Temperature and pressure response type plugging agent evaluation device and evaluation method

Abstract

The invention belongs to the field of performance evaluation of plugging agents for petroleum drilling, and particularly relates to a temperature and pressure response type plugging agent evaluation device and method. The device comprises a hydraulic device, a plurality of temperature and pressure reaction kettles are arranged in the heating box, and the temperature and pressure reaction kettles are respectively communicated with the hydraulic device. By adopting the device, the temperature and the pressure of the plugging agent can be controlled in a hydraulic and heating manner, so that conditions are provided for further evaluating the tensile strength, the compression strength and the rheological strength of a sample under different temperatures and pressures by adopting a universal testing machine and a rheometer system so as to determine the mechanical property and the rheological property of the plugging agent under different temperature and pressure conditions.

Description

Technical Field

[0001] The invention belongs to the field of performance evaluation of plugging agents for oil drilling, and in particular relates to a temperature and pressure responsive plugging agent evaluation device and an evaluation method. Background Art

[0002] During the drilling process, problems such as leakage, collapse, diameter shrinkage, and damage to oil and gas layers usually occur due to poor wellbore sealing performance, which is particularly serious in high-temperature and high-pressure wells. In recent years, in order to improve my country's energy security level and alleviate the pressure of my country's dependence on foreign energy, my country's oil and gas production has gradually moved to deep layers. High temperature and high salt, collapse and drilling, and well wall instability often occur. Ultra-deep wells have high bottom temperatures and complex geological conditions. The plugging performance of drilling fluid is greatly affected by bottom hole environmental factors, especially harsh environments such as high temperature and high pressure. Therefore, it is particularly important to systematically evaluate the effects of temperature and pressure on plugging agents.

[0003] Temperature and pressure responsive plugging agents mainly refer to materials that are stimulated at a certain temperature or pressure, thereby gradually changing their properties or performance. At present, the performance of plugging agents is mainly evaluated by evaluating the pressure-bearing performance of plugging agents at a certain temperature to determine their stability, but this evaluation method cannot determine the differences and changes in the mechanical and rheological properties of plugging agents under corresponding temperature or pressure conditions. In particular, for temperature and pressure sensitive temperature and pressure responsive plugging agents, systematic evaluation of their mechanical and rheological properties at different temperatures and pressures can explore the effects of temperature and pressure coupling on the performance of plugging agents, and optimize the best applicable conditions for plugging agents. According to the response performance at different temperatures and pressures, the response characteristics and mechanisms of plugging agents can be explored, providing a complete and scientific indoor evaluation basis for the research and development of high-temperature and high-pressure plugging agents and ultra-deep well crack plugging. Therefore, it is necessary to invent a temperature and pressure responsive plugging agent evaluation device and evaluation method to meet the current needs for evaluating the performance of temperature and pressure responsive plugging agents. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the present invention provides a temperature-pressure responsive plugging agent evaluation device and evaluation method. The present invention combines hydraulic pressure and blast heating, and uses the temperature-pressure responsive plugging agent evaluation device with a universal testing machine and a rheometer, which can be used to study the tensile, compressive and rheological strength of the plugging agent. Furthermore, according to the response characteristics of the plugging agent under different temperatures and pressures, it can be used to explore the influence of the temperature and pressure coupling on the performance of the plugging agent, and to optimize the best applicable conditions of the plugging agent, and explore the response characteristics and mechanism of the plugging agent according to the performance changes under different temperatures and pressures. This provides a basis for the research and development of high-temperature and high-pressure plugging agents and the plugging of ultra-deep well cracks.

[0005] The technical solution provided by the present invention is as follows:

[0006] A temperature and pressure responsive plugging agent evaluation device, comprising:

[0007] Hydraulic device;

[0008] A heating box is provided with a plurality of temperature and pressure reactors, and each of the temperature and pressure reactors is connected to the hydraulic device respectively.

[0009] Based on the above technical scheme, the temperature and pressure of the plugging agent can be controlled by hydraulic pressure and heating, thereby providing conditions for further using a universal testing machine and rheometer system to evaluate the tensile, compressive and rheological strength of samples at different temperatures and pressures, so as to determine the mechanical and rheological properties of the plugging agent under different temperature and pressure conditions.

[0010] Specifically, the temperature and pressure reactor comprises:

[0011] A plurality of vertically arranged cylinders;

[0012] An upper plug detachably mounted at the opening of the upper end of the cylinder, the upper plug being connected to an exhaust valve;

[0013] A lower plug fixedly mounted at the opening of the lower end of the cylinder, the lower plug being provided with an oil inlet, the oil inlet being connected to the hydraulic device;

[0014] and a piston slidingly fitted within the cylinder.

[0015] Based on the above technical solution:

[0016] The piston can apply upward pressure to the sample under the pressure of hydraulic pressure; the cylinder is made of heat-conducting material, so that the temperature and pressure of the plugging agent can be controlled.

[0017] In addition, the sample can be easily added by removing the upper plug, or the sample can be taken out after the reaction is completed.

[0018] Further:

[0019] An upper pressure cap is detachably mounted on the upper end of the cylinder, and the upper pressure cap is detachably connected to the upper plug;

[0020] A pressing cap is fixedly mounted on the lower end of the cylinder, and the pressing cap is fixedly connected to the lower plug.

[0021] Based on the above technical solution, the corresponding plug can be limited or fixed by a pressure cap.

[0022] Further:

[0023] The upper plug is provided with a sealing ring at the contact surface with the cylinder;

[0024] The lower plug is provided with a sealing ring at the contact surface with the cylinder;

[0025] The upper plug passes through the upper pressure cap and is detachably connected to the upper pressure cap via a retaining spring;

[0026] The lower plug passes through the lower pressure cap and is detachably connected to the lower pressure cap via a retaining spring.

[0027] Specifically, the hydraulic device includes:

[0028] Hydraulic pumps;

[0029] A pair of hydraulic main valves and back pressure main valves;

[0030] A plurality of groups of hydraulic valves and back pressure valves, each of the hydraulic valves is connected to the corresponding lower plug through a pipeline.

[0031] The present invention also provides a method for evaluating a temperature-pressure responsive plugging agent, and the evaluation is performed using the temperature-pressure responsive plugging agent evaluation device provided by the present invention.

[0032] Based on this technical solution, the temperature and pressure of the plugging agent can be controlled by hydraulic pressure and heating, and then the tensile, compressive and rheological strength of the samples under different temperatures and pressures can be evaluated using a universal testing machine and rheometer system, thereby determining the mechanical and rheological properties of the plugging agent under different temperature and pressure conditions.

[0033] Specifically, the evaluation method of the temperature-pressure responsive plugging agent includes the following steps:

[0034] Step S1, mixing the temperature-pressure responsive plugging agent and the working fluid, and stirring them evenly at room temperature;

[0035] Step S2, adding the mixed solution obtained in step S1 to the pistons in each of the temperature and pressure reactors, and keeping each exhaust valve in an open state;

[0036] Step S3, closing the hydraulic main valve and opening the back pressure main valve, and then injecting back pressure into each of the temperature and pressure reactors in turn;

[0037] Step S4, closing the back pressure main valve and opening the hydraulic main valve, then injecting pressure into each of the temperature and pressure reactors in turn, and closing each of the exhaust valves after the pressure in the reactor is stable;

[0038] Step S5, heating the reaction in a heating box;

[0039] Step S6, after the reaction is finished, turn off the heating button, and open the hydraulic main valve, each of the hydraulic valves and each of the exhaust valves;

[0040] Step S7: After the heating device is cooled to room temperature, the temperature and pressure reactor is opened, and the plugging agent is taken out and tested.

[0041] The above technical solution provides an operating method for evaluating a temperature-pressure responsive plugging agent.

[0042] Specifically, the working fluid in step S1 is one of 5% bentonite slurry, clean water, 5% NaCl solution, 10% NaCl solution or polysulfone drilling fluid;

[0043] Specifically, in step S1, the mass ratio of the plugging agent to the working fluid is (5-10):100, and the stirring time is 10-60 min;

[0044] Specifically, the mixed solution added in step S2 is 120-200 g;

[0045] Specifically, the back pressure injected into each of the temperature and pressure reactors in step S3 is 0-20 MPa;

[0046] Specifically, the pressure injected into each of the temperature and pressure reactors in step S4 is 0-20 MPa;

[0047] Specifically, the reaction temperature in step S5 is 25-250°C;

[0048] Specifically, the reaction time in step S6 is 6-24 hours.

[0049] Furthermore, the plugging agent obtained in step S7 is cut into a cuboid, and its tensile properties are tested at a certain tensile rate using a universal testing machine, wherein the breaking stress is used as an index of the tensile properties.

[0050] Furthermore, the plugging agent obtained in step S7 is cut into cylinders, and its compression performance is tested at a certain compression rate using a universal testing machine, wherein the stress under a fixed strain is used as a compression performance index.

[0051] Furthermore, the plugging agent obtained in step S7 is cut into circular pieces, and its rheological strength is tested by a rheometer, wherein the average storage modulus in the viscoelastic range is used as a rheological performance index.

[0052] Specifically, the plugging agent is cut into a cuboid with a length of 30-40 mm, a width of 10-15 mm, and a height of 3-10 mm, and the stretching rate is 50-100 mm / min.

[0053] Specifically, the plugging agent is cut into a cylinder with a diameter of 8-10 mm and a height of 12-20 mm, the compression rate is 2-10 mm / min, and the compression strain is 50-95%.

[0054] Specifically, the plugging agent is cut into discs with a diameter of 8-15 mm and a height of 2-4 mm. The rheological test is set to a spacing of 1 mm. Then the gel is placed on the test lower plate, the oscillation scanning frequency is fixed at 1 Hz, and the strain amplitude scanning range is 0.1% to 1000%. The viscoelastic range of the gel is determined by strain scanning. Within the viscoelastic range of the gel, the strain of the oscillation scanning is fixed, and the frequency scanning is performed within the frequency range of 0.1 to 100 Hz.

[0055] More specifically, the evaluation method of the temperature-pressure responsive plugging agent includes the following steps:

[0056] Step S1, mixing the temperature and pressure responsive plugging agent and the working fluid, and stirring them evenly at room temperature;

[0057] Step S2, pouring the mixed solution obtained in step S1 into the temperature and pressure reactors 1 to 3 respectively, sealing the reactor bodies, and keeping the exhaust valves in an open state;

[0058] Step S3, close the hydraulic main valve and open the back pressure main valve, then open the back pressure valve 1, close the back pressure valves 2 and 3, and inject back pressure into the No. 1 warm and pressure reactor through the hydraulic hand pump;

[0059] Step S4, open back pressure valve 2, close back pressure valves 1 and 3, and inject back pressure into the No. 2 temperature and pressure reactor through a hydraulic hand pump;

[0060] Step S5, open back pressure valve 3, close back pressure valves 1 and 2, and inject back pressure into the No. 3 temperature and pressure reactor through a hydraulic hand pump;

[0061] Step S6, close the back pressure main valve and open the hydraulic main valve, then open hydraulic valve 1, close hydraulic valves 2 and 3, inject pressure into the No. 1 temperature and pressure reactor through the hydraulic hand pump, and close the exhaust valve after the reactor pressure stabilizes;

[0062] Step S7, open hydraulic valve 2, close hydraulic valves 1 and 3, inject pressure into the No. 2 temperature and pressure reactor through the hydraulic hand pump, and close the exhaust valve after the reactor pressure stabilizes;

[0063] Step S8, open hydraulic valve 3, close hydraulic valves 1 and 2, inject pressure into the No. 3 temperature and pressure reactor through the hydraulic hand pump, and close the exhaust valve after the reactor pressure stabilizes;

[0064] Step S9, turn on the blast heating power supply, set the reaction temperature and turn on the rapid heating and blast buttons, and start timing after the blast heating temperature stabilizes;

[0065] Step S10: After the reaction is completed, turn off the heating button, and open the hydraulic main valve, hydraulic valves 1 to 3 and the exhaust valve;

[0066] Step S11, after the heating device is cooled to room temperature, the temperature and pressure reactor is opened and the plugging agent is taken out;

[0067] Step S12, cutting the plugging agent obtained in step S12 into a cuboid, and testing its tensile properties at a certain tensile rate using a universal testing machine, wherein the breaking stress is used as a tensile performance index;

[0068] Step S13, cutting the plugging agent obtained in step S12 into a cylinder, and testing its compression performance at a certain compression rate using a universal testing machine, wherein the stress under a fixed strain is used as a compression performance index;

[0069] Step S14, cutting the plugging agent obtained in step S12 into circular pieces, and testing its rheological strength by a rheometer, wherein the average storage modulus in the viscoelastic range is used as a rheological performance index.

[0070] Beneficial effects of the present invention:

[0071] 1) The present invention provides a temperature-pressure responsive plugging agent evaluation device and evaluation method, which can systematically test the temperature-pressure response characteristics of the plugging agent at 25-250°C and 0-20MPa, and determine the tensile, compressive and rheological properties of the plugging material at different temperatures and pressures.

[0072] 2) The present invention provides a temperature-pressure responsive plugging agent evaluation device and evaluation method, which combines hydraulic pressure and blast heating, and uses the temperature-pressure responsive plugging agent evaluation device with a universal testing machine and a rheometer to systematically explore the tensile, compressive and rheological properties of the plugging agent. According to the response characteristics of the plugging agent under different temperatures and pressures, the influence of the coupling of temperature and pressure on the performance of the plugging agent can be explored, and the best applicable conditions of the plugging agent can be selected, and the response characteristics and mechanism of the plugging agent can be explored according to the response performance under different temperatures and pressures. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a schematic diagram of the overall structure of the temperature and pressure responsive plugging agent evaluation device provided by the present invention.

[0074] Figure 2 It is a structural schematic diagram of the temperature and pressure reactor of the temperature and pressure responsive plugging agent evaluation device provided by the present invention.

[0075] Figure 3 It is a hydraulic principle diagram of the temperature and pressure responsive plugging agent evaluation device provided by the present invention.

[0076] Attached Figure 1 , 2 , 3, the structure list represented by each number is as follows:

[0077] 1. Hydraulic device, 2. Heating box, 3. Temperature and pressure reactor, 301. Cylinder, 302. Upper plug, 303. Lower plug, 304. Upper pressure cap, 305. Lower pressure cap, 306. Piston, 4. Hydraulic pump, 5. Hydraulic main valve, 6. Back pressure main valve, 7. Hydraulic valve, 8. Back pressure valve, 9. Exhaust valve, 10. Sealing ring, 11. Circlip. DETAILED DESCRIPTION

[0078] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0079] In a specific embodiment, Figure 1 As shown, the temperature-pressure responsive plugging agent evaluation device comprises: a hydraulic device 1; a heating box 2, in which a plurality of temperature-pressure reactors 3 are arranged, and each temperature-pressure reactor 3 is connected to the hydraulic device 1 respectively.

[0080] like Figure 2 As shown, the thermostatic reactor 3 includes: a plurality of vertically arranged cylinders 301; an upper plug 302 detachably mounted at the upper opening of the cylinder 301, the upper plug 302 being connected to an exhaust valve 9; a lower plug 303 fixedly mounted at the lower opening of the cylinder 301, the lower plug 303 being provided with an oil inlet, the oil inlet being connected to the hydraulic device 1; and a piston 306 slidingly fitted in the cylinder 301. An upper pressure cap 304 is detachably mounted at the upper end of the cylinder 301, and the upper pressure cap 304 is detachably connected to the upper plug 302. A lower pressure cap 305 is fixedly mounted at the lower end of the cylinder 301, and the lower pressure cap 305 is fixedly connected to the lower plug 303. Specifically, the number of thermostatic reactors 3 can be three. The upper pressure cap 304 can be threadedly connected to the cylinder 301, and the lower pressure cap 305 can be threadedly connected to the cylinder 301, and can be disassembled and fixedly mounted with the upper pressure cap.

[0081] like Figure 3 As shown, the hydraulic device 1 includes: a hydraulic pump 4; a pair of hydraulic main valves 5 and a back-pressure main valve 6; and a plurality of groups of hydraulic valves 7 and back-pressure valves 8. Specifically, the hydraulic pump 4 can be a hydraulic hand pump. The hydraulic device 1 includes three groups, corresponding to the number of the temperature and pressure reactors 3. The hydraulic pump 4 is connected to the buffer tank, and is respectively connected to the hydraulic main valve 5 and the back-pressure main valve 6. The hydraulic main valve 5 is respectively connected to each hydraulic valve 7, and the back-pressure main valve 6 is respectively connected to each back-pressure valve 8. Each hydraulic valve 7 is connected to the corresponding lower plug 303 through a pipeline. Each back-pressure valve 8 is connected to a piston container for balancing pressure through a buffer container, and each hydraulic valve 7 is also connected to a piston container for balancing pressure.

[0082] Based on the above specific implementation methods, Figure 2As shown, the upper plug 302 passes through the upper pressure cap 304 and is detachably connected to the upper pressure cap 304 through the retaining spring 11. The lower plug 303 passes through the lower pressure cap 305 and is detachably connected to the lower pressure cap 305 through the retaining spring 11, which is convenient for the removal and fixed installation of the upper pressure cap.

[0083] Based on the above specific implementation methods, Figure 2 As shown, the upper plug 302 is provided with a sealing ring 10 at the contact surface with the cylinder 301. The lower plug 303 is provided with a sealing ring 10 at the contact surface with the cylinder 301 to prevent oil leakage.

[0084] On the basis of the above specific implementation, a piston 306 tool push rod can be set, an external thread is set at its end, and a corresponding internal thread is set on the upper end surface of the piston 306. After removing the upper pressure cap 304 and the upper plug 302, the tool push rod is threadedly connected to the piston 306, that is, the piston 306 can be pushed downward or pulled upward.

[0085] Example 1

[0086] Step S1, 5 parts by weight of the temperature-pressure responsive plugging agent and 100 parts by weight of clean water are mixed, and the mixture is stirred at room temperature for 30 minutes.

[0087] Step S2, pour 150 parts by weight of the mixed solution obtained in step S1 into three temperature and pressure reactors 3 respectively, seal the reactor bodies and keep the exhaust valves 9 in an open state.

[0088] Step S3, close the hydraulic main valve 5 and open the back pressure main valve 6, then open the back pressure valve 1, close the back pressure valves 2 and 3, and inject a back pressure of 2MPa into the No. 1 temperature and pressure reactor 3 through the hydraulic hand pump.

[0089] Step S4, open the back pressure valve 2, close the back pressure valves 1 and 3, and inject a back pressure of 5 MPa into the No. 2 temperature and pressure reactor 3 through the hydraulic hand pump.

[0090] Step S5, open the back pressure valve 3, close the back pressure valves 1 and 2, and inject a back pressure of 8 MPa into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump.

[0091] Step S6, close the back pressure main valve 6 and open the hydraulic main valve 5, then open the hydraulic valve 1, close the hydraulic valves 2 and 3, inject 2MPa of pressure into the No. 1 temperature and pressure reactor 3 through the hydraulic hand pump, and close the exhaust valve 9 after the reactor pressure stabilizes.

[0092] Step S7, open hydraulic valve 2, close hydraulic valves 1 and 3, inject 5MPa of pressure into No. 2 temperature and pressure reactor 3 through a hydraulic hand pump, and close exhaust valve 9 after the reactor pressure stabilizes.

[0093] Step S8, open the hydraulic valve 3, close the hydraulic valves 1 and 2, inject 8MPa of pressure into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump, and close the exhaust valve 9 after the reactor pressure stabilizes.

[0094] Step S9, turn on the blast heating power supply, set the reaction temperature to 150°C, turn on the rapid heating and blast buttons, and start timing after the blast heating temperature stabilizes.

[0095] Step S10, after reacting for 6 hours, turn off the heating button, and open the hydraulic main valve 5, hydraulic valves 1-3 and exhaust valve 9.

[0096] Step S11, after the heating device is cooled to room temperature, the temperature and pressure reactor 3 is opened and the plugging agent is taken out.

[0097] Step S12, cutting the plugging agent obtained in step S12 into a cuboid with a length of 30 mm, a width of 12 mm, and a height of 3 mm, and testing the tensile properties by a universal testing machine at a tensile rate of 100 mm / min, and taking the breaking stress as the tensile performance index.

[0098] Step S13, cutting the plugging agent obtained in step S12 into a cylinder with a diameter of 8 mm and a height of 20 mm, and testing the compression performance at a compression strain of 90% using a universal testing machine at a compression rate of 5 mm / min, and taking the stress at 90% strain as the compression performance index.

[0099] Step S14, cut the plugging agent obtained in step S12 into discs with a diameter of 8 mm and a height of 4 mm, and test the rheological strength by a rheometer, and the rheological test is set to a spacing of 1 mm. Then put the gel on the test lower plate, fix the oscillation scanning frequency to 1 Hz, and the strain amplitude scanning range to 0.1% to 1000%, and determine the viscoelastic range of the gel by strain scanning. In the viscoelastic range of the gel, fix the strain of the oscillation scanning, and perform a frequency scan in the frequency range of 0.1 to 100 Hz, and the average storage modulus in the viscoelastic range is used as the rheological performance index.

[0100] According to the above steps, the performance of the samples in the three temperature and pressure reactors (3) is shown in the following table:

[0101] Sample No. Tensile properties (MPa) Compression performance (MPa) Rheological properties(Pa) 1 2.5 6.5 6210 2 3.9 8.4 8700 3 2.0 4.2 4029

[0102] Example 2

[0103] Step S1, 10 parts by weight of the temperature-pressure responsive plugging agent and 100 parts by weight of 5% bentonite slurry are mixed, and the mixture is stirred at room temperature for 30 minutes.

[0104] Step S2, pour 150 parts by weight of the mixed solution obtained in step S1 into three temperature and pressure reactors 3 respectively, seal the reactor bodies and keep the exhaust valves 9 in an open state.

[0105] Step S3, close the hydraulic main valve 5 and open the back pressure main valve 6, then open the back pressure valve 1, close the back pressure valves 2 and 3, and inject a back pressure of 5 MPa into the No. 1 temperature and pressure reactor 3 through the hydraulic hand pump.

[0106] Step S4, open the back pressure valve 2, close the back pressure valves 1 and 3, and inject a back pressure of 10 MPa into the No. 2 temperature and pressure reactor 3 through the hydraulic hand pump.

[0107] Step S5, open the back pressure valve 3, close the back pressure valves 1 and 2, and inject a back pressure of 15 MPa into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump.

[0108] Step S6, close the back pressure main valve 6 and open the hydraulic main valve 5, then open the hydraulic valve 1, close the hydraulic valves 2 and 3, inject 5MPa of pressure into the No. 1 temperature and pressure reactor 3 through the hydraulic hand pump, and close the exhaust valve 9 after the reactor pressure stabilizes.

[0109] Step S7, open hydraulic valve 2, close hydraulic valves 1 and 3, inject 10 MPa of pressure into No. 2 temperature and pressure reactor 3 through a hydraulic hand pump, and close exhaust valve 9 after the reactor pressure stabilizes.

[0110] Step S8, open the hydraulic valve 3, close the hydraulic valves 1 and 2, inject 15MPa of pressure into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump, and close the exhaust valve 9 after the reactor pressure stabilizes.

[0111] Step S9, turn on the blast heating power supply, set the reaction temperature to 220°C, turn on the rapid heating and blast buttons, and start timing after the blast heating temperature stabilizes.

[0112] Step S10, after reacting for 24 hours, turn off the heating button, and open the hydraulic main valve 5, hydraulic valves 1-3 and exhaust valve 9.

[0113] Step S11, after the heating device is cooled to room temperature, the temperature and pressure reactor 3 is opened and the plugging agent is taken out.

[0114] Step S12, cutting the plugging agent obtained in step S12 into a cuboid with a length of 30 mm, a width of 12 mm, and a height of 3 mm, and testing the tensile properties by a universal testing machine at a tensile rate of 100 mm / min, and taking the breaking stress as the tensile performance index.

[0115] Step S13, cutting the plugging agent obtained in step S12 into a cylinder with a diameter of 8 mm and a height of 20 mm, and testing the compression performance at a compression strain of 90% using a universal testing machine at a compression rate of 5 mm / min, and taking the stress at 90% strain as the compression performance index.

[0116] Step S14, cut the plugging agent obtained in step S12 into discs with a diameter of 8 mm and a height of 4 mm, and test the rheological strength by a rheometer, and the rheological test is set to a spacing of 1 mm. Then put the gel on the test lower plate, fix the oscillation scanning frequency to 1 Hz, and the strain amplitude scanning range to 0.1% to 1000%, and determine the viscoelastic range of the gel by strain scanning. In the viscoelastic range of the gel, fix the strain of the oscillation scanning, and perform a frequency scan in the frequency range of 0.1 to 100 Hz, and the average storage modulus in the viscoelastic range is used as the rheological performance index.

[0117] According to the above steps, the performance of the samples in the three temperature and pressure reactors (3) is shown in the following table:

[0118]

[0119]

[0120] Example 3

[0121] Step S1, 20 parts by weight of the temperature-pressure responsive plugging agent and 100 parts by weight of 5% bentonite slurry are mixed, and the mixture is stirred at room temperature for 30 minutes.

[0122] Step S2, pour 150 parts by weight of the mixed solution obtained in step S1 into three temperature and pressure reactors 3 respectively, seal the reactor bodies and keep the exhaust valves 9 in an open state.

[0123] Step S3, close the hydraulic main valve 5 and open the back pressure main valve 6, then open the back pressure valve 2, close the back pressure valves 1 and 3, and inject a back pressure of 6 MPa into the No. 2 temperature and pressure reactor 3 through the hydraulic hand pump.

[0124] Step S4, open the back pressure valve 3, close the back pressure valves 1 and 2, and inject a back pressure of 12 MPa into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump.

[0125] Step S5, close the back pressure main valve 6 and open the hydraulic main valve 5, then open the hydraulic valve 2, close the hydraulic valves 1 and 3, inject 6MPa of pressure into the No. 2 temperature and pressure reactor 3 through the hydraulic hand pump, and close the exhaust valve 9 after the reactor pressure stabilizes.

[0126] Step S6, open the hydraulic valve 3, close the hydraulic valves 1 and 2, and inject 12MPa of pressure into the No. 3 temperature and pressure reactor 3 through the hydraulic hand pump. After the reactor pressure is stable, close the exhaust valve 9.

[0127] Step S7, turn on the blast heating power supply, set the reaction temperature to 250°C, turn on the rapid heating and blast buttons, and start timing after the blast heating temperature stabilizes.

[0128] Step S8, after reacting for 14 hours, turn off the heating button, and open the hydraulic main valve 5, hydraulic valves 1-3 and exhaust valve 9.

[0129] Step S9, after the heating device is cooled to room temperature, the temperature and pressure reactor 3 is opened and the plugging agent is taken out.

[0130] Step S10, cutting the plugging agent obtained in step S12 into a cuboid with a length of 30 mm, a width of 12 mm, and a height of 3 mm, and testing the tensile properties by a universal testing machine at a tensile rate of 100 mm / min, and taking the breaking stress as the tensile performance index.

[0131] Step S11, cutting the plugging agent obtained in step S12 into a cylinder with a diameter of 8 mm and a height of 20 mm, and testing the compression performance at a compression strain of 90% using a universal testing machine at a compression rate of 5 mm / min, and taking the stress at 90% strain as the compression performance index.

[0132] Step S12, cutting the plugging agent obtained in step S12 into discs with a diameter of 8 mm and a height of 4 mm, and testing the rheological strength by a rheometer, with the rheological test setting interval of 1 mm. Then put the gel on the test lower plate, fix the oscillation scanning frequency to 1 Hz, and the strain amplitude scanning range to 0.1% to 1000%, and determine the viscoelastic range of the gel by strain scanning. In the viscoelastic range of the gel, fix the strain of the oscillation scanning, and perform a frequency scan in the frequency range of 0.1 to 100 Hz, and the average storage modulus in the viscoelastic range is used as the rheological performance index.

[0133] According to the above steps, the performance of the samples in the three temperature and pressure reactors (3) is shown in the following table:

[0134] Sample No. Tensile properties (MPa) Compression performance (MPa) Rheological properties(Pa) 1 0.9 3.8 2087 2 1.4 4.9 3201 3 2.2 5.0 4427

[0135] 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, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A temperature and pressure responsive plugging agent evaluation device, characterized in that: include: Hydraulic device (1); A heating box (2), wherein a plurality of temperature-pressure reaction kettles (3) are arranged in the heating box (2), and each of the temperature-pressure reaction kettles (3) is connected to the hydraulic device (1) respectively.

2. The temperature-pressure responsive plugging agent evaluation device according to claim 1, characterized in that: The temperature and pressure reactor (3) comprises: A plurality of vertically arranged cylinders (301); An upper plug (302) detachably mounted at the upper opening of the cylinder (301), wherein the upper plug (302) is connected to an exhaust valve (9); A lower plug (303) fixedly mounted at the lower end opening of the cylinder (301), the lower plug (303) being provided with an oil inlet, the oil inlet being connected to the hydraulic device (1); and a piston (306) slidingly fitted in the cylinder (301).

3. The temperature-pressure responsive plugging agent evaluation device according to claim 2, characterized in that: An upper pressure cap (304) is detachably mounted on the upper end of the cylinder (301), and the upper pressure cap (304) is detachably connected to the upper plug (302); A pressing cap (305) is fixedly mounted on the lower end of the cylinder (301), and the pressing cap (305) is fixedly connected to the lower plug (303).

4. The temperature-pressure responsive plugging agent evaluation device according to claim 3, characterized in that: The upper plug (302) is provided with a sealing ring (10) at the contact surface with the cylinder (301); The lower plug (303) is provided with a sealing ring (10) at the contact surface with the cylinder (301); The upper plug (302) passes through the upper pressure cap (304) and is detachably connected to the upper pressure cap (304) via a retaining spring (11); The lower plug (303) passes through the lower pressing cap (305) and is detachably connected to the lower pressing cap (305) via a retaining spring (11).

5. The temperature-pressure responsive plugging agent evaluation device according to claim 4, characterized in that: The hydraulic device (1) comprises: Hydraulic pump (4); A pair of hydraulic main valves (5) and a back pressure main valve (6); A plurality of groups of hydraulic valves (7) and back pressure valves (8), each of the hydraulic valves (7) being connected to the corresponding lower plug (303) via a pipeline.

6. A method for evaluating a temperature-pressure responsive plugging agent, characterized in that: The evaluation is performed using the temperature-pressure responsive plugging agent evaluation device described in claim 5.

7. The method for evaluating a temperature-pressure responsive plugging agent according to claim 6, characterized in that: The following steps are involved: Step S1, mixing the temperature and pressure responsive plugging agent and the working fluid, and stirring them evenly at room temperature; Step S2, adding the mixed solution obtained in step S1 to the top of the piston (306) in each of the temperature and pressure reactors (3), and keeping each exhaust valve (9) in an open state; Step S3, closing the hydraulic main valve (5) and opening the back pressure main valve (6), and then injecting back pressure into each of the temperature and pressure reactors (3) in sequence; Step S4, close the back pressure main valve (6) and open the hydraulic main valve (5), then inject pressure into each of the temperature and pressure reactors (3) in turn, and after the pressure in the reactor is stable, close each of the exhaust valves (9); Step S5, heating the reaction in the heating box (2); Step S6, after the reaction is completed, turn off the heating button, open the hydraulic main valve (5), each of the hydraulic valves (7) and each of the exhaust valves (9); Step S7: After the heating device is cooled to room temperature, the temperature and pressure reactor (3) is opened, and the plugging agent is taken out and tested.

8. The method for evaluating a temperature-pressure responsive plugging agent according to claim 7, characterized in that: At least one of the following conditions is met: The working fluid in step S1 is one of 5% bentonite slurry, clean water, 5% NaCl solution, 10% NaCl solution or polysulfone drilling fluid; In step S1, the mass ratio of the plugging agent to the working fluid is (5-10):100, and the stirring time is 10-60 min; The mixed solution added in step S2 is 120-200 g; In step S3, the back pressure injected into each of the temperature and pressure reactors (3) is 0-20 MPa; The pressure injected into each of the temperature and pressure reactors (3) in step S4 is 0-20 MPa; The reaction temperature in step S5 is 25-250°C; The reaction time in step S6 is 6-24h.

9. The method for evaluating a temperature-pressure responsive plugging agent according to claim 7, characterized in that: Also includes at least one of the following steps: The plugging agent obtained in step S7 is cut into a cuboid, and its tensile properties are tested at a certain tensile rate using a universal testing machine, wherein the breaking stress is used as a tensile performance index; The plugging agent obtained in step S7 is cut into a cylinder, and its compression performance is tested at a certain compression rate using a universal testing machine, wherein the stress under a fixed strain is used as a compression performance index; The plugging agent obtained in step S7 is cut into circular pieces, and its rheological strength is tested by a rheometer, wherein the average storage modulus in the viscoelastic range is used as a rheological performance index.

10. The method for evaluating a temperature-pressure responsive plugging agent according to claim 9, characterized in that: Cut the plugging agent into a cuboid with a length of 30-40 mm, a width of 10-15 mm, and a height of 3-10 mm, and the stretching rate is 50-100 mm / min; Cut the plugging agent into a cylinder with a diameter of 8-10 mm and a height of 12-20 mm, with a compression rate of 2-10 mm / min and a compression strain of 50-95%; The plugging agent is cut into discs with a diameter of 8-15mm and a height of 2-4mm. The rheological test is set to a spacing of 1mm. Then the gel is placed on the test lower plate, the oscillation scanning frequency is fixed at 1Hz, and the strain amplitude scanning range is 0.1% to 1000%. The viscoelastic range of the gel is determined by strain scanning. Within the viscoelastic range of the gel, the strain of the oscillation scanning is fixed, and the frequency scan is performed in the frequency range of 0.1 to 100Hz.

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