Fracturing fluid drag reduction and dynamic sand carrying performance testing device and testing method

Abstract

The present application relates to the technical field of oil and gas field fracturing fluid performance evaluation, and particularly relates to a kind of fracturing fluid drag reduction and dynamic sand carrying performance testing device and testing method, wherein the testing device comprises: circulating pump, liquid supply unit and blowdown unit. By parallelly integrating straight pipe friction test branch and flat plate fracture test branch in the same test unit, and sharing the same circulating pump and liquid supply unit, one set of device has drag reduction performance test function and sand carrying performance test function, can realize significant reduction of equipment occupied space and substantial reduction of experimental cost, solves the technical problems of large equipment occupied space and high experimental cost caused by purchasing, installing and maintaining two independent devices in the prior art.

Description

Technical Field

[0001] This invention relates to the field of performance evaluation technology for fracturing fluids in oil and gas fields, and in particular to a testing device and method for testing the drag reduction and dynamic proppant carrying performance of fracturing fluids. Background Technology

[0002] Hydraulic fracturing is a crucial production enhancement measure in unconventional oil and gas reservoir development. During fracturing operations, fracturing fluid needs to flow at high speeds through surface manifolds and wellbore strings at high flow rates, while simultaneously carrying proppant into formation fractures to provide effective support. The drag-reducing properties of the fracturing fluid (determining the frictional pressure drop during pipeline transport) and its proppant-carrying capacity (determining the proppant's transport distance and placement pattern within the fracture) directly impact the design of pump pressure and flow rate during field operations, as well as the final fracture support effect. Therefore, accurately evaluating the drag-reducing and proppant-carrying properties of fracturing fluids under laboratory experimental conditions is of great significance for fracturing fluid system selection, drag-reducing agent evaluation, and construction parameter design.

[0003] Currently, most existing fracturing fluid performance evaluation devices test only a single property. Specifically: On the one hand, drag reduction performance testing devices typically use straight or curved pipes to simulate pipelines, evaluating their drag reduction effect by measuring the pressure difference between the two ends of the pipeline as the fracturing fluid flows through it. These devices generally consist of a storage tank, a circulating pump, a simulated test pipeline, a differential pressure sensor, and a flow meter, and can measure the frictional pressure drop of the fracturing fluid at different flow rates under certain temperature and pressure conditions. However, these devices only focus on the flow resistance characteristics of the fracturing fluid in the pipeline and do not address the migration behavior of the fracturing fluid carrying proppant within the fracture.

[0004] On the other hand, proppant-carrying capacity testing devices typically use flat plate fracture models to simulate formation fractures, observing the settlement, migration, and placement of proppant within the fractures through visualization. These devices generally consist of a mixing tank, a flat plate fracture model, a high-speed camera system, and a waste fluid recovery system. However, these devices only focus on the fracturing fluid's ability to carry proppant through fractures and do not address the drag-reduction performance of the fracturing fluid during pipeline transport.

[0005] The two types of experimental setups described above are typically independent of each other, each equipped with its own liquid storage system, pumping system, and control system. This functionally separated testing mode has the following drawbacks: First, the equipment occupies a large space, and the two sets of equipment need to be purchased, installed and maintained separately, which increases the experimental cost; Second, the testing system is redundantly configured, with each of the two sets of equipment equipped with independent pumping, metering and control units, resulting in low resource utilization. Third, the experimental process is fragmented, requiring operators to transfer samples and switch operations between different devices, resulting in low testing efficiency; Fourth, since the two tests were conducted on two separate sets of equipment, the pumping conditions, metering accuracy, and control parameters were not completely consistent, resulting in a lack of comparability of the test results for drag reduction performance and sand carrying performance under the same conditions, making it difficult to comprehensively and accurately evaluate the overall performance of the fracturing fluid.

[0006] Therefore, a technical solution is needed to address the technical problems in existing technologies, such as the independent nature of drag reduction performance testing devices and sand carrying performance testing devices, redundant equipment configuration, large space occupation, low testing efficiency, and difficulty in ensuring consistency in pumping conditions, metering accuracy, and control parameters between the two tests, resulting in a lack of comparability of test results under the same conditions. Summary of the Invention

[0007] The purpose of this invention is to overcome the technical problems in the prior art where the drag reduction performance testing device and the sand carrying performance testing device are independent of each other, the equipment is repeatedly configured, the space occupied is large, the testing efficiency is low, and the pumping conditions, metering accuracy and control parameters of the two tests are difficult to be consistent, resulting in the lack of comparability of test results under the same conditions. The invention provides a fracturing fluid drag reduction and dynamic sand carrying performance testing device and testing method.

[0008] In a first aspect, the present invention provides a fracturing fluid drag reduction and dynamic proppant carrying performance testing device, comprising: Circulating pump; The liquid supply unit includes a liquid mixing tank and a sand mixing tank. The liquid mixing tank is connected to the inlet pipe of the circulating pump, and the sand mixing tank is connected to the pipe between the liquid mixing tank and the circulating pump. The test unit has an inlet side connected to the outlet pipe of the circulating pump and an outlet side connected to the inlet pipe of the circulating pump. The test unit includes a straight pipe friction test branch and a flat plate crack test branch arranged in parallel. The sewage discharge unit is connected to the pipeline between the test unit and the circulation pump.

[0009] This invention discloses a fracturing fluid drag reduction and dynamic proppant carrying performance testing device, comprising four core components: a circulating pump, a fluid supply unit, a testing unit, and a sludge discharge unit. The fluid supply unit includes a mixing tank and a sand mixing tank. The mixing tank is connected to the inlet pipe of the circulating pump, and the sand mixing tank is connected to the pipe between the mixing tank and the circulating pump. The mixing tank is used to hold fracturing fluid base fluid without proppant for drag reduction performance testing. The sand mixing tank is used to hold sand-carrying fluid mixed with proppant for sand-carrying performance testing. The two tanks are connected to the inlet of the circulating pump through the pipeline and share the same circulating pump as the power source. By switching the on and off of different tanks and pipelines, the two test modes can be flexibly switched. The inlet side of the test unit is connected to the outlet pipe of the circulation pump, and the outlet side is connected to the inlet pipe of the circulation pump, forming a circulation loop. The test unit includes a straight pipe friction test branch and a flat plate fracture test branch set in parallel. The straight pipe friction test branch is used to simulate the surface manifold and wellbore string, and the drag reduction performance is evaluated by measuring the pressure difference when the fracturing fluid flows through the straight pipe. The flat plate fracture test branch is used to simulate formation fractures, and the proppant carrying capacity is evaluated by visually observing the migration behavior of proppant in the fracture. The two branches are set in parallel and share the same circulation pump and piping system. Different test branches can be selected for operation by switching valves, without interference between them. The sewage discharge unit is connected to the pipeline between the test unit and the circulation pump. It is used to discharge the sand-carrying liquid after it flows through the flat crack module during the sand-carrying performance test, so as to prevent the sand-carrying liquid from flowing back to the inlet of the circulation pump. The aforementioned device integrates the straight pipe friction test branch and the flat plate fracture test branch into the same circulation system, sharing the fluid supply unit and circulation pump. This effectively solves the technical problems of large space occupation, redundant equipment configuration, and low testing efficiency of existing independent devices. At the same time, since the two tests are performed on the same circulation pump and the same pipeline system, the pumping conditions, flow conditions, and control parameters are consistent, ensuring the comparability of drag reduction performance and sand carrying performance test results under the same conditions. This allows for a comprehensive and accurate evaluation of the overall performance of the fracturing fluid.

[0010] Preferably, the straight pipe friction test branch includes a first valve, a test pipe and a second valve connected in sequence through a pipeline, and also includes a differential pressure sensor, the two pressure measuring ends of which are respectively connected to the two ends of the test pipe.

[0011] The first and second valves enable independent on / off control of the straight pipe friction test branch. The branch is opened when drag reduction performance needs to be tested and closed during other tests to avoid interference with the parallel flat plate fracture test branch. Differential pressure sensors are installed at both ends of the test tube to accurately measure the friction pressure drop of fracturing fluid flowing through the test tube in real time, providing an accurate data basis for drag reduction rate calculation.

[0012] Preferably, the flat plate crack test branch pipe includes a third valve, a flat plate crack module, and a fourth valve connected in sequence through a pipeline, and also includes a monitoring system. The monitoring system is located outside the flat plate crack module and faces the flat plate crack module, and is used to collect images of the dynamic migration, settlement, and placement of the proppant within the flat plate crack module in real time. The flat plate crack module includes an upper plate and a lower plate. The upper plate has a first groove, and the lower plate has a second groove. The upper plate and the lower plate are connected by fasteners so that the first groove and the second groove enclose a cavity. The upper plate has a liquid inlet communicating with the cavity. The liquid inlet is connected to the third valve through a pipe. The lower plate has a liquid outlet communicating with the cavity. The liquid outlet is connected to the fourth valve through a pipe.

[0013] Independent on / off control of the flat plate fracture test branch is achieved through the third and fourth valves, which do not interfere with the straight pipe friction test branch. The flat plate fracture module simulates formation fractures. The monitoring system is set outside the module and facing the module. It can collect images of the dynamic migration, settlement and placement of proppant in the fracture in real time and non-invasively, so as to realize the visualization and quantitative evaluation of the proppant carrying capacity.

[0014] Preferably, it also includes an exhaust valve, which is disposed on a pipe on the outlet side of the test unit.

[0015] Before the test begins, open the vent valve to release the gas in the pipeline, ensuring that the test pipeline is filled with liquid. This prevents air bubbles from interfering with the accuracy of differential pressure measurement and the flow pattern of the sand-carrying liquid, thereby improving the accuracy and reliability of the test results.

[0016] Preferably, the sewage discharge unit includes a fifth valve and a waste liquid tank connected in sequence by a pipeline, the waste liquid tank is equipped with a filter, and the waste liquid tank is connected to a drain pipe.

[0017] After the sand-carrying performance test is completed, the fifth valve can be opened to discharge the sand-carrying liquid into the waste liquid tank; the filter inside the waste liquid tank can retain and recycle the proppant, and the liquid is discharged through the drain pipe, realizing the recycling and reuse of the proppant and avoiding resource waste and environmental pollution.

[0018] Preferably, the system further includes a sixth valve, which is disposed on the pipeline between the sewage unit and the circulation pump.

[0019] The sixth valve is located on the pipeline between the sewage unit and the inlet of the circulating pump. It is a shut-off valve between the sewage unit and the inlet of the circulating pump. During the sand carrying performance test, the sixth valve is kept closed to ensure that the sand carrying liquid can only be discharged through the sewage unit after flowing through the flat crack module.

[0020] Preferably, it also includes a flow meter, which is disposed on the pipe between the circulating pump and the inlet side of the test unit.

[0021] The flow meter monitors the liquid flow rate in the pipeline in real time. On the one hand, it can provide real-time feedback for operators to adjust the speed of the circulating pump, ensuring that the test flow rate accurately reaches the preset value. On the other hand, it can record the flow rate data in real time and collect it synchronously with the differential pressure data, providing complete experimental data support for the evaluation of drag reduction performance.

[0022] Preferably, it also includes a seventh valve, which is disposed on the pipeline between the flow meter and the circulating pump.

[0023] The seventh valve serves as the on / off control for the main liquid supply pipeline. During the test, opening the seventh valve connects the liquid supply unit to the circulating pump; closing the seventh valve after the test disconnects the liquid supply unit from the circulating pump, facilitating device maintenance and pipeline cleaning.

[0024] Preferably, the system further includes a control system, wherein the first valve, second valve, third valve, fourth valve, fifth valve, sixth valve, seventh valve, flow meter, differential pressure sensor, monitoring system and exhaust valve are electrically connected to the control system.

[0025] The control system enables automatic switching control of each valve, automatic acquisition and processing of data from flow meters and differential pressure sensors, and automatic recording and storage of images from the monitoring system. This reduces manual operation and human error, and improves the level of automation, testing efficiency, and data accuracy of the test.

[0026] In a second aspect, the present invention provides a method for testing the drag reduction and dynamic proppant carrying performance of fracturing fluid, including drag reduction performance testing and proppant carrying performance testing, using the fracturing fluid drag reduction and dynamic proppant carrying performance testing device as described above, the steps of which are as follows: Drag Reduction Performance Test S1: Add the test fracturing fluid base to the mixing tank; close the third, fourth, and fifth valves, and open the first, second, sixth, and seventh valves; S2: Start the circulation pump, open the vent valve, and close the vent valve after the gas in the pipeline is exhausted; the fracturing fluid base fluid enters the test unit through the circulation pump, flows through the straight pipe friction test branch, and then flows back to the inlet of the circulation pump through the pipeline to form a circulation flow. S3: Adjust the speed of the circulating pump to the preset flow rate value, the differential pressure sensor collects the differential pressure data at both ends of the test tube, the flow meter collects the flow rate data in the pipeline, and the control system records and stores the differential pressure and flow rate data; S4: Calculate the drag reduction rate of the fracturing fluid based on the measured differential pressure data; Sand-carrying performance test S1: Add the sand-carrying liquid mixed with proppant to the sand mixing tank; close the first valve, the second valve and the sixth valve, and open the third valve, the fourth valve, the fifth valve and the seventh valve; S2: Start the circulation pump, open the exhaust valve, and close the exhaust valve after the gas in the pipeline is exhausted. The sand-carrying liquid enters the test unit through the circulation pump, flows through the flat plate crack test branch, and is then discharged through the sewage discharge unit. S3: When the proppant-carrying fluid flows through the flat plate fracture module, the monitoring system collects images of the dynamic migration, settlement and placement of the proppant in the flat plate fracture module in real time, and the control system records and stores the image data. S4: Process the acquired images to evaluate the sand-carrying performance.

[0027] This invention relates to a testing device and method for testing the drag reduction and dynamic proppant carrying capacity of fracturing fluid: During the drag reduction performance test, fracturing fluid base fluid is added to the mixing tank. The mixing tank is connected to the circulating pump by switching valves, while the passage between the proppant tank and the circulating pump is cut off. After starting the circulating pump, the fracturing fluid base fluid is controlled by valves to flow only through the straight pipe friction test branch. The liquid flowing through the test pipe returns to the inlet of the circulating pump through the pipeline, forming a closed loop. The speed of the circulating pump is adjusted to the preset flow rate. The differential pressure sensor collects the differential pressure data at both ends of the test pipe in real time, and the flow meter collects the flow rate data. Finally, the drag reduction rate is calculated based on the differential pressure data. During the sand-carrying performance test, sand-carrying liquid is added to the sand mixing tank. The mixing tank is connected to the circulation pump by switching valves, while the passage between the dispensing tank and the circulation pump is cut off. After the circulation pump is started, the sand-carrying liquid is controlled by valves to flow only through the flat plate crack test branch. The sand-carrying liquid after flowing through the flat plate crack module is discharged through the sewage discharge unit. When the sand-carrying liquid flows through the flat plate crack module, the monitoring system collects images of the dynamic migration, settlement, and placement of the proppant in the crack in real time. Finally, the images are processed to evaluate the sand-carrying performance. In the above method, by integrating the straight pipe friction test branch and the flat plate fracture test branch in parallel into the same device, sharing the fluid supply unit and circulation pump, and coordinating valve switching to achieve free switching between the circulating flow mode for drag reduction performance testing and the direct discharge non-circulating mode for sand carrying performance testing, the drag reduction performance test and the sand carrying performance test can share a single testing device. This achieves the technical effects of reducing equipment space occupation, lowering experimental costs, and improving testing efficiency. At the same time, since the two tests are carried out on the same device under the same flow conditions, with consistent pumping conditions, metering accuracy, and control parameters, the technical effect of achieving good comparability of drag reduction performance and sand carrying performance test results under the same conditions is achieved, enabling a comprehensive and accurate evaluation of the overall performance of fracturing fluid.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a fracturing fluid drag reduction and dynamic proppant carrying performance testing device. By integrating a straight pipe friction test branch and a flat plate fracture test branch in parallel into the same test unit, and sharing the same circulating pump and fluid supply unit, a single device can simultaneously perform drag reduction performance testing and proppant carrying performance testing functions. This significantly reduces the space occupied by the equipment and greatly reduces the experimental cost, solving the technical problem of large equipment space and high experimental cost caused by the separate purchase, installation and maintenance of two independent devices in the prior art. 2. This invention provides a fracturing fluid drag reduction and dynamic proppant carrying performance testing device. By integrating the straight pipe friction test branch and the flat plate fracture test branch on the same circulating pump and the same pipeline system, the drag reduction performance test and the proppant carrying performance test are carried out on the same device under the same pumping and flow conditions. This solves the technical problem in the prior art where the two tests are carried out on two separate devices, and the pumping conditions and control parameters are difficult to be consistent, resulting in a lack of comparability of test results under the same conditions and difficulty in comprehensively and accurately evaluating the overall performance of fracturing fluid. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to the present invention; Figure 2 This is a cross-sectional structural diagram of the flat plate crack module described in this invention; Marked in the image: 1-Circulating pump, 201-Liquid mixing tank, 202-Sand mixing tank, 301-First valve, 302-Test tube, 303-Second valve, 304-Differential pressure sensor, 401-Third valve, 402-Plate crack module, 4021-Upper plate, 40211-First groove, 4022-Lower plate, 40221-Second groove, 4023-Fasteners, 4024-Elastic sealing ring, 403-Fourth valve, 404-Monitoring system, 501-Waste liquid tank, 502-Fifth valve, 6-Exhaust valve, 7-Sixth valve, 8-Flow meter, 9-Seventh valve. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0031] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0032] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0033] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0034] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0035] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0036] Example 1 like Figure 1 and Figure 2 As shown, a fracturing fluid drag reduction and dynamic sand-carrying performance testing device includes a circulating pump 1, a fluid supply unit, a testing unit, and a sewage discharge unit.

[0037] Circulation pump 1: This is the power source of the device. Its inlet end is connected to the pipeline of the supply unit, and its outlet end is connected to the pipeline on the inlet side of the test unit. Circulation pump 1 is used to pump the fracturing fluid base fluid or proppant-carrying fluid in the supply unit to the test unit and to provide driving force for the flow of liquid in the pipeline. Circulation pump 1 is preferably a screw pump or centrifugal pump with stepless speed regulation function. It can stably deliver fracturing fluid and proppant-carrying fluid in a wide flow range and has good passability for proppant particles in the proppant-carrying fluid, and is not prone to clogging and wear. A seventh valve 9 and a flow meter 8 are sequentially installed on the pipeline between the outlet end of the circulating pump 1 and the inlet side of the test unit. The seventh valve 9 is used to control the opening and closing of the pipeline between the outlet end of the circulating pump 1 and the test unit. The flow meter 8 is used to monitor the liquid flow rate in the pipeline in real time, providing real-time feedback for the operator to adjust the speed of the circulating pump 1, ensuring that the test flow rate accurately reaches the preset value, and simultaneously recording the flow data in real time, which is collected synchronously with the differential pressure data to provide complete experimental data support for the drag reduction performance evaluation.

[0038] Liquid supply unit: The liquid supply unit includes a liquid mixing tank 201 and a sand mixing tank 202. The liquid mixing tank 201 is connected to the inlet pipe of the circulating pump 1 through a first liquid supply pipe. The sand mixing tank 202 is connected to the first liquid supply pipe through a second liquid supply pipe. That is, the sand mixing tank 202 merges into the pipeline between the liquid mixing tank 201 and the circulating pump 1 through the second liquid supply pipe, thereby realizing the pipeline connection with the inlet of the circulating pump 1. The sand mixing tank 202 is used to hold the sand-carrying liquid mixed with proppant for sand-carrying performance testing. The two tanks are connected to the inlet of the circulation pump 1 through pipelines and share the same circulation pump 1 as the power source. By switching the on and off of different tanks and pipelines, the two test modes can be flexibly switched. The mixing tank 201 and the sand mixing tank 202 are equipped with a stirrer to maintain the homogeneity of the liquid and prevent the proppant from settling. The sand mixing tank 202 can also be equipped with a heating device to simulate the sand-carrying behavior of fracturing fluid under different temperature conditions.

[0039] Test unit: The inlet side of the test unit is connected to the outlet end pipe of the circulation pump 1, and the outlet side of the test unit is connected to the inlet end pipe of the circulation pump 1, thereby forming a loop for liquid circulation between the circulation pump 1 and the test unit. The test unit includes a straight pipe friction test branch and a flat plate crack test branch arranged in parallel. The straight pipe friction test branch includes a first valve 301, a test pipe 302, and a second valve 303 connected sequentially by a pipeline. The test pipe 302 is a straight pipe structure, and its inner diameter and length can be selected according to different specifications according to actual simulation needs. It is used to simulate surface manifolds and wellbore strings with different pipe diameters and lengths. Pressure measuring ports are provided at both ends of the test pipe 302. The two pressure measuring ends of the differential pressure sensor 304 are connected to the pressure measuring ports at both ends of the test pipe 302 through pressure taps. It is used to measure the pressure difference at both ends when the fracturing fluid flows through the test pipe 302 in real time. The straight pipe friction test branch is used to simulate surface manifolds and wellbore strings. The drag reduction performance is evaluated by measuring the pressure difference when the fracturing fluid flows through the straight pipe. The independent on / off control of the straight pipe friction test branch can be realized by opening and closing the first valve 301 and the second valve 303. The flat plate fracture test branch includes a third valve 401, a flat plate fracture module 402, and a fourth valve 403 connected sequentially by pipes. The flat plate fracture module 402 includes two parallel transparent plates, the spacing between which can be adjusted according to the required simulated fracture width to simulate formation fractures of different openings. The inlet and outlet ends of the flat plate fracture module 402 are equipped with flow equalization structures to ensure uniform flow of the proppant-carrying fluid after entering the fracture. The flat plate fracture test branch is used to simulate formation fractures, and the proppant-carrying performance is evaluated by visually observing the proppant migration behavior within the fracture. Independent on / off control of the flat plate fracture test branch can be achieved by opening and closing the third valve 401 and the fourth valve 403. A monitoring system 404 is located outside the flat plate fracture module 402 and faces it, used to acquire real-time images of the dynamic migration, settlement, and placement of the proppant within the flat plate fracture module 402. The flat plate fracture module 402 includes an upper plate 4021 and a lower plate 4021. 22. The upper plate 4021 has a first groove 40211, and the lower plate 4022 has a second groove 40221. The upper plate 4021 and the lower plate 4022 are fastened together by bolts. The first groove 40211 and the second groove 40221 are joined to form a cavity for the flow of fracturing fluid. An annular groove is provided on the top surface of the lower plate 4022, surrounding the second groove 40221. An elastic sealing ring 4024 is embedded in the annular groove. When 4022 is tightened, the elastic sealing ring 4024 seals the gap between the two. The left end face of the upper plate 4021 is provided with an inlet connected to the third valve, and the right end face of the lower plate 4022 is provided with an outlet connected to the fourth valve. The fracturing fluid enters through the inlet, flows through the cavity, and is discharged through the outlet. At the same time, the upper plate 4021 is made of transparent material, such as glass, or a transparent observation window is provided on the upper plate 4021. The monitoring system is set facing the transparent material area or the transparent observation window. Sewage Discharge Unit: The sewage discharge unit is connected to the pipeline between the outlet of the test unit and the inlet of the circulation pump 1. It is used to discharge the sand-carrying liquid after flowing through the flat crack module 402 during the sand-carrying performance test, preventing the sand-carrying liquid from flowing back to the inlet of the circulation pump 1. The sewage discharge unit includes a fifth valve 502 and a waste liquid tank 501 connected in sequence by pipelines. The waste liquid tank 501 is equipped with a filter, and a drain pipe is connected to the bottom or side wall of the waste liquid tank 501. The filter inside the waste liquid tank 501 can intercept and recycle the proppant, and the liquid is discharged through the drain pipe, realizing the recycling and reuse of the proppant. A sixth valve 7 is installed on the pipeline between the sewage discharge unit and the inlet end of the circulating pump 1. The sixth valve 7 is located on the pipeline between the outlet of the waste liquid tank 501 and the inlet end of the circulating pump 1. The sixth valve 7 is a shut-off valve between the sewage discharge unit and the inlet end of the circulating pump 1. It is kept closed during the sand carrying performance test and is used to cut off the connection path between the sewage discharge unit and the inlet end of the circulating pump 1.

[0040] This embodiment integrates the straight pipe friction test branch and the flat plate fracture test branch into the same circulation system, sharing the fluid supply unit and circulation pump 1. This effectively solves the technical problems of large space occupation, redundant equipment configuration, and low testing efficiency of the two independent devices in the prior art. At the same time, since the two tests are completed on the same circulation pump 1 and the same pipeline system, the pumping conditions, flow conditions, and control parameters are consistent, ensuring the comparability of the drag reduction performance and sand carrying performance test results under the same conditions, and enabling a comprehensive and accurate evaluation of the overall performance of the fracturing fluid.

[0041] In an optional implementation, an exhaust valve 6 can be installed on the outlet side of the test unit. Before the test begins, the exhaust valve 6 can be opened to release the gas in the pipeline, ensuring that the test tube 302 is filled with liquid, avoiding air bubbles from interfering with the differential pressure measurement accuracy and the flow pattern of the sand-carrying liquid, thereby improving the accuracy and reliability of the test results.

[0042] In an optional implementation, a control system may also be provided. The first valve 301, the second valve 303, the third valve 401, the fourth valve 403, the fifth valve 502, the sixth valve 7, and the seventh valve 9 are all electric valves. The first valve 301, the second valve 303, the third valve 401, the fourth valve 403, the fifth valve 502, the sixth valve 7, the seventh valve 9, the flow meter 8, the differential pressure sensor 304, and the monitoring system 404 are electrically connected to the control system. The control system is used to realize the automatic opening and closing control of each valve, the automatic acquisition and processing of data from the flow meter 8 and the differential pressure sensor 304, and the automatic recording and storage of images from the monitoring system 404.

[0043] Example 2 like Figure 1 As shown, this embodiment provides a method for testing the drag reduction and dynamic proppant carrying capacity of fracturing fluid, using the fracturing fluid drag reduction and dynamic proppant carrying capacity testing device described in Embodiment 1. The steps are as follows: Drag Reduction Performance Test S1: Add test fracturing fluid base to the mixing tank 201; close the third valve 401, the fourth valve 403 and the fifth valve 502, and open the first valve 301, the second valve 303, the sixth valve 7 and the seventh valve 9; S2: Start the circulation pump 1, open the exhaust valve 6, and close the exhaust valve 6 after the gas in the pipeline is exhausted; the fracturing fluid base fluid enters the test unit through the circulation pump 1, flows through the straight pipe friction test branch, and then flows back to the inlet end of the circulation pump 1 through the pipeline to form a circulating flow. S3: Adjust the speed of circulating pump 1 to the preset flow value, the differential pressure sensor 304 collects the differential pressure data at both ends of test tube 302, the flow meter 8 collects the flow data in the pipeline, and the control system records and stores the differential pressure and flow data; S4: Calculate the drag reduction rate of the fracturing fluid based on the measured differential pressure data; During the test, the displacement of circulating pump 1 can be adjusted to allow fracturing fluid to pass through the straight pipe friction test branch under different flow conditions, and the corresponding pressure difference can be recorded. By comparing the pressure difference of clean water, base fluid, and the fracturing fluid under the same flow conditions, the drag reduction rate of the fracturing fluid can be calculated. The drag reduction rate can be calculated using the following formula: Drag reduction rate = (Blank fluid pressure difference - Test fracturing fluid pressure difference) / Blank fluid pressure difference × 100% In the formula, the pressure difference of the blank fluid is the pressure difference of clean water or base fluid without drag-reducing agent at the same flow rate; the pressure difference of the fracturing fluid to be tested is the pressure difference of the fracturing fluid to be tested at the same flow rate.

[0044] Sand-carrying performance test S1: Add sand-carrying liquid mixed with proppant to sand mixing tank 202; close the first valve 301, the second valve 303 and the sixth valve 7, and open the third valve 401, the fourth valve 403, the fifth valve 502 and the seventh valve 9; S2: Start the circulation pump 1, open the exhaust valve 6, and close the exhaust valve 6 after the gas in the pipeline is exhausted. The sand-carrying liquid enters the test unit through the circulation pump 1, flows through the flat plate crack test branch, and is then discharged through the sewage discharge unit. S3: When the proppant-carrying fluid flows through the flat plate crack module 402, the monitoring system 404 collects images of the dynamic movement, settlement and placement of the proppant in the flat plate crack module 402 in real time, and the control system records and stores the image data. S4: Process the acquired images and evaluate the sand-carrying performance; In the dynamic sand-carrying performance test, manual weighing can be used to assist in calculating the sand-carrying rate. Before the test, weigh the mass of the proppant added to the sand mixing tank 202 and record it as m0. After the test, collect the proppant in the waste liquid tank 501 and the filter, clean it, dry it in an oven until constant weight, cool it, weigh it, and record it as m1. The dynamic sand-carrying rate can be calculated by the following formula: Dynamic sand carrying capacity = m1 / m0 × 100% In the formula, m0 represents the mass of proppant added to the mixing tank 202 before the test, in grams; m1 represents the mass of proppant recovered, cleaned, and dried from the waste liquid tank 501 and filter after the test, in grams. This result can be combined with the image results recorded by the high-definition monitoring system 404 to evaluate the ability of fracturing fluid to carry proppant through fractures.

[0045] If further analysis of the proppant retention in the crack is required, the flat plate crack test branch can be disassembled after the test, and the proppant remaining in the crack flow channel can be collected. After cleaning, drying and weighing, the proppant retention ratio in the crack can be calculated. This step is a supplement to the experimental data analysis and does not affect the basic structure of the device and the test procedure.

[0046] In summary, by setting up straight pipe friction test branches and flat plate fracture test branches in parallel and using valve groups to achieve selective connection of different test pipelines, the present invention can complete the fracturing fluid drag reduction performance test and dynamic sand carrying performance test in the same pumping, metering and control system.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for testing the drag reduction and dynamic proppant carrying capacity of fracturing fluid, characterized in that, include: Circulating pump (1); The liquid supply unit includes a liquid mixing tank (201) and a sand mixing tank (202). The liquid mixing tank (201) is connected to the inlet pipe of the circulating pump (1), and the sand mixing tank (202) is connected to the pipe between the liquid mixing tank (201) and the circulating pump (1). The test unit has an inlet side connected to the outlet pipe of the circulating pump (1) and an outlet side connected to the inlet pipe of the circulating pump (1). The test unit includes a straight pipe friction test branch and a flat plate crack test branch arranged in parallel. The sewage discharge unit is connected to the pipeline between the test unit and the circulation pump (1).

2. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 1, characterized in that, The straight pipe friction test branch includes a first valve (301), a test pipe (302), and a second valve (303) connected in sequence through a pipeline, and also includes a differential pressure sensor (304). The two pressure measuring ends of the differential pressure sensor (304) are respectively connected to the two ends of the test pipe (302).

3. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 2, characterized in that, The flat plate crack test branch includes a third valve (401), a flat plate crack module (402), and a fourth valve (403) connected in sequence through a pipeline, and also includes a monitoring system (404). The monitoring system (404) is located outside the flat plate crack module (402) and faces the flat plate crack module (402), and is used to collect images of the dynamic movement, settlement, and placement of the proppant inside the flat plate crack module (402) in real time. The flat plate crack module (402) includes an upper plate (4021) and a lower plate (4022). The upper plate (4021) is provided with a first groove (40211), and the lower plate (4022) is provided with a second groove (40221). The upper plate (4021) and the lower plate (4022) are connected by fasteners, so that the first groove (40211) and the second groove (40221) enclose a cavity. The upper plate (4021) is provided with a liquid inlet communicating with the cavity. The liquid inlet is connected to the third valve through a pipe. The lower plate (4022) is provided with a liquid outlet communicating with the cavity. The liquid outlet is connected to the fourth valve through a pipe.

4. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 3, characterized in that, It also includes an exhaust valve (6), which is installed on the pipe on the outlet side of the test unit.

5. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 4, characterized in that, The sewage discharge unit includes a fifth valve (502) and a waste liquid tank (501) connected in sequence by a pipeline. The waste liquid tank (501) is equipped with a filter and is connected to a drain pipe.

6. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 5, characterized in that, It also includes a sixth valve (7), which is installed on the pipeline between the sewage unit and the circulating pump (1).

7. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 6, characterized in that, It also includes a flow meter (8), which is installed on the pipe between the circulating pump (1) and the inlet side of the test unit.

8. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 7, characterized in that, It also includes a seventh valve (9), which is installed on the pipeline between the flow meter (8) and the circulating pump (1).

9. The fracturing fluid drag reduction and dynamic proppant carrying performance testing device according to claim 8, characterized in that, It also includes a control system, wherein the first valve (301), the second valve (303), the third valve (401), the fourth valve (403), the fifth valve (502), the sixth valve (7), the seventh valve (9), the flow meter (8), the differential pressure sensor (304), the monitoring system (404), and the exhaust valve (6) are electrically connected to the control system.

10. A method for testing the drag reduction and dynamic proppant carrying performance of fracturing fluid, comprising drag reduction performance testing and proppant carrying performance testing, using the fracturing fluid drag reduction and dynamic proppant carrying performance testing device as described in claim 9, the steps of which are as follows: Drag Reduction Performance Test S1: Add test fracturing fluid base fluid to the mixing tank (201); close the third valve (401), the fourth valve (403) and the fifth valve (502), and open the first valve (301), the second valve (303), the sixth valve (7) and the seventh valve (9); S2: Start the circulation pump (1), open the exhaust valve (6), and close the exhaust valve (6) after the gas in the pipeline is exhausted; the fracturing fluid base fluid enters the test unit through the circulation pump (1), flows through the straight pipe friction test branch, and then flows back to the inlet end of the circulation pump (1) through the pipeline to form a circulating flow; S3: Adjust the speed of the circulating pump (1) to the preset flow rate value, the differential pressure sensor (304) collects the differential pressure data at both ends of the test tube (302), the flow meter (8) collects the flow rate data in the pipeline, and the control system records and stores the differential pressure and flow rate data; S4: Calculate the drag reduction rate of the fracturing fluid based on the measured differential pressure data; Sand-carrying performance test S1: Add sand-carrying liquid mixed with proppant to the sand mixing tank (202); close the first valve (301), the second valve (303) and the sixth valve (7), and open the third valve (401), the fourth valve (403), the fifth valve (502) and the seventh valve (9); S2: Start the circulation pump (1), open the exhaust valve (6), and close the exhaust valve (6) after the gas in the pipeline is exhausted. The sand-carrying liquid enters the test unit through the circulation pump (1), flows through the flat crack test branch, and is then discharged through the sewage discharge unit. S3: When the proppant-carrying fluid flows through the flat plate crack module (402), the monitoring system (404) collects images of the dynamic movement, settlement and laying of the proppant in the flat plate crack module (402) in real time, and the control system records and stores the image data. S4: Process the acquired images to evaluate the sand-carrying performance.

Images