A compact gas reservoir deliverability testing device

Abstract

The application discloses a compact gas reservoir productivity testing device, which comprises a fixed pipe, the outer wall of the fixed pipe is fixed with two symmetrical fixed cylinders, the outer wall of the fixed cylinder is provided with a sealing ring, the outer wall of the fixed pipe between the two fixed cylinders is circumferentially provided with a plurality of flat pipes, the flat pipes are rotatably connected with the two fixed cylinders, vertical grooves are arranged on the outer wall of the fixed pipe between adjacent flat pipes, and a limiting assembly is arranged at the bottom of the fixed pipe; the fixed cylinder is further provided with an exciter and a receiver, and the inside of the fixed cylinder is in communication with each flat pipe. Compared with the prior art, the application not only improves the testing precision and reliability, but also optimizes the operation process, reduces the production cost, and provides strong support for the sustainable development of oil and gas fields.

Description

Technical Field

[0001] This invention relates to the field of tight gas extraction technology, specifically a tight gas reservoir productivity testing device. Background Technology

[0002] With the increasing global energy demand, tight gas reservoirs, as an important energy source, are receiving increasing attention for their exploitation and utilization. Tight gas reservoirs typically have low porosity and low permeability, and their production capacity testing is a crucial step in the oil and gas exploration and development process. It is of great significance for accurately assessing reservoir potential and formulating reasonable exploitation plans.

[0003] Existing tight gas reservoir productivity testing equipment typically employs various structural forms to adapt to the needs of different testing scenarios. These include: flowing pressure testing: by adjusting the downhole pressure of the producing well to allow gas to flow out, measuring the gas flow rate and bottom hole pressure, thereby assessing productivity; and acoustic testing: using acoustic technology to evaluate parameters such as rock porosity, permeability, and gas saturation, thereby inferring the productivity of the gas reservoir.

[0004] By deploying sensors and samplers, gases in reservoirs are monitored and sampled in real time for analysis. However, these devices often cannot effectively isolate external interference during testing, affecting the accuracy of the results. Due to the complex geological structure of reservoirs, gases may flow from multiple directions. However, existing testing devices often can only perform sealing tests in one direction, failing to seal different directions simultaneously, which limits the comprehensiveness and accuracy of the test results.

[0005] Besides the sealing issue, existing technologies also suffer from shortcomings in acoustic excitation and transmission. Current exciters are directly attached to the wellbore, limiting placement space and resulting in insufficient exciter power. This leads to inadequate acoustic signal strength, failing to fully detect deep reservoir information. Furthermore, the lack of an effective amplification mechanism during acoustic transmission causes the signal to gradually attenuate, further affecting the accuracy of the test results.

[0006] Therefore, it is necessary to provide a tight gas reservoir productivity testing device to solve the problems mentioned in the background art. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: a tight gas reservoir production capacity testing device, comprising a fixed tube, two symmetrical fixed cylinders fixed on the outer wall of the fixed tube, a sealing ring provided on the outer wall of the fixed cylinder, a plurality of flat tubes distributed circumferentially on the outer wall of the fixed tube between the two fixed cylinders, the flat tubes being rotatably connected to the two fixed cylinders, a vertical groove being provided on the outer wall of the fixed tube between adjacent flat tubes, and a limiting component being provided at the bottom of the fixed tube;

[0008] The fixed cylinder is also equipped with an exciter and a receiver, and the interior of the fixed cylinder is connected to each flat tube.

[0009] Furthermore, preferably, the sealing ring is an elastic rubber ring.

[0010] Furthermore, as a preferred embodiment, the fixed tube is rotatably provided with an inner tube, the inner tube passing through the center of the fixed tube, the fixed tube having multiple side gears distributed circumferentially inside, and the fixed tube also having a central gear fixedly connected to the inner tube at the center, the central gear meshing with each side gear;

[0011] The center of the side gear is connected to the fixed cylinder via a rotating shaft, and the rotating shaft passes through the fixed cylinder and is fixed to one side of the flat tube.

[0012] Furthermore, as a preferred embodiment, the inner tube is radially divided into multiple spaces by a partition plate, and each space has a transverse groove on the outer wall of the inner tube.

[0013] Furthermore, preferably, the fixed cylinder has an opening at the top, a toothed ring is rotatably provided on the inner wall of the fixed cylinder, the toothed ring meshes with each side gear, a threaded ring is rotatably fitted on the outer wall of the fixed cylinder, the toothed ring and the threaded ring are fixed together by a connecting ring, a sliding ring is threadedly fitted on the outer wall of the threaded ring, the outer wall of the sliding ring is inclined, and the sealing ring is fitted on the outer wall of the sliding ring.

[0014] Furthermore, as a preferred embodiment, multiple guide shafts are fixed to the bottom outside the side wall of the fixed cylinder, and the guide shafts are slidably inserted into the sliding ring.

[0015] Furthermore, as a preferred embodiment, a tapered cylinder is fixed in the fixing tube above the fixing cylinder, the lower edge of the tapered cylinder is fitted with the connecting ring by a rubber ring, and the rotating shaft is rotatably connected to the tapered cylinder.

[0016] Furthermore, as a preferred embodiment, the bottom of the fixed cylinder is provided with a waist-shaped groove, which communicates with the interior of the flat tube.

[0017] Furthermore, as a preferred embodiment, a fan-shaped baffle is fixed to the outer wall of the flat tube near the bottom of the fixed cylinder.

[0018] Furthermore, as a preferred embodiment, the limiting component includes a connecting plate fixed to the bottom of the fixing tube, and a plurality of pawls are distributed around the circumference of the connecting plate. The pawls are rotatably connected to the connecting plate by a torsion spring, and the torsion spring provides the torque to open the pawls.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] In this invention, the exciter has a larger fixed space inside the fixed cylinder, which allows for the arrangement of more powerful exciters, ensuring the strength and stability of the acoustic signal, increasing the distance and depth of acoustic wave propagation in the reservoir, thereby expanding the test range and improving the comprehensiveness of the test.

[0021] Secondly, as a key component for sound wave transmission, the flat tube's unique structure allows the sound wave to be effectively amplified within it. The design of the flat tube causes the sound wave to be continuously reflected and scattered during propagation, forming a standing wave, which in turn generates a large vibration amplitude in certain areas. This not only enhances the intensity of the sound wave signal but also improves the sound wave signal's ability to perceive the physical properties of the reservoir rock.

[0022] In addition, the flat tube can effectively transmit acoustic signals to different directions and depths of the reservoir. By adjusting the direction and position of the flat tube, precise testing of different areas of the reservoir can be achieved, thereby gaining a more comprehensive understanding of the reservoir's production potential.

[0023] In this invention, the flat tube can be rotated and adjusted as needed to fit tightly against the test well wall, thereby improving the sound wave transmission efficiency and test accuracy. At the same time, the synchronous expansion of the sealing ring makes the test well horizontally sealed, avoiding gas leakage and external interference, and further ensuring the reliability of the test results.

[0024] Furthermore, gas extraction and testing enable real-time monitoring of gas production at different depths and directions. With the assistance of pressure sensors, concentration sensors, and other devices, engineers can gain a comprehensive understanding of the distribution and migration patterns of gas within the reservoir, providing a strong basis for developing targeted extraction strategies. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a tight gas reservoir productivity testing device.

[0026] Figure 2 This is a schematic diagram of the internal structure of the fixed cylinder;

[0027] Figure 3 This is a structural schematic diagram of the cross-section of a fixed tube;

[0028] Figure 4 A schematic diagram of the side gear and the center gear;

[0029] Figure 5 This is a schematic diagram of the structure at the bottom of the fixed cylinder;

[0030] Figure 6 This is a schematic diagram of the limit component.

[0031] In the diagram: 1. Fixed tube; 2. Fixed cylinder; 21. Conical cylinder; 22. Waist-shaped groove; 3. Sealing ring; 4. Flat tube; 41. Baffle; 5. Limiting assembly; 51. Connecting disc; 52. Pawl; 53. Torsion spring; 6. Inner tube; 61. Vertical groove; 62. Horizontal groove; 63. Partition plate; 7. Side gear; 8. Center gear; 9. Rotating shaft; 10. Gear ring; 11. Connecting ring; 12. Threaded ring; 13. Sliding ring; 14. Guide shaft. Detailed Implementation

[0032] Please see Figure 1 In this embodiment of the invention, a tight gas reservoir production capacity testing device includes a fixed tube 1, with two symmetrical fixed cylinders 2 fixed on the outer wall of the fixed tube 1. The outer wall of the fixed cylinder 2 is provided with a sealing ring 3. Multiple flat tubes 4 are distributed circumferentially on the outer wall of the fixed tube 1 between the two fixed cylinders 2. The flat tubes 4 are rotatably connected to the two fixed cylinders 2. A vertical groove 61 is opened on the outer wall of the fixed tube 1 between adjacent flat tubes 4. A limiting component 5 is provided at the bottom of the fixed tube 1.

[0033] The fixed cylinder 2 is also equipped with an exciter and a receiver, and the interior of the fixed cylinder 2 is connected to each flat tube 4.

[0034] The exciter can be a sound wave generator, which generates a sound wave signal with controllable frequency and amplitude in the fixed cylinder 2 and transmits it evenly to each flat tube 4. In the flat tube 4, the sound wave will be reflected and scattered inside the cavity wall. Waves with opposite propagation direction will meet and superimpose with waves with the same propagation direction. At a specific frequency, these superpositions form standing waves, which make the vibration amplitude larger in some areas. Using sound waves with larger vibration amplitude, parameters such as porosity, permeability and gas saturation of rocks can be evaluated more accurately and at a distance, thereby inferring the production capacity of gas reservoirs in the test well.

[0035] Furthermore, the sealing rings 3 outside the two fixed cylinders 2 can seal the test well laterally, and the flat tube 4 can vertically divide the test well into multiple spaces in different directions. Gas extraction tests can be performed through the vertical grooves 61 in each direction via the fixed tube 1, and the gas production at different depths and directions in the test well can be monitored by pressure sensors, concentration sensors and other devices.

[0036] In this embodiment, the sealing ring 3 is an elastic rubber ring. The sealing ring 3 can deform to adapt well to test wells with different inner diameters.

[0037] Please see Figure 2 In this embodiment, the fixed tube 1 is rotatably provided with an inner tube 6, the inner tube 6 passes through the center of the fixed cylinder 2, a plurality of side gears 7 are distributed around the inner circumference of the fixed cylinder 2, and a central gear 8 fixedly connected to the inner tube 6 is also provided in the center of the fixed cylinder 2, the central gear 8 meshing with each side gear 7;

[0038] The center of the side gear 7 is connected to the fixed cylinder 2 via a rotating shaft 9. The rotating shaft 9 passes through the fixed cylinder 2 and is fixed to one side of the flat tube 4.

[0039] In other words, by rotating the inner tube 6, each flat tube 4 can be rotated and its direction changed. When the flat tube 4 is close to the radial direction of the fixed cylinder 2, the radius of the flat tube 4 is larger, so that it can fit tightly against the test well wall, improving the airtightness of the space between the flat tubes 4 and the transmission efficiency of sound waves to the gas reservoir.

[0040] Please see Figure 3 In this embodiment, the inner tube 6 is radially divided into multiple spaces by a partition plate 63, and a transverse groove 62 is formed on the outer wall of the inner tube 6 corresponding to each space. Furthermore, the width of the vertical groove 61 is smaller than the width of the outer wall of the inner tube 6 between adjacent transverse grooves 62.

[0041] In other words, no matter what angle the inner tube 6 is rotated to, the space divided by a partition plate 63 is connected to only one vertical groove 61, ensuring that the gas extracted through each vertical groove 61 is independently collected into different test sensors.

[0042] Please see Figure 2 and Figure 4 In this embodiment, the upper part of the fixed cylinder 2 is open, and the inner wall of the fixed cylinder 2 is rotatably provided with a toothed ring 10. The toothed ring 10 meshes with each side gear 7. The outer wall of the fixed cylinder 2 is rotatably fitted with a threaded ring 12. The toothed ring 10 and the threaded ring 12 are fixed together by a connecting ring 11. The outer wall of the threaded ring 12 is threadedly fitted with a sliding ring 13. The outer wall of the sliding ring 13 is inclined, and the sealing ring 3 is fitted on the outer wall of the sliding ring 13.

[0043] In other words, when the inner tube 6 rotates and the flat tube 4 changes direction to fit tightly against the test well wall, the threaded ring 12 also rotates synchronously and drives the sliding ring 13 to slide. The sliding direction of the sliding ring 13 makes the opening radius of the flat tube 4 larger, and the slope of the sliding ring 13 expands the sealing ring 3 to a greater extent, so that the sealing ring 3 can also fit tightly against the test well wall, improving the airtightness of the space between the flat tubes 4.

[0044] In this embodiment, multiple guide shafts 14 are fixed to the bottom of the outer side wall of the fixed cylinder 2, and the guide shafts 14 slidably penetrate into the sliding ring 13. This prevents insufficient circumferential friction between the sliding ring 13 and the sealing ring 3 from causing the sliding ring 13 to rotate with the threaded ring 12.

[0045] In this embodiment, a conical tube 21 is fixed in the fixed tube 1 above the fixed tube 2. The lower edge of the conical tube 21 is attached to the connecting ring 11 by a rubber ring, and the rotating shaft 9 is rotatably connected to the conical tube 21. The conical tube 21 can seal the inside of the fixed tube 2, preventing debris from falling into the fixed tube 2, and does not hinder the rotation of the connecting ring 11.

[0046] Please see Figure 2 and Figure 5 In this embodiment, the bottom of the fixed cylinder 2 is provided with a waist-shaped groove 22, which is connected to the inside of the flat tube 4.

[0047] In this embodiment, a fan-shaped baffle 41 is fixed to the outer wall of the flat tube 4 near the bottom of the fixed cylinder 2. The baffle 41 can block the waist-shaped groove 22 outside the flat tube 4, preventing the sound waves generated inside the fixed cylinder 2 from being directly transmitted out of the waist-shaped groove 22 and affecting the amplification effect of the flat tube 4 on the sound waves.

[0048] Please see Figure 6 In this embodiment, the limiting component 5 includes a connecting plate 51, which is fixed to the bottom of the fixing tube 1. Multiple pawls 52 are distributed around the circumference of the connecting plate 51. The pawls 52 are rotatably connected to the connecting plate 51 via a torsion spring 53, which provides the torque to open the pawls 52. Under the action of the torsion spring 53, the pawls 52 tend to open. When the fixing tube 1 rotates in the direction of the pawls 52, it can overcome the elastic force of the torsion spring 53 and cause the pawls 52 to retract, allowing the fixing tube 1 to rise and fall within the test well. When the fixing tube 1 rotates against the direction of the pawls 52, the pawls 52 embed into the side wall of the test well, at which point the height of the fixing tube 1 is fixed.

[0049] In practice,

[0050] Fixing and Lifting: Rotate the fixing tube 1 in the direction of the pawl 52 to place it in the test well, ensuring that the fixing tube 1 is placed vertically. When it is necessary to fix the height of the fixing tube 1, rotate the fixing tube 1 in the opposite direction of the pawl 52 so that the pawl 52 is embedded in the side wall of the test well.

[0051] Direction adjustment and enhanced sealing: Rotating the inner tube 6 inside the fixed tube 1, through the meshing of the central gear 8 and the side gear 7, drives each flat tube 4 to rotate and change direction. When the flat tube 4 approaches the radial direction of the fixed tube 2, the larger the radius of the flat tube 4 is opened, the tighter it fits against the test well wall, improving the sealing. At the same time, the threaded ring 12 rotates, causing the sliding ring 13 to slide, so that the inclined surface of the sliding ring 13 opens the sealing ring 3, ensuring that the sealing ring 3 fits tightly against the test well wall.

[0052] Acoustic excitation and reception: An exciter generates a controllable acoustic signal in the fixed cylinder 2, ensuring that the acoustic signal can be uniformly transmitted to each flat tube 4. The acoustic wave propagates in the flat tube 4 and forms a standing wave after reflection and scattering, resulting in larger vibration amplitude in some areas. The receiver receives and analyzes the acoustic signal, and the porosity, permeability and gas saturation of the rock are evaluated through the acoustic wave with larger vibration amplitude.

[0053] Gas extraction and testing: Gas extraction tests are conducted through the vertical grooves 61 in each direction via the fixed pipe 1. Pressure sensors, concentration sensors and other devices are used to monitor the gas production at different depths and directions in the test well. Since the inner pipe 6 is divided into multiple spaces by the partition plate 63, it is ensured that the gas extracted through each vertical groove 61 is independently collected into different test sensors.

[0054] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A tight gas reservoir productivity testing device, comprising a fixed tube (1), characterized in that, The outer wall of the fixed tube (1) is fixed with two symmetrical fixed cylinders (2), and the outer wall of the fixed cylinder (2) is provided with a sealing ring (3). Multiple flat tubes (4) are distributed around the outer wall of the fixed tube (1) between the two fixed cylinders (2). The flat tubes (4) are rotatably connected to the two fixed cylinders (2). The outer wall of the fixed tube (1) between adjacent flat tubes (4) is provided with a vertical groove (61). The bottom of the fixed tube (1) is provided with a limiting component (5). The fixed cylinder (2) is also equipped with an exciter and a receiver, and the interior of the fixed cylinder (2) is connected to each flat tube (4); The fixed tube (1) is rotatably provided with an inner tube (6), which passes through the center of the fixed cylinder (2). Multiple side gears (7) are distributed around the circumference of the fixed cylinder (2). The center of the fixed cylinder (2) is also provided with a central gear (8) that is fixedly connected to the inner tube (6). The central gear (8) meshes with each side gear (7). The center of the side gear (7) is connected to the fixed cylinder (2) through the rotating shaft (9), and the rotating shaft (9) passes through the fixed cylinder (2) and is fixed to one side of the flat tube (4); The inner tube (6) is radially divided into multiple spaces by a partition plate (63), and a transverse groove (62) is provided on the outer wall of the inner tube (6) corresponding to each space; The fixed cylinder (2) has an opening at the top. The inner wall of the fixed cylinder (2) is rotatably provided with a toothed ring (10). The toothed ring (10) meshes with each side gear (7). The outer wall of the fixed cylinder (2) is rotatably fitted with a threaded ring (12). The toothed ring (10) and the threaded ring (12) are fixed together at the top by a connecting ring (11). The outer wall of the threaded ring (12) is threadedly fitted with a sliding ring (13). The outer wall of the sliding ring (13) is inclined. The sealing ring (3) is fitted on the outer wall of the sliding ring (13). The exciter is a sound wave generator. It generates a sound wave signal with controllable frequency and amplitude in the fixed cylinder (2) and transmits it evenly to each flat tube (4). The sound wave will be reflected and scattered inside the cavity wall in the flat tube (4). The wave with the opposite direction of propagation will meet the wave with the same direction of propagation and superimpose with each other to form a standing wave, so as to evaluate the porosity, permeability and gas saturation number of the rock, thereby inferring the production capacity of the gas reservoir in the test well. By rotating the inner tube (6), each flat tube (4) is driven to rotate and change direction. When the flat tube (4) is closer to the radial direction of the fixed cylinder (2), the radius of the flat tube (4) is larger, so that it can fit tightly with the test well wall, improve the airtightness of the space between the flat tubes (4) and the transmission efficiency of sound waves to the gas reservoir. When the inner tube (6) rotates and causes the flat tube (4) to change direction and stick to the test well wall, the threaded ring (12) rotates synchronously and drives the sliding ring (13) to slide. The sliding direction of the sliding ring (13) makes the opening radius of the flat tube (4) larger, and the slope of the sliding ring (13) expands the sealing ring (3) to a greater extent, so that the sealing ring (3) is tightly attached to the test well wall, improving the airtightness of the space between the flat tubes (4).

2. The tight gas reservoir productivity testing device according to claim 1, characterized in that, The sealing ring (3) is an elastic rubber ring.

3. The tight gas reservoir productivity testing device according to claim 1, characterized in that, Multiple guide shafts (14) are fixed to the bottom outside the side wall of the fixed cylinder (2), and the guide shafts (14) can slide through the sliding ring (13).

4. The tight gas reservoir productivity testing device according to claim 1, characterized in that, A conical tube (21) is fixed in the fixed tube (1) above the fixed tube (2). The lower edge of the conical tube (21) is attached to the connecting ring (11) by a rubber ring. The rotating shaft (9) is rotatably connected to the conical tube (21).

5. The tight gas reservoir productivity testing device according to claim 1, characterized in that, The bottom of the fixed cylinder (2) is provided with a waist-shaped groove (22), which is connected to the inside of the flat tube (4).

6. The tight gas reservoir productivity testing device according to claim 5, characterized in that, A fan-shaped baffle (41) is fixed on the outer wall of the flat tube (4) near the bottom of the fixed cylinder (2).

7. The tight gas reservoir productivity testing device according to claim 1, characterized in that, The limiting component (5) includes a connecting plate (51) which is fixed to the bottom of the fixing tube (1). A plurality of pawls (52) are distributed around the connecting plate (51). The pawls (52) are rotatably connected to the connecting plate (51) by a torsion spring (53). The torsion spring (53) provides the torque to open the pawls (52).

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