Wellhead throttling device of gas storage

Abstract

The utility model relates to a gas storage wellhead throttling device which comprises a fixed sleeve, a medium heat exchange structure, a conical primary throttling inner cover and a screw expander, the fixed sleeve is vertically arranged, and the medium heat exchange structure is arranged on the side wall of the lower portion of the fixed sleeve. The first-stage throttling inner cover is fixed to the inner wall of the middle section of the fixed sleeve, the conical end of the first-stage throttling inner cover faces upwards, a liquid collecting tank is formed between the first-stage throttling inner cover and the inner wall of the fixed sleeve, a liquid discharging opening with a valve is formed in the side wall of the liquid collecting tank, and the screw expander is installed on the upper portion of the interior of the fixed sleeve. The screw expander is connected with a connecting shaft transversely penetrating through the side wall of the fixing sleeve, and the connecting shaft is in transmission connection with a power generator. The throttling device has the advantages that the structural design is simple and reasonable, the stored gas can be effectively throttled and output, meanwhile, power can be generated by utilizing fluid kinetic energy during throttling, and heat exchange and cooling can be effectively carried out in the stored gas output link.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas storage and transportation, and particularly relates to a throttling device for a gas storage wellhead. Background Art

[0002] Conventionally, throttling at the gas storage wellhead generally adopts the method of installing a throttling nozzle, and the pressure is reduced by controlling the flow rate to meet the requirements of external transportation. However, the throttling nozzle can only play the role of regulating the flow rate, rather than truly reducing the pressure. At the same time, during use, it only has a single function of regulating the flow rate, and the kinetic energy of the high-pressure gas flow is not well recovered and utilized.

[0003] Currently, the patent with the publication number CN105507856B: a throttling device for a gas storage wellhead, sends the gas stored in the gas storage into a screw expander to drive the conical screw to rotate, so that the kinetic energy of the gas flow is converted into the energy to drive the conical screw to do work, thereby continuously reducing the temperature and pressure of the exported gas and achieving better throttling. However, this device does not recover and utilize the thermal energy of the gas, and it is necessary to inject substances such as alcohol at the wellhead to prevent freezing and blocking during use.

[0004] In addition, the patent with the publication number CN113251232B: a throttling device for a gas storage wellhead, also like the above-mentioned patent, converts the kinetic energy of the gas flow into the energy to drive the conical screw to do work, thereby continuously reducing the temperature and pressure of the exported gas and achieving better throttling. For the thermal energy of the gas, a structure with heat exchange fins is added inside to recover it, and it is transported into a container placed on the well wall to release heat to prevent freezing and blocking. However, in this design, due to the installation of heat exchange fins inside, to a certain extent, it affects the normal transportation of the stored gas and may cause the phenomenon of "pressure buildup". At the same time, the internal heat exchange fins are very difficult to repair, and the external pipeline layout is also relatively redundant and complex.

[0005] Based on this, it is necessary to develop a throttling device for a gas storage wellhead to overcome the above technical problems. Summary of the Utility Model

[0006] The technical problem to be solved by the utility model is to provide a throttling device for a gas storage wellhead, which effectively overcomes the defects of the prior art.

[0007] The technical solution of the utility model to solve the above technical problems is as follows:

[0008] A throttle device for a gas storage wellhead, comprising a fixed sleeve, a medium heat exchange structure, a conical primary throttle inner cover, and a screw expander. The fixed sleeve is vertically arranged. The medium heat exchange structure is installed on the lower side wall of the fixed sleeve. The primary throttle inner cover is fixed on the inner wall of the middle section of the fixed sleeve, with its conical end facing upward. A liquid collection tank is formed between the primary throttle inner cover and the inner wall of the fixed sleeve. A drain port with a valve is provided on the side wall of the liquid collection tank. The screw expander is installed in the upper part inside the fixed sleeve. The screw expander is connected with a coupling shaft that penetrates the side wall of the fixed sleeve, and the coupling shaft is in transmission connection with a generator.

[0009] On the basis of the above technical solution, the present utility model can also be improved as follows.

[0010] Further, the medium heat exchange structure includes a heat exchange coil spirally wound around the side wall of the fixed sleeve, and both ends of the heat exchange coil are respectively connected to a liquid circulation and delivery system.

[0011] Further, a circular connection ring is connected below the fixed sleeve through a connecting rod, and an antifreeze heating cavity extending downward is connected. An annular circulation cavity is provided inside the antifreeze heating cavity. An inlet and an outlet are respectively provided on both sides of the upper end of the circulation cavity. The liquid circulation and delivery system includes a liquid storage tank with an electric heating device and a pump body. The inlet of the liquid storage tank is connected to one end of the heat exchange coil through a pipeline. The outlet of the liquid storage tank is connected to the inlet of the circulation cavity through a pipeline. The outlet of the circulation cavity is connected to the other end of the heat exchange coil through a pipeline. The pump body is arranged on the pipeline connecting the liquid storage tank and the heat exchange coil.

[0012] Further, internal threads are provided on the inner wall of the lower end of the fixed sleeve, and an annular connection ring is screwed thereon. The lower end of the connection ring is connected to the circulation cavity through multiple connecting rods.

[0013] Further, the lower end face of the antifreeze heating cavity is set as a conical surface with the conical end facing upward.

[0014] Further, a variable diameter section with an increasing diameter is provided on a section of the fixed sleeve corresponding to the liquid collection tank.

[0015] Further, an extended flow channel is provided on the inner wall of a section of the fixed sleeve corresponding to the medium heat exchange structure.

[0016] Further, the extended flow channel includes baffles spirally wound and fixed on the inner wall of the fixed sleeve, and a spiral flow channel is formed between the baffles.

[0017] Further, an installation flange is provided at the lower end of the fixed sleeve.

[0018] Furthermore, a ring-shaped connecting portion is provided at the lower end of the above-mentioned first-stage throttling inner cover, and the connecting portion is threadedly connected to the inner wall of the fixed sleeve.

[0019] The beneficial effects of the present utility model are as follows: The structure design is simple and reasonable, which can effectively throttle and output the stored gas. At the same time, it can utilize the fluid kinetic energy to generate electricity while throttling, and effectively heat exchange and cool down the stored gas output link; at the same time, the overall throttling device layout is more compact and the throttling effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the throttling device at the wellhead of the gas storage reservoir of the present utility model;

[0021] Figure 2 is a schematic structural diagram of another embodiment of the throttling device at the wellhead of the gas storage reservoir of the present utility model;

[0022] Figure 3 is a schematic structural diagram of yet another embodiment of the throttling device at the wellhead of the gas storage reservoir of the present utility model.

[0023] In the drawings, the list of components represented by each reference numeral is as follows:

[0024] 1, fixed sleeve; 2, medium heat exchange structure; 3, first-stage throttling inner cover; 4, screw expander; 5, generator; 6, anti-freeze heating cavity; 8, extended flow channel; 11, connecting ring; 12, mounting flange; 31, liquid collection tank; 32, connecting portion; 71, liquid storage tank; 72, pump body; 311, liquid discharge port. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The principles and features of the present utility model will be described below with reference to the accompanying drawings. The examples given are only used to explain the present utility model and are not intended to limit the scope of the present utility model.

[0026] Embodiment: As Figure 1 shown, the throttling device at the wellhead of the gas storage reservoir in this embodiment includes a fixed sleeve 1, a medium heat exchange structure 2, a conical first-stage throttling inner cover 3 and a screw expander 4. The fixed sleeve 1 is arranged vertically, the medium heat exchange structure 2 is installed on the lower side wall of the fixed sleeve 1, the first-stage throttling inner cover 3 is fixed on the inner wall of the middle section of the fixed sleeve 1, its conical end is upward, a liquid collection tank 31 is formed between the first-stage throttling inner cover 3 and the inner wall of the fixed sleeve 1, a liquid discharge port 311 with a valve is provided on the side wall of the liquid collection tank 31, the screw expander 4 is installed in the upper part inside the fixed sleeve 1, the screw expander 4 is connected with a coupling shaft that penetrates the side wall of the fixed sleeve 1, and the coupling shaft is in transmission connection with a generator 5.

[0027] When the gas storage wellhead throttling device of this embodiment is in use, the lower end of the fixed sleeve 1 is docked with the gas storage wellhead. The high-temperature and high-pressure gas storage enters the fixed sleeve 1 upward through the wellhead, and then undergoes a certain degree of throttling through the primary throttling inner cover 3. Then, the gas flow acts on the screw expander 4, causing the screw expander 4 to do work and driving the generator 5 to generate electricity, making full use of the kinetic energy of the outgoing gas flow. After this link, both the outgoing gas pressure and temperature are reduced well. At the same time, after the gas storage enters the fixed sleeve 1, it exchanges heat with the medium heat exchange structure 2, and the gas storage is cooled before power generation (or throttling), and heat energy is recovered using the medium. Overall, the structure inside the fixed sleeve 1 has relatively minor changes compared to traditional technologies. Only the primary throttling inner cover 3 is added, which better improves the throttling effect. The internal throughput of the fixed sleeve 1 is large and does not affect normal gas transmission. The structural design is simple and reasonable, which can effectively throttle and output the gas storage. At the same time, it can generate electricity using the fluid kinetic energy during throttling and effectively cool and heat the gas storage output link.

[0028] It should be supplemented and explained that when the gas storage acts on the screw expander 4 to do work, the gas temperature and pressure continuously decrease, and the oil and water condensed in the high-temperature and high-pressure gas gradually precipitate and are thrown onto the inner wall of the fixed sleeve 1. The oil-water mixture flows down along the inner wall of the fixed sleeve 1 into the liquid collection tank 31 for collection and can be discharged outside through the liquid discharge port 311 after opening the valve.

[0029] As a preferred implementation manner, the above-mentioned medium heat exchange structure 2 includes heat exchange coils spirally wound around the side wall of the above-mentioned fixed sleeve 1, and both ends of the above-mentioned heat exchange coils are respectively connected to a liquid circulation and transportation system.

[0030] In the above-mentioned implementation scheme, the medium heat exchange structure 2 adopts heat exchange coils wound around the side wall (outer side) of the fixed sleeve 1, which is very convenient to install, does not change the original structure of the fixed sleeve 1, and is very convenient and practical.

[0031] As a preferred implementation manner, as Figure 2 shown, a circular connection with a downward-extending anti-freeze heating cavity 6 is connected to the lower part of the above-mentioned fixed sleeve 1 through a connecting rod. An annular circulation cavity is provided in the above-mentioned anti-freeze heating cavity 6. An inlet and an outlet are respectively provided on both sides of the upper end of the above-mentioned circulation cavity. The above-mentioned liquid circulation and transportation system includes a liquid storage tank 71 with an electric heating device and a pump body 72. The inlet of the above-mentioned liquid storage tank 71 is connected to one end of the above-mentioned heat exchange coil through a pipeline, the outlet of the above-mentioned liquid storage tank 71 is connected to the inlet of the above-mentioned circulation cavity through a pipeline, the outlet of the above-mentioned circulation cavity is connected to the other end of the above-mentioned heat exchange coil through a pipeline, and the above-mentioned pump body 72 is arranged on the pipeline connecting the above-mentioned liquid storage tank 71 and the above-mentioned heat exchange coil.

[0032] In the above-mentioned implementation scheme, after the heat exchange coil exchanges heat with the gas in the fixed sleeve 1, it absorbs heat energy and is then transported into the liquid storage tank 71. Then, it is transported from the liquid storage tank 71 to the antifreeze heating chamber 6 to release heat energy to heat the wellhead. After that, it flows back to the heat exchange coil to absorb heat again, forming a better "heat energy cycle" and making full use of the stored gas heat energy to perform antifreeze treatment on the wellhead.

[0033] In this embodiment, if the heat of the medium in the liquid storage tank 71 is insufficient, it can be supplemented by heating through an electric heating device, and the electric energy of the electric heating device can partially come from the power generated by the generator 5, so that the energy forms a circulation system and fully utilizes the kinetic energy of the stored gas flow.

[0034] As a preferred embodiment, the inner wall of the lower end of the fixed sleeve 1 is provided with a thread, and a ring-shaped connecting ring 11 is screwed on it, and the lower end of the connecting ring 11 is connected to the circulation chamber through a plurality of connecting rods.

[0035] In the above embodiment, the design of the connecting ring 11 facilitates assembly with the fixed sleeve 1, so that the circulation chamber can be stably installed, and the disassembly and assembly are very simple and quick.

[0036] In this embodiment, the lower end surface of the antifreeze heating chamber 6 is set as a conical surface with the conical end facing upward. The design of the conical surface can reduce the resistance to the external transmission of the stored gas.

[0037] As a preferred embodiment, a section of the fixed sleeve 1 corresponding to the liquid collecting tank 31 is configured as a diameter-reducing section with an increased diameter.

[0038] In the above embodiment, the design of the variable diameter section increases the volume of the liquid collecting tank 31 , which can store more oil and water condensed in the gas and reduce the frequency of opening and closing the liquid discharge port 311 .

[0039] As a preferred embodiment, Figure 3 As shown, an extended flow channel 8 is provided on a section of the inner wall of the fixed sleeve 1 corresponding to the medium heat exchange structure 2 .

[0040] In the above-mentioned embodiment, the design of the extended flow channel 8 can extend the heat exchange path of the gas flowing through the lower section of the fixed sleeve 1 to a certain extent, thereby improving the heat exchange effect.

[0041] In this embodiment, the extended flow channel 8 includes a baffle that is spirally fixed around the inner wall of the fixed sleeve 1, and a spiral flow channel is formed between the baffles.

[0042] In this embodiment, the lower end of the fixing sleeve 1 is provided with a mounting flange 12. The mounting flange 12 is conveniently connected to the wellhead flange (bolted connection).

[0043] As a preferred embodiment, a ring-shaped connecting portion 32 is provided at the lower end of the above-mentioned first-stage throttling inner cover 3, and the connecting portion 32 is threadedly connected to the inner wall of the fixed sleeve 1.

[0044] In the above-mentioned implementation, the design of the connecting portion 32 and its threaded connection with the fixed sleeve 1 facilitate the disassembly and assembly of the entire first-stage throttling inner cover 3.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 should not be construed as a limitation to the present invention.

[0046] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0049] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0050] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A throttling device for the wellhead of a gas storage reservoir, characterized in that: It includes a fixed sleeve (1), a medium heat exchange structure (2), a conical primary throttling inner cover (3), and a screw expander (4). The fixed sleeve (1) is vertically arranged. The medium heat exchange structure (2) is installed on the lower side wall of the fixed sleeve (1). The primary throttling inner cover (3) is fixed on the inner wall of the middle section of the fixed sleeve (1) with its conical end facing upward. A liquid collecting tank (31) is formed between the primary throttling inner cover (3) and the inner wall of the fixed sleeve (1). A drain port (311) with a valve is provided on the side wall of the liquid collecting tank (31). The screw expander (4) is installed in the upper part inside the fixed sleeve (1). The screw expander (4) is connected with a coupling shaft that passes through the side wall of the fixed sleeve (1), and the coupling shaft is in transmission connection with a generator (5).

2. The throttling device for the gas storage wellhead according to claim 1, characterized in that: The medium heat exchange structure (2) includes heat exchange coils spirally wound around the side wall of the fixed sleeve (1), and both ends of the heat exchange coils are respectively connected to a liquid circulation and conveying system.

3. The throttling device for the gas storage wellhead according to claim 2, wherein: A ring-shaped anti-freezing heating chamber (6) extending downward is connected below the fixed sleeve (1) through a connecting rod. An annular circulation chamber is provided in the anti-freezing heating chamber (6). An inlet and an outlet are respectively provided on both sides of the upper end of the circulation chamber. The liquid circulation and conveying system includes a liquid storage tank (71) with an electric heating device and a pump body (72). The inlet of the liquid storage tank (71) is connected to one end of the heat exchange coils through a pipeline. The outlet of the liquid storage tank (71) is connected to the inlet of the circulation chamber through a pipeline. The outlet of the circulation chamber is connected to the other end of the heat exchange coils through a pipeline. The pump body (72) is arranged on the pipeline connecting the liquid storage tank (71) and the heat exchange coils.

4. The throttling device for the gas storage wellhead according to claim 3, wherein: Internal threads are provided on the lower end inner wall of the fixed sleeve (1), and a ring-shaped connecting ring (11) is screwed thereon. The lower end of the connecting ring (11) is connected to the circulation chamber through multiple connecting rods.

5. The throttling device for the gas storage wellhead according to claim 3, wherein: The lower end face of the anti-freezing heating chamber (6) is a conical surface with its conical end facing upward.

6. The throttling device for the wellhead of a gas storage reservoir according to claim 1, wherein: A section of the fixed sleeve (1) corresponding to the liquid collecting tank (31) is a variable-diameter section with an increasing diameter.

7. The throttling device for the gas storage wellhead according to claim 1, wherein: An extended flow channel (8) is provided on the inner wall of a section of the fixed sleeve (1) corresponding to the medium heat exchange structure (2).

8. The throttling device for the wellhead of a gas storage reservoir according to claim 7, characterized in that: The extended flow channel (8) includes baffles spirally wound and fixed on the inner wall of the fixed sleeve (1), and spiral flow channels are formed between the baffles.

9. A throttling device for the wellhead of a gas storage reservoir according to any one of claims 1 to 8, characterized in that: An installation flange (12) is provided at the lower end of the fixed sleeve (1).

10. A throttling device for a gas storage wellhead according to any one of claims 1 to 8, characterized in that: An annular connecting portion (32) is provided at the lower end of the primary throttling inner cover (3), and the connecting portion (32) is in threaded connection with the inner wall of the fixed sleeve (1).

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