Gas well bailing and draining device

Abstract

The utility model relates to the field of natural gas extraction equipment, and discloses a gas well bailing and draining device which comprises a connector, a sealing upper cover, an expansion sleeve, a sealing sleeve, a sealing ring, a valve body, a sealing lower cover, a valve clack and a tail cover. A movable valve clack is arranged in the end, away from the connector, of the valve body, the hollow tail cover limits the valve clack in the valve body, an expansion sleeve and a sealing sleeve are sequentially arranged on the outer side of a pressure guide hole of the valve body, one end of the expansion sleeve is fixed to the valve body, and the other end of the expansion sleeve is circumferentially divided to form a plurality of elastic pieces extending in the axial direction. A sealing ring composed of a plurality of sealing pieces is arranged on the outer side of the sealing sleeve, and the sealing ring is installed on the valve body through a sealing upper cover and a sealing lower cover. The device is simple in structure, easy to assemble, convenient to use and suitable for being applied to a gas well bailing and draining device.

Description

Technical Field

[0001] The utility model relates to the field of natural gas mining equipment, in particular to a device used for gas well fishing and liquid drainage operations. Background Art

[0002] Liquid accumulation in gas wells seriously affects gas production. Drainage and gas recovery is an important measure to tap the production potential of gas wells and improve natural gas recovery rate.

[0003] The applicant has previously developed numerous drainage and gas production robots and shut-off valves for these robots. These robots typically rely on the pressure differential within the wellbore above and below the variable-diameter expansion section, after a variable-diameter seal. The core improvements to both the drainage and gas production robots and their shut-off valves lie in their variable-diameter design: This requires both minimizing friction with the wellbore wall during the robot's descent and maintaining a seal and appropriate friction with the wellbore wall during its ascent to complete the drainage operation.

[0004] Lifting and drainage is a key method for natural gas recovery. Gas well lift and drainage devices are typically powered by a hoist mechanism located outside the well and are often used in conjunction with a tool string. During natural gas well lift and drainage operations, these devices remove accumulated liquid from the well. Their structural design requires sufficient strength to prevent deformation and jamming within the well tubing. Lifting and drainage must be performed safely and reliably, effectively increasing gas well productivity.

[0005] In summary, compared to drainage and gas production robots, the variable diameter section of a gas well lifting and drainage device allows for greater frictional resistance, but also requires higher wear resistance and sealing. Therefore, designing a more rational gas well lifting and drainage device for drainage operations, drawing on the variable diameter structure of existing drainage and gas production robots, would help restore or improve the gas production capacity of gas wells. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a gas well lifting and draining device which is easy to use.

[0007] The technical solution adopted by the utility model to solve its technical problems is as follows: A gas well lifting and liquid discharging device includes a connector, a sealing upper cover, an expansion sleeve, a sealing sleeve, a sealing ring, a valve body, a sealing lower cover, a valve flap and a tail cover. One end of the connector is set as a connecting section, and the other end of the connector is connected to the hollow valve body and conducts the inside and outside of the valve body. A pressure guiding hole penetrating the wall of the valve body is provided at the middle position of the valve body. A movable valve flap is arranged inside the end of the valve body far from the connector. The tail cover is a hollow cover, and the tail cover confines the valve flap within the valve body. The expansion sleeve and the sealing sleeve are arranged in sequence outside the pressure guiding hole of the valve body. One end of the expansion sleeve is fixed to the valve body, and the free end of the expansion sleeve is provided with axial gaps along the circumferential direction to form N elastic pieces (N≥2), and the elastic pieces axially extend to a position beyond the pressure guiding hole. One end of the sealing sleeve is fixed on the valve body, and the free end of the sealing sleeve axially extends in the reverse direction and covers the outside of the elastic pieces. A sealing ring is arranged outside the sealing sleeve, and both ends of the sealing ring are installed on the valve body through the sealing upper cover and the sealing lower cover respectively. The sealing ring includes a plurality of sealing pieces arranged in a circumferential combination.

[0008] The design of this device refers to the applicant's previous optimization design of the variable diameter component and its sealing performance for the drainage gas production robot, forming a unique structure suitable for application on the gas well lifting and liquid discharging device. The structure is simple and easy to assemble, convenient to use, can meet the requirements of the lifting and liquid discharging operation and complete the lifting and liquid discharging operation well.

[0009] A spacer sleeve is arranged between the fixed end of the expansion sleeve and the connector. The sealing upper cover is sleeved on the outer wall of the spacer sleeve to limit the fixed end of the expansion sleeve. The connector is threadedly connected to the end of the valve body to limit the sealing upper cover and the spacer sleeve. This design facilitates the assembly of the expansion sleeve, the sealing sleeve and the sealing ring and is convenient for the maintenance of the device.

[0010] A positioning screw hole is provided on the connector, and a positioning groove is correspondingly provided on the sealing upper cover. A limit screw matching the positioning screw hole is screwed into the positioning groove to prevent the connector from loosening from the device.

[0011] Inner convex platforms for limiting are respectively provided on the sealing upper cover and the expansion sleeve. The inner convex platforms cooperate with the correspondingly provided limiting grooves on the valve body to achieve accurate positioning between relevant parts, facilitating assembly and fixation.

[0012] The spacer sleeve is provided with partition strips, and the partition strips cooperate with the limiting grooves provided on the valve body to increase the rigidity of the end of the valve body.

[0013] Grooves are provided on both the sealing upper cover and the sealing lower cover, and a positioning ring is installed in the grooves. The grooves and the positioning ring limit each sealing piece. The limiting directions include the axial direction of the sealing piece, the radial direction and the circumferential direction of the sealing ring, preventing misalignment between the sealing pieces, resulting in the inability of the sealing pieces to contract or sealing failure.

[0014] The sealing piece is a metal sealing piece. The adjacent sealing pieces of the sealing ring are staggered and limited through a serrated structure. The metal material has a smaller friction coefficient compared with the conventional rubber material, which can reduce the resistance during the process of the device being lowered into the well. The serrated structure can prevent the liquid above the device from leaking to the lower part, which is beneficial to improving the operation efficiency.

[0015] The middle diameter of the sealing ring is larger than the diameters at both ends. The larger part in the middle forms a seal with the well wall, while the slightly smaller diameters at both ends are beneficial for guiding during the up and down process.

[0016] The valve flap is matched with the inner cavity at one end of the valve body. The outer circumference of the valve flap is provided with a flow-through groove for fluid passage. The inside of the tail cover is provided with a sealing boss for sealing cooperation with the valve flap, which is beneficial for the smooth flow of liquid during the descent process of the device and is also convenient for forming a well-sealed plunger during the ascent process of the device in the well.

[0017] The outer wall of the valve body is provided with a step, through which the elastic piece of the expansion sleeve is deformed, realizing the elastic effect of the elastic piece while reducing the complexity of the structure.

[0018] The beneficial effects of the present utility model are as follows: The structure is simple, the assembly and maintenance are convenient, and it has good reliability and safety. It is an economical and reliable fishing and liquid drainage tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the front view of the gas well fishing and liquid drainage device of the present utility model.

[0020] Figure 2 It is the sectional view of the gas well fishing and liquid drainage device of the present utility model.

[0021] Figure 3 It is Figure 1 the axonometric drawing of the connector in

[0022] Figure 4 It is Figure 1 the sectional view of the connector in

[0023] Figure 5 It is Figure 1 the axonometric drawing of the spacer sleeve in

[0024] Figure 6 It is Figure 1 the axonometric drawing of the upper sealing cover in

[0025] Figure 7 It is Figure 1 the axonometric drawing of the expansion sleeve in

[0026] Figure 8 It is Figure 1 the left view of the expansion sleeve in

[0027] Figure 9 is Figure 1 The axonometric drawing of the positioning ring in

[0028] Figure 10 is Figure 1 The sectional view of the sealing sleeve in

[0029] Figure 11 is Figure 1 The axonometric drawing of the sealing ring in

[0030] Figure 12 is Figure 11 The front view of the sealing piece in

[0031] Figure 13 is Figure 1 The axonometric drawing of the valve body in

[0032] Figure 14 is Figure 1 The sectional view of the valve body in

[0033] Figure 15 is Figure 1 The axonometric drawing of the valve flap in

[0034] Figure 16 is Figure 1 The sectional view of the tail cover in

[0035] Figure 17 It is a schematic diagram of the downward state of the gas well lifting and draining device of the present utility model in the gas well.

[0036] Figure 18 It is a schematic diagram of the upward state of the gas well lifting and draining device of the present utility model in the gas well.

[0037] Figure 19 It is a schematic diagram of the series connection of the gas well lifting and draining device of the present utility model.

[0038] Figure 20 It is a schematic diagram of the operation process of the gas well lifting and draining operation of the present utility model.

[0039] The markings in the figure are: 1 - connector, 2 - limit screw, 3 - spacer sleeve, 4 - upper sealing cover, 5 - expansion sleeve, 6 - positioning ring, 7 - sealing sleeve, 8 - sealing ring, 9 - valve body, 10 - lower sealing cover, 11 - valve flap, 12 - tail cover, 101 - internal thread section, 301 - separating strip, 401 - positioning groove, 402 - inner convex platform of the upper sealing cover, 501 - elastic piece, 502 - inner convex platform of the expansion sleeve, 601 - limit teeth, 701 - fixing ring, 801 - sealing piece, 8011 - serrated structure, 901 - limit groove, 902 - step, 903 - pressure guiding hole, 904 - end point of the external thread section, 1101 - flow-through groove, 1201 - sealing convex platform, 100 - wire operation tool, 101 - wellbore, 102 - fluid flow direction indication mark (relative to the gas well lifting and draining device), 103 - tool string, 104 - gas well lifting and draining device, 105 - liquid. Detailed implementation mode

[0040] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] Embodiment 1:

[0042] As Figures 1 to 16As shown in the figure, the gas well bailing liquid drainage device of the utility model comprises a connector 1, a sealing upper cover 4, an expansion sleeve 5, a sealing sleeve 7, a sealing ring 8, a valve body 9, a sealing lower cover 10, a valve flap 11 and a tail cover 12. One end of the connector 1 is set as a connecting section, and the specific structure of the connecting section is determined according to the structure of the downhole tool string 103. Specifically, an external thread is provided on the outer circumference of the connecting section for connecting with the tool string 103. The other end of the connector 1 is provided with a stepped counter bore with an internal thread section, and a through hole is provided on the counter bore wall, so as to connect with the hollow valve body 9 and form a fluid passage for conducting the inside and outside of the valve body 9. A pressure guiding hole 903 penetrating the wall of the valve body 9 is provided at the middle position of the valve body 9. A movable valve flap 11 is arranged inside the valve body 9 at the end far away from the connector 1. The valve flap 11 is installed in the cavity at the tail end of the valve body 9. The tail cover 12 is fixedly installed at the tail of the valve body 9. The tail cover 12 is a hollow cover, and the tail cover 12 confines the valve flap 11 inside the valve body 9. An expansion sleeve 5 and a sealing sleeve 7 are arranged in sequence outside the pressure guiding hole 903 of the valve body 9. The expansion sleeve 5 is sleeved between the sealing upper cover 4 and the valve body 9. The sealing sleeve 7 is sleeved between the expansion sleeve 5 and the sealing ring 8. One end of the expansion sleeve 5 is fixed to the valve body 9. The free end of the expansion sleeve 5 extends towards the tail cover 12 to a position beyond the pressure guiding hole 903. Axial gaps are provided on the free end of the expansion sleeve 5 along the circumferential direction to form N elastic pieces 501, where N is a positive integer greater than or equal to 2. One end of the sealing sleeve 7 is provided with a fixing ring 701 for cooperating with the corresponding groove on the valve body 9, so that the fixing ring 701 of the sealing sleeve 7 is fixed at the groove of the valve body 9. The sealing sleeve 7 is made of rubber material, and its free end extends towards the connector 1 to a position beyond the elastic pieces 501 of the expansion sleeve 5 and beyond the pressure guiding hole 903. A sealing ring 8 is arranged outside the sealing sleeve 7. In order to fix the sealing ring 8, grooves are respectively provided on the sealing upper cover 4 and the sealing lower cover 10, and positioning rings 6 are installed in the grooves. The sealing ring 8 is limited by the grooves and the positioning rings 6, so that both ends of the sealing ring 8 are installed on the valve body 9 through the sealing upper cover 4 and the sealing lower cover 10 respectively. Specifically, the sealing lower cover 10 is threadedly connected with the valve body 9, and the sealing upper cover 4 can slide relative to the valve body 9 within the range defined by the connector 1, so as to cooperate with the expansion of the sealing ring 8 during the upward movement of the device in the well. The sealing ring 8 is composed of several sealing pieces 801 divided according to the circumference.

[0043] As Figures 2 to 8 shown, for the convenience of fixing and assembling the expansion sleeve 5 relative to the valve body 9, a spacer sleeve 3 is arranged between the fixed end of the expansion sleeve 5 and the connector 1. The sealing upper cover 4 is sleeved on the outer wall of the spacer sleeve 3 to limit the fixed end of the expansion sleeve 5. The connector 1 is threadedly connected with the end of the valve body to limit the sealing upper cover 4 and the spacer sleeve 3.

[0044] As Figure 2 、 Figure 13 、 Figure 14As shown, in addition to the pressure guiding hole 903 being provided on the valve body 9, a limiting groove 901 is also provided at one end of the valve body 9. At this end, there is also an external thread section for mating with the internal thread section 101 on the connecting head 1. A channel is axially provided inside the valve body 9 for fluid passage. Figure 13 A simple schematic of the external thread section at the end of the valve body in Figure 13 , only showing the end point 904 of the external thread section, without drawing the threads.

[0045] As Figure 2 、 Figure 6 、 Figure 7 and Figure 8 As shown, internal bosses for limiting are respectively provided on the sealing upper cover 4 and the expansion sleeve 5, namely the internal boss 402 of the sealing upper cover and the internal boss 502 of the expansion sleeve. The internal bosses cooperate with the limiting groove 901 of the valve body 9 to prevent rotation between the sealing upper cover 4 and the expansion sleeve 5 and the valve body 9, ensure that the expansion sleeve does not shift axially, and prevent the sealing ring 8 from loosening.

[0046] As Figure 2 、 Figure 5 and Figure 13 As shown, a partition strip 301 is provided on the spacer sleeve 3. The partition strip 301 cooperates with the limiting groove 901 of the valve body 9, which can increase the rigidity at the end of the limiting groove of the valve body.

[0047] As Figure 2 、 Figure 3 、 Figure 6 As shown, a threaded hole is provided on the connecting head 1. After passing through the threaded hole, the limiting screw 2 is screwed into the positioning groove 401 provided on the sealing upper cover 4 to limit the rotational movement of the connecting head 1 and prevent the connecting head 1 from loosening.

[0048] As Figure 2 、 Figure 7 、 Figure 8 and Figure 13 As shown, the expansion sleeve 5 is made of metal, and axial gaps are provided along the circumferential direction to form N elastic pieces 501 (N≥2). A step 902 is provided on the valve body 9. Through the step 902, the elastic pieces 501 of the expansion sleeve 5 are deformed, and the free end of the expansion sleeve 5 expands, thereby squeezing to expand the sealing sleeve 7 and the sealing ring 8. In existing drainage gas production robots, the expansion of the expansion sleeve 5 usually relies on the movement control of the valve rod or piston inside the valve body. However, the gas well bailing liquid drainage device is driven by an external force to rise, so the step structure on the outer wall of the valve body can be directly used to make it expand appropriately.

[0049] As Figure 2 、 Figure 9 、 Figure 11 、 Figure 12As shown, the sealing ring 8 is made of metal. The diameter in the middle is slightly larger than the diameters at both ends. The middle part of the sealing ring 8 serves to fit and seal with the inner wall of the wellbore. The sealing ring 8 is divided into N sealing pieces 801 along the circumference. There are interlaced serrated structures 8011 between adjacent sealing pieces 801, so that adjacent sealing pieces 801 are cross-embedded with each other. Limited position grooves are provided at both ends of the sealing piece 801 and cooperate with the limited position teeth provided on the positioning ring 6. The limited position teeth of the positioning ring 6 are used to limit the movement of the sealing piece 801 and prevent the sealing pieces 801 from being misaligned with each other.

[0050] As Figure 2 , Figure 13 , Figure 14 , Figure 15 and Figure 16 As shown, a flow-through groove 1101 for flow-through is provided on the outer circumference of the valve flap 11. A sealing boss 1201 is provided inside the end cap 12 for sealing cooperation with the valve flap 11.

[0051] Referring to the above description, as Figure 17 , Figure 20 shown, the gas well lifting and draining device 104 is connected to the tool string 103. The tool string 103 and the gas well lifting and draining device 104 are lowered into the gas well through the wire operation tool 100. During the lowering process, the fluid in the wellbore can push open the valve flap 11, enter the central channel inside the valve body 9 through the flow-through groove 1101 on the circumference of the valve flap 11, and finally flow upward through the channel on the connector 1. In this way, the fluid resistance received during the lowering process of the tool string 103 can be greatly reduced. Since the sealing ring 8 and the sealing sleeve 7 are expanded by the expansion sleeve 5, the sealing ring 8 is expanded and closely adheres to the inner wall of the wellbore. During the lowering process of the tool string 103 and the gas well lifting and draining device 104, frictional resistance generated by the friction between the sealing ring 8 and the inner wall of the wellbore will be received. However, since the sealing ring 8 is made of metal, its friction coefficient is small, and the frictional force generated between it and the inner wall of the wellbore is relatively small. Coupled with the overall self-weight of the downhole tool string and the gas well lifting and draining device, it is sufficient to overcome the frictional force and the fluid resistance and smoothly lower the tool string 103.

[0052] As Figure 18As shown, after the tool string 103 is lowered to the predetermined position, the wireline operation tool 100 starts to lift the tool string 103. At this time, under the action of gravity, the valve flap 11 automatically contacts the tail cover 12, closing the central flow channel of the tail cover 12. At the same time, the pressure of the fluid above the gas well bailing and drainage device 104 on the valve flap 11 will make the seal between the valve flap 11 and the tail cover 12 airtight. After the fluid passes through the pressure guiding hole 903, the fluid pressure acts on the sealing sleeve 7 and the sealing ring 8, increasing the contact pressure between the sealing ring 8 and the inner wall of the wellbore, thereby strengthening the sealing performance between the sealing ring 8 and the inner wall of the wellbore. The sealing pieces 801 of the sealing ring 8 reduce the liquid leakage during the upward movement of the tool string 103 by the interlacing of the serrated structures 8011. Therefore, during the upward movement of the tool string 103, a plunger will be formed in the wellbore at the position of the gas well bailing and drainage device 104, making the liquid in its upper part not easily leak downward into the wellbore. As the wireline operation tool 100 lifts the tool string 103 and the gas well bailing and drainage device 104 to the wellhead, the liquid in the gas well is also discharged from the gas well.

[0053] Embodiment 2:

[0054] Referring to Embodiment 1, during the upward movement of the tool string, there will be a certain leakage in the gas well bailing and drainage device. To reduce the leakage rate, the structures of the tail cover and the connector can be simply modified. For example: as Figure 19 shown, the connector of the second gas well bailing and drainage device is a hollow integral structure, threadedly connected to the tail cover of the first gas well bailing and drainage device. Multiple gas well bailing and drainage devices 104 are connected in series, forming a multi-stage seal in the wellbore for the entire tool string, reducing the leakage rate of the gas well bailing and drainage device, and thus ensuring the working efficiency of the bailing and drainage operation.

[0055] Embodiment 3:

[0056] Referring to Embodiment 1 and Embodiment 2, the sealing ring of the gas well bailing and drainage device can be replaced with the sealing sleeve described in the patents of CN218206642U or CN217681662U to improve the sealing performance of a single gas well bailing and drainage device.

[0057] Embodiment 4:

[0058] A sensor module with the function of collecting pressure and temperature data is connected in series with the gas well bailing and drainage device 104, forming a bailing and drainage tool for data collection inside the wellbore together with the rest of the tool string. The advantage of this is that the collected data can be used for later analysis of the well conditions, facilitating the implementation of subsequent processes.

Claims

1. Gas well lifting and drainage device, characterized by: The invention comprises a connector (1), a sealing upper cover (4), an expansion sleeve (5), a sealing sleeve (7), a sealing ring (8), a valve body (9), a sealing lower cover (10), a valve disc (11) and a tail cover (12), one end of the connector (1) is set as a connecting section, the other end of the connector (1) is connected to the hollow valve body (9) and conducts the inner and outer sides of the valve body (9), a pressure guide hole (903) penetrating the wall of the valve body (9) is set in the middle position of the valve body (9), a movable valve disc (11) is built in the end of the valve body (9) away from the connector (1), the tail cover (12) is a hollow cover, the tail cover (12) confines the valve disc (11) in the valve body (9), and the expansion sleeves are arranged in sequence on the outer side of the pressure guide hole of the valve body (9). (5) and a sealing sleeve (7), one end of the expansion sleeve (5) is fixed to the valve body (9), the free end of the expansion sleeve (5) is provided with an axial gap along the circumferential direction to form N spring pieces (501) (N≥2), the spring pieces (501) extend axially to a position beyond the pressure guide hole (903), one end of the sealing sleeve (7) is fixed to the valve body (9), the free end of the sealing sleeve (7) extends in the axial reverse direction and covers the outside of the spring piece (501), a sealing ring (8) is provided on the outside of the sealing sleeve (7), the two ends of the sealing ring (8) are respectively installed on the valve body (9) through the sealing upper cover (4) and the sealing lower cover (10), and the sealing ring (8) includes a plurality of sealing pieces (801) arranged in a circumferential combination.

2. The gas well fishing and drainage device according to claim 1, characterized in that: A spacer sleeve (3) is provided between the fixed end of the expansion sleeve (5) and the connector (1); the sealing upper cover (4) is sleeved on the outer wall of the spacer sleeve (3) to define the fixed end of the expansion sleeve (5); the connector (1) is threadedly connected to the end of the valve body (9) to define the sealing upper cover (4) and the spacer sleeve (3).

3. The gas well fishing and drainage device according to claim 2, characterized in that: A positioning screw hole is provided on the connector (1), and a positioning groove (401) is correspondingly provided on the sealing upper cover (4), and a limiting screw (2) matching the positioning screw hole is screwed into the positioning groove (401).

4. The gas well fishing and drainage device according to claim 2, characterized in that: The sealing upper cover (4) and the expansion sleeve (5) are respectively provided with inner bosses for limiting positions, and the inner bosses cooperate with corresponding limiting grooves (901) provided on the valve body (9).

5. The gas well fishing and drainage device according to claim 4, characterized in that: The spacer sleeve (3) is provided with a spacer bar (301), and the spacer bar (301) cooperates with a limiting groove (901) provided on the valve body (9).

6. The gas well fishing and drainage device according to claim 1, characterized in that: The sealing upper cover (4) and the sealing lower cover (10) are both provided with grooves, and positioning rings (6) are installed in the grooves. The grooves and the positioning rings (6) limit the position of each sealing sheet (801).

7. The gas well fishing and drainage device according to claim 6, characterized in that: The sealing sheets (801) are metal sealing sheets (801), and adjacent sealing sheets (801) of the sealing ring (8) are staggered and limited by a sawtooth structure (8011).

8. The gas well fishing and drainage device according to claim 6, characterized in that: The diameter of the middle portion of the sealing ring (8) is larger than the diameters at both ends.

9. The gas well fishing and drainage device according to claim 1, characterized in that: The valve flap (11) cooperates with the inner cavity at one end of the valve body (9), the outer circumference of the valve flap (11) is provided with a flow groove for flow, and the interior of the tail cover (12) is provided with a sealing boss for sealing with the valve flap (11).

10. The gas well fishing and drainage device according to claim 1, characterized in that: A step (902) is provided on the outer wall of the valve body (9), and the spring piece (501) of the expansion sleeve (5) is deformed by the step (902).

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