CO2-water core displacement experiment operation method

Abstract

The invention discloses a CO2-water core displacement experiment operation method, and belongs to the technical field of displacement experiment methods. The method comprises the following steps that S1, limiting of the first fixing sleeve is completed; s2, hydraulic oil with corresponding pressure is injected into the elastic bag, a heating ring and a detection unit are started, and preparation before testing is completed; s3, completing the test of the to-be-measured object, wherein the detection unit records the test data; and S4, after the test is completed, sequentially closing the heating ring and the detection unit, controlling the elastic bag to reset, then opening the first fixing sleeve through the first power piece, taking out the object to be measured, and subsequently controlling the first power piece to reset, thereby completing the test experiment. Through elastic deformation of the elastic bag, the elastic bag can be tightly attached to the side wall of a to-be-measured object conveniently, and it is guaranteed that a medium permeates into the to-be-measured object; in addition, through the limiting effect of a second sliding column and a fifth spring and the like, the medium can permeate into the object to be measured at stable pressure, and the accuracy of experimental data is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of displacement experimental methods, and specifically proposes a CO2-water core displacement experimental operation method. Background Art

[0002] The CO2-water two-phase flow displacement experiment is a research method that simulates the flow and interaction of carbon dioxide (CO2) and water in porous media (such as rocks and soil) under laboratory conditions. This experiment is crucial for understanding CO2 geological storage, improving oil recovery, and evaluating underground fluid dynamics.

[0003] In the existing core displacement experiment, the core sample needs to be placed in a core holder first, and then CO2 is injected into one end of the core sample to test the gas-water relative permeability of the core. In this process, CO2 is easy to overflow from the gap between the core sample and the core holder, affecting the accuracy of the test results. In addition, when testing core samples of different sizes, it is difficult to control the sealing and extrusion pressure between the core holder and the core samples of different sizes. If the extrusion pressure is too large, the core sample is easy to break, causing CO2 to overflow from the cracks of the core sample, resulting in a large deviation in the test results. Summary of the invention

[0004] In order to overcome the above-mentioned technical problems, the present invention provides a CO2-water two-phase flow displacement experimental device and method.

[0005] The technical solution of the present invention is:

[0006] A CO2-water two-phase flow displacement experimental device comprises a workbench, a first fixed seat is embedded in the middle of the workbench, a side wall of the first fixed seat is connected to an exhaust pipe, a switch valve is installed in the exhaust pipe, a symmetrical first power member is fixedly connected to the workbench, a first fixed shell is commonly installed on the symmetrical first power member, a first fixed shell is provided with a first fixed sleeve, the length of the inner diameter of the first fixed sleeve is greater than the length of the maximum diameter of the first fixed seat, a second fixed seat is fixedly connected to the upper part of the first fixed sleeve, a side wall of the second fixed seat is connected to a filling pipe for installing a switch valve, an elastic bag is fixedly connected in the first fixed sleeve, a heating ring and uniformly distributed detection units are fixedly connected to the side wall of the first fixed sleeve, second fixed sleeves are fixedly connected to the opposite sides of the first fixed seat and the second fixed seat, and two second fixed sleeves are commonly provided with a centering mechanism for locating the object to be measured in the middle of the elastic bag.

[0007] More preferably, the elastic bag is embedded with uniformly distributed elastic rings, and the cross section of the elastic ring is an isosceles trapezoid.

[0008] More preferably, the centering mechanism includes two first sliding shells which are symmetrical in upper and lower directions, the two first sliding shells are respectively slidably disposed on adjacent second fixing sleeves, and the side walls of the first sliding shells are fixedly connected with first springs which are fixedly connected to the adjacent second fixing sleeves.

[0009] More preferably, a sliding ring is slidably arranged inside the first fixed sleeve, the sliding ring is located on the lower side of the elastic bag and fixed thereto, and a plurality of concentric elastic convex rings are arranged on the lower side of the sliding ring, and a plurality of concentric annular grooves are arranged on the first fixed seat, and the annular grooves of the first fixed seat are squeezed and fitted with the adjacent elastic convex rings on the sliding ring to improve the sealing between the first fixed seat and the sliding ring.

[0010] More preferably, it also includes a locking mechanism for locking the first fixed sleeve, the locking mechanism is arranged on the workbench, the first fixed shell and the first fixed sleeve are slidably matched, the locking mechanism includes a fixing ring, the fixing ring is fixedly connected to the upper surface of the workbench, the fixing ring is provided with a centrally symmetrical limiting groove, the lower part of the first fixed sleeve is rotatably provided with a rotating ring, the lower surface of the rotating ring is fixedly connected with a symmetrical L-shaped rod, the L-shaped rod is limitedly matched with the adjacent limiting groove on the fixing ring, the side wall of the first fixed sleeve is fixedly connected with a fixing plate, a torsion spring is installed between the fixing plate and the rotating ring, a second spring is fixedly connected between the first fixed shell and the first fixed sleeve, and the upper surface of the rotating ring is fixedly connected with a symmetrical guide rod, the first fixed shell is provided with a centrally symmetrical guide groove, and the guide rod is slidably matched with the adjacent guide groove on the first fixed shell.

[0011] More preferably, it also includes a pressurizing mechanism for strengthening the sealing between the elastic bag and the object to be measured, the pressurizing mechanism is arranged on the elastic bag, and the elastic bag is provided with evenly distributed grooves, the pressurizing mechanism includes evenly distributed annular sleeves, the evenly distributed annular sleeves are all fixed in the elastic bag, and the annular sleeves are directly opposite to the adjacent grooves on the elastic bag, the annular sleeves and the elastic bag cooperate to form an annular cavity filled with hydraulic oil, the elastic bag is fixed with multiple evenly distributed groups of second fixed shells, each group of the second fixed shells includes multiple second fixed shells distributed equidistantly in the circumferential direction, the number of multiple groups of the second fixed shells is one less than the number of evenly distributed grooves on the elastic bag, and the multiple groups of the second fixed shells are respectively located in adjacent grooves on the elastic bag, the second fixed shell is slidably provided with a first sliding column penetrating the elastic bag and slidably connected thereto, the second fixed shell is connected with a first conduit, the first conduit penetrates the adjacent annular sleeve and is fixed thereto, and the first conduit is connected to the annular sleeve on its lower side.

[0012] More preferably, it also includes a uniform exhaust mechanism for controlling the pressure environment of the object to be measured, the uniform exhaust mechanism is arranged on the first fixed seat, the uniform exhaust mechanism includes a second sliding shell, the second sliding shell is slidably arranged in the first fixed seat, a first sliding plate is slidably arranged in the first fixed seat, a third spring is fixedly connected between the first sliding plate and the second sliding shell, a limit ring is fixedly connected in the first fixed seat for limiting the movement of the second sliding shell, the second sliding shell is connected to a second conduit for installing a switch valve, the second conduit penetrates the first sliding plate and the first fixed seat and slidably cooperates with the two, the second sliding shell is provided with a circular hole for communicating with the exhaust pipe, the first fixed seat is threaded with a first threaded rod, and the first threaded rod is rotatably connected to the first sliding plate. More preferably, it also includes a pressing mechanism for uniformly squeezing the medium in the second fixed seat, the pressing mechanism is arranged on the second fixed seat, a switch valve is installed in the second fixed seat, the pressing mechanism includes a second power member, the second power member is installed on the second fixed seat, a third sliding shell is slidably arranged in the second fixed seat, a fourth sliding shell connected to the second power member is slidably arranged in the third sliding shell, a fourth spring is installed between the fourth sliding shell and the third sliding shell, and the fourth sliding shell is provided with a uniform component for constantly discharging the medium in the second fixed seat.

[0013] More preferably, the uniform component includes a third fixed shell, the third fixed shell is fixedly connected to the fourth sliding shell, and the third fixed shell is communicated with the fourth sliding shell, a second sliding column is slidably arranged in the third fixed shell, the second sliding column is provided with an L-shaped hole, the third fixed shell is threadedly provided with a second threaded rod, the second threaded rod is rotatably provided with a second sliding plate that slides in the third fixed shell, a fifth spring is fixedly connected between the second sliding plate and the second sliding column, a third conduit is communicated with the side wall of the third fixed shell, the third conduit is communicated and cooperated with the L-shaped hole on the second sliding column, and the third sliding plate is slidably arranged in the third conduit.

[0014] The present invention also provides an operating method for a CO2-water two-phase flow displacement experiment, based on the above-mentioned CO2-water two-phase flow displacement experiment device, specifically comprising the following steps:

[0015] S1: First, the first power member is started to move the first fixing sleeve upward, wherein the limiting groove of the fixing ring releases the limiting of the L-shaped rod, and then the object to be measured is placed on the corresponding first sliding shell, and then the first power member is started to move the first fixing sleeve downward and reset, and at the same time, the L-shaped rod slides back into the limiting groove of the fixing ring to complete the limiting of the first fixing sleeve;

[0016] S2: After the object to be measured enters the first fixed sleeve, hydraulic oil of corresponding pressure is injected into the elastic bag and the heating ring and the detection unit are started. The elastic bag tightly wraps the object to be measured under the pressure of the hydraulic oil, and the heating ring keeps the object to be measured at a set temperature, thus completing the preparation before the test;

[0017] S3: After the preparation before the test is completed, a medium of a specified pressure is injected into the first fixed sleeve through the filling tube, and the first threaded rod and the second threaded rod are adjusted according to the corresponding data of the experiment, and then the second power member is started to work, wherein the reciprocating movement of the second sliding column causes the medium in the first fixed sleeve to penetrate into the object to be measured at a set pressure when the third sliding shell moves, and under the reciprocating movement of the second sliding shell, the set pressure is maintained in the first fixed seat, and the test of the object to be measured is completed, wherein the detection unit records the test data;

[0018] S4: After the test is completed, the heating ring and the detection unit are closed in sequence, and the elastic bag is controlled to be reset. Then, the first fixing sleeve is opened by the first power member, and the object to be measured is taken out. Subsequently, the first power member is controlled to be reset to complete the test experiment.

[0019] The beneficial technical effects of the present invention are as follows:

[0020] The present invention facilitates the elastic bag to be closely attached to the side wall of the object to be measured through the elastic deformation of the elastic bag, ensures that the medium penetrates into the object to be measured, and improves the accuracy of experimental data. The first springs on the two first sliding shells are used to facilitate the object to be measured to be centered in the middle of the elastic bag, so that the elastic bag can apply a uniform and stable extrusion force to the object to be measured. The cooperation of multiple elastic rings on the sliding ring and multiple annular grooves on the first fixed seat is used to improve the sealing performance of the device and prevent the medium from leaking to the outside. The cooperation of the L-shaped rod and the upper limit groove of the fixed ring is used to improve the limiting of the first fixed sleeve and further prevent the medium from leaking to the outside. The limiting effect of the second sliding shell and the third spring facilitates one end of the object to be measured to maintain a stable pressure. In combination with the work of the second power piece and the limiting effect of the second sliding column and the fifth spring, the medium penetrates into the object to be measured with a stable pressure, thereby providing the accuracy of the experimental data of the present device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of the components in the first fixed sleeve of the present invention;

[0023] Figure 3 It is a cross-sectional view of the components of the first fixing sleeve and the elastic bag of the present invention;

[0024] Figure 4It is a cross-sectional view of the components at the first fixing seat and the second fixing seat of the present invention;

[0025] Figure 5 is a cross-sectional view of the centering mechanism of the present invention;

[0026] Figure 6 An exploded view of the locking mechanism of the present invention;

[0027] Figure 7 is a cross-sectional view of the pressurizing mechanism of the present invention;

[0028] Figure 8 is a cross-sectional view of the uniform exhaust mechanism of the present invention;

[0029] Fig. 9 It is a cross-sectional view of the pressing mechanism of the present invention.

[0030] The markings in the figure are:

[0031] 1. workbench, 11. first fixing seat, 111. exhaust pipe, 12. first power member, 13. first fixing shell, 14. first fixing sleeve, 141. second fixing seat, 142. filling tube, 15. elastic bag, 16. heating ring, 17. detection unit, 18. second fixing sleeve;

[0032] 2. Elastic ring;

[0033] 3. a first sliding shell, 31. a first spring;

[0034] 4. Sliding ring;

[0035] 5. fixed ring, 51. rotating ring, 511. L-shaped rod, 52. fixed plate, 53. torsion spring, 54. second spring, 55. guide rod;

[0036] 6. annular sleeve, 61. second fixed shell, 62. first sliding column, 63. first guide tube;

[0037] 7. second sliding shell, 71. first sliding plate, 72. third spring, 73. limiting ring, 74. second guide tube, 75. first threaded rod;

[0038] 8. a second power member, 81. a third sliding shell, 82. a fourth sliding shell, 83. a fourth spring;

[0039] 9. a third fixed shell, 91. a second sliding column, 92. a second threaded rod, 93. a second sliding plate, 94. a fifth spring, 95. a third guide tube, 96. a third sliding plate. DETAILED DESCRIPTION

[0040] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The first power member and the second power member are both hydraulic push rods.

[0041] Example 1

[0042] A CO2-water two-phase flow displacement experimental device, such as Figure 1-Figure 4 As shown, it includes a workbench 1, a control panel is fixedly connected to the front side of the workbench 1, a first fixed seat 11 is embedded in the middle of the workbench 1, the right side of the first fixed seat 11 is connected to an exhaust pipe 111, a switch valve is installed in the exhaust pipe 111, two first power members 12 symmetrically connected to the workbench 1 are fixedly connected, the two first power members 12 are electrically connected to the control panel, a first fixed shell 13 is commonly installed at the telescopic ends of the two first power members 12, a first fixed sleeve 14 is arranged in the first fixed shell 13, the length of the inner diameter of the first fixed sleeve 14 is greater than the length of the maximum diameter of the first fixed seat 11, so that the first fixed seat 11 is convenient to be inserted into the first fixed sleeve 14, a second fixed seat 141 is fixedly connected to the upper part of the first fixed sleeve 14, the left side of the second fixed seat 141 is connected to a stuffing pipe 142 for installing the switch valve, an elastic bag 15 is fixedly connected to the first fixed sleeve 14, and the elastic bag 15 is resistant High temperature material, the elastic bag 15 is embedded with uniformly distributed elastic rings 2, the cross-section of the elastic ring 2 is an isosceles trapezoid, the elastic coefficient of the elastic ring 2 is greater than the elastic coefficient of the elastic bag 15, the elastic bag 15 is provided with a pipeline penetrating the first fixed sleeve 14, the pipeline is connected to the external hydraulic pump, and the external hydraulic pump is electrically connected to the control panel, the side wall of the first fixed sleeve 14 is fixed with a heating ring 16 and three uniformly distributed detection units 17, the detection unit 17 is used to detect the penetration efficiency of CO2 in the core sample, the heating ring 16 and the three detection units 17 are electrically connected to the control panel, the first fixed seat 11 and the second fixed seat 141 are fixed with second fixed sleeves 18 on the opposite sides, the two second fixed sleeves 18 are jointly provided with a centering mechanism, the centering mechanism is used for the object to be measured to be located in the middle of the elastic bag 15, the switch valve on the exhaust pipe 111 and the switch valve of the filling pipe 142 are electrically connected to the control panel.

[0043] like Figure 4 and Figure 5As shown, the centering mechanism includes two first sliding shells 3 that are symmetrical in upper and lower directions. The two first sliding shells 3 are respectively slidably arranged on adjacent second fixed sleeves 18. The side walls of the first sliding shells 3 are fixedly connected with first springs 31 that are fixedly connected with the adjacent second fixed sleeves 18. The elastic action of the two first springs 31 is utilized to keep the core sample centered in the elastic bag 15, so that the elastic bag 15 can apply uniform extrusion pressure to the core sample. A sliding ring 4 is slidably arranged in the lower part of the first fixed sleeve 14. The sliding ring 4 is located on the lower side of the elastic bag 15 and is fixed thereto, and a plurality of concentric elastic convex rings are arranged on the lower side of the sliding ring 4. The first fixed seat 11 is provided with a plurality of concentric annular grooves. The annular grooves of the first fixed seat 11 are squeezed and matched with the adjacent elastic convex rings on the sliding ring 4, so that the fitting surface forms a wavy sealing fitting surface, thereby improving the sealing between the first fixed seat 11 and the sliding ring 4 and preventing CO2 from leaking from the first fixed sleeve 14.

[0044] When conducting the CO2-water two-phase flow displacement experiment, the operator first dried the core sample for 24 hours, then placed the core sample in a vacuum saturation device and evacuated it for 3 hours, and then pressurized it to 25MPa with distilled water and maintained it for 24 hours to fill the core sample with distilled water.

[0045] After the preliminary operation and processing of the core sample is completed, the operator controls the two first power members 12 to fully extend through the control panel on the workbench 1, and the telescopic end of the first power member 12 drives the first fixed shell 13 and the first fixed sleeve 14 to move upward, and then the operator places the core sample on the upper surface of the lower first sliding shell 3, and then the operator controls the two first power members 12 to retract and reset through the control panel on the workbench 1, and the two first power members 12 drive the first fixed sleeve 14 to move downward through the first fixed shell 13, so that the core sample is located in the elastic bag 15, and the elastic bag 15 expands and squeezes the sliding ring 4 to move, and the sliding ring 4 moves and is close to the upper surface of the first fixed seat 11, and at the same time, under the elastic force of the first springs 31 on the two first sliding shells 3, the two first sliding shells 3 clamp the core sample in the center, thereby ensuring that the core sample is centered in the elastic bag 15, which is convenient for the subsequent elastic bag 15 to apply uniform circumferential extrusion force to the core sample.

[0046] After the first power member 12 is reset, the operator starts the external hydraulic pump, the heating ring 16 and the detection unit 17 through the control panel. The external hydraulic pump works to inject hydraulic oil into the elastic bag 15 through the pipeline. As the hydraulic oil enters, the elastic bag 15 will gradually expand. The expanded elastic bag 15 will fully wrap the core sample. At this time, the external hydraulic pump works to make the elastic bag 15 apply a confining pressure of 20MPa to the core sample, wherein the heating ring 16 works to maintain 40°C in the first fixed sleeve 14. The elastic bag 15 expands and squeezes the sliding ring 4 downward and close to the upper surface of the first fixed seat 11. At this time, the confining pressure application operation on the core sample is completed.

[0047] After completing the confining pressure application operation, the operator opens the switch valve on the exhaust pipe 111 and the switch valve on the filling pipe 142, and then the operator connects the supercritical CO2 tank filled with high pressure to the filling pipe 142, and then the supercritical CO2 gradually flows to the upper side of the core sample through the filling pipe 142 under the action of high pressure. Under the action of pressure, the supercritical CO2 gradually penetrates into the core sample, and the infiltrated supercritical CO2 drives the distilled water in the core sample to gradually seep downward. During this process, the detection unit 17 works to record the displacement time, displacement pressure difference, cumulative fluid production, cumulative water production and initial gas point at each moment. The gas-liquid relative permeability is subsequently calculated by the control panel, thereby completing the CO2-water two-phase flow displacement experiment. In this process, the separation effect of multiple elastic rings 2 separates the contact surface between the elastic capsule 15 and the core sample into multiple layers, thereby preventing the supercritical CO2 from flowing downward through the gap between the elastic capsule 15 and the core sample during the experiment, thereby improving the accuracy of the experimental data.

[0048] After the measurement is completed, the operator controls the elastic bag 15 to reset by controlling the external hydraulic pump, and at the same time starts the two first power members 12 to fully extend through the control panel. The operator then takes out the core sample, and then controls the two first power members 12 to work in the reverse direction and reset through the control panel. At the same time, the operator turns off the heating ring 16 and the detection unit 17 through the control panel.

[0049] Example 2

[0050] On the basis of Example 1, Figure 5 and Figure 6As shown, it also includes a locking mechanism, which is arranged on the workbench 1, and is used to lock the first fixed sleeve 14. The first fixed shell 13 and the first fixed sleeve 14 are slidably matched. The locking mechanism includes a fixing ring 5, which is fixedly connected to the upper surface of the workbench 1, and the center line of the fixing ring 5 coincides with the center line of the first fixed sleeve 14. The fixing ring 5 is provided with two centrally symmetrical limiting grooves, and the limiting grooves are divided into two sections, which are respectively a vertical section and a horizontal section. A rotating ring 51 is rotatably provided at the lower part of the first fixed sleeve 14, and two left-right symmetrical L-shaped rods 511 are fixedly connected to the lower surface of the rotating ring 51. The L-shaped rods 511 are limitedly matched with the adjacent limiting grooves on the fixing ring 5, and the side wall of the first fixed sleeve 14 is fixed A fixed plate 52 is connected, and the fixed plate 52 is located above the rotating ring 51. A torsion spring 53 fixed to the upper side of the rotating ring 51 is fixed to the lower side of the fixed plate 52. A second spring 54 is fixed between the first fixed shell 13 and the first fixed sleeve 14. Two guide rods 55 symmetrical in front and back are fixed to the upper surface of the rotating ring 51. The first fixed shell 13 is provided with two centrally symmetrical guide grooves, which are approximately horizontally V-shaped. The guide rods 55 slide in the adjacent guide grooves on the first fixed shell 13. The upper limit groove of the fixed ring 5 is used to limit the two L-shaped rods 511, so as to improve the sealing between the sliding ring 4 and the first fixed seat 11, keep the core sample in a high-pressure state, and further avoid CO2 leakage.

[0051] like Figure 4 and Figure 7 As shown, it also includes a pressurizing mechanism, which is arranged on the elastic bag 15. The pressurizing mechanism is used to strengthen the sealing between the elastic bag 15 and the object to be measured. Six evenly distributed grooves are arranged in the elastic bag 15. The pressurizing mechanism includes six evenly distributed annular sleeves 6. The annular sleeves 6 are made of elastic material. The elastic coefficient of the annular sleeves 6 is greater than the elastic coefficient of the elastic bag 15. The six annular sleeves 6 are all fixed to the inner wall of the elastic bag 15. The annular sleeves 6 and the elastic bag 15 cooperate to form an annular cavity filled with hydraulic oil. The elastic bag 15 is fixed with five evenly distributed groups of second fixed shells 61. Each group of second fixed shells 61 includes six second fixed shells 61 distributed equidistantly in the circumferential direction. The five groups of second The fixed shells 61 are respectively located at the five grooves on the upper side of the elastic bag 15. The second fixed shell 61 is slidably provided with a first sliding column 62 that penetrates the elastic bag 15 and is slidably connected thereto. The second fixed shell 61 is connected with a first conduit 63. The first conduit 63 penetrates the adjacent annular sleeve 6 and is fixed thereto, and the first conduit 63 is connected to the annular sleeve 6 on the lower side thereof. Under the separating action of the elastic ring 2, when CO2 penetrates into the gap between the elastic bag 15 and the core sample, CO2 will squeeze the corresponding first sliding column 62 to move, so that the elastic bag 15 at the lower annular sleeve 6 increases the squeezing force with the core sample, which is convenient for accurately measuring the penetration efficiency of CO2 in the core sample.

[0052] During the displacement experiment, in the initial state, the L-shaped rod 511 is located at one end of the horizontal section of the adjacent limiting groove on the fixed ring 5 away from its vertical section, and the guide rod 55 is located in the middle of the V-shaped guide groove on the first fixed shell 13. As the two first power members 12 work and drive the first fixed shell 13 to move upward, the first fixed shell 13 moves upward to compress the second spring 54, and at the same time, the lower half of the two guide grooves on the first fixed shell 13 squeezes the two guide rods 55. The two guide rods 55 are squeezed and drive the rotating ring 51 to rotate clockwise, and the rotating ring 51 rotates to twist the torsion spring 53, and The rotation of the rotating ring 51 drives the two L-shaped rods 511 to rotate in the two limit grooves of the fixed ring 5. When the L-shaped rods 511 rotate to the vertical section of the adjacent limit grooves on the fixed ring 5, the two limit grooves of the fixed ring 5 release the limit on the two L-shaped rods 511. At this time, under the elastic force of the second spring 54, the rotating ring 51 drives the two L-shaped rods 511 to move upward. After the two L-shaped rods 511 are separated from the contact with the fixed ring 5, the torsion spring 53 and the second spring 54 return to their initial state. The above operation is repeated subsequently to place the core sample on the upper surface of the lower first sliding shell 3.

[0053] After the core sample is placed, the operator starts the reset of the two first power members 12 through the control panel, so that the two L-shaped rods 511 contact the upper surface of the fixing ring 5, and then squeezes the two guide rods 55 in the upper half of the two guide grooves on the first fixing shell 13, so that the two guide rods 55 drive the rotating ring 51 and the two L-shaped rods 511 to rotate clockwise and twist the torsion spring 53, so that the two L-shaped rods 511 are respectively opposite to the vertical sections of the adjacent limit grooves on the fixing ring 5, and then under the torsion force of the torsion spring 53, the two L-shaped rods 511 are reinserted into the two limit grooves on the fixing ring 5, restoring the initial state, and completing the limitation of the first fixing sleeve 14 again.

[0054] After the core sample enters the first fixed sleeve 14, the operator starts the external air pressure pump, the heating ring 16 and the detection unit 17 through the control panel, and continuously injects high-pressure supercritical CO2 into the filling tube 142 to conduct a CO2-water two-phase flow displacement experiment. During the above experiment, when the supercritical CO2 flows to the gap between the elastic capsule 15 and the core sample, the supercritical CO2 will first squeeze the adjacent first sliding column 62 to move under the separation effect of the corresponding elastic ring 2. The first sliding column 62 moves to squeeze the hydraulic oil in the adjacent second fixed shell 61 through the adjacent first guide tube 63 into the lower annular sleeve 6. The hydraulic oil squeezes the annular sleeve 6 at this location, so that the part of the annular sleeve 6 facing the elastic capsule 15 at this location further squeezes the core sample, further improves the sealing performance of the elastic capsule 15 at this location and the core sample, ensures that the supercritical CO2 flows in the core sample, and further improves the accuracy of the experimental data. After the test is completed, the operator repeats the above operation to take out the core sample.

[0055] Example 3

[0056] On the basis of Example 2, Figure 4 and Figure 8 As shown, it also includes a uniform exhaust mechanism, which is arranged on the first fixed seat 11. The uniform exhaust mechanism is used to control the pressure environment of the object to be measured. The uniform exhaust mechanism includes a second sliding shell 7, which is slidably arranged at the lower part of the first fixed seat 11. A first sliding plate 71 is slidably arranged in the first fixed seat 11. The first sliding plate 71 is located below the second sliding shell 7. A third spring 72 is fixedly connected between the first sliding plate 71 and the second sliding shell 7. A limiting spring 72 for limiting the movement of the second sliding shell 7 is fixedly connected in the first fixed seat 11. The limiting ring 73 has an upper surface in the shape of a truncated cone. The lower side of the second sliding shell 7 is connected with a second conduit 74 for installing a switch valve. The switch valve is electrically connected to the control panel. The second conduit 74 penetrates the first sliding plate 71 and the first fixed seat 11 and slides with the two. The second sliding shell 7 is provided with a circular hole for communicating with the exhaust pipe 111. The first fixed seat 11 is threadedly provided with a first threaded rod 75 rotatably connected to the first sliding plate 71. The spring force of the third spring 72 is used to regulate the pressure in the first fixed seat 11 to improve the accuracy of the test results.

[0057] like Figure 4 and Fig. 9 As shown, it also includes a pressing mechanism, which is arranged on the second fixed seat 141. The pressing mechanism is used to uniformly squeeze the CO2 in the second fixed seat 141. A switch valve electrically connected to the control panel is installed in the second fixed seat 141. The pressing mechanism includes a second power member 8 electrically connected to the control panel. The second power member 8 is installed at the rear of the upper surface of the second fixed seat 141. A third sliding shell 81 is slidably arranged in the second fixed seat 141. A sealing ring with a triangular cross section is fixed to the lower surface of the third sliding shell 81 to improve the sealing performance of the third sliding shell 81 and the second fixed seat. The sealing between the seats 141, the upper sliding shell 81 is slidingly provided with a fourth sliding shell 82 fixedly connected to the telescopic end of the second power member 8, a fourth spring 83 is installed between the fourth sliding shell 82 and the third sliding shell 81, the fourth sliding shell 82 and the third sliding shell 81 are filled with hydraulic oil, the fourth sliding shell 82 is provided with a uniform component for constantly discharging CO2 in the second fixed seat 141, and the relative sliding of the fourth sliding shell 82 and the third sliding shell 81 is utilized to make CO2 penetrate into the core sample at a constant pressure, thereby improving the stability of the experimental data.

[0058] like Fig. 9As shown, the uniform component includes a third fixed shell 9, which is fixed to the upper surface of the fourth sliding shell 82, and the third fixed shell 9 is communicated with the fourth sliding shell 82. A second sliding column 91 is slidably arranged in the third fixed shell 9, and the third fixed shell 9 is provided with a convex ring for limiting the movement of the second sliding column 91. An L-shaped hole is arranged in the second sliding column 91, and a second threaded rod 92 is threadedly arranged on the upper part of the third fixed shell 9. The lower part of the second threaded rod 92 is rotatably provided with a second sliding plate 93 sliding in the third fixed shell 9, and a fifth spring 94 fixed to the upper side of the second sliding column 91 is fixed to the lower surface of the second sliding plate 93. The side wall of the third fixed shell 9 is fixed and communicated with a third conduit 95, and the third conduit 95 is communicated and matched with the L-shaped hole on the second sliding column 91. A third sliding plate 96 is slidably arranged in the upper part of the third conduit 95. The elastic force of the fifth spring 94 is adjusted by rotating the second threaded rod 92, so as to control the penetration of CO2 into the core sample at different pressures and improve the comprehensiveness of the experimental data.

[0059] When conducting a CO2-water two-phase flow displacement experiment on a core sample, the operator repeats the above operation so that the core sample is circumferentially wrapped by the elastic bag 15, and then the operator opens the switch valve on the filling tube 142 and the switch valve on the exhaust pipe 111, wherein the switch valve in the second fixed seat 141 is in a closed state, and then the operator injects supercritical CO2 into the second fixed seat 141 through the filling tube 142, and the supercritical CO2 maintains the set pressure intensity in the second fixed seat 141.

[0060] After the supercritical CO2 is added, the operator closes the switch valve on the filling tube 142 and opens the switch valve in the second fixed seat 141 through the control panel. The control panel simultaneously controls the operation of the second power member 8. The second power member 8 drives the third sliding shell 81 to move downward at a uniform speed through the fourth sliding shell 82 and the fourth spring 83. The movement of the third sliding shell 81 pushes the supercritical CO2 in the second fixed seat 141 to penetrate into the fixed core sample at a stable pressure.

[0061] When the penetration efficiency of supercritical CO2 is slow, the second power part 8 works, and the pressure of supercritical CO2 squeezes the third sliding shell 81 to move upward relative to the fourth sliding shell 82 and compresses the adjacent fourth spring 83. At the same time, the hydraulic oil in the third sliding shell 81 and the fourth sliding shell 82 squeezes the second sliding column 91 to move upward along the third fixed shell 9 and compresses the fifth spring 94. When the second sliding column 91 moves to connect its L-shaped hole with the third conduit 95, the hydraulic oil in the third sliding shell 81 and the fourth sliding shell 82 enters the third conduit 95 through the L-shaped hole of the second sliding column 91, and the hydraulic oil squeezes the third sliding plate 96 upward, so that the supercritical CO2 squeezed on the lower side of the third sliding shell 81 penetrates into the core sample with a stable pressure, thereby improving the stability and accuracy of the testing device.

[0062] Before the test, the operator rotates the second threaded rod 92, which drives the second sliding plate 93 to move, thereby changing the elastic force of the fifth spring 94 in the initial state, so as to control the supercritical CO2 to penetrate into the core sample at different pressures, thereby improving the diversity of the test of the device, further simulating the core samples under different pressure states, and further improving the accuracy of the test of the device.

[0063] Supercritical CO2 squeezes the water vapor in the core sample into the first fixed seat 11, so that the pressure in the first fixed seat 11 gradually increases. After the pressure increases, the second sliding shell 7 is squeezed downward and the third spring 72 is compressed. After the through hole on the second sliding shell 7 is connected with the exhaust pipe 111, the high-pressure gas is gradually discharged from the first fixed seat 11, so that the lower pressure of the core sample remains stable. In this process, the operator changes the spring force between the first sliding plate 71 and the second sliding shell 7 in the initial state by rotating and adjusting the first threaded rod 75, so that the operator can simulate the upper and lower sides of the core sample under different pressure states to perform CO2-water two-phase flow displacement experiments, so as to make the experimental data more comprehensive and further improve the accuracy of the experiment. After the test is completed, the operator repeats the above operation to take out the core sample.

[0064] Example 4

[0065] On the basis of Example 3, the present invention further provides an operating method for a CO2-water two-phase flow displacement experiment, based on the above-mentioned CO2-water two-phase flow displacement experimental device, specifically comprising the following steps:

[0066] S1: First start the first power member 12 to move the first fixing sleeve 14 upward, wherein the limiting groove of the fixing ring 5 releases the limiting of the L-shaped rod 511, and then place the object to be measured on the corresponding first sliding shell 3, and then start the first power member 12 to move the first fixing sleeve 14 downward and reset, and at the same time, the L-shaped rod 511 slides back into the limiting groove of the fixing ring 5 to complete the limiting of the first fixing sleeve 14.

[0067] S2: After the object to be measured enters the first fixing sleeve 14, hydraulic oil of corresponding pressure is injected into the elastic bag 15 and the heating ring 16 and the detection unit 17 are started. The elastic bag 15 tightly wraps the object to be measured under the pressure of the hydraulic oil, and the heating ring 16 keeps the object to be measured at a set temperature, thereby completing the preparation before the test.

[0068] S3: After the preparation before the test is completed, the medium of the specified pressure is injected into the first fixed sleeve 14 through the filling tube 142, and the first threaded rod 75 and the second threaded rod 92 are adjusted according to the corresponding data of the experiment, and then the second power member 8 is started to work, wherein the reciprocating movement of the second sliding column 91 causes the third sliding shell 81 to move and the medium in the first fixed sleeve 14 to penetrate into the object to be measured at the set pressure, and under the reciprocating movement of the second sliding shell 7, the set pressure is maintained in the first fixed seat 11, and the test of the object to be measured is completed, wherein the detection unit 17 records the test data.

[0069] S4: After the test is completed, the heating ring 16 and the detection unit 17 are closed in sequence, and the elastic bag 15 is controlled to be reset. Then, the first fixing sleeve 14 is opened by the first power member 12, and the object to be measured is taken out. Subsequently, the first power member 12 is controlled to be reset to complete the test experiment.

[0070] The above describes the specific implementation of the present invention with reference to the accompanying drawings, but does not limit the scope of the present invention. Any modification, equivalent substitution and improvement made by those skilled in the art without departing from the scope and essence of the present invention shall be within the scope of the present invention.

Claims

1. A CO2-water core flooding experimental operation method, characterized in that: A CO2-water two-phase flow displacement experimental device is used, which includes a workbench, a first fixed seat is embedded in the middle of the workbench, the side wall of the first fixed seat is connected to an exhaust pipe, a switch valve is installed in the exhaust pipe, a symmetrical first power member is fixedly connected to the workbench, and the symmetrical first power members are jointly installed with a first fixed shell, the first fixed shell is provided with a first fixed sleeve, the length of the inner diameter of the first fixed sleeve is greater than the length of the maximum diameter of the first fixed seat, a second fixed seat is fixedly connected to the upper part of the first fixed sleeve, the side wall of the second fixed seat is connected to a filling pipe for installing the switch valve, an elastic capsule is fixedly connected in the first fixed sleeve, a heating ring and uniformly distributed detection units are fixedly connected to the side wall of the first fixed sleeve, the first fixed seat and the second fixed seat are both fixedly connected to the opposite sides thereof, and the two second fixed sleeves are jointly provided with a centering mechanism for locating the object to be measured in the middle of the elastic capsule; The method specifically comprises the following steps: S1: First, the first power member is started to move the first fixing sleeve upward, wherein the limiting groove of the fixing ring releases the limiting of the L-shaped rod, and then the object to be measured is placed on the corresponding first sliding shell, and then the first power member is started to move the first fixing sleeve downward and reset, and at the same time, the L-shaped rod slides back into the limiting groove of the fixing ring to complete the limiting of the first fixing sleeve; S2: After the object to be measured enters the first fixed sleeve, hydraulic oil of corresponding pressure is injected into the elastic bag and the heating ring and the detection unit are started. The elastic bag tightly wraps the object to be measured under the pressure of the hydraulic oil, and the heating ring keeps the object to be measured at a set temperature, thus completing the preparation before the test; S3: After the preparation before the test is completed, a medium of a specified pressure is injected into the first fixed sleeve through the filling tube, and the first threaded rod and the second threaded rod are adjusted according to the corresponding data of the experiment, and then the second power member is started to work, wherein the reciprocating movement of the second sliding column causes the medium in the first fixed sleeve to penetrate into the object to be measured at a set pressure when the third sliding shell moves, and under the reciprocating movement of the second sliding shell, the set pressure is maintained in the first fixed seat, and the test of the object to be measured is completed, wherein the detection unit records the test data; S4: After the test is completed, the heating ring and the detection unit are closed in sequence, and the elastic bag is controlled to be reset. Then, the first fixing sleeve is opened by the first power member, and the object to be measured is taken out. Subsequently, the first power member is controlled to be reset to complete the test experiment.

2. A CO2-water core flooding experimental operation method according to claim 1, characterized in that: The elastic bag is embedded with uniformly distributed elastic rings, and the cross section of the elastic ring is an isosceles trapezoid.

3. A CO2-water core flooding experimental operation method according to claim 2, characterized in that: The centering mechanism includes two first sliding shells that are symmetrical in upper and lower directions. The two first sliding shells are respectively slidably arranged on adjacent second fixing sleeves. The side wall of the first sliding shell is fixedly connected with a first spring that is fixedly connected to the adjacent second fixing sleeve.

4. A CO2-water core flooding experimental operation method according to claim 3, characterized in that: A sliding ring is slidably arranged inside the first fixed sleeve, and the sliding ring is located on the lower side of the elastic bag and fixed thereto, and a plurality of concentric elastic convex rings are arranged on the lower side of the sliding ring, and a plurality of concentric annular grooves are arranged on the first fixed seat, and the annular grooves of the first fixed seat are squeezed and fitted with the adjacent elastic convex rings on the sliding ring, so as to improve the sealing between the first fixed seat and the sliding ring.

5. A CO2-water core flooding experimental operation method according to claim 4, characterized in that: The locking mechanism further comprises a locking mechanism for locking the first fixing sleeve, the locking mechanism being arranged on the workbench, the first fixing shell being slidably matched with the first fixing sleeve, the locking mechanism comprising a fixing ring, the fixing ring being fixedly connected to the upper surface of the workbench, the fixing ring being provided with a centrally symmetrical limiting groove, a rotating ring being rotatably arranged at the lower portion of the first fixing sleeve, a symmetrical L-shaped rod being fixedly connected to the lower surface of the rotating ring, the L-shaped rod being limitedly matched with the adjacent limiting groove on the fixing ring, a fixing plate being fixedly connected to the side wall of the first fixing sleeve, a torsion spring being installed between the fixing plate and the rotating ring, a second spring being fixedly connected between the first fixing shell and the first fixing sleeve, a symmetrical guide rod being fixedly connected to the upper surface of the rotating ring, the first fixing shell being provided with a centrally symmetrical guide groove, and the guide rod being slidably matched with the adjacent guide groove on the first fixing shell.

6. A CO2-water core flooding experimental operation method according to claim 5, characterized in that: The invention also includes a pressurizing mechanism for strengthening the sealing between the elastic bag and the object to be measured, the pressurizing mechanism is arranged on the elastic bag, and the elastic bag is provided with evenly distributed grooves. The pressurizing mechanism includes evenly distributed annular sleeves, and the evenly distributed annular sleeves are all fixed in the elastic bag, and the annular sleeves are directly opposite to the adjacent grooves on the elastic bag. The annular sleeves and the elastic bag cooperate to form an annular cavity filled with hydraulic oil. The elastic bag is fixed with multiple evenly distributed groups of second fixed shells, each group of the second fixed shells includes multiple second fixed shells distributed equidistantly in the circumferential direction, and the number of multiple groups of the second fixed shells is one less than the number of evenly distributed grooves on the elastic bag. The multiple groups of the second fixed shells are respectively located in adjacent grooves on the elastic bag, and the second fixed shell is slidably provided with a first sliding column penetrating the elastic bag and slidably connected thereto, and the second fixed shell is connected with a first conduit, the first conduit penetrates the adjacent annular sleeve and is fixed thereto, and the first conduit is connected to the annular sleeve on its lower side.

7. A CO2-water core flooding experimental operation method according to claim 6, characterized in that: The invention also includes a uniform exhaust mechanism for controlling the pressure environment of the object to be measured, wherein the uniform exhaust mechanism is arranged on the first fixed seat, and the uniform exhaust mechanism includes a second sliding shell, the second sliding shell is slidably arranged in the first fixed seat, a first sliding plate is slidably arranged in the first fixed seat, a third spring is fixedly connected between the first sliding plate and the second sliding shell, a limit ring is fixedly connected in the first fixed seat for limiting the movement of the second sliding shell, the second sliding shell is connected to a second conduit for installing a switch valve, the second conduit penetrates the first sliding plate and the first fixed seat and slidably cooperates with the two, the second sliding shell is provided with a circular hole for communicating with the exhaust pipe, the first fixed seat is threadedly provided with a first threaded rod, and the first threaded rod is rotatably connected to the first sliding plate.

8. A CO2-water core flooding experimental operation method according to claim 7, characterized in that: The invention also includes a pressing mechanism for uniformly squeezing the medium in the second fixed seat, the pressing mechanism is arranged on the second fixed seat, a switch valve is installed in the second fixed seat, the pressing mechanism includes a second power member, the second power member is installed on the second fixed seat, a third sliding shell is slidably arranged in the second fixed seat, a fourth sliding shell connected to the second power member is slidably arranged in the third sliding shell, a fourth spring is installed between the fourth sliding shell and the third sliding shell, and the fourth sliding shell is provided with a uniform component for constantly discharging the medium in the second fixed seat.

9. A CO2-water core flooding experimental operation method according to claim 8, characterized in that: The uniform component includes a third fixed shell, the third fixed shell is fixedly connected to the fourth sliding shell, and the third fixed shell is communicated with the fourth sliding shell, a second sliding column is slidably arranged in the third fixed shell, the second sliding column is provided with an L-shaped hole, the third fixed shell is threadedly provided with a second threaded rod, the second threaded rod is rotatably provided with a second sliding plate that slides in the third fixed shell, a fifth spring is fixedly connected between the second sliding plate and the second sliding column, a third conduit is communicated with the side wall of the third fixed shell, the third conduit is communicated and matched with the L-shaped hole on the second sliding column, and the third sliding plate is slidably arranged in the third conduit.

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