Non-contact plunger wellhead buffer device and working method thereof

Abstract

The invention discloses a non-contact plunger wellhead buffer device and a working method thereof. The buffer device comprises a blowout prevention pipe, a damping assembly, a blowout prevention cap, a plunger body and a catcher. The damping assembly comprises a limiting ring arranged on the inner side of the upper end of the blowout prevention pipe and a blowout prevention pipe secondary protection rubber sleeve arranged in the limiting ring, and a powerful neodymium iron boron magnet is arranged in the blowout prevention pipe secondary protection rubber sleeve; the blowout prevention cap covers the upper end of the blowout prevention pipe, and a pressing cap is arranged on the outer side of the upper end of the blowout prevention pipe and used for pressing and fixing the blowout prevention cap to the upper end of the blowout prevention pipe. The plunger body is movably arranged in the blowout prevention pipe, the NdFeB magnetic plunger head is fixedly arranged in the top end of the plunger body, the plunger secondary protection rubber sleeve is arranged at the top end of the plunger body, and the magnetism of the upper end of the NdFeB magnetic plunger head is the same as that of the lower end of the strong NdFeB magnet; the catcher is arranged on the side face of the middle of the lubricator. In the production process, due to the fact that no moving part exists, the whole buffering device is resistant to corrosion, not affected by various substances such as sand grains, stable and reliable in magnetism and capable of achieving non-contact buffering.

Description

Technical Field

[0001] The invention belongs to the technical field of gas field development, and in particular relates to a non-contact plunger wellhead buffer device and a working method thereof. Background Art

[0002] With the continuous development of gas fields, natural gas wells have entered a low-pressure, low-yield stage, with low single-well production and poor liquid-carrying capacity. Liquid is gradually accumulated at the bottom of the well and in the wellbore, which seriously affects the production of the gas well. Effective drainage measures need to be taken. As an effective and economical drainage and gas production method for gas fields at home and abroad, plunger gas lift has achieved good application results. Plunger gas lift uses the plunger as a mechanical interface between gas and liquid, and uses the energy of the gas well itself to push the plunger to periodically lift liquid in the tubing. It can effectively prevent gas from rising and liquid from falling back, reduce the liquid "slippage" effect, and increase intermittent gas lift efficiency. Taking advantage of the characteristics of plunger gas lift's automatic control of opening and closing wells, this process technology is implemented for low-pressure and low-yield wells, so that gas wells can be opened intermittently periodically and the liquid-carrying efficiency of gas wells can be improved.

[0003] In the plunger system, the fundamental principle is the up and down movement of the plunger body. When it moves upward, it brings out the liquid. When it reaches the wellhead, the speed is relatively high, and the impact force on the wellhead equipment and pipes is relatively large. In order to solve this problem, a buffer device is required. The conventional one is a spring type. During operation, due to corrosion and fatigue of the spring, it is damaged, resulting in impact damage to the wellhead. Summary of the invention

[0004] In view of the above-mentioned problems, the purpose of the present invention is to provide a non-contact plunger wellhead buffer device and a working method thereof, which can effectively meet the operation of the existing plunger system, reduce failures, and effectively improve the operation effect of the plunger.

[0005] The technical solution of the present invention is: a non-contact plunger wellhead buffer device, comprising:

[0006] A blowout preventer pipe is used to be fixedly installed on the wellhead blowout preventer valve through a connecting mechanism;

[0007] The shock absorbing assembly comprises a limiting ring arranged on the inner side of the upper end of the lubricating pipe and a secondary protective rubber sleeve of the lubricating pipe arranged in the limiting ring, wherein a strong Ni-Fe-B magnet is arranged in the secondary protective rubber sleeve of the lubricating pipe;

[0008] A blowout preventer cap is provided at the upper end of the blowout preventer pipe, and the upper end of the secondary protective rubber sleeve of the blowout preventer pipe is located at the top of the blowout preventer cap;

[0009] The plunger body is movably arranged inside the blowout preventer, a NiFeBo magnetic plunger head is fixedly arranged inside the top of the plunger body, a plunger secondary protection rubber sleeve is arranged on the top of the plunger body, and the upper end of the NiFeBo magnetic plunger head has the same magnetic properties as the lower end of the strong NiFeBo magnet;

[0010] A catcher is arranged on the side of the middle part of the lubricant preventer and is used for dropping or catching the plunger body.

[0011] Furthermore, the connecting mechanism comprises:

[0012] A connecting flange, fixedly connected to the lower end of the blowout preventer by a first set screw, and the connecting flange is also connected to the wellhead blowout preventer valve;

[0013] The first sealing ring is arranged between the connecting flange and the lubricating pipe.

[0014] Furthermore, a thread is provided on the outer side of the upper end of the blowout preventer, and a pressing cap is screwed on the outer side of the thread, and the pressing cap is used to press and fix the blowout preventer cap on the upper end of the blowout preventer.

[0015] Furthermore, a quick-release handle is provided on the side of the pressing cap.

[0016] Furthermore, a retaining ring is provided on the side of the blowout preventer cap, and the retaining ring is fixed to the blowout preventer cap by a second set screw.

[0017] Furthermore, the lower end of the blowout preventer cap is movably embedded inside the upper end of the blowout preventer pipe, and a second sealing ring is provided between the blowout preventer cap and the blowout preventer pipe.

[0018] Furthermore, a plug is provided at the top of the spray cap.

[0019] Furthermore, a joint is provided on the side of the blowout preventer, and a sampling pressure relief valve is connected to the outer end of the joint.

[0020] Working principle of the present invention:

[0021] The wellhead blowout preventer valve and the lower part of the blowout preventer are fixedly connected through the connecting flange, the shock absorbing assembly is installed on the upper end of the blowout preventer, and then the blowout preventer cap is installed on the upper end of the blowout preventer, the blowout preventer cap is pressed and fixed by the pressing cap, the catcher is opened, and the plunger body is dropped into the wellbore;

[0022] When the gas well is opened for production, the plunger body carries the liquid upward. After reaching the wellhead, the liquid on the upper part of the plunger body will buffer part of the impact force of the plunger body. When the plunger body is close to the shock absorbing assembly, due to the strong magnetism of the strong NiFeB magnet and the NiFeB magnetic plunger head, the opposite poles repel each other, and the rising speed of the plunger body gradually decreases, and finally stops, realizing the liquid discharge production of the plunger body;

[0023] During the production process, since there are no moving parts, the entire buffer device is not afraid of corrosion and is not affected by various substances such as sand. The magnetism is stable and reliable, and contactless buffering is achieved.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The buffering function of the plunger is realized by using the principle of magnetic attraction between like poles and opposition between opposite poles.

[0026] 2. A secondary protective rubber sleeve is added to further ensure the cushioning effect.

[0027] 3. An isolation protection rubber sleeve is added to the outside of the NdFeB magnet to ensure that it is not corroded under natural gas medium conditions, protect the magnet and extend its service life.

[0028] 4. It can be applied to various wellhead and downhole buffer positions. Due to the non-contact buffering, the service life is greatly extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the lubricant preventer structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the plunger body structure of the present invention.

[0031] Among them, 1. connecting flange; 2. first sealing ring; 3. first tightening screw; 4. sampling pressure relief valve; 5. joint; 6. blowout preventer; 7. limit ring; 8. secondary protective rubber sleeve of blowout preventer; 9. strong NiFeBo magnet; 10. second sealing ring; 11. quick release handle; 12. second tightening screw; 13. plug; 14. blowout preventer; 15. retaining ring; 16. pressure cap; 17. catcher; 18. plunger body; 19. NiFeBo magnetic plunger head; 20. secondary protective rubber sleeve of plunger. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1 To the attached Figure 2 , the specific embodiments of the present invention are described in detail. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the 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 element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0034] Example: Figure 1As shown, a non-contact plunger wellhead buffer device includes a blowout preventer 6, a shock absorbing assembly, a blowout preventer cap 14, a plunger body 18 and a catcher 17. Among them:

[0035] The lubricating pipe 6 is used to be fixedly installed on the wellhead blowout preventer valve through a connecting mechanism, and the connecting mechanism includes a connecting flange 1 and a first sealing ring 2. The connecting flange 1 is fixedly connected to the lower end of the lubricating pipe 6 through a first set screw 3, and the connecting flange 1 is also connected to the wellhead blowout preventer valve; the first sealing ring 2 is arranged between the connecting flange 1 and the lubricating pipe 6, and a joint 5 is arranged on the side of the lubricating pipe 6, and a sampling pressure relief valve 4 is connected to the outer end of the joint 5;

[0036] The shock absorbing assembly includes a limiting ring 7 arranged on the inner side of the upper end of the lubricating pipe 6 and a lubricating pipe secondary protection rubber sleeve 8 arranged in the limiting ring 7, and a strong Ni-Fe-B magnet 9 is arranged in the lubricating pipe secondary protection rubber sleeve 8;

[0037] The spray cap 14 is arranged on the upper end of the spray preventer 6, the upper end of the secondary protective rubber sleeve 8 of the spray preventer is located at the top of the spray cap 14, the outer side of the upper end of the spray preventer 6 is provided with a thread, and a pressure cap 16 is screwed on the outer side of the thread, and the pressure cap 16 is used to press and fix the spray cap 14 on the upper end of the spray preventer 6, and a quick-release handle 11 is provided on the side of the pressure cap 16. A retaining ring 15 is provided on the side of the spray cap 14, and the retaining ring 15 is fixed to the spray cap 14 through a second set screw 12. The lower end of the spray cap 14 is movably embedded in the inner side of the upper end of the spray preventer 6, a second sealing ring 10 is provided between the spray cap 14 and the spray preventer 6, and a plug 13 is provided on the top of the spray cap 14;

[0038] The plunger body 18 is movably arranged inside the lubricator 6. Figure 2 As shown, a NiFeBo magnetic plunger head 19 is fixed inside the top of the plunger body 18, and a plunger secondary protective rubber sleeve 20 is provided on the top of the plunger body 18. The upper end of the NiFeBo magnetic plunger head 19 has the same magnetic properties as the lower end of the strong NiFeBo magnet 9;

[0039] The catcher 17 is arranged on the side of the middle part of the lubricator 6 and is used for dropping or catching the plunger body 18 .

[0040] The working principle of the above embodiment is:

[0041] The wellhead blowout preventer valve and the lower part of the blowout preventer pipe 6 are fixedly connected through the connecting flange 1, the shock absorbing assembly is installed on the upper end of the blowout preventer pipe 6, and then the blowout preventer cap 14 is installed on the upper end of the blowout preventer pipe 6, the blowout preventer cap 14 is pressed and fixed by the pressing cap 16, the catcher 17 is opened, and the plunger body 18 is dropped into the wellbore;

[0042] When the gas well is opened for production, the plunger body 18 carries the liquid upward. After reaching the wellhead, the liquid on the upper part of the plunger body 18 will buffer part of the impact force of the plunger body 18. When the plunger body 18 is close to the shock absorbing assembly, due to the strong magnetic force of the strong Ni-Fe-B magnet 9 and the Ni-Fe-B magnetic plunger head 19, the opposite poles repel each other, and the rising speed of the plunger body 18 gradually decreases, and finally stops, realizing the liquid discharge production of the plunger body 18;

[0043] During the production process, since there are no moving parts, the entire buffer device is not afraid of corrosion and is not affected by various substances such as sand. The magnetism is stable and reliable, and contactless buffering is achieved.

[0044] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims

1. A non-contact plunger wellhead buffer device, characterized in that: include: A blowout preventer (6), which is used to be fixedly mounted on a wellhead blowout preventer valve via a connecting mechanism; The shock absorbing assembly comprises a limiting ring (7) arranged on the inner side of the upper end of the lubricating pipe (6) and a lubricating pipe secondary protective rubber sleeve (8) arranged in the limiting ring (7), wherein a strong Ni-Fe-B magnet (9) is arranged in the lubricating pipe secondary protective rubber sleeve (8); A spray cap (14) is arranged on the upper end of the spray preventer (6), and the upper end of the secondary protective rubber sleeve (8) of the spray preventer is located at the top of the spray cap (14); A plunger body (18) is movably arranged inside the blowout preventer (6), a NiFeBo magnetic plunger head (19) is fixedly arranged inside the top of the plunger body (18), a plunger secondary protection rubber sleeve (20) is arranged at the top of the plunger body (18), and the upper end of the NiFeBo magnetic plunger head (19) has the same magnetic properties as the lower end of the strong NiFeBo magnet (9); A catcher (17) is arranged on the side of the middle part of the lubricant preventer (6) and is used to release or catch the plunger body (18).

2. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: The connecting mechanism comprises: A connecting flange (1) is fixedly connected to the lower end of the blowout preventer (6) via a first set screw (3), and the connecting flange (1) is also connected to the wellhead blowout preventer valve; The first sealing ring (2) is arranged between the connecting flange (1) and the anti-blowout pipe (6).

3. A non-contact plunger wellhead buffer device as claimed in claim 2, characterized in that: The outer side of the upper end of the blowout preventer (6) is provided with a thread, and a pressing cap (16) is screwed on the outer side of the thread. The pressing cap (16) is used to press and fix the blowout preventer cap (14) on the upper end of the blowout preventer (6).

4. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: A quick-release handle (11) is provided on the side of the pressing cap (16).

5. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: A retaining ring (15) is provided on the side of the spray-proof cap (14), and the retaining ring (15) is fixed on the spray-proof cap (14) by a second fixing screw (12).

6. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: The lower end of the anti-spray cap (14) is movably embedded in the inner side of the upper end of the anti-spray pipe (6), and a second sealing ring (10) is provided between the anti-spray cap (14) and the anti-spray pipe (6).

7. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: A plug (13) is provided at the top of the spray-proof cap (14).

8. A non-contact plunger wellhead buffer device as claimed in claim 1, characterized in that: A joint (5) is provided on the side of the anti-blowout pipe (6), and a sampling pressure relief valve (4) is connected to the outer end of the joint (5).

9. A method for operating a non-contact plunger wellhead buffer device as claimed in claim 3, characterized in that: The following steps are involved: The wellhead blowout preventer valve and the lower part of the blowout preventer (6) are fixedly connected via a connecting flange 1, the shock absorbing assembly is installed on the upper end of the blowout preventer (6), and then the blowout preventer cap (14) is installed on the upper end of the blowout preventer (6), the blowout preventer cap (14) is pressed and fixed by a pressing cap (16), the catcher (17) is opened, and the plunger body (18) is dropped into the wellbore; When the gas well is opened for production, the plunger body (18) carries liquid upward. After reaching the wellhead, the liquid on the upper part of the plunger body (18) will buffer a part of the impact force of the plunger body (18). When the plunger body (18) approaches the shock absorbing component, due to the strong magnetism of the strong NiFeB magnet (9) and the NiFeB magnetic plunger head (19), the opposite poles repel each other, and the rising speed of the plunger body (18) gradually decreases, and finally stops, thereby realizing the liquid discharge production of the plunger body (18).

Images