Liquid slip-off prevention plunger

Abstract

The present application relates to the technical fields of plunger drainage gas recovery, and is a kind of anti-liquid slip plunger, comprising a plunger body and an impeller, the upper end of the plunger body is provided with a fishing head, a plurality of annular grooves are arranged on the outer side of the middle part of the plunger body in an upper and lower interval, and the lower part of the plunger body is rotatably connected with the impeller through a bearing assembly. The present application has a reasonable and compact structure. When rapidly ascending under the action of gas pressure in the well, the upward channeling gas acts on the lower part of the impeller, driving the impeller to rotate at high speed. When the downward flowing liquid flows to the area above the impeller, a high-speed fluid rotation zone is formed around the upper part of the impeller due to the high-speed rotation of the impeller, and the downward flowing liquid in the upper part is effectively blocked. The use of high-speed fluid area prevents and blocks liquid slip, which can effectively improve the liquid carrying efficiency of the plunger, is suitable for various types of plungers, and can carry solid substances and scale in the well wall. The structure is novel, simple to use, safe and reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plunger drainage gas recovery, and is a liquid slip prevention plunger. BACKGROUND

[0002] The plunger gas lift drainage gas recovery process is one of effective processes for solving the problems of low formation energy, serious water production and difficulty in normal liquid discharge of gas wells in the late development stage. The process is an intermittent liquid discharge production technology. An effective sealing interface is formed at a certain position in the production string by the plunger, and the formation energy is utilized to realize liquid discharge and gas production. The conventional plunger has a certain liquid slip during operation, such as the bullet plunger, the turbulent plunger and the brush plunger, which reduces the efficiency of the plunger gas lift drainage gas recovery operation. SUMMARY

[0003] The present application provides a liquid slip prevention plunger, which overcomes the shortcomings of the prior art and effectively solves the problem of low liquid carrying efficiency of the existing plunger, thereby reducing the efficiency of the plunger drainage gas recovery process.

[0004] The technical scheme of the present application is realized by the following measures: a liquid slip prevention plunger, comprising a plunger body and an impeller, a fishing head is arranged at the upper end of the plunger body, a plurality of annular grooves are arranged on the outer side of the middle part of the plunger body in an upper and lower spaced manner, the impeller is rotatably connected to the lower part of the plunger body through a bearing assembly, and a protective cap is arranged at the lower end of the plunger body.

[0005] The following is a further optimization or / and improvement of the above-mentioned technical scheme of the application:

[0006] The above-mentioned impeller can include a sleeve and at least four blades uniformly distributed in a circumferential direction on the outer side of the sleeve, and each blade includes a vertical segment and a spiral segment from top to bottom.

[0007] The bottom diameter of the above-mentioned annular groove can be not less than 20 mm, and the height of the annular groove can be not less than 10 mm.

[0008] The above-mentioned plunger body, impeller and protective cap can be made of forty-five steel with chrome plating on the surface.

[0009] The inner side of the above-mentioned protective cap can be screwed on the outer side of the lower end of the shaft, and the protective cap and the shaft are fixedly connected together by a lock pin.

[0010] The above-mentioned plunger body, impeller and protective cap can be made of forty-five steel with chrome plating on the surface.

[0011] This invention features a rational and compact structure. When the plunger moves rapidly upward under the pressure of the gas inside the well, the upward-rushing gas (gas-liquid mixture) acts on the lower part of the impeller, driving the impeller to rotate at high speed. As the plunger body moves upward, the sliding liquid flows to the area above the impeller. Due to the high-speed rotation of the impeller, a high-speed fluid rotation zone is formed around the impeller, effectively blocking the sliding liquid. Simultaneously, it effectively suspends and carries away solid materials from the well. The retrieval head facilitates retrieval, and the protective cap prevents the impeller from falling off and acts as a limiting element. Utilizing a high-speed fluid zone to prevent and block liquid slippage effectively improves the plunger's liquid-carrying efficiency. It is suitable for various types of plungers and can carry away solid materials and scale from the well wall. The structure is novel, simple to use, and safe and reliable. Attached Figure Description

[0012] Appendix Figure 1 This is a schematic diagram of the main view half-section structure of the present invention.

[0013] Appendix Figure 2 This is a schematic diagram of the three-dimensional structure of the impeller in this invention.

[0014] The codes in the attached diagram are as follows: 1 is the plunger body, 2 is the impeller, 3 is the retrieval head, 4 is the protective cap, 5 is the annular groove, 6 is the first bearing, 7 is the second bearing, 8 is the shaft, 9 is the first bushing, 10 is the second bushing, 11 is the sleeve, 12 is the vertical section, 13 is the spiral section, 14 is the anti-loosening pin, D is the groove bottom diameter, and H is the height of the annular groove. Detailed Implementation

[0015] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0016] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0017] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0018] As attached Figure 1 , 2 As shown, the anti-liquid slippage plunger includes a plunger body 1, a bearing assembly and an impeller 2. The upper end of the plunger body 1 is provided with a retrieval head 3. Several annular grooves 5 are provided at intervals on the outer side of the middle part of the plunger body 1. The lower part of the plunger body 1 is rotatably connected to the impeller 2 through the bearing assembly. A protective cap 4 is installed at the lower end of the plunger body 1 corresponding to the position below the impeller 2.

[0019] Depending on the requirements, the plunger body 1, the retrieval head 3, and the annular groove 5 are designed as a single piece. The annular groove 5 can also be replaced by a spring-loaded or brush-type design. During use, when the liquid rises rapidly under the pressure of the gas in the well, the upward-rushing gas (gas-liquid mixture) acts on the lower part of the impeller 2, driving the impeller 2 to rotate at high speed. As the plunger body 1 moves upward, when the sliding liquid flows to the area above the impeller 2, a high-speed fluid rotation zone is formed around the impeller 2 due to its high-speed rotation. This effectively blocks the sliding liquid and also effectively suspends and carries away solid materials from the well. The retrieval head 3 facilitates retrieval, and the cap 4 prevents the impeller 2 from falling off and acts as a limit. By using a high-speed fluid zone to prevent and block liquid slippage, the plunger's liquid-carrying efficiency can be effectively improved. It is suitable for various types of plungers and can carry away solid materials and scale from the well wall. The structure is novel, easy to use, and safe and reliable.

[0020] The above-mentioned anti-liquid slippage plunger can be further optimized and / or improved according to actual needs:

[0021] As attached Figure 1 , 2 As shown, the impeller 2 includes a sleeve 11, a first blade 12, and a second blade 13. At least four spiral blade-shaped first blades 12 are evenly distributed circumferentially on the lower outer side of the sleeve 11. A vertically arranged second blade 13 is fixedly installed on the upper outer side of the sleeve corresponding to each first blade position. The lower side of each second blade is fixedly connected to the upper side of the corresponding first blade.

[0022] During operation, the upward-flowing gas (gas-liquid mixture) acts on the blades of the spiral section 13 at the lower part of the impeller 2, thereby driving the impeller 2 to rotate at high speed. As the plunger body 1 moves upward, the liquid sliding down flows to the top of the impeller 2. Because the upper part of the impeller 2 blades is vertical, the liquid and the impeller 2 rotate at high speed simultaneously, creating a high-speed fluid rotation zone around the upper part of the impeller 2. This further effectively blocks the liquid sliding down from the top. This impeller 2 structure can further generate high-speed rotation when the high-speed fluid passes upward, effectively improving the dynamic sealing performance of the plunger during operation within the tubing string, increasing the plunger's liquid-carrying efficiency, and simultaneously carrying solid materials out of the wellbore.

[0023] As attached Figure 1 As shown, the bottom diameter D of the annular groove 5 is not less than 20mm, and the height H of the annular groove 5 is not less than 10mm.

[0024] Depending on the requirements, there may be no fewer than six annular grooves 5. During use, this size design can further reduce fluid slippage, increase fluid carrying efficiency, and carry solid materials out of the wellbore.

[0025] As attached Figure 1 As shown, it also includes a first bushing 9 and a second bushing 10. The bearing assembly includes a first bearing 6 and a second bearing 7. A shaft 8 with a diameter smaller than the bottom diameter D of the groove is fixed at the lower part of the plunger body 1. The first bushing 9, the first bearing 6, the impeller 2, the second bearing 7, the second bushing 10 and the protective cap 4 are sequentially fitted on the outer side of the shaft 8 from top to bottom.

[0026] According to requirements, both the first bushing 9 and the second bushing 10 are made of brass. The first bearing 6 and the second bearing 7 are existing known technologies, such as thrust bearings, capable of withstanding axial impact loads of not less than 80KN. During use, the first bushing 9 is fitted onto the upper end of the shaft 8, with the top of the first bushing 9 abutting against the lower middle part of the plunger body 1, preventing the first bushing 9 from sliding upwards. The lower end of the first bushing 9 is nested with the first bearing 6, which is nested inside the upper end of the impeller 2. The lower inner side of the impeller 2 is nested outside the upper end of the second bearing 7, and the lower end of the second bearing 7 is nested with the second bushing 10. The protective cap 4 is screwed onto the lower end of the shaft 8, with the upper end of the protective cap 4 abutting against the lower end of the first bushing 9, preventing the second bushing 10 and the impeller 2 from falling downwards. The impeller 2 can rotate through the first bearing 6 and the second bearing 7.

[0027] As attached Figure 1 As shown, the inner side of the cap 4 is screwed to the outer side of the lower end of the shaft 8, and is fixedly connected to the shaft 8 by the anti-loosening pin 14.

[0028] During use, the anti-loosening pin 14 prevents the protective cap 4 from coming loose from the shaft 8.

[0029] As attached Figure 1 As shown, the plunger body 1, impeller 2, and cap 4 are all made of chrome-plated No. 45 steel.

[0030] During use, chrome plating can prevent corrosion; the overall tensile strength of No. 45 steel is not less than 5T, the compressive strength is not less than 1T, the strength is relatively high, the plasticity and toughness are good, and the mechanical properties are excellent.

[0031] The above technical features constitute the preferred embodiment of the present invention, which has strong adaptability and optimal implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the requirements of different situations.

Claims

1. A liquid-resistant slippage plunger, characterized in that: The device includes a plunger body and an impeller. The upper end of the plunger body is equipped with a retrieval head. Several annular grooves are spaced vertically on the outer side of the middle part of the plunger body. The impeller is rotatably connected to the lower part of the plunger body through a bearing assembly. A protective cap is installed at the lower end of the plunger body. The impeller includes a sleeve and blades. At least four blades are evenly distributed circumferentially on the outer side of the sleeve. Each blade includes a vertical section and a spiral section from top to bottom. The bottom diameter of the annular groove is not less than 20 mm, and the height of the annular groove is not less than 10 mm. The device also includes a first bushing and a second bushing. The bearing assembly includes a first bearing and a second bearing. The lower part of the plunger body is equipped with a shaft with a diameter smaller than the bottom diameter of the groove. The outer side of the shaft is nested from top to bottom with the first bushing, the first bearing, the impeller, the second bearing, the second bushing, and the protective cap.

2. The anti-liquid slippage plunger according to claim 1, characterized in that... The inner side of the protective cap is screwed to the outer side of the lower end of the shaft and is fixedly connected to the shaft by anti-loosening pins.

3. The anti-liquid slippage plunger according to claim 1 or 2, characterized in that... The plunger body, impeller, and protective cap are all made of chrome-plated No. 45 steel.

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