A comprehensive testing instrument for conductivity of proppant and core flow

Abstract

The application discloses a proppant conductivity and core flow comprehensive tester, and relates to the field of fluidity testing equipment. The proppant conductivity and core flow comprehensive tester comprises a liquid supply mechanism, a conductivity testing mechanism, a core flow testing mechanism and a receiving assembly. The liquid supply mechanism comprises a constant-flow constant-pressure pump and a liquid supply pipe connected to the constant-flow constant-pressure pump. A first liquid inlet pipe is connected between the liquid supply pipe and a liquid inlet of the conductivity testing mechanism. A second liquid inlet pipe is connected between the liquid supply pipe and a liquid inlet of the core flow testing mechanism. Liquid inlet control valves are arranged on the first liquid inlet pipe and the second liquid inlet pipe. The receiving assembly comprises a receiving pipe. A first liquid outlet pipe is connected between the receiving pipe and a liquid outlet of the conductivity testing mechanism. A second liquid outlet pipe is connected between the receiving pipe and a liquid outlet of the core flow testing mechanism. Liquid outlet control valves are arranged on the first liquid outlet pipe and the second liquid outlet pipe. The application has the capability of testing the proppant conductivity or the core flow performance, and has a comprehensive effect.

Description

Technical Field

[0001] This application relates to the field of fluidity testing equipment, and in particular to a comprehensive tester for proppant conductivity and core flow. Background Technology

[0002] In oil extraction, the conductivity of proppant and the flowability of core samples are core factors affecting oil and gas production. These two factors directly determine the final recovery rate of oil and gas wells by controlling the flow efficiency of fracture channels and formation fluids. Proppant conductivity is typically tested using a conductivity meter, which simulates formation conditions and measures the proppant's conductivity under different pressures. Core flowability is tested using a core flow meter, which assesses the flowability of the core by measuring its permeability under different fluid pressures.

[0003] Patent application CN102183796B discloses a test device for simulating proppant reflux, mainly composed of a storage tank, a chamber pump, a pipeline heating jacket, a flow meter, a flow guide chamber, a displacement sensor, a hydraulic press, a sand sample collector, a waste liquid tank, a data acquisition and control board, and a computer. In practical application, proppant is placed between two rock slabs and loaded into the flow guide chamber; the chamber pump is turned on to displace it at a small displacement; displacement sensors are installed on both sides of the hydraulic press and the pressure is increased to the design pressure; the computer, pipeline heating jacket, and heating rod are started, and the displacement of the chamber pump is adjusted. All data is transmitted to the computer through the data acquisition and control board; by gradually increasing the displacement, the critical flow rate of proppant reflux under a certain closing pressure is obtained; by gradually increasing the closing pressure, the critical flow rate of proppant reflux under different closing pressure conditions can be obtained.

[0004] However, the aforementioned testing device can only be used to test the conductivity of the proppant, and its function is relatively limited, leaving room for improvement. Utility Model Content

[0005] To improve upon the limited functionality of proppant conductivity testing devices in related technologies, this application provides a comprehensive testing instrument for proppant conductivity and core flow.

[0006] This application provides a comprehensive testing instrument for proppant conductivity and core flow, which adopts the following technical solution: A proppant conductivity and core flow comprehensive testing instrument includes a liquid supply mechanism, a flow testing mechanism, a core flow testing mechanism, and a receiving component. The liquid supply mechanism includes a constant flow and constant pressure pump and a liquid supply pipe connected to the constant flow and constant pressure pump. A first liquid inlet pipe is connected between the liquid supply pipe and the liquid inlet of the flow testing mechanism, and a second liquid inlet pipe is connected between the liquid supply pipe and the liquid inlet of the core flow testing mechanism. Both the first liquid inlet pipe and the second liquid inlet pipe are equipped with liquid inlet control valves. The receiving component includes a receiving tube, a first drain pipe is connected between the receiving tube and the liquid outlet of the flow guiding test mechanism, and a second drain pipe is connected between the receiving tube and the liquid outlet of the core flow test mechanism. Both the first drain pipe and the second drain pipe are equipped with a drain control valve.

[0007] By adopting the above technical solution, in practical applications, the two sets of inlet and outlet control valves can be controlled, allowing operators to switch between the proppant conduction testing mechanism and the core flow testing mechanism to perform corresponding testing operations according to actual testing needs. In this way, the comprehensive testing instrument can test both the proppant conduction capacity and core flow performance separately, making it quite versatile.

[0008] Preferably, the flow guiding test mechanism includes an operating table and a flow guiding base disposed on the operating table. A flow guiding chamber test groove is provided through the middle of the flow guiding base from top to bottom. A squeezing piston is embedded on both the upper and lower sides of the flow guiding chamber test groove. The two squeezing pistons are slidably connected to the flow guiding chamber test groove along the vertical direction. The operating table is also provided with a pressing component for pressing down the squeezing piston located on the upper side and a pressing component for pressing up the squeezing piston located on the lower side. The flow guide chamber test tank has connecting ports on its two opposite side walls in the horizontal direction. Each of the two connecting ports is equipped with a filter screen, and the two connecting ports are respectively connected to the first liquid inlet pipe and the first liquid outlet pipe.

[0009] By adopting the above technical solution, in practical applications, the upper squeezing piston can be removed first, the proppant can be placed in the flow chamber test tank, and then the upper squeezing piston can be installed. The lower pressure assembly and the top pressure assembly work together to apply pressure to the two squeezing pistons and apply pressure to the proppant, simulating the underground pressure environment, which helps to ensure the normal conduction of the proppant flow test.

[0010] Preferably, the operating table is provided with a mounting bracket, the pressing component is located above the flow guide base, the pressing component includes a positioning screw, the positioning screw is arranged downward, and the positioning screw is threadedly connected to the mounting bracket and used to press down the extrusion piston located on the upper side; The top-pressing assembly is located below the flow guide base. The top-pressing assembly includes a top-pressing cylinder, the piston rod of which is arranged upward and used to press against the extrusion piston located on the lower side.

[0011] By adopting the above technical solution, in practical applications, the positioning screw can be rotated to press down the extrusion piston located on the upper side, and the position of the proppant in the test tank of the flow chamber can be initially positioned and compacted; then, the top pressure cylinder presses down the extrusion piston located on the lower side to apply pressure to the proppant, simulating the underground pressure environment.

[0012] Preferably, the core flow testing mechanism includes an outer cylinder, both ends of which are detachably connected to a plugging ring. A rubber tube is also provided inside the outer cylinder, with both ends of the rubber tube embedded in and pressed against the plugging ring. A pressure space is formed between the rubber tube and the outer cylinder, and an injection pipe is provided on the outer cylinder, which is connected to the pressure space. Both of the plugging rings are threadedly connected to the inner side of the plugging rings, and both of the plugging rings are provided with a drainage channel along their axis. The two drainage channels are respectively connected to the second liquid inlet pipe and the second liquid outlet pipe. The outer cylinder is covered with a flexible heating element.

[0013] By adopting the above technical solution, before testing, the rock core can be obtained from underground or pre-obtained by compressing the corresponding rock material to simulate underground pressure and temperature environments. During testing, the rock core is placed inside a rubber tube, and two compression rods are tightened to clamp the rock core. High-pressure liquid is injected into the pressure space through an injection pipe to simulate underground pressure. Simultaneously, a flexible heating element heats the outer cylinder, and the rock core is heated through heat conduction to simulate underground temperature. This ensures the normal conduction of the rock core flow test.

[0014] Preferably, the liquid supply mechanism includes a piston container, the outlet of the constant flow and constant pressure pump is connected to one side chamber of the piston container, and the other side chamber of the piston container is connected to the liquid supply pipe.

[0015] By adopting the above technical solution, in practical applications, the test liquid can be placed in the chamber of the piston container connected to the supply pipe. The constant flow and constant pressure pump first draws the liquid and then supplies it to the lower part of the piston container, thereby squeezing the test liquid in the piston container and allowing the test liquid to enter the test process. This effectively reduces the corrosion of the supply pump by the test liquid and helps to ensure the stability of the test liquid supply during the test process.

[0016] Preferably, a silicon-saturated container for holding silicon sand is connected in series on the first liquid inlet pipe.

[0017] By adopting the above technical solution, during the experiment, the test liquid flows through the silicon-saturated container, and the silicon sand will release silicon elements, so that the test liquid reaches the silicon saturation state, simulating the underground fluid environment, thereby reducing the erosion of the proppant when flowing through it and ensuring the smooth progress of the experiment.

[0018] Preferably, a back pressure mechanism is connected in series in the middle of the receiving tube. The back pressure mechanism includes a back pressure body and a back pressure piston. A back pressure chamber is provided in the back pressure body. The back pressure piston is slidably disposed in the back pressure chamber. An inlet channel and an outlet channel are provided on the back pressure body. The inlet channel and the outlet channel are located on the same side of the direction of the back pressure piston. The inlet channel and the outlet channel are both connected to the back pressure chamber. The inlet channel is disposed opposite to the back pressure piston. The back pressure mechanism is connected in series to the receiving tube through the inlet channel and the outlet channel. The back pressure body is provided with a back pressure port on the side away from the inlet channel for supplying high-pressure fluid to the back pressure piston on the side away from the inlet channel.

[0019] By adopting the above technical solution, in practical applications, high-pressure liquid can be injected into the side of the back pressure chamber away from the inlet channel through the back pressure port to pressurize the back pressure piston. During the test, when the test liquid flows to the inlet channel, it will be intercepted by the back pressure piston, thereby giving the test liquid back pressure, stabilizing the flow state of the test liquid, further simulating the underground pressure environment, and helping to improve the accuracy of the test results.

[0020] Preferably, the back pressure port is connected to a buffer container, and the buffer container is also connected to a pressure pump.

[0021] By adopting the above technical solution, the buffer container has a large capacity, while the diameter of the back pressure port is relatively small. Through the buffer container, the impact of high pressure fluid pressure fluctuations on the back pressure body and back pressure piston can be reduced. In addition, the pressure loss of the fluid in the buffer container is relatively slow, which can relatively ensure the stability of the fluid pressure.

[0022] Preferably, the receiving tube is connected to a vacuum tube on the side of the back pressure mechanism near the first drain pipe. A one-way valve is connected in series in the middle of the vacuum tube to prevent gas and liquid from flowing back to the receiving tube through the vacuum tube, and a vacuum pump is connected to the end of the vacuum tube away from the receiving tube.

[0023] By adopting the above technical solution, the entire system is evacuated by a vacuum pump during testing, which reduces the interference of residual air in the pipeline, core, or support gaps on the test results, improves the accuracy of the simulated environment, and helps to improve the accuracy of the test results.

[0024] Preferably, the top pressure cylinder is a top pressure oil cylinder, and the oil inlet of the top pressure oil cylinder is connected to a first oil supply pipe, and the first oil supply pipe is connected to an oil supply pump; The receiving pipe is provided with a first pressure detection unit for detecting the fluid pressure inside the receiving pipe on the side of the back pressure mechanism near the first drain pipe, and a second pressure detection unit for detecting the fluid pressure inside the first oil supply pipe is provided on the first oil supply pipe. It also includes a control unit, which is electrically connected to the first pressure detection unit and the second pressure detection unit, and receives pressure signals transmitted by the first pressure detection unit and the second pressure detection unit; The control unit stores pressure thresholds and includes a calculation module and a comparison module. The calculation module is used to calculate the pressure difference between the pressure value measured by the second pressure detection unit and the pressure value measured by the first pressure detection unit. The comparison module is used to compare the pressure difference with the pressure threshold to obtain a comparison result; Furthermore, the control unit controls the oil supply pump to perform corresponding operations based on the comparison results.

[0025] By adopting the above technical solution, in practical application, the first pressure detection unit detects the back pressure of the fluid in the receiving pipe, the second pressure detection unit detects the fluid pressure in the first oil supply pipe, and according to the comparison results, the control unit promptly controls the oil supply pump to perform the corresponding operation, ensuring the stability of the simulated underground pressure environment, and helping to reduce the occurrence of excessive back pressure causing the test liquid to leak from the squeeze piston.

[0026] Preferably, the injection pipe is connected to a second oil supply pipe, and the second oil supply pipe is connected to an oil supply pump; The receiving pipe is provided with a first pressure detection unit for detecting the fluid pressure inside the receiving pipe on the side of the back pressure mechanism near the first drain pipe, and the second oil supply pipe is provided with a third pressure detection unit for detecting the fluid pressure inside the second oil supply pipe. It also includes a control unit, which is electrically connected to the first pressure detection unit and the third pressure detection unit, and receives pressure signals transmitted by the first pressure detection unit and the third pressure detection unit; The control unit stores pressure thresholds and includes a calculation module and a comparison module. The calculation module is used to calculate the pressure difference between the pressure value measured by the third pressure detection unit and the pressure value measured by the first pressure detection unit. The comparison module is used to compare the pressure difference with the pressure threshold to obtain a comparison result; Furthermore, the control unit controls the oil supply pump to perform corresponding operations based on the comparison results.

[0027] By adopting the above technical solution, in practical application, the first pressure detection unit detects the back pressure of the fluid in the receiving pipe, the third pressure detection unit detects the fluid pressure in the second oil supply pipe, and according to the comparison results, the control unit promptly controls the oil supply pump to perform corresponding operations, ensuring the stability of the simulated underground pressure environment, and helping to reduce the occurrence of excessive back pressure causing the test liquid to leak from the rubber tube and the plug ring. Attached Figure Description

[0028] Figure 1 This embodiment mainly illustrates a system diagram of a proppant conductivity and core flow integrated testing instrument; Figure 2 This is a schematic diagram illustrating the piston container structure, which is the main feature of this embodiment. Figure 3 This is a schematic diagram illustrating the structure of the flow guiding test mechanism in this embodiment; Figure 4 This is a schematic diagram illustrating the flow guide base, flow guide chamber test groove, and extrusion piston structure, which are the main components of this embodiment. Figure 5 This is a schematic diagram illustrating the structure of the top pressure assembly, which is the main feature of this embodiment. Figure 6 This is a schematic diagram illustrating the structure of the core flow testing mechanism in this embodiment; Figure 7 This is a cross-sectional view that mainly illustrates the internal structure of the core flow testing mechanism in this embodiment; Figure 8 This is a schematic diagram illustrating the structure of the back pressure mechanism, which is the main feature of this embodiment. Figure 9 This is a schematic diagram illustrating the top pressure cylinder and the oil supply system for the pressurized space, which are the main features of this embodiment.

[0029] Reference numerals: 1. Liquid supply mechanism; 11. Liquid supply pipe; 111. First control valve; 12. Water storage container; 13. Supply pump; 14. Piston container; 141. Receptacle; 142. Separating piston; 15. Bypass pipe; 151. Second control valve; 16. Flow supply pipe; 161. Third control valve; 2. Flow guiding test mechanism; 21. First inlet pipe; 211. Inlet control valve; 22. First outlet pipe; 221. Outlet control valve 23. Operating table; 231. Slide rail; 232. Mounting bracket; 24. Flow guide base; 241. Flow guide chamber test slot; 2411. Connecting port; 2412. Filter screen; 242. Extrusion piston; 2421. Pressure seat plate; 2422. Positioning rod; 243. Slider; 244. Heating rod; 25. Downward pressing assembly; 251. Positioning screw; 252. Turntable; 253. First pressure plate; 26. Top pressing assembly; 261. Top pressure cylinder; 2611, Top pressure oil cylinder; 262, Second pressure plate; 263, First oil supply pipe; 2631, Oil supply control valve; 27, Sliding frame; 3, Core flow testing mechanism; 31, Second liquid inlet pipe; 32, Second liquid outlet pipe; 33, Outer cylinder; 331, Plug ring; 332, Rubber hose; 333, Pressure application space; 334, Liquid injection pipe; 335, Extrusion rod; 3351, Drainage channel; 336, Flexible heating element; 33 7. Second oil supply pipe; 4. Receiving assembly; 41. Receiving pipe; 42. Electronic balance; 43. Collection container; 5. Silicon saturation container; 6. Back pressure mechanism; 61. Back pressure body; 611. Back pressure chamber; 612. Inlet channel; 613. Outlet channel; 614. Back pressure port; 62. Back pressure piston; 63. Buffer container; 64. Pressure pump; 7. Vacuum pipe; 71. Check valve; 72. Vacuum pump; 8. Oil supply pump; 9. Pressure sensor. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the accompanying drawings.

[0031] This application discloses a comprehensive testing instrument for proppant conductivity and core flow.

[0032] Reference Figure 1The proppant conductivity and core flow comprehensive testing instrument includes a liquid supply mechanism 1, a flow testing mechanism 2, a core flow testing mechanism 3, and a receiving component 4. The liquid supply mechanism 1 includes a liquid supply pipe 11, a first inlet pipe 21 connecting the liquid supply pipe 11 to the inlet of the flow testing mechanism 2, and a second inlet pipe 31 connecting the liquid supply pipe 11 to the inlet of the core flow testing mechanism 3. Both the first inlet pipe 21 and the second inlet pipe 31 are equipped with inlet control valves 211. The receiving component 4 includes a receiving pipe 41, a first drain pipe 22 connecting the receiving pipe 41 to the outlet of the flow testing mechanism 2, and a second drain pipe 32 connecting the receiving pipe 41 to the outlet of the core flow testing mechanism 3. Both the first drain pipe 22 and the second drain pipe 32 are equipped with drain control valves 221. In practical applications, the two sets of inlet control valves 211 and outlet control valves 221 are controlled, and the flow guiding test mechanism 2 and the core flow test mechanism 3 can be switched to perform corresponding test operations according to actual test requirements.

[0033] The liquid supply mechanism 1 includes a water storage container 12, a supply pump 13, and a piston container 14. The supply pump 13 is a constant flow and constant pressure pump. The pump port of the supply pump 13 is connected to the lower side of the water storage container 12, and the pump outlet is connected to the supply pipe 11. A first control valve 111 is connected in series in the middle of the supply pipe 11. The piston container 14 is placed vertically, and a receiving cavity 141 is formed inside the piston container 14. A dividing piston 142 is slidably disposed inside the receiving cavity 141, dividing the receiving cavity 141 into upper and lower chambers. Furthermore, the piston container 14 is hollow cylindrical, and the dividing piston 142 slides axially within the receiving cavity 141. The outlet of the supply pump 13 is also connected to a bypass pipe 15. The bypass pipe 15 is connected to the lower chamber of the receiving cavity 141 through the lower end of the piston container 14, and a second control valve 151 is connected in series in the middle of the bypass pipe 15. The upper end of the piston container 14 is connected to a supply pipe 16, which is connected to the upper chamber of the receiving cavity 141. The end of the supply pipe 16 away from the piston container 14 is connected to the side of the supply pipe 11 away from the supply pump 13, located at the first control valve 111. A third control valve 161 is connected in series on the supply pipe 16. To facilitate the addition of test liquid to the upper chamber of the piston container 14, a liquid addition pipe can be provided at the upper end of the piston container 14, and a liquid addition control valve can be provided on the liquid addition pipe. Alternatively, the upper end of the piston container 14 can be made detachable, such as by setting the upper end of the piston container 14 as a cover, and making the cover threadedly connected to the lower main body of the piston container 14.

[0034] In other embodiments, the integrated testing instrument can be configured with multiple piston containers 14 to hold different test liquids, and the bypass pipe 15, the second control valve 151, the supply pipe 16, and the third control valve 161 are all configured in a one-to-one correspondence with the piston containers 14. In practical applications, corrosive test liquids can be stored in the chamber of the piston container 14 near the supply pipe 16. When the first control valve 111 is opened and the second control valve 151 and the third control valve 161 are closed, the supply pump 13 directly supplies test liquids to the first inlet pipe 21 or the second inlet pipe 31 via the supply pipe 11. When the first control valve 111 is closed and the second control valve 151 and the third control valve 161 are opened, the supply pump 13 supplies liquid to the piston container 14 and pushes the test liquid in the piston container 14 to the first inlet pipe 21 or the second inlet pipe 31.

[0035] In other embodiments, the water in the storage container 12 can be deoxygenated using a deaerator. Using water directly as the test liquid helps ensure the accuracy of the test results.

[0036] Meanwhile, a silicon saturated container 5 for holding silicon sand is connected in series on the first liquid inlet pipe 21. The outside of the silicon saturated container 5 can be covered with a flexible heater. In order to facilitate the replacement of silicon sand, the silicon saturated container 5 can be mainly composed of a main cylinder and an end cap. One end of the main cylinder is open, and the end cap is threadedly connected to the open end of the main cylinder and closes the open end of the main cylinder.

[0037] See Figure 2 and Figure 3 The flow guiding test mechanism 2 includes an operating platform 23 and a flow guiding base 24. The flow guiding base 24 is slidably mounted on the operating platform 23 in a horizontal direction. A flow guiding chamber test groove 241 is formed through the center of the flow guiding base 24 from top to bottom. Squeezing pistons 242 are embedded and slidably connected to the upper and lower sides of the flow guiding chamber test groove 241. To improve the sealing between the squeezing piston 242 and the side wall of the flow guiding chamber test groove 241, multiple sealing rings can be arranged around the squeezing piston 242 at intervals. In addition, multiple heating rods 244 are also installed on the flow guiding base 24 to heat the proppant and the test fluid to simulate underground temperature. The operating platform 23 is also equipped with a pressing assembly 25 for pressing down the upper squeezing piston 242 and a pressing assembly 26 for pressing up the lower squeezing piston 242.

[0038] A slide rail 231 is fixed on the upper side of the operating table 23. The slide rail 231 is arranged along the sliding direction of the guide base 24. Two slide rails 231 are arranged in parallel at intervals. A sliding frame 27 is arranged on the lower side of the guide base 24. Sliding blocks 243 are fixed on the lower side of the sliding frame 27 on both sides. The two sliding blocks 243 are respectively slidably engaged with the two slide rails 231 to ensure the stability of the sliding of the guide base 24.

[0039] The lower side of the extrusion piston 242 has an integrally formed pressure seat plate 2421, which extends vertically through the sliding frame 27 and slides in cooperation with it. The flow chamber test tank 241 has connecting ports 2411 on its two opposite side walls in the horizontal direction. Each connecting port 2411 is equipped with a filter screen 2412, and the two connecting ports 2411 are respectively connected to the first inlet pipe 21 and the first outlet pipe 22. The filter screen 2412 is a metal filter screen, and its mesh size is smaller than the particle size of the proppant, thus preventing the proppant from passing through. To ensure that the position of the proppant in the flow chamber test slot 241 corresponds to the connecting port 2411, a positioning rod 2422 is provided on the pressure plate 2421. The positioning rod 2422 passes through the pressure plate 2421 from bottom to top and is threadedly connected to the pressure plate 2421. The lower end of the positioning rod 2422 has a hexagonal groove for easy rotation, and the upper end of the positioning rod 2422 abuts against the flow guide base 24. There is one positioning rod 2422 on each side of the pressure plate 2421. In actual use, the two positioning rods 2422 can be rotated to adjust the distance between the pressure plate 2421 and the flow guide base 24, thereby positioning the lower extrusion piston 242 in the flow chamber test slot 241. The lower end of the positioning rod 2422 is recessed into the inside of the pressure plate 2421.

[0040] A mounting bracket 232 is fixed on the operating table 23, and the pressing assembly 25 is mounted on the mounting bracket 232 and located above the flow guide base 24. The pressing assembly 25 includes a positioning screw 251, which is vertically downward and threadedly connected to the mounting bracket 232. Furthermore, a turntable 252 is coaxially fixed to the upper end of the positioning screw 251, and a first pressure plate 253 is coaxially fixed to the lower end of the positioning screw 251. To facilitate the positioning of the upper extrusion piston 242 by the pressing assembly 25, a scale can be set on the positioning screw 251 along its axial direction, enabling relatively accurate determination of the position of the extrusion piston 242.

[0041] See Figure 2 and Figure 4The operating platform 23 is hollow, and the top-pressing assembly 26 is located inside the operating platform 23 and below the flow guide base 24. The top-pressing assembly 26 includes a top-pressing cylinder 261, the cylinder body of which is fixed to the operating platform 23, and the piston rod of which extends vertically upward through the top plate of the operating platform 23. A second pressure plate 262 is coaxially fixed to the upper end of the piston rod of the top-pressing cylinder 261, and the second pressure plate 262 is located between two slide rails 231. In this embodiment, the top-pressing cylinder 261 is a top-pressing hydraulic cylinder 2611; the operating platform 23 can also be equipped with a displacement sensor, such as a magnetostrictive displacement sensor or a laser displacement sensor, to detect the position of the lower extrusion piston 242, and combine the position of the upper extrusion piston 242 with the area under the horizontal cross section of the flow guide chamber test groove 241 to calculate the volume of the proppant, so as to facilitate the calculation of the flow guiding capacity.

[0042] See Figure 5 and Figure 6 The core flow testing mechanism 3 includes an outer cylinder 33, with threaded plugging rings 331 at both ends. A rubber tube 332 is also installed inside the outer cylinder 33, with each end of the rubber tube 332 embedded in and pressed against the corresponding plugging ring 331. A pressure space 333 is formed between the rubber tube 332 and the outer cylinder 33, and the inner diameter of the plugging ring 331 is not less than the inner diameter of the rubber tube 332. An injection pipe 334 is installed on the outer cylinder 33, communicating with the pressure space 333. A squeezing rod 335 is threaded to the inner side of each of the two plugging rings 331, and a drainage channel 3351 is provided along the axis of each of the two squeezing rods 335. The two drainage channels 3351 are respectively connected to the second inlet pipe 31 and the second outlet pipe 32. Furthermore, a flexible heating element 336, which is also a flexible heater, is wrapped around the outer side of the outer cylinder 33.

[0043] Also see Figure 8 A backpressure mechanism 6 is connected in series in the middle of the receiving tube 41. The backpressure mechanism 6 includes a backpressure body 61 and a backpressure piston 62. The backpressure body 61 is a hollow column with a backpressure cavity 611 formed inside. The backpressure piston 62 is slidably disposed in the backpressure cavity 611 along the axial direction of the backpressure body 61. An inlet channel 612 and an outlet channel 613 are provided on the backpressure body 61. The inlet channel 612 and the outlet channel 613 are located on the same side along the axial direction of the backpressure body 61. Both the inlet channel 612 and the outlet channel 613 are connected to the backpressure cavity 611, and the inlet channel 612 is disposed opposite to the backpressure piston 62. The backpressure mechanism 6 is connected in series to the receiving tube 41 through the inlet channel 612 and the outlet channel 613. Furthermore, the end of the back pressure body 61 facing away from the inlet channel 612 is provided with a back pressure port 614 for supplying high-pressure fluid to the back pressure chamber 611 located on the side of the back pressure piston 62 facing away from the inlet channel 612. The back pressure port 614 is connected to a buffer container 63, and the buffer container 63 is also connected to a pressure pump 64.

[0044] In practical applications, the pressure pump 64 draws liquid and supplies it to the buffer container 63, which then supplies it to the back pressure chamber 611 located on the side of the back pressure piston 62 near the back pressure port 614. During the test, when the test liquid flows to the inlet channel 612, it is intercepted by the back pressure piston 62, thereby giving the test liquid back pressure and improving the accuracy of the test results.

[0045] See Figure 1 and Figure 3 The receiving assembly 4 also includes an electronic balance 42 and a collection container 43. The electronic balance 42 is placed inside the operating table 23, and the collection container 43 is placed on the electronic balance 42. The end of the receiving tube 41 facing away from the first drain pipe 22 extends into the collection container 43. The liquid discharged from the receiving tube 41 is weighed by the electronic balance 42 to calculate the proppant conductivity and core flow capacity.

[0046] The receiving tube 41 is located on the side of the back pressure mechanism 6 near the first drain pipe 22 and is connected to a vacuum tube 7. A one-way valve 71 is connected in series in the middle of the vacuum tube 7 to prevent gas and liquid from flowing back to the receiving tube 41 through the vacuum tube 7. A vacuum pump 72 is connected to the end of the vacuum tube 7 away from the receiving tube 41. During testing, the system is evacuated by the vacuum pump 72 to reduce the interference of air on the test results and improve the accuracy of the simulated environment.

[0047] See Figure 9 In this embodiment, the top-pressing cylinder 2611 can be a single-acting cylinder. The top-pressing cylinder 2611 extends the piston rod by supplying oil to the lower cavity of the piston. The return stroke of the piston rod can be pushed by the outer thrust.

[0048] The inlet of the top-pressure cylinder 2611 is connected to the first oil supply pipe 263, and the injection pipe 334 is connected to the second oil supply pipe 337. Both the first oil supply pipe 263 and the second oil supply pipe 337 are equipped with oil supply control valves 2631. The first oil supply pipe 263 is connected to an oil supply pump 8, and the outlet of the oil supply pump 8 is connected to both the first oil supply pipe 263 and the second oil supply pipe 337. A first pressure detection unit for detecting the fluid pressure inside the receiving pipe 41 is located on the side of the back pressure mechanism 6 near the first discharge pipe 22. A second pressure detection unit for detecting the fluid pressure inside the first oil supply pipe 263 is located on the side of the first oil supply control valve 2631 near the top-pressure cylinder 2611. A third pressure detection unit for detecting the fluid pressure inside the second oil supply pipe 337 is located on the side of the second oil supply control valve 2631 near the injection pipe 334.

[0049] The first pressure detection unit, the second pressure detection unit, and the third pressure detection unit are electrically connected to a control unit, which receives pressure signals transmitted from the first pressure detection unit, the second pressure detection unit, and the third pressure detection unit.

[0050] The control unit stores pressure thresholds and includes a calculation module and a comparison module. The calculation module calculates the pressure difference between the pressure measured by the second pressure detection unit and the pressure measured by the first pressure detection unit; it also calculates the pressure difference between the pressure measured by the third pressure detection unit and the pressure measured by the first pressure detection unit. The comparison module compares the pressure differences with the pressure thresholds to obtain a comparison result.

[0051] Finally, the control unit controls the oil supply pump 8 to perform the corresponding operation based on the comparison results.

[0052] The first, second, and third pressure detection units can all be pressure sensors 9. The pressure threshold is a pressure range, and can be set according to different simulated underground environments at different depths. The control unit can be a computer, PLC controller, etc.

[0053] For example, in the proppant conductivity test, the third pressure detection unit is off, the first pressure detection unit detects the back pressure in the receiving pipe 41, and the second pressure detection unit detects the oil pressure in the first oil supply pipe 263. The pressure threshold can be set to [30-40] MPa. When the pressure difference between the pressure value measured by the second pressure detection unit and the pressure value measured by the first pressure detection unit is less than 30 MPa, the control unit controls the oil supply pump 8 to increase its power and pressurize the top pressure cylinder 2611, reducing the leakage of test liquid between the extrusion piston 242 and the side wall of the flow guide chamber test tank 241; when the pressure difference is within the range of [30-40] MPa, the control unit controls the oil supply pump 8 to maintain its power and keep the test operation running normally; when the pressure difference is greater than 40 MPa, the control unit controls the oil supply pump 8 to reduce its power to ensure the stability of the test operation and the accuracy of the test results.

[0054] During the core flowability test, the second pressure detection unit is shut down, the first pressure detection unit detects the back pressure in the receiving pipe 41, and the third pressure detection unit detects the oil pressure in the second oil supply pipe 337. The pressure threshold can also be set to [30-40] MPa. When the pressure difference between the pressure value measured by the third pressure detection unit and the pressure value measured by the first pressure detection unit is less than 30 MPa, the control unit controls the oil supply pump 8 to increase its power to pressurize the pressure application space 333, reducing the possibility of leakage of the test liquid between the rubber tube 332 and the plug ring 331; when the pressure difference is within the range of [30-40] MPa, the control unit controls the oil supply pump 8 to maintain its power to ensure the normal operation of the test; when the pressure difference is greater than 40 MPa, the control unit controls the oil supply pump 8 to reduce its power to ensure the stability of the test and the accuracy of the test results.

[0055] It should be noted that both the top-pressure cylinder 2611 and the pressure application space 333 are designed to create the corresponding underground environment. During the testing operation, the top-pressure cylinder 2611 will apply significant pressure to the proppant, and the fluid within the pressure application space 333 will apply significant pressure to the core. Simultaneously, the pressure values ​​measured by the second and third pressure detection units are both greater than the pressure difference measured by the first pressure detection unit.

[0056] In addition, flow meters, pressure sensors, thermometers, differential pressure sensors, etc., can be installed on the entire fluid flow system as needed. For example, a flow meter can be installed on the side of the supply pipe 11 near the first inlet pipe 21 to monitor the flow rate of the test liquid; a thermometer can be installed on the guide base 24 or the outer cylinder 33 to monitor the simulated temperature environment; a pressure sensor can be installed on the supply pipe 11 to monitor the initial pressure of the test liquid; and differential pressure sensors can be installed between the first inlet pipe 21 and the first outlet pipe 22, and between the second inlet pipe 31 and the second outlet pipe 32, to monitor the differential pressure. These monitoring methods can be configured according to needs and will not be elaborated here.

[0057] Meanwhile, in this embodiment, the supply pump 13, pressure supply pump 64, and oil supply pump 8 can all be constant flow and constant pressure type pumps, such as single-cylinder constant flow and constant pressure pumps or multi-cylinder constant flow and constant pressure pumps, to ensure the stable operation of the test. The first control valve 111, second control valve 151, third control valve 161, liquid addition control valve, liquid inlet control valve 211, liquid discharge control valve 221, and oil supply control valve 2631 can all be solenoid valves, facilitating the control of the entire system.

[0058] The implementation principle of the proppant conductivity and core flow integrated testing instrument in this application embodiment is as follows: In actual use, the two sets of liquid inlet control valves 211 and liquid outlet control valves 221 can be controlled according to the actual testing requirements to switch the flow guiding testing mechanism 2 and the core flow testing mechanism 3 to perform corresponding testing operations; at the same time, the first control valve 111, the second control valve 151 and the third control valve 161 can be used to supply different testing liquids.

[0059] Before the proppant flow test, pull the flow guide base 24 out from between the first pressure plate 253 and the second pressure plate 262, and remove the upper extrusion piston 242. Then, place the proppant into the flow chamber test slot 241, and then install the upper extrusion piston 242. Subsequently, push the flow guide base 24 between the first pressure plate 253 and the second pressure plate 262, and rotate the turntable 252 and the positioning screw 251. The first pressure plate 253 presses down on the upper extrusion piston 242, and the scale on the positioning screw 251 is used to measure the flow of the upper extrusion piston 242. The compression piston 242 is positioned and presses the proppant, and the compression piston 242 located on the lower side abuts against the second pressure plate 262, and the two positioning rods 2422 abut against the lower side of the guide base 24; finally, the oil supply pump 8 supplies oil to the top pressure cylinder 2611, and the second pressure plate 262 applies pressure to the compression piston 242 located on the lower side and the proppant. The compression piston 242 located on the lower side and the guide base 24 move upward synchronously to simulate the underground pressure environment, and the electric heating rod 244 heats the guide base 24, the proppant and the test liquid to simulate the underground temperature environment.

[0060] During the proppant flow test, the liquid supply mechanism 1 delivers the test liquid into the first inlet pipe 21. The test liquid flows sequentially through the flow chamber test tank 241, the first drain pipe 22, and the receiving pipe 41, and then enters the collection container 43, where it is weighed by the electronic balance 42. The backpressure mechanism 6 provides backpressure to the test liquid to ensure the stability of the simulated underground pressure environment.

[0061] Before the core flow test, unscrew the compression rod 335 on one side, place the core inside the rubber tube 332, and tighten the compression rod 335; then, the oil supply pump 8 supplies oil to the pressure space 333 to pressurize the rubber tube 332 and the core, simulating the underground pressure environment; at the same time, the flexible heating body 336 heats the outer cylinder 33, and heats the core through heat transfer, simulating the underground temperature environment.

[0062] During core flow testing, the liquid supply mechanism 1 delivers the test liquid into the second inlet pipe 31. The test liquid flows sequentially through the rubber tube 332, the second outlet pipe 32, and the receiving pipe 41, and then enters the collection container 43, where it is weighed by the electronic balance 42. Similarly, the backpressure mechanism 6 provides backpressure to the test liquid to ensure the stability of the simulated underground pressure environment.

[0063] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A proppant conductivity and core flow comprehensive testing instrument, comprising a liquid supply mechanism (1), a conductivity testing mechanism (2), a core flow testing mechanism (3), and a receiving component (4), characterized in that: The liquid supply mechanism (1) includes a constant flow and constant pressure pump and a liquid supply pipe (11) connected to the constant flow and constant pressure pump. The liquid supply pipe (11) is connected to the inlet of the flow guiding test mechanism (2) by a first liquid inlet pipe (21), and the liquid supply pipe (11) is connected to the inlet of the core flow test mechanism (3) by a second liquid inlet pipe (31). Both the first liquid inlet pipe (21) and the second liquid inlet pipe (31) are equipped with liquid inlet control valves (211). The receiving component (4) includes a receiving pipe (41), a first drain pipe (22) is connected between the receiving pipe (41) and the outlet of the flow guiding test mechanism (2), and a second drain pipe (32) is connected between the receiving pipe (41) and the outlet of the core flow test mechanism (3). Both the first drain pipe (22) and the second drain pipe (32) are equipped with drain control valves (221).

2. The proppant conductivity and core flow comprehensive testing instrument according to claim 1, characterized in that: The flow guiding test mechanism (2) includes an operating table (23) and a flow guiding base (24) set on the operating table (23). A flow guiding chamber test groove (241) is opened from top to bottom in the middle of the flow guiding base (24). A squeeze piston (242) is embedded on both the upper and lower sides of the flow guiding chamber test groove (241). The two squeeze pistons (242) are slidably connected to the flow guiding chamber test groove (241) in a vertical direction. The operating table (23) is also provided with a pressing component (25) for pressing down the upper squeeze piston (242) and a pressing component (26) for pressing up the lower squeeze piston (242). The flow chamber test tank (241) has a connecting port (2411) on each of its two opposite side walls in the horizontal direction. A filter screen (2412) is provided at each of the two connecting ports (2411), and the two connecting ports (2411) are respectively connected to the first liquid inlet pipe (21) and the first liquid outlet pipe (22).

3. The proppant conductivity and core flow comprehensive testing instrument according to claim 2, characterized in that: The operating table (23) is provided with a mounting bracket (232). The pressing component (25) is located above the flow guide base (24). The pressing component (25) includes a positioning screw (251). The positioning screw (251) is set downwards and is threadedly connected to the mounting bracket (232) and used to press down the extrusion piston (242) located on the upper side. The top pressure assembly (26) is located below the flow guide base (24). The top pressure assembly (26) includes a top pressure cylinder (261), the piston rod of which is arranged upward and used to press against the extrusion piston (242) located on the lower side.

4. The proppant conductivity and core flow comprehensive testing instrument according to claim 1, characterized in that: The core flow testing mechanism (3) includes an outer cylinder (33), both ends of which are detachably connected to a plug ring (331). A rubber tube (332) is also provided inside the outer cylinder (33). Both ends of the rubber tube (332) are respectively embedded in the corresponding plug ring (331) and pressed against the plug ring (331). A pressure space (333) is formed between the rubber tube (332) and the outer cylinder (33). An injection pipe (334) is provided on the outer cylinder (33), and the injection pipe (334) is connected to the pressure space (333). Both of the plugging rings (331) are threaded with a squeezing rod (335) on their inner sides. Both squeezing rods (335) are provided with a drainage channel (3351) along their axis. The two drainage channels (3351) are respectively connected to the second liquid inlet pipe (31) and the second liquid outlet pipe (32). The outer cylinder (33) is covered with a flexible heating element (336).

5. The proppant conductivity and core flow comprehensive testing instrument according to claim 1, characterized in that: The liquid supply mechanism (1) includes a piston container (14), the outlet of the constant flow and constant pressure pump is connected to one side chamber of the piston container (14), and the other side chamber of the piston container (14) is connected to the liquid supply pipe (11).

6. A proppant conductivity and core flow comprehensive testing instrument according to claim 1, 3, or 4, characterized in that: A back pressure mechanism (6) is connected in series in the middle of the receiving tube (41). The back pressure mechanism (6) includes a back pressure body (61) and a back pressure piston (62). A back pressure chamber (611) is provided inside the back pressure body (61). The back pressure piston (62) is slidably disposed in the back pressure chamber (611). An inlet channel (612) and an outlet channel (613) are provided on the back pressure body (61). The inlet channel (612) and the outlet channel (613) are located on the same side of the back pressure piston (62). The inlet channel (612) and the outlet channel (613) are both connected to the back pressure chamber (611). The inlet channel (612) is disposed opposite to the back pressure piston (62). The back pressure mechanism (6) is connected in series to the receiving tube (41) through the inlet channel (612) and the outlet channel (613). The back pressure body (61) is provided with a back pressure port (614) on the side away from the inlet channel (612) for supplying high pressure fluid to the back pressure piston (62) on the side away from the inlet channel (612).

7. The proppant conductivity and core flow comprehensive testing instrument according to claim 6, characterized in that: The back pressure port (614) is connected to a buffer container (63), and the buffer container (63) is also connected to a pressure pump (64).

8. The proppant conductivity and core flow comprehensive testing instrument according to claim 6, characterized in that: The receiving tube (41) is located on the side of the back pressure mechanism (6) near the first drain pipe (22) and is connected to a vacuum tube (7). A one-way valve (71) is connected in series in the middle of the vacuum tube (7) to prevent gas and liquid from flowing back to the receiving tube (41) through the vacuum tube (7). A vacuum pump (72) is connected to the end of the vacuum tube (7) away from the receiving tube (41).

9. A proppant conductivity and core flow comprehensive testing instrument according to claim 6 of claim 3, characterized in that: The top pressure cylinder (261) is a top pressure oil cylinder (2611), and the oil inlet of the top pressure oil cylinder (2611) is connected to a first oil supply pipe (263), and the first oil supply pipe (263) is connected to an oil supply pump (8). The receiving pipe (41) is located on the side of the back pressure mechanism (6) near the first drain pipe (22) and is provided with a first pressure detection unit for detecting the fluid pressure inside the receiving pipe (41). The first oil supply pipe (263) is provided with a second pressure detection unit for detecting the fluid pressure inside the first oil supply pipe (263). It also includes a control unit, which is electrically connected to the first pressure detection unit and the second pressure detection unit, and receives pressure signals transmitted by the first pressure detection unit and the second pressure detection unit; The control unit stores pressure thresholds and includes a calculation module and a comparison module. The calculation module is used to calculate the pressure difference between the pressure value measured by the second pressure detection unit and the pressure value measured by the first pressure detection unit. The comparison module is used to compare the pressure difference with the pressure threshold to obtain a comparison result; Furthermore, the control unit controls the oil supply pump (8) to perform the corresponding operation based on the comparison result.

10. A proppant conductivity and core flow comprehensive testing instrument according to claim 6 of claim 4, characterized in that: The injection pipe (334) is connected to a second oil supply pipe (337), and the second oil supply pipe (337) is connected to an oil supply pump (8). The receiving pipe (41) is located on the side of the back pressure mechanism (6) near the first drain pipe (22) and is provided with a first pressure detection unit for detecting the fluid pressure inside the receiving pipe (41). The second oil supply pipe (337) is provided with a third pressure detection unit for detecting the fluid pressure inside the second oil supply pipe (337). It also includes a control unit, which is electrically connected to the first pressure detection unit and the third pressure detection unit, and receives pressure signals transmitted by the first pressure detection unit and the third pressure detection unit; The control unit stores pressure thresholds and includes a calculation module and a comparison module. The calculation module is used to calculate the pressure difference between the pressure value measured by the third pressure detection unit and the pressure value measured by the first pressure detection unit. The comparison module is used to compare the pressure difference with the pressure threshold to obtain a comparison result; Furthermore, the control unit controls the oil supply pump (8) to perform the corresponding operation based on the comparison result.

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