reducing agent together with the proppant to increase the viscosity of the proppant-carrying liquid.

[0063] In this embodiment, because the fracture system is made of a transparent material, it is possible to observe how the size and concentration of the proppant affect its distribution in different parts (top, middle, and bottom) within the fracture system, thereby clarifying the specific settling location of the proppant within the fracture system. The inner cavity of the fracture system is divided into four independent, non-communicating sub-chambers, and by setting perforations on the horizontal pipe that correspond one-to-one with the sub-chambers, it is ensured that the proppant can enter each sub-chamber uniformly, thus simulating the uniform distribution of proppant in an actual horizontal well. After the experiment, by measuring the proppant in each sub-chamber, the distribution of the proppant in the fracture system can be quantified.

[0064] This application, by simulating actual proppant placement within horizontal well fractures, can precisely control parameters such as the properties of the proppant-carrying fluid, the type and concentration of the proppant, and the characteristics of the fracture system. This allows for a systematic study of the influence of various factors on the proppant placement effect. By measuring the proppant distribution in the four sub-chambers, the proppant placement within the fracture system can be quantitatively analyzed, providing a scientific basis for optimizing proppant use. Furthermore, this method provides a standardized experimental procedure, which helps improve the repeatability and comparability of experimental results, which is crucial for both scientific research and industrial applications.

[0065] Example 9 This embodiment provides a simulation experiment method for proppant placement in horizontal well fractures, including the following steps: Step 1: Based on the mine conditions, confirm the multiple fracture systems and the inner wall roughness of each fracture system, and connect the horizontal pipe 7 and the fracture system 6 with suitable roughness to the circuit; then check the integrity of the device and the reliability of the fracture system. Step 2: Weigh the required volume concentration of proppant, which conforms to the relevant API specifications; Step 3: Prepare the sand-carrying solution in the mixing tank; Step 4: Pump the sand-carrying fluid into the horizontal pipe, and use camera 11 to record and capture the flow of the sand-carrying fluid in the horizontal pipe 7, the perforation hole 15, and the four sub-chambers of the fracture system. The data acquisition unit 12 records the readings of the pressure sensors (5, 8) before and after the crack system 6 until the end of the experiment. Step 5: Measure the proppant in the four sub-chambers of the fracture system to quantify the distribution of proppant at different locations within the fracture system.

[0066] In this embodiment, by simulating the actual proppant placement within horizontal well fractures, this method specifically addresses potential problems encountered in field operations, enhancing the guidance of experimental results for practical operations. This invention can precisely control parameters such as the properties of the proppant-carrying fluid, the type and concentration of the proppant, and the characteristics of the fracture system, thereby enabling a systematic study of the influence of various factors on the proppant placement effect. By measuring the proppant distribution in the four sub-chambers, the proppant placement within the fracture system can be quantitatively analyzed, providing a scientific basis for optimizing proppant use. Furthermore, this method provides a standardized experimental procedure, helping to improve the repeatability and comparability of experimental results, which is crucial for both scientific research and industrial applications.

[0067] Example 10 This embodiment involves a simulation experiment of proppant placement in perforated fractures of a horizontal well in a limestone reservoir. The simulation uses 20-40 mesh ceramsite, 40-70 mesh ceramsite, and slickwater. The specific steps include: Step 1: Install the test apparatus and, based on the reservoir conditions of the horizontal well, select a single fracture system 6 to connect to the circuit. The mixing tank 1 and the collecting tank 9 in this apparatus each have a capacity of 1.5 m³. 3 The horizontal pipe 7 has a diameter of 5cm and a length of 20cm; the crack system 6 has a diameter of 45cm and a width of 0.65cm; the perforation hole diameter is 0.65cm.

[0068] The inner wall of the crack system 6 is uniformly distributed with protrusions, the distance between the protrusions is 4mm, and the height of the protrusions is 1mm.

[0069] Step 2: Use tap water to circulate in the device to check the integrity of the device and the reliability of the crack system. There are no leaks in the circuit. Step 3: Sieve analysis was performed on 20-40 mesh and 40-70 mesh ceramsite. All indicators of the ceramsite met the relevant specifications. Step 4: For 40-70 mesh ceramsite and 20-40 mesh ceramsite, respectively, apply 12 kg / m³ of water. 3 24 kg / m 3 and 36 kg / m 3 The volume concentration was tested; Step 5: Set the constant displacement of centrifugal pump 3 to 0.34 m³ / s. 3 / min, start the experiment; Step 6: During the experiment, camera 11 is used to record and capture the flow of sand-carrying fluid in the horizontal pipe 7, perforation hole 15, and the four sub-chambers of the fracture system. The data acquisition unit 12 records the readings of the pressure sensors (5, 8) before and after the crack system 6 until the end of the experiment. Step 7: After the experiment, the proppant in the four sub-chambers of the fracture system is measured to quantify the distribution of proppant at different locations within the fracture system.

[0070] The distribution of the two proppants in the entire fracture system 6 is as follows: Figure 1 and Figure 2 As shown in the figure. The results indicate that compared to 20-40 mesh proppant, 40-70 mesh proppant produced a more uniform distribution after passing through the perforation holes. However, it was found that although proppant entered the top of fracture system 6, no proppant sedimentation was observed in this part of the fracture system. This is mainly because gravity caused the proppant to flow back towards the horizontal tube 7. Since gravity plays a dominant role in controlling proppant sedimentation at the top of the fracture, the roughness and width of the fracture significantly improve the proppant distribution in the upper half of the fracture. Furthermore, increasing the proppant concentration leads to more proppant entering the fracture system, indicating that proppant concentration plays an important role in proppant distribution.

[0071] Therefore, this device can determine the proppant size, concentration, and key liquid parameters that affect the sand-carrying and sand-suspending capacity of slickwater.

[0072] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A simulation experimental device for proppant placement in horizontal well fractures, characterized in that, Includes a mixing tank, horizontal pipes, a cracking system, and a collection tank, wherein: The mixing tank is provided with a sand-carrying liquid outlet, which is connected to the inlet of a horizontal pipe, and the sand-carrying liquid outlet of the horizontal pipe is connected to a collection tank. The crack system is mounted on a horizontal pipe. The crack system is a transparent cylindrical structure, including a main body. The main body is a cavity structure, and the cavity of the main body is divided into four non-interconnected sub-cavities along the circumference. The horizontal tube has four perforations evenly distributed along its circumference, and each of the four perforations is connected to one of the four sub-chambers.

2. The experimental apparatus for simulating proppant placement in horizontal well fractures according to claim 1, characterized in that, The outer wall of the main body has four sand-carrying liquid cleaning holes evenly distributed along the circumference, and the four sand-carrying liquid cleaning holes are respectively connected to the four sub-chambers one by one.

3. The experimental apparatus for simulating proppant placement in horizontal well fractures according to claim 1, characterized in that, The crack system is provided in multiple ways, and the multiple crack systems are arranged at equal intervals along the axial direction of the horizontal pipe.

4. The horizontal wellbore proppant placement simulation experimental device according to claim 3, characterized in that, The spacing between two adjacent crack systems is 10.0~15.0 cm.

5. A simulation experimental device for proppant placement in horizontal well fractures according to any one of claims 1 to 4, characterized in that, The inner wall of the cavity of the body has a rough structure.

6. The horizontal wellbore proppant placement simulation experimental device according to claim 5, characterized in that, The inner wall of the hollow body is evenly distributed with protrusions, the distance between two protrusions is 3.0~5.0mm; the height of each protrusion is 0.5~1.5mm.

7. The experimental apparatus for simulating proppant placement in horizontal well fractures according to claim 1, characterized in that, A centrifugal pump is installed on the connecting pipe between the mixing tank and the horizontal pipe.

8. The horizontal wellbore proppant placement simulation experimental device according to claim 7, characterized in that, A first valve is installed on the connecting pipe between the centrifugal pump and the mixing tank; a flow meter and a camera are installed sequentially on the connecting pipe between the centrifugal pump and the horizontal pipe.

9. The experimental apparatus for simulating proppant placement in horizontal well fractures according to claim 1, characterized in that, Two pressure sensors are installed on the horizontal pipe, with the two pressure sensors located upstream and downstream of the crack system, respectively.

10. A method for simulating proppant placement in horizontal well fractures, characterized in that, Includes the following steps: Step 1: Based on the mine conditions, confirm the number of fracture systems and the roughness of the inner wall of the fracture systems, install the experimental device according to any one of claims 1-9, and check the integrity of the device and the reliability of the fracture system. Step 2: Weigh the required volume concentration of proppant; Step 3: Prepare the sand-carrying solution in the mixing tank; Step 4: Pump the sand-carrying liquid into the horizontal pipe until the experiment is completed; Step 5: Measure the proppant in the four sub-chambers of the fracture system to quantify the distribution of proppant at different locations within the fracture system.

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