Compression type polish rod sealer capable of quickly replacing sealing box

Abstract

The utility model discloses a compression type polish rod sealer capable of quickly replacing a sealing box, which relates to the technical field of wellhead sealing equipment and comprises a shell, the sealing box, a one-way grease injection mechanism and a pressure separation transmission mechanism. The shell is provided with a central hole; a sealing filler opening is formed in the inner wall of the shell, and the sealing box is arranged in the sealing filler opening. A compression cavity is formed in the shell and communicates with the sealing filler opening. The one-way grease injection mechanism is communicated with the compression cavity, and a pressure separation and transmission mechanism is arranged in the compression cavity. According to the utility model, the sealing box can be quickly replaced, and in the process of replacing the sealing box, the pressure separation transmission mechanism isolates the one-way grease injection mechanism from crude oil, so that the service life of the one-way grease injection mechanism is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of wellhead sealing equipment, in particular to a compression type polished rod sealer capable of quickly replacing a sealing box. Background Art

[0002] The sealing ring of the currently commonly used polished rod sealer uses spiral packing. When the packing is severely worn, the machine must be shut down and replaced with new packing. At the same time, to prevent the packing from leaking, the packing is compressed significantly, resulting in significant friction during the vertical movement of the polished rod, increasing energy consumption in oilfield production.

[0003] A search of existing patents revealed the following prior art.

[0004] Announcement No.: CN214221134U discloses a maintenance-free polished rod sealer, which consists of a first-stage packing and a second-stage packing to form a two-stage seal. The first-stage seal is composed of an energy-storage combined disc spring and the first-stage packing. When the packing is worn, the energy-storage combined spring squeezes the first-stage packing downward to compensate for the worn part, thereby ensuring that the first-stage packing and the polished rod are always in a sealed state, solving the problem of daily maintenance of the polished rod sealer.

[0005] The disadvantage of this technology is that when the packing wears evenly around the circumference, this technology can effectively solve the problem of loose sealing of the sealing ring. However, when the packing wears eccentrically on one side, the energy storage spring cannot compress the packing downward, and thus cannot compensate for the wear caused by eccentric wear. Therefore, this technology cannot solve the problem of packing leakage caused by eccentric wear. According to the field experience of packing replacement, about 30% of the packing is due to loose sealing due to eccentric wear, so this technology cannot meet the requirements of field use.

[0006] Announcement No.: CN216950301U, discloses a multi-stage stepped airbag self-compensating multifunctional polished rod sealer, including a first-stage packing, an airbag, a second-stage packing, a third-stage gate packing, and a fourth-stage packing, characterized in that: an airbag shell is provided at the upper end of the sealer, an airbag is provided inside the airbag shell, the upper end of the airbag shell is threadedly connected to the airbag pressure cap, a pressure gauge is provided outside the airbag shell, the pressure gauge is connected to the airbag inside the airbag shell through an air guide tube, an upper cylinder is provided at the lower part of the airbag shell, an upper galvanizer is provided on the inner side of the upper end of the upper cylinder, and the top surface of the upper galvanizer abuts against the lower end surface of the airbag shell.

[0007] Disadvantages of this technology include: It consists of multiple sealing stages, requiring multiple and time-consuming steps to replace the packing. Furthermore, this technology primarily addresses the issue of poor sealing due to eccentric packing wear through the self-compensating airbag seal. However, since the airbag itself acts as a sealant, it can wear during production. Once the sealant leaks, the seal will fail.

[0008] Publication No.: CN104675359A discloses a shale gas well safety plugging device, which consists of a metal cylinder and a rubber cylinder. The rubber cylinder is placed in the metal cylinder to form a hollow cavity in the middle to allow a polished rod to pass through smoothly. An injection pipe is provided on the rubber cylinder, which passes out of the metal cylinder and is provided with a one-way valve at the head end. The upper and lower ends of the metal cylinder are threaded. When the pressure of the casing and the oil pipe is within a safe range, the rubber cylinder does not inject liquid or gas, and its inner edge maintains a gap with the polished rod to enable the polished rod to work normally. When the pressure values ​​of the casing and the oil pipe exceed the normal range, liquid or gas is injected from the injection pipe of the rubber cylinder, the rubber cylinder rapidly expands, fills the hollow cavity, and locks the polished rod inward to achieve plugging of the gushing shale gas.

[0009] The shortcomings of this existing technology are: when the rubber barrel is worn and fails to leak, the crude oil will corrode the one-way valve, reducing the service life of the one-way valve. In addition, when the rubber barrel is normally replaced in this existing technology, the crude oil on the polished rod may drip onto the wall near the one-way valve. After subsequent injection and pressure, this part of the crude oil will be integrated into the injection liquid, causing corrosion to the one-way valve.

[0010] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from those of the present utility model. Regarding the more technical features, technical problems to be solved and the beneficial effects of the present utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0011] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a compression type polished rod sealer with a quickly replaceable sealing gland.

[0012] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0013] A compression-type polished rod sealer with a quickly replaceable sealing box comprises a housing, a sealing box, a one-way grease injection mechanism, and a pressure separation and transmission mechanism; the housing is provided with a center hole; a sealing packing port is provided on the inner wall of the housing, and the sealing box is arranged in the sealing packing port; a compression chamber is provided in the housing, and the compression chamber is communicated with the sealing packing port; the one-way grease injection mechanism is communicated with the compression chamber, and the pressure separation and transmission mechanism is provided in the compression chamber.

[0014] Furthermore, the pressure separation transmission mechanism includes a rubber cylinder and a piston;

[0015] Specifically, the rubber cylinder separates the sealing box from the compression chamber, the piston separates the one-way grease injection mechanism from the compression chamber, the rubber cylinder transmits pressure to the sealing box through deformation, and the piston transmits pressure to the rubber cylinder through movement, and the rubber cylinder prevents crude oil from entering the compression chamber.

[0016] Furthermore, the shell is annular, the compression chamber is annular, and the rubber cylinder and the piston are both annular.

[0017] Furthermore, the housing includes an upper pressure cap, an outer cylinder, and a lower pressure cap;

[0018] Specifically, the outer wall of the upper pressure cap is threadedly connected to the inner wall of the upper end of the outer cylinder;

[0019] Specifically, the outer wall of the pressing cap is threadedly connected to the inner wall of the lower end of the outer cylinder;

[0020] Specifically, a protruding sealing pressure ring is provided at the lower end of the upper pressure cap, a protruding sealing seat ring is provided at the upper end of the lower pressure cap, a sealing filler port is provided between the lower end surface of the sealing pressure ring and the upper end surface of the sealing seat ring, the sealing box is provided on the upper end surface of the sealing seat ring, and the upper end of the sealing box contacts the lower end surface of the sealing pressure ring;

[0021] Specifically, the space between the inner wall of the outer tube, the outer wall of the sealing pressure ring, and the outer wall of the sealing seat ring is a compression chamber, the rubber tube and the piston are arranged in the compression chamber, and the inner wall of the rubber tube contacts the outer wall of the sealing pressure ring and the outer wall of the sealing seat ring.

[0022] Furthermore, the one-way grease injection mechanism is provided on the pressing cap;

[0023] Specifically, the one-way grease injection mechanism includes a hydraulic channel, an injection valve ball, an injection hole, and an injection spring;

[0024] Specifically, the pressing cap is provided with a radial liquid injection countersunk hole on the outer wall, the pressing cap is provided with a hydraulic channel, the hydraulic channel connects the liquid injection countersunk hole with the compression chamber, the liquid injection hole is provided on the outer cylinder, the liquid injection hole corresponds to the liquid injection countersunk hole, and the diameter of the liquid injection hole is smaller than the diameter of the liquid injection countersunk hole;

[0025] Specifically, the injection valve ball and the injection spring are arranged in the injection counterbore, and the injection spring pushes the injection valve ball onto the injection hole to seal the injection hole;

[0026] Specifically, the piston sleeve is arranged on the outer wall of the sealing seat ring, the piston can move up and down along the outer wall of the sealing seat ring, and the upper end surface of the piston contacts the lower end surface of the rubber cylinder.

[0027] Furthermore, the inner diameter of the outer cylinder, the outer diameter of the rubber cylinder, and the outer diameter of the piston are equal, and the outer diameters of the sealing pressure ring, the outer diameters of the sealing seat ring, and the inner diameter of the rubber cylinder are equal;

[0028] The upper end and the lower end of the outer wall of the rubber cylinder are both provided with a tapered cut angle.

[0029] Furthermore, the outer wall and the inner wall of the piston are both provided with seals.

[0030] Furthermore, the upper pressure cap is screwed and sealed with the outer cylinder.

[0031] Furthermore, an upper limit ring is provided at the upper end of the outer wall of the upper pressure cap, and a lower limit ring is provided at the lower end of the outer wall of the lower pressure cap.

[0032] Furthermore, a wellhead connector is provided at the lower end of the pressure cap.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The utility model realizes the quick replacement of the sealing box. The sealing box can be removed by releasing the hydraulic rubber cylinder to restore it to its natural state. After the sealing box is replaced, the sealing box can be squeezed by the rubber cylinder through the hydraulic action to achieve the seal between the sealing box and the polished rod. During the replacement of the sealing box, the rubber cylinder and the piston isolate the one-way grease injection mechanism from the crude oil, thereby extending the service life of the one-way grease injection mechanism.

[0035] 2. The utility model adopts a sealing box structure with circumferential compression of the rubber tube. The rubber tube has a certain strength and plays a certain role in straightening the polished rod. At the same time, the rubber tube has a certain degree of elasticity and flexibility. Under the circumferential compression of the rubber tube, the sealing box is easy to stick to the polished rod.

[0036] 3. The utility model adopts hydraulic method to adjust the stress state between the polished rod and the sealing box. Hydraulic pressure is more stable than air pressure. Therefore, the hydraulic pressure can be quantitatively adjusted according to the sealing condition of the polished rod, and the rubber cylinder is always in a soft squeezing state on the sealing box, thereby ensuring that the friction force of the polished rod on the sealing basis is minimized, improving system efficiency, extending the service life of the sealing box, and saving consumables costs.

[0037] 4. The sealing performance of the polished rod of the utility model is greatly improved. No matter whether the sealing box is subjected to circumferential wear or eccentric wear, the circumferential extrusion of the rubber cylinder can improve the sealing effect.

[0038] 5. The utility model has a simple structure, low manufacturing cost, and is easy to use, and has good promotion and use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The utility model is a structural schematic diagram of a compression type polished rod sealer with a quickly replaceable sealing box.

[0040] In the figure: upper pressure cap 1, outer tube 2, rubber tube 3, sealing box 4, piston 5, lower pressure cap 6, hydraulic channel 7, injection hole 8, injection valve 9, injection spring 10. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] Example 1:

[0043] See also Figure 1 The utility model provides a compression type polished rod sealer with a quickly replaceable sealing box, comprising a shell, a sealing box 4, and a one-way grease injection mechanism. The shell is provided with a center hole, a sealing packing port is provided on the inner wall of the shell, the sealing box 4 is arranged in the sealing packing port, a compression chamber is provided in the shell, the compression chamber is communicated with the sealing packing port, the one-way grease injection mechanism is communicated with the compression chamber, and a pressure separation and transmission mechanism is provided in the compression chamber.

[0044] The pressure separation and transmission mechanism includes a rubber cylinder 3 and a piston 5. The shell is annular, and the compression chamber is annular. The rubber cylinder 3 and the piston 5 are both annular. The rubber cylinder 3 separates the sealing box 4 from the compression chamber, and the piston 5 separates the one-way grease injection mechanism from the compression chamber. The rubber cylinder 3 transmits pressure to the sealing box 4 through deformation, and the piston 5 transmits pressure to the rubber cylinder 3 through movement. The rubber cylinder 3 prevents crude oil from entering the compression chamber.

[0045] Furthermore, the shell includes an upper pressure cap 1, an outer tube 2, and a lower pressure cap 6. The outer wall of the upper pressure cap 1 is threadedly connected to the inner wall of the upper end of the outer tube 2, and the outer wall of the lower pressure cap 6 is threadedly connected to the inner wall of the lower end of the outer tube 2; a protruding sealing pressure ring is provided at the lower end of the upper pressure cap 1, and a protruding sealing seat ring is provided at the upper end of the lower pressure cap 6. A sealing filler port is provided between the lower end face of the sealing pressure ring and the upper end face of the sealing seat ring. The sealing box 4 is provided on the upper end face of the sealing seat ring, and the upper end of the sealing box 4 contacts the lower end face of the sealing pressure ring; the space between the inner wall of the outer tube 2, the outer wall of the sealing pressure ring, and the outer wall of the sealing seat ring is a compression chamber, and the rubber cylinder 3 and the piston 5 are provided in the compression chamber, and the inner wall of the rubber cylinder 3 contacts the outer wall of the sealing pressure ring and the outer wall of the sealing seat ring.

[0046] Furthermore, the one-way grease injection mechanism is provided on the upper pressure cap 1 or the lower pressure cap 6 .

[0047] Preferably, the upper pressure cap 1 needs to movably press the sealing box 4, and it is most preferred that the one-way grease injection mechanism is provided on the lower pressure cap 6.

[0048] The one-way grease injection mechanism includes a hydraulic channel 7, an injection valve ball 8, an injection hole 9, and an injection spring 10. The pressure cap 6 is provided with a radial injection countersunk hole on the outer wall. The pressure cap 6 is provided with a hydraulic channel 7. The hydraulic channel 7 connects the injection countersunk hole with the compression chamber. The injection hole 9 is provided on the outer cylinder 2. The injection hole 9 corresponds to the injection countersunk hole. The aperture of the injection hole 9 is smaller than the aperture of the injection countersunk hole. The injection valve ball 8 and the injection spring 10 are provided in the injection countersunk hole. The injection spring 10 pushes the injection valve ball 8 on the injection hole 9 to seal the injection hole 9; the piston 5 is sleeved on the outer wall of the sealing seat ring. The piston 5 can move up and down along the outer wall of the sealing seat ring. The upper end face of the piston 5 contacts the lower end face of the rubber cylinder 3.

[0049] Specifically, the inner diameter of the outer tube 2, the outer diameter of the rubber tube 3, and the outer diameter of the piston 4 are equal, the outer diameter of the sealing pressure ring, the outer diameter of the sealing seat ring, and the inner diameter of the rubber tube 3 are equal, which is convenient for assembly. The upper and lower ends of the outer wall of the rubber tube 3 are both provided with tapered cut angles to facilitate deformation.

[0050] Specifically, the piston 5 body is made of stainless steel, and two soft seals are provided on the outer wall and the inner wall of the piston 5.

[0051] Specifically, the upper pressure cap 1 and the outer cylinder 2 are screwed together and sealed.

[0052] Specifically, an upper limit ring is provided on the upper end of the outer wall of the upper pressure cap 1 , and a lower limit ring is provided on the lower end of the outer wall of the lower pressure cap 6 . The limit rings are used to position the upper pressure cap 1 and the lower pressure cap 6 .

[0053] Specifically, a wellhead connector is provided at the lower end of the pressure cap 6 for connection to the wellhead.

[0054] Preferably, a packing is used as the sealing gland 4 .

[0055] Example 2:

[0056] Based on Example 1, this embodiment provides an installation method for a compression-type polished rod sealer capable of quickly replacing a sealing gland, comprising the following steps:

[0057] Connect the pressure cap 6 to the upper opening of the wellhead, place the injection spring 10 and the injection valve ball 8 into the injection countersunk hole on the side wall of the pressure cap 6, connect the outer tube 2 to the outer wall of the pressure cap 6, insert the piston 5 between the sealing seat ring and the outer tube 2, push open the injection valve ball 8, make the piston 5 sit on the bottom, put in the rubber cylinder 3, place the sealing box 4 on the upper end of the sealing seat ring, connect the upper pressure cap 1 to the outer tube 2, tighten the sealing box 4, and complete the installation.

[0058] Example 3:

[0059] Based on Example 2, this embodiment provides a method for using a compression-type polished rod sealer capable of quickly replacing a sealing gland, comprising the following steps:

[0060] After the sealing box 4 is installed, the upper pressure cap 1 is screwed in and the pumping unit is started. When there is leakage between the polished rod and the upper pressure cap 1, pressurized oil is slowly pumped in through the injection hole 9. Under the action of the liquid pressure, the piston 5 moves upward and squeezes the rubber cylinder 3. The rubber cylinder 3 is radially compressed and deformed, thereby squeezing the sealing box 4 to improve the sealing between the sealing box 4 and the polished rod; slowly and continuously inject liquid until there is no more leakage at the upper pressure cap, then stop injecting liquid and resume normal production.

[0061] After a period of production, if leakage occurs at the upper pressure cap due to eccentric wear of the sealing box packing, repeat the above process to resume normal production.

[0062] When the sealing box 4 needs to be replaced, after closing the well, use a tool to press the injection valve ball 8 into the injection sink hole to relieve the pressure, then remove the upper pressure cap 1 to replace the sealing box 4, and reinstall the upper pressure cap 1 to resume production. It is fast and efficient. If there is leakage, strengthen the seal by pressing through the injection hole 9.

[0063] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.

[0064] In this utility model, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.

[0065] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0066] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A compression type polished rod sealer with a quickly replaceable sealing gland, comprising a housing, a sealing gland, and a one-way grease injection mechanism, characterized in that: Also included is a pressure separation transmission mechanism; The housing is provided with a central hole; a sealing filler port is provided on the inner wall of the housing, and the sealing box is arranged in the sealing filler port; a compression chamber is provided in the housing, and the compression chamber is communicated with the sealing filler port; The one-way grease injection mechanism is communicated with the compression chamber, and a pressure separation and transmission mechanism is provided in the compression chamber.

2. A compression type polished rod sealer with a quickly replaceable sealing gland according to claim 1, characterized in that: The pressure separation transmission mechanism includes a rubber cylinder and a piston; The rubber cylinder separates the sealing box from the compression chamber, and the piston separates the one-way grease injection mechanism from the compression chamber. The rubber cylinder transmits pressure to the sealing box through deformation, and the piston transmits pressure to the rubber cylinder through movement. The rubber cylinder prevents crude oil from entering the compression chamber.

3. A compression type polished rod sealer with a quickly replaceable sealing gland according to claim 2, characterized in that: The shell is annular, the compression chamber is annular, and the rubber cylinder and the piston are both annular.

4. A compression type polished rod sealer with a quickly replaceable sealing gland according to claim 3, characterized in that: The housing comprises an upper pressure cap, an outer cylinder and a lower pressure cap; The outer wall of the upper pressure cap is threadedly connected to the inner wall of the upper end of the outer cylinder; The outer wall of the pressing cap is threadedly connected to the inner wall of the lower end of the outer cylinder; A protruding sealing pressure ring is provided at the lower end of the upper pressure cap, and a protruding sealing seat ring is provided at the upper end of the lower pressure cap. A sealing filler port is provided between the lower end surface of the sealing pressure ring and the upper end surface of the sealing seat ring. The sealing box is provided on the upper end surface of the sealing seat ring, and the upper end of the sealing box contacts the lower end surface of the sealing pressure ring. The space between the inner wall of the outer tube, the outer wall of the sealing pressure ring and the outer wall of the sealing seat ring is a compression chamber, the rubber tube and the piston are arranged in the compression chamber, and the inner wall of the rubber tube contacts the outer wall of the sealing pressure ring and the outer wall of the sealing seat ring.

5. A compression type polished rod sealer with a quickly replaceable sealing gland according to claim 4, characterized in that: The one-way grease injection mechanism is arranged on the pressing cap; The one-way grease injection mechanism includes a hydraulic channel, an injection valve ball, an injection hole, and an injection spring; The pressing cap is provided with a radial liquid injection countersunk hole on the outer wall, and the pressing cap is provided with a hydraulic channel, and the hydraulic channel connects the liquid injection countersunk hole with the compression chamber. The liquid injection hole is provided on the outer cylinder, and the liquid injection hole corresponds to the liquid injection countersunk hole, and the aperture of the liquid injection hole is smaller than the aperture of the liquid injection countersunk hole; The injection valve ball and the injection spring are arranged in the injection counterbore, and the injection spring pushes the injection valve ball onto the injection hole to seal the injection hole; The piston sleeve is arranged on the outer wall of the sealing seat ring. The piston can move up and down along the outer wall of the sealing seat ring. The upper end surface of the piston contacts the lower end surface of the rubber cylinder.

6. A compression type polished rod sealer with a quickly replaceable sealing gland according to claim 5, characterized in that: The inner diameter of the outer cylinder, the outer diameter of the rubber cylinder, and the outer diameter of the piston are equal, and the outer diameters of the sealing pressure ring, the outer diameters of the sealing seat ring, and the inner diameter of the rubber cylinder are equal; The upper end and the lower end of the outer wall of the rubber cylinder are both provided with a conical cut angle.

7. The compression type polished rod sealer with a quickly replaceable sealing gland according to claim 5, characterized in that: The outer wall and the inner wall of the piston are both provided with seals.

8. The compression type polished rod sealer with a quickly replaceable sealing gland according to claim 5, characterized in that: The upper pressure cap is screwed and sealed with the outer cylinder.

9. The compression type polished rod sealer with a quickly replaceable sealing gland according to claim 5, characterized in that: An upper limit ring is provided at the upper end of the outer wall of the upper pressure cap, and a lower limit ring is provided at the lower end of the outer wall of the lower pressure cap.

10. The compression type polished rod sealer with a quickly replaceable sealing gland according to claim 5, characterized in that: A wellhead connector is provided at the lower end of the pressure cap.

Images