A device for visualizing coal measure reservoir gas percolation simulation

Abstract

The application discloses a visual coal measure reservoir gas seepage simulation device, which comprises an openable and closable shell, a base is fixed in the shell, two vertical plates are distributed on the base, a plurality of through holes are formed in the vertical plates, a rotating disc is rotationally arranged on the opposite side of each vertical plate, a plurality of through holes are also formed in the rotating discs, a plurality of transparent sample tubes are distributed between the opposite through holes of the rotating discs, and a CT scanner is arranged on one side of the base and used for aligning the sample tubes. Compared with the prior art, the application is especially suitable for precise seepage characteristic research in the fields of shale gas development and CO2 geological storage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological simulation testing, and particularly relates to a visual coal measure reservoir gas seepage simulation device. BACKGROUND

[0002] The gas seepage mechanism research of coal measure reservoirs (such as coalbed methane reservoirs and shale gas reservoirs) has great significance for efficient exploitation of unconventional natural gas and safety evaluation of CO2 geological storage. Traditional methods rely on physical simulation of core columns to indirectly calculate seepage parameters, but cannot directly obtain the dynamic migration path of gas in a complex pore network, resulting in significant deviation between the theoretical model and the actual geological conditions. Therefore, developing a seepage experiment device that can accurately simulate the formation environment in real time and visually has become a technical bottleneck to be broken through in the industry.

[0003] The current mainstream visualization schemes mainly include two types: a transparent microfluidic chip is etched on a glass or polymer substrate to form an artificial pore network, and the gas flow is observed by a microscopic camera. The artificial pores cannot restore the heterogeneous structure (such as natural fractures and organic inclusions) of real coal rocks, and it is difficult to simulate the stress conditions of the formation, so the experimental data have low engineering applicability. A small rock sample is placed in a closed chamber by a micro-CT scanning + static holder, and CT scanning is performed after the gas is introduced. A single scan only captures a static image, and cannot continuously record the gas seepage process; the chamber needs to be disassembled to replace the sample, which easily damages the brittle coal rock, lacks integrated sample cleaning and compaction modules, residual gas interferes with the test results, and manual compaction leads to poor consistency of the sample density.

[0004] Therefore, it is necessary to provide a visual coal measure reservoir gas seepage simulation device to solve the problems in the background art. SUMMARY

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a visual coal measure reservoir gas seepage simulation device, comprising an openable and closable shell, a base is fixed in the shell, two vertical plates are distributed on the base, a plurality of through holes are formed in the vertical plates, a rotating disc is rotatably arranged on the opposite side of each vertical plate, a plurality of through holes are also formed in the rotating discs, a plurality of transparent sample tubes are distributed between the opposite through holes of the two rotating discs, and a CT scanner is arranged on one side of the base and aligned with the sample tubes.

[0006] Further, the two through holes on the two sides of one vertical plate are respectively connected to a cleaning inlet and a test inlet, the through hole of the other vertical plate corresponding to the cleaning inlet is connected to a cleaning outlet, and the through hole corresponding to the test inlet is connected to a test outlet.

[0007] Further, a gear slot is formed in the edge of one rotating disc, a driving gear is arranged in the corresponding vertical plate, and the driving gear is engaged with the gear slot of the rotating disc.

[0008] Further, each sample tube is rotationally arranged between two rotating discs, and the outer wall of one end of the sample tube close to one rotating disc is fixed with a gear ring, the center of the rotating disc is rotationally arranged with a center gear, and the center gear is engaged with each gear ring, and the center gear is connected with a driving motor.

[0009] Further, the bottom is provided with a placing groove at the position of the through hole below the two vertical plates.

[0010] Further, the two placing grooves are provided with a pressing plate with the same inner diameter as the sample tube, and the back of each pressing plate is fixed with a guide shaft and a screw rod, and the guide shaft and the screw rod are slidingly penetrated into the connecting block.

[0011] Further, the connecting block is provided with a driving nut threadedly connected with the screw rod.

[0012] Further, each connecting block is slidingly connected to a vertical guide rail, and the vertical guide rail is provided with a driving device capable of driving the connecting block to slide up and down.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] In the present application, the automatic sample loading, mechanical compaction, independent cleaning station, seepage test and CT scanning are integrated, and the pollution and errors caused by manual intervention are eliminated.

[0015] The revolution of the rotating disc realizes batch rotation detection of multiple sample tubes, and the sample tube rotation system makes the CT scanner capture the seepage process without dead angle at 360°, and obtains full-angle three-dimensional data.

[0016] The double placing grooves and the pressing plate realize synchronous loading and unloading, and cooperate with the matrix sample tube layout of the rotating disc to greatly improve the experimental flux.

[0017] Anti-pollution protection - closed shell and clean gas purging system to isolate environmental interference, ensure the reliability of experimental results. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic view of a visual coal reservoir gas seepage simulation device;

[0019] Figure 2 It is a structural schematic view of the inside of the shell;

[0020] Figure 3 It is a structural schematic view of the cross section of the sample tube;

[0021] Figure 4 It is a structural schematic view of the cross section of the sample tube;

[0022] Fig. 1, housing; 2, base; 21, placing groove; 3, sample tube; 4, CT scanner; 5, vertical plate; 51, cleaning inlet; 52, cleaning outlet; 53, test inlet; 54, test outlet; 55, gear ring; 56, central gear; 57, rotating disc; 58, driving gear; 6, pressing plate; 7, vertical guide rail; 71, driving device; 72, connecting block; 73, guide shaft; 74, screw rod; 75, driving nut. DETAILED DESCRIPTION

[0023] Please refer to Figures 1-4 In the embodiment of the present application, the simulation device comprises a housing 1 which can be opened and closed, the housing 1 is fixed with a base 2 inside, two vertical plates 5 are distributed on the base 2, a plurality of through holes are formed in the vertical plates 5, rotating discs 57 are rotatably arranged on the opposite sides of the vertical plates 5, a plurality of through holes are also formed in the rotating discs 57, a plurality of transparent sample tubes 3 are distributed between the opposite through holes of the rotating discs 57, and a CT scanner 4 is arranged on one side of the base 2 and is aligned with the sample tubes 3.

[0024] The diameters of the through holes of the rotating discs 57 and the vertical plates 5 are the same as the inner diameter of the sample tubes 3, that is to say, when the through holes of the rotating discs 57 are aligned with the through holes of the vertical plates 5, the sample tubes 3 can be placed with samples, and different samples can be aligned with the CT scanner 4 by rotating the rotating discs 57, so that the samples at different positions can be detected.

[0025] In the embodiment, the two through holes on the two sides of one of the vertical plates 5 are respectively connected to the cleaning inlet 51 and the test inlet 53, the through hole of the other vertical plate 5 corresponding to the cleaning inlet 51 is connected to the cleaning outlet 52, and the through hole corresponding to the test inlet 53 is connected to the test outlet 54.

[0026] When the sample tube 3 rotates between the cleaning inlet 51 and the cleaning outlet 52, clean air is introduced therebetween, so that the sample can be cleaned to remove the to-be-tested gas possibly contained in the sample, and when the sample tube 3 rotates between the test inlet 53 and the test outlet 54, the to-be-tested gas is introduced therebetween, so that the sample can be subjected to a gas permeation simulation test.

[0027] In the embodiment, a gear slot is formed in the edge of one of the rotating discs 57, a driving gear 58 is arranged in the corresponding vertical plate 5, and the driving gear 58 is engaged with the gear slot of the rotating disc 57.

[0028] The rotating disc 57 can be driven to rotate by the driving gear 58.

[0029] In the embodiment, each sample tube 3 is arranged between two rotating discs 57, and the outer wall of one end of the sample tube 3 close to one rotating disc 57 is fixed with a gear ring 55, the center of the rotating disc 57 is arranged with a center gear 56, and the center gear 56 is engaged with each gear ring 55, and the center gear 56 is connected with a driving motor.

[0030] The center gear 56 can drive each sample tube 3 to rotate, so that the sample tube 3 can be aligned with the CT scanner 4 at different angles, so that the gas seepage condition in the sample tube 3 can be monitored in all directions.

[0031] In the embodiment, the base 2 is provided with a placing groove 21 at the position of the through hole below the two vertical plates 5.

[0032] The sample can be placed on the placing groove 21 for feeding and discharging.

[0033] In the embodiment, the two placing grooves 21 are arranged with a pressing plate 6 with the same inner diameter as the sample tube 3, the back surface of each pressing plate 6 is fixed with a guide shaft 73 and a lead screw 74, the guide shaft 73 and the lead screw 74 are slidingly penetrated into a connecting block 72, and the connecting block 72 is provided with a driving nut 75 threadedly connected with the lead screw 74.

[0034] The rotation of the driving nut 75 can drive the lead screw 74 to push the pressing plate 6 to approach or move away from the sample tube 3 below, so that the sample can be pushed from the front placing groove 21 into the sample tube 3 or pushed out from the sample tube 3 to the rear placing groove 21, so as to facilitate feeding and discharging.

[0035] In the embodiment, each connecting block 72 is slidingly connected to a vertical guide rail 7, and the vertical guide rail 7 is provided with a driving device 71 capable of driving the connecting block 72 to slide up and down.

[0036] The driving device 71 and the vertical guide rail 7 can drive the pressing plate 6 to rise to the position of the sample tube 3 above, when the sample tube 3 passes through the cleaning inlet 51 and the cleaning outlet 52 for cleaning and rotates to the position above, the two pressing plates 6 move to the sample tube 3 at the same time, so as to compact the sample in the sample tube 3, so that the sample reaches the predetermined density, and then rotates to the test inlet 53 and the test outlet 54, so as to perform the gas seepage simulation test on the sample with the predetermined density.

[0037] In specific implementation:

[0038] Open the device housing 1, expose the internal working area, place the sample to be tested on the front of the base 2 slot 21, confirm that the pressure plate 6 is in the initial position away from the sample tube 3, rotate the turntable 57 by driving the gear 58, align the empty sample tube 3 directly below the placement slot 21, ensure that the turntable 57 is completely aligned with the through hole of the vertical plate 5, start the drive nut 75 in front, push the lead screw 74 to make the front pressure plate 6 push the sample into the sample tube 3;

[0039] Rotate the turntable 57 to align the sample tube 3 with the cleaning inlet 51 / cleaning outlet 52, and introduce compressed air into the cleaning inlet 51, continuously blowing the sample to remove residual gas;

[0040] Rotate the turntable 57 to move the sample tube 3 containing the sample to the directly above the compaction station, drive the device 71 to start, make the connecting block 72 rise along the vertical guide rail 7, drive the pressure plate 6 to resist the sample tube 3 on both sides, and move the pressure plate 6 to the center at the same time, compact the sample to the predetermined density, retract the pressure plate 6 after compaction is completed, and drive the device 71 to lower the pressure plate 6 to the initial height

[0041] Rotate the turntable 57 to align the sample tube 3 with the test inlet 53 / test outlet 54, introduce the target gas from the test inlet 53, and connect the test outlet 54 to the monitoring equipment, drive the center gear 56 to rotate, drive the sample tube 3 to rotate by the gear ring 55, and perform multi-angle tomography on the sample tube 3 by the CT scanner 4, rotate the sample tube 3 by the preset angle, and obtain full-range seepage data;

[0042] Rotate the turntable 57 to align the sample tube 3 after the test with the rear placement slot 21, drive the rear pressure plate 6 to push the sample out to the placement slot 21, and manually take away the sample after the test;

[0043] Optionally, rotate the empty sample tube 3 to the cleaning station, and introduce air to flush the residual gas.

[0044] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A visualization device for simulating gas seepage in coal-bearing reservoirs, comprising an openable and closable outer shell (1), characterized in that, The outer shell (1) has a base (2) fixed inside. Two upright plates (5) are distributed on the base (2). Multiple through holes are opened in the upright plates (5). Turntables (57) are rotatably arranged on the opposite side of the two upright plates (5). Multiple through holes are also opened in the two turntables (57). Multiple transparent sample tubes (3) are distributed between the opposite through holes of the two turntables (57). A CT scanner (4) aligned with the sample tubes (3) is arranged on one side of the base (2). Two through holes on both sides of one of the upright plates (5) are connected to the cleaning inlet (51) and the test inlet (53) respectively. The through hole corresponding to the cleaning inlet (51) of the other upright plate (5) is connected to the cleaning outlet (52), and the through hole corresponding to the test inlet (53) is connected to the test outlet (54). The base (2) has a placement groove (21) at the through hole position corresponding to the two upright plates (5) located directly below. Both of the placement slots (21) are equipped with pressure plates (6) with the same inner diameter as the sample tube (3). Each pressure plate (6) has a guide shaft (73) and a lead screw (74) fixed on its back. The guide shaft (73) and the lead screw (74) slide through the connecting block (72).

2. The visualization device for simulating gas seepage in coal-bearing reservoirs according to claim 1, characterized in that, One of the turntables (57) has a toothed groove on its edge, and a drive gear (58) is provided in the corresponding upright plate (5), and the drive gear (58) meshes with the toothed groove of the turntable (57).

3. The visualization device for simulating gas seepage in coal-bearing reservoirs according to claim 1, characterized in that, Each sample tube (3) is rotatably disposed between two turntables (57), and a toothed ring (55) is fixed on the outer wall of one end of the sample tube (3) near one of the turntables (57). A central gear (56) is rotatably disposed at the center of the turntable (57), and the central gear (56) meshes with each toothed ring (55). The central gear (56) is connected to a drive motor.

4. The visualization device for simulating gas seepage in coal-bearing reservoirs according to claim 1, characterized in that, The connecting block (72) is provided with a drive nut (75) that is threadedly connected to the lead screw (74).

5. The visualization device for simulating gas seepage in coal-bearing reservoirs according to claim 1, characterized in that, Each of the connecting blocks (72) is slidably connected to a vertical guide rail (7), and the vertical guide rail (7) is provided with a driving device (71) capable of driving the connecting blocks (72) to slide up and down.

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