Anti-freezing constant pressure deflation device

Abstract

The utility model relates to the method or equipment field of obtaining oil, gas, water, soluble or fusible material or mineral pulp from well, especially relate to a kind of freeze-proof constant pressure gas releasing device.The freeze-proof constant pressure gas releasing device includes device shell, device shell includes the tubing connection pipe for being connected in series in tubing and the casing connection pipe for being connected in casing, tubing connection pipe and casing connection pipe form tee structure, adjustable constant pressure gas releasing valve is installed in casing connection pipe, adjustable constant pressure gas releasing valve includes valve body, valve body is equipped with valve core and pre-tightening spring on the back of valve core, the end of pre-tightening spring away from valve core is provided with adjusting pressure plate, adjusting top pin is installed on tubing connection pipe, and the inner end of adjusting top pin is in abutment with adjusting pressure plate.The above structural design can set adjusting top pin through the pipe wall on casing connection pipe, realize the elastic force adjustment of pre-tightening spring, thereby solve the problem that existing freeze-proof constant pressure gas releasing valve cannot be adjusted in real time.

Description

Technical Field

[0001] This utility model relates to the field of methods or equipment for obtaining oil, gas, water, soluble or fusible substances or mineral slurry from wells, and in particular to an antifreeze constant pressure venting device. Background Technology

[0002] In oil well production systems, the dynamic balance of casing gas is crucial for maintaining high-efficiency production. When the casing gas pressure in the annulus continuously increases, it creates additional back pressure at the bottom of the well. This increased back pressure reduces the efficiency of formation fluid flow into the wellbore, causing the annular fluid level to drop continuously. As the annular fluid column height decreases, the submersion of the pump decreases accordingly, causing the pump inlet pressure to drop below the crude oil saturation pressure. At this point, the gas dissolved in the crude oil rapidly precipitates, forming a gas-liquid two-phase flow within the pump chamber. This free gas not only occupies the effective volume of the pump chamber but also creates a "gas lock-in" effect during the piston's reciprocating motion, preventing the pump valves from opening and closing properly, ultimately leading to a significant reduction in pump efficiency. To address these issues, constant-pressure venting is commonly used, directing the casing gas into the production pipeline. Constant-pressure venting, by precisely controlling the venting pressure, solves these problems while recovering the casing gas, eliminating safety hazards and greenhouse gas emissions, and achieving full energy utilization.

[0003] The constant-pressure discharge of casing gas is implemented through a constant-pressure discharge valve. The basic components of the constant-pressure discharge valve include a valve body, a valve core, and a valve seat. The valve core is equipped with a pressure setting module, the core component of which is a spring. The opening pressure of the constant-pressure discharge valve is controlled by adjusting the spring pre-compression. When the accumulated casing gas pressure is lower than the opening pressure, the spring force is greater than the gas thrust, the valve core is tightly pressed against the valve seat, and the valve is in the closed state. Once the casing pressure rises and exceeds the opening pressure, the gas thrust overcomes the spring pre-compression force, pushing the valve core (such as a valve ball or valve stem) to displace, thereby opening the exhaust passage and discharging the gas into the production pipeline. As the gas is discharged, the pressure before the valve drops. When the gas thrust is again less than the spring force, the spring pushes the valve core to reset, resealing the valve seat, and the valve closes, waiting for the next working cycle.

[0004] Because the expansion and heat absorption of casing gas within the valve can cause a sudden drop in local temperature below freezing, the resulting condensate can freeze and jam the valve core. In the context of low winter temperatures, this freezing blockage will inevitably occur, leading to venting failure and severely impacting normal well production. To address this issue, patent specification CN205135572U provides a cartridge-type anti-freezing casing gas recovery device. The main components of this device include a one-way valve and a constant-pressure venting valve connected in series with the one-way valve. The valve core of the constant-pressure venting valve has its end facing away from its preload spring and towards the downstream channel of the one-way valve, with the valve core located at the end of the channel.

[0005] The pressure relief valve disclosed in the aforementioned patent specification is designed to be inserted entirely into the oil pipe, allowing its key components (such as the valve core and valve seat) to be continuously immersed in relatively high-temperature crude oil. This achieves passive heat tracing and insulation. During operation, the flowing crude oil acts as a stable heat source, continuously transferring heat to the valve body. This counteracts the heat absorption effect generated when the high-pressure bushing gas expands through the valve, thereby fundamentally preventing the valve core from freezing due to condensate freezing.

[0006] However, similar to most conventional constant pressure venting valves, in the device disclosed in the above patent, the opening pressure of the constant pressure venting valve is a preset pressure. Since the spring is always located in the oil pipe, the preset pressure cannot be adjusted during use. Moreover, the preset pressure is not always matched with production, so it is impossible to reduce the back pressure effect while maintaining a certain production pressure difference. Utility Model Content

[0007] The purpose of this invention is to provide an antifreeze constant pressure venting device to solve the problem that the venting pressure of existing antifreeze constant pressure venting valves cannot be adjusted in real time.

[0008] To achieve the above objectives, the antifreeze constant pressure venting device of this utility model adopts the following technical solution: An antifreeze constant pressure venting device includes a device housing. The device housing includes an oil pipe connecting pipe for connecting to an oil pipe and a casing connecting pipe for connecting to a casing. The oil pipe connecting pipe and the casing connecting pipe form a tee structure. An adjustable constant pressure venting valve is installed on the casing connecting pipe. The adjustable constant pressure venting valve includes a valve body, a valve core and a preload spring mounted on the back of the valve core. An adjusting pressure plate is provided at the end of the preload spring away from the valve core. An adjusting screw is installed on the oil pipe connecting pipe, and the inner end of the adjusting screw abuts against the adjusting pressure plate.

[0009] Furthermore, the valve core includes an end sealing part at the front end and a rear sealing part after the end sealing part. The rear sealing part and the valve body form a slide valve structure. When the end sealing part cooperates with the valve seat to close the valve port, the rear sealing part closes the vent hole on the valve body. When the end sealing part opens the valve port, the rear sealing part opens the vent hole on the valve body.

[0010] Furthermore, an adjustable constant pressure venting valve with a relatively lower venting pressure is also provided upstream of the adjustable constant pressure venting valve. The constant pressure venting valve and the adjustable constant pressure venting valve are connected by an insulation shell. The insulation shell is at least partially located in the oil pipe connection pipe, forming an oil bath heater structure that can be heated by the crude oil passing through the oil pipe connection pipe.

[0011] Furthermore, the longitudinal section of the insulation shell is a hollow inverted U-shape, and the valve core of the constant pressure venting valve is at least partially located in the opening of the U-shape.

[0012] Furthermore, the valve body of the constant pressure venting valve is fixed by a threaded engagement between the external thread and the insulation shell.

[0013] Furthermore, the valve body of the constant pressure valve is threadedly engaged with the sleeve connecting pipe and fixed to the sleeve connecting pipe, and the heat insulation shell is installed on the device housing by connecting with the constant pressure valve.

[0014] Furthermore, the adjustable pressure relief valve is fixedly installed in the insulation shell and is installed in the device housing through a fixed fit with the insulation shell.

[0015] Furthermore, the vent of the constant pressure valve is designed as a slow-release vent, and is connected to the insulation shell through the slow-release vent.

[0016] Furthermore, the end sealing part of the valve core of the adjustable constant pressure venting valve has a needle-shaped structure.

[0017] Furthermore, the valve core and valve seat of the constant pressure venting valve are fitted with a conical fit.

[0018] The beneficial effects of the technical solution of this utility model's antifreeze constant pressure venting device are as follows: This utility model's antifreeze constant pressure venting device adopts a completely new structure. By installing the valve body and valve core of the adjustable constant pressure venting valve on the sleeve connecting pipe and placing it in the oil pipe connecting pipe, the temperature of the crude oil flowing in the oil pipe can be used to heat the adjustable constant pressure venting valve during use, preventing it from freezing and becoming blocked. In addition, through the above structural design, an adjusting set screw passing through the pipe wall can be set on the sleeve connecting pipe to adjust the elasticity of the preload spring, thereby solving the problem that the venting pressure of existing antifreeze constant pressure venting valves cannot be adjusted in real time. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of one embodiment of the antifreeze constant pressure venting device of this utility model; Figure 2 yes Figure 1 A schematic diagram of the shell structure in the middle; Figure 3 yes Figure 1 A schematic diagram showing the fit between the first-stage valve core and the first-stage preload spring; Figure 4 This is a schematic diagram of the valve body of a primary constant pressure venting valve; Figure 5 This is a schematic diagram of the insulation shell structure; Figure 6 yes Figure 1 A schematic diagram of the structure of the two-stage constant pressure vent valve; Figure 7This is a schematic diagram illustrating the usage state of one embodiment of the antifreeze constant pressure venting device of this utility model.

[0020] In the diagram: 1. Device housing; 101. Oil pipe connection pipe; 102. Casing connection pipe; 2. Production pipeline; 3. Casing; 4. Constant pressure vent valve; 401. Primary valve body; 402. Primary valve seat; 403. Primary valve core; 404. Primary valve port; 405. Primary preload spring; 406. Slow-release hole; 407. Primary sealing ring; 5. Adjustable constant pressure vent valve; 501. Secondary valve body; 502. Secondary valve core; 503. Secondary valve seat; 504. Secondary preload spring; 505. Adjusting pressure plate; 506. Adjusting set screw; 6. Insulation housing; 601. Screw sleeve; 7. Oil sleeve connection pipeline. Detailed Implementation

[0021] The features and performance of this utility model will be further described in detail below with reference to specific embodiments.

[0022] Existing constant-pressure venting devices, in order to prevent freezing and blockage, typically place the entire valve body (including the preload spring) inside the production pipeline, relying on fluid temperature for heating. While this structure solves the freezing and blockage problem, it introduces another issue: the preload spring, enclosed inside the pipeline, cannot regulate pressure. Since the optimal casing pressure required by an oil well varies at different production stages, this fixed design prevents the device from responding to dynamic operating conditions, thus losing its ability to "produce using casing pressure."

[0023] This invention decouples heat tracing and regulation functions by incorporating an independent insulation chamber within the casing. The insulation chamber utilizes pipeline fluid to efficiently heat critical parts of the valve body, maintaining its original antifreeze effect without relying on the entire pipe being inserted. Simultaneously, the spring adjustment mechanism is externally mounted. Through external adjustment components (such as adjusting set screws), operators can conveniently adjust the spring preload based on real-time production data, thereby precisely setting the discharge pressure. By adjusting the discharge pressure in a timely manner, the casing pressure can be stabilized within the optimal range. While maintaining a reasonable production pressure differential to ensure output, the casing pressure effectively suppresses gas escape and stabilizes the annular liquid level, ultimately achieving efficient discharge of casing gas while utilizing casing pressure to assist production.

[0024] The specific embodiments of the antifreeze constant pressure venting device of this utility model will be described below with reference to the accompanying drawings: like Figure 1 As shown, the antifreeze constant pressure venting device of this utility model includes a device housing 1, the structure of which is as follows: Figure 2 , Figure 7As shown, it includes an oil pipe connecting pipe 101 and a casing connecting pipe 102 forming a tee structure with the oil pipe connecting pipe 101. The oil pipe connecting pipe 101 is used to connect in series to the production pipeline 2, and its two ends are respectively provided with joints for connecting to the production pipeline 2. One end of the casing connecting pipe 102 is connected to the oil pipe connecting pipe 101, and the other end is used to connect to the casing 3 (e.g., Figure 7 ).exist Figure 2 In the embodiment shown, the casing connection pipe 102 is perpendicular to the oil pipe connection pipe 101. In other embodiments, the included angle between the casing connection pipe 102 and the oil pipe connection pipe 101 can be other values, which can be designed according to the application scenario.

[0025] exist Figure 2 In the illustrated embodiment, the tubing connector 101 and the casing connector 102 are integrated into a single structure, which can be formed using casting and machining processes. However, those skilled in the art should understand that integrating the tubing connector 101 and the casing connector 102 is not unique; in other embodiments, they can also be separate structures, connected by flanges, threads, or other connection methods.

[0026] like Figure 1 As shown, a constant pressure venting valve 4 is installed in the sleeve connection pipe 102. The constant pressure venting valve 4 constitutes a first-stage constant pressure venting valve relative to the adjustable constant pressure venting valve 5 mentioned below. Correspondingly, the adjustable constant pressure venting valve 5 constitutes a second-stage constant pressure venting valve relative to the constant pressure venting valve 4.

[0027] The structure of the primary constant pressure vent valve is as follows: Figure 3 , Figure 4 As shown, it includes a primary valve body 401, a primary valve seat 402, and a primary valve core 403 installed in the primary valve body 401. The primary valve body 401 is installed in the outer port of the sleeve connection pipe 102 via external threads. Figure 4In the illustrated embodiment, the primary valve body 401 has a stepped bushing structure, with the large-diameter section located upstream and the small-diameter section downstream. The aforementioned external thread is provided in the large-diameter section, and an annular platform protruding towards the center is provided inside the large-diameter section. The primary valve seat 402 is formed by the annular platform, and the center of the annular platform forms the primary valve port 404. The primary valve core 403 is slidably installed in the small-diameter section of the primary valve body 401. On the back of the primary valve core 403, i.e., the side facing away from the primary valve seat 402, a primary preload spring 405 is mounted on top. The primary preload spring 405 limits the opening pressure of the primary constant pressure vent valve, that is, limits the pressure of the sleeve. Multiple connecting holes are arranged on the step at the transition between the large-diameter and small-diameter sections of the primary valve body 401. The connecting holes form a slow-release hole 406. When the primary valve core 403 moves under the action of the sleeve air pressure and opens the primary valve port 404, the sleeve air entering the primary valve body 401 will flow downstream through the slow-release hole 406. The slow-release orifice 406 can, to some extent, suppress the expansion of the gas in the casing within the first-stage valve body 401, alleviate its cooling phenomenon, and prevent icing.

[0028] exist Figure 3 , Figure 4 In the illustrated embodiment, the primary valve port 404 is a conical port, and correspondingly, the primary valve core 403 is provided with a frustum-shaped sealing head, on which a primary sealing ring 407 is provided to seal with the primary valve port 404. However, those skilled in the art should understand that in other embodiments, the primary valve port 404 can be a planar valve port, and the primary valve core 403 can be a planar valve core, so that a surface-to-surface sealing fit is formed between the two.

[0029] like Figure 1 As shown, the antifreeze constant pressure venting device of this utility model has an insulation shell 6 installed downstream of the primary constant pressure venting valve. The structure of the insulation shell 6 is as follows: Figure 5 As shown, the inverted U-shaped, hollow insulation shell 6 forms an insulation chamber within its cavity. This insulation chamber is connected to the aforementioned slow-release hole 406. Gas discharged through the primary pressure venting valve enters the insulation chamber of the insulation shell 6, thus preventing icing. The insulation principle of the insulation shell 6 is as follows: A portion of the insulation shell 6 is located within the aforementioned oil pipe connection pipe 101, and therefore is submerged in crude oil during use. The crude oil itself has a high temperature, causing the insulation shell 6 to function as an oil bath heater. Gas discharged through the primary pressure venting valve enters the insulation chamber of the insulation shell 6 and is then heated and insulated.

[0030] exist Figure 1 , Figure 5In the embodiment shown, the insulation shell 6 is installed on the sleeve connection pipe 102 by engaging with the external thread provided on the small diameter section of the first-stage valve body 401. Of course, in other embodiments, the insulation shell 6 and the sleeve connection pipe 102 can also be directly connected, such as by threaded connection or welding, which are all feasible connection methods.

[0031] like Figure 1 As shown, an adjustable constant pressure vent valve 5 is installed at the outlet of the insulation air chamber of the insulation shell 6. The adjustable constant pressure vent valve 5 is the two-stage constant pressure vent valve mentioned above. The vent pressure of the two-stage constant pressure vent valve is greater than that of the first-stage constant pressure vent valve. Its structure is as follows. Figure 6 As shown, it includes a secondary valve body 501, a secondary valve core 502, and a secondary valve seat 503. The secondary valve seat 503 is fixedly connected to the secondary valve body 501, thus encapsulating the secondary valve core 502 within the valve cavity formed by the two. A pre-tensioning spring, a secondary pre-tensioning spring 504, is also mounted on the back of the secondary valve core 502. One end of the secondary valve body 501 is threaded into a threaded sleeve 601 at the outlet of the insulation housing 6, placing the secondary valve seat 503 within the insulation chamber. After installation, the secondary valve body 501 is tightly fitted against the side wall of the corresponding position on the oil pipe connection pipe 101, thus ensuring stable placement within the oil pipe connection pipe 101. At the end of the secondary pre-tensioning spring 504 facing away from the secondary valve core 502, an adjusting pressure plate 505 is also provided within the secondary valve body 501, with the adjusting pressure plate 505 providing a guiding engagement with the secondary valve body 501. An adjusting screw 506 corresponding to the adjusting pressure plate 505 is provided on the oil pipe connecting pipe 101. By adjusting the adjusting screw 506, the adjusting pressure plate 505 can be pressed, thereby adjusting the pre-compression amount of the secondary pre-tightening spring 504, and thus achieving the purpose of adjusting the venting pressure of the secondary constant pressure venting valve.

[0032] The secondary constant pressure vent valve adopts a needle valve structure, thus having a needle-shaped end seal. However, unlike existing technologies, the tail end of the secondary valve core is also equipped with a sealing section that slides and seals with the secondary valve seat, i.e., a rear seal. This sealing section, together with the secondary valve body 501, forms a spool valve structure. When the needle valve and the secondary valve seat 503 are in a sealing fit, the sealing section simultaneously blocks the vent hole of the secondary constant pressure vent valve. When the needle valve and the valve seat are released from the sealing fit, the sealing section simultaneously opens up the vent hole of the secondary constant pressure vent valve, allowing it to connect with the space inside the oil pipe connection pipe.

[0033] Since the entire valve is located within the oil pipe connection pipe 101 and is completely submerged in crude oil during operation, the secondary constant pressure venting valve also does not have the problem of freezing or clogging.

[0034] This utility model's antifreeze constant pressure venting device is mainly used in the oil and gas production process of the petroleum industry, achieving automatic venting of casing and antifreeze protection of valve bodies in winter. In specific applications, such as... Figure 7As shown, the oil pipe connection pipe 101 can be connected in series in the production pipeline 2, i.e., the oil pipe. The casing connection pipe 102 is connected to the casing 3 through the oil-casing connection pipe 7. When the pressure inside the casing 3 is sufficient to overcome the elastic force of the first-stage preload spring 405 but insufficient to overcome the elastic force of the second-stage preload spring 504, the first-stage constant pressure venting valve opens, and the casing gas enters the insulation shell 6, where it is heated and insulated using the crude oil produced during production. When the pressure inside the casing 3 is sufficient to overcome the elastic force of the second-stage preload spring 504, the second-stage constant pressure venting valve opens, and the casing gas is discharged into the oil pipe connection pipe 101. On the one hand, the two-stage buffering can alleviate the expansion of the casing gas, thereby reducing the freezing blockage problem caused by icing. On the other hand, the antifreeze constant pressure venting device always receives heat from the crude oil, which will also prevent icing and thus avoid the freezing blockage problem. In particular, by setting the regulating pressure plate 505 and the regulating top screw 506, the venting pressure can be adjusted in a timely manner, thereby stabilizing the casing pressure in the optimal range, and ultimately achieving efficient discharge of casing gas while using the casing pressure to assist production.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. An antifreeze constant pressure venting device, characterized in that, The device includes a housing, which includes an oil pipe connecting pipe for connecting to an oil pipe and a casing connecting pipe for connecting to a casing. The oil pipe connecting pipe and the casing connecting pipe form a tee structure. An adjustable constant pressure vent valve is installed on the casing connecting pipe. The adjustable constant pressure vent valve includes a valve body, in which a valve core and a preload spring mounted on the back of the valve core are provided. An adjusting pressure plate is provided at the end of the preload spring away from the valve core. An adjusting screw is installed on the oil pipe connecting pipe, and the inner end of the adjusting screw abuts against the adjusting pressure plate.

2. The antifreeze constant pressure venting device according to claim 1, characterized in that, The valve core includes an end sealing part at the front end and a rear sealing part after the end sealing part. The rear sealing part and the valve body form a slide valve structure. When the end sealing part cooperates with the valve seat to close the valve port, the rear sealing part closes the vent hole on the valve body. When the end sealing part opens the valve port, the rear sealing part opens the vent hole on the valve body.

3. The antifreeze constant pressure venting device according to claim 1 or 2, characterized in that, An adjustable constant pressure venting valve with a relatively lower venting pressure is also provided upstream of the adjustable constant pressure venting valve. The constant pressure venting valve and the adjustable constant pressure venting valve are connected by an insulation shell. The insulation shell is at least partially located in the oil pipe connection pipe, forming an oil bath heater structure that can be heated by the crude oil passing through the oil pipe connection pipe.

4. The antifreeze constant pressure venting device according to claim 3, characterized in that, The longitudinal section of the insulation shell is a hollow inverted U-shape, and the valve core of the constant pressure venting valve is at least partially located in the opening of the U-shape.

5. The antifreeze constant pressure venting device according to claim 4, characterized in that, The valve body of the constant pressure vent valve is fixed by the threaded engagement between the external thread and the insulation shell.

6. The antifreeze constant pressure venting device according to claim 5, characterized in that, The valve body of the constant pressure valve is fixed to the sleeve connection pipe by thread engagement with the sleeve connection pipe, and the heat insulation shell is installed on the device housing by connecting with the constant pressure valve.

7. The antifreeze constant pressure venting device according to claim 6, characterized in that, The adjustable constant pressure vent valve is fixedly installed in the insulation shell and is installed in the device housing through a fixed fit with the insulation shell.

8. The antifreeze constant pressure venting device according to claim 3, characterized in that, The vent of the constant pressure valve is designed as a slow-release vent and is connected to the insulation shell through the slow-release vent.

9. The antifreeze constant pressure venting device according to claim 2, characterized in that, The end sealing part of the valve core of the adjustable constant pressure venting valve has a needle-shaped structure.

10. The antifreeze constant pressure venting device according to claim 3, characterized in that, The valve core and valve seat of the constant pressure venting valve are fitted with a conical fit.

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