Non-metal valve core sleeve gas recovery device and method

Abstract

The invention belongs to the technical field of associated gas recovery, and particularly relates to a non-metal valve element casing gas recovery device and method.The device comprises an upper connector, a connecting pipe, an outer sleeve, an upper leather cup, a lower leather cup and a plug, and the upper connector is provided with a gas inlet; the first end of the connecting pipe is detachably connected with the second end of the upper connector, and the second end of the connecting pipe is provided with an overflowing hole. The outer sleeve is detachably connected with the connecting pipe, the second end of the connecting pipe is arranged in the inner space of the outer sleeve, a center pipe is arranged in the inner space of the outer sleeve, and the lower end of the outer sleeve is connected with a plug which is provided with an exhaust hole. And the upper leather cup and the lower leather cup are respectively sleeved on the central pipe, are in interference fit with the inner wall of the outer sleeve in a sealing manner, and are made of non-metal materials. The sleeve gas recovery requirements under different working conditions are difficult to meet in the prior art. Therefore, a novel device and a novel method which can effectively solve the problem of freezing and blocking of the device and achieve complete recovery of the casing gas are urgently needed.

Description

Technical Field

[0001] The invention belongs to the technical field of associated gas recovery, and in particular relates to a non-metallic valve core casing gas recovery device and method. Background Art

[0002] At present, the domestic oilfield casing gas recovery process mainly adopts the wellhead constant pressure valve to collect gas and mix it. The constant pressure valve absorbs heat when the gas is released, and condensed water is generated when it is opened to exhaust. It is easy to gather and freeze in the gas path, causing the valve core to freeze and become unusable; especially when the gas volume is large, the insufficient exhaust capacity leads to an increase in the casing pressure of the oil well, which poses a safety production risk. Therefore, there is an urgent need for a new device and method that can effectively solve the freezing problem of the device and achieve complete recovery of casing gas. Summary of the invention

[0003] The purpose of the present invention is to provide a non-metallic valve core casing gas recovery device and method to solve the problem of freezing and blocking of the device and achieve the purpose of completely recovering the casing gas.

[0004] A non-metallic valve core casing gas recovery device, comprising an upper joint, a connecting pipe, an outer sleeve, an upper leather bowl, a lower leather bowl and a plug, the upper joint is provided with an air inlet, the first end of the upper joint is connected to the oil well casing through a pipeline; the first end of the connecting pipe is detachably connected to the second end of the upper joint, the connecting pipe is provided with a cavity, the cavity is communicated with the air inlet, and the second end of the connecting pipe is provided with a flow hole; the outer sleeve is detachably connected to the connecting pipe, the second end of the connecting pipe is arranged in the internal space of the outer sleeve, the flow hole is communicated with the internal space, the internal space of the outer sleeve is provided with an upper center pipe and a lower center pipe, the lower end is connected with a plug, and the plug is provided with an exhaust hole; the upper leather bowl and the lower leather bowl are respectively mounted on the center pipe, the openings of the upper leather bowl and the lower leather bowl face the plug, and are interference fit and sealed with the inner wall of the outer sleeve, and the upper leather bowl and the lower leather bowl are made of non-metallic material.

[0005] Optionally, the non-metallic material is rubber, plastic or silicone.

[0006] Optionally, the center tube includes an upper center tube and a lower center tube, the first end of the upper center tube is threadedly connected to the second end of the connecting tube, the second end of the upper center tube is threadedly connected to the lower center tube, the upper leather cup is sleeved on the upper center tube, and the lower leather cup is sleeved on the lower center tube.

[0007] Optionally, the upper leather cup includes a first fixing portion and a first leather cup portion, the first fixing portion is sleeved on the upper center tube, and the lower leather cup includes a second fixing portion and a second leather cup portion, the second fixing portion is sleeved on the lower center tube, the first leather cup portion and the second leather cup portion respectively have openings facing the plug, and the diameters of the first fixing portion and the second fixing portion are smaller than the inner diameter of the outer sleeve.

[0008] Optionally, there are multiple flow holes, which are evenly distributed on the side wall of the second end of the connecting pipe.

[0009] Optionally, the exhaust hole is provided with a filtering device to prevent foreign matter from entering.

[0010] Optionally, a first sealing ring is provided at the connection between the connecting pipe and the upper joint, and a second sealing ring is provided at the connection between the connecting pipe and the outer sleeve.

[0011] Optionally, a pressure sensor is provided on the upper joint for detecting the casing pressure.

[0012] Optionally, a temperature sensor is provided on the plug to detect the exhaust temperature.

[0013] A non-metallic valve core casing gas recovery method comprises the following steps:

[0014] S1. Connect the first end of the upper joint of the device to the oil well casing through a pipeline. The device is vertically inserted into the oil pipe at the wellhead tee of the oil well, and the outer jacket is completely immersed in crude oil;

[0015] S2. When the pressure in the casing is higher than the oil pressure, the casing gas enters the cavity of the connecting pipe through the air inlet, and the casing gas enters the annular space between the outer sleeve and the upper center pipe through the flow hole. The casing gas drives the upper leather cup to contract radially, and a first exhaust channel is formed between the upper leather cup and the outer sleeve. Then, the casing gas drives the lower leather cup to contract radially, and a second exhaust channel is formed between the lower leather cup and the outer sleeve. The casing gas enters the production process through the exhaust hole for mixed transportation;

[0016] S3. When the pressure in the casing is lower than the oil pressure, the back pressure drives the upper and lower cups to open radially, and the exhaust passage is closed to prevent the liquid from flowing back.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention adopts a non-metallic valve core casing gas recovery device. Since the device is inserted into the process, the produced liquid always flushes the device and keeps it warm, which can effectively solve the freezing problem of the device, ensure the normal operation of the device, and improve the exhaust efficiency and reliability.

[0019] 2. The present invention adopts a double-stage leather cup structure, which can effectively prevent liquid backflow and gas leakage, ensure the complete recovery of casing gas, improve the utilization rate of oil and gas resources, and reduce environmental pollution.

[0020] 3. The present invention adopts a detachable plug and an adjustable exhaust hole, which can conveniently inspect, clean and replace the device, and adjust the exhaust volume and speed according to different production conditions and requirements to ensure the safe operation of the oil well.

[0021] 4. The present invention adopts a pressure sensor and a temperature sensor, which can monitor the changes of casing pressure and exhaust temperature in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 This is a structural schematic diagram of a non-metallic valve core sleeve gas recovery device of the present invention.

[0024] Figure 2 It is a schematic flow chart of an embodiment of a non-metallic valve core casing gas recovery method of the present invention.

[0025] Among them: 1-air inlet, 2-upper joint, 3-connecting pipe, 4-jacket, 5-flow hole, 6-upper center tube, 7-upper leather bowl, 8-lower center tube, 9-lower leather bowl, 10-plug, 11-exhaust hole. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0027] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention.

[0028] like Figure 1 As shown, the embodiments of the present invention are further described:

[0029] A non-metallic valve core casing gas recovery device, comprising an upper joint 2, a connecting pipe 3, an outer sleeve 4, an upper leather cup 7, a lower leather cup 9 and a plug 10, wherein the upper joint 2 is provided with a penetrating air inlet 1, and the first end of the upper joint 2 is connected to the oil well casing through a pipeline; the first end of the connecting pipe 3 is detachably connected to the second end of the upper joint 2, the connecting pipe 3 has a cavity, the cavity is connected to the air inlet 1, and the second end of the connecting pipe 3 is provided with a flow hole 5; the first end of the outer sleeve 4 is detachably connected to the outer wall of the connecting pipe 3, and the second end of the connecting pipe 3 is arranged inside the outer sleeve 4 The space, the flow hole 5 is connected with the internal space, a central tube is installed in the center of the internal space of the outer sleeve 4, and a plug 10 is connected to the second end of the outer sleeve 4, and an exhaust hole 11 is provided on the plug 10; the upper leather bowl 7 and the lower leather bowl 9 are respectively mounted on the central tube. Specifically, the large ends of the upper leather bowl 7 and the lower leather bowl 9 face downward, and the roots of the upper leather bowl 7 and the lower leather bowl 9 are respectively vulcanized and mounted on the central tube, and the openings of the upper leather bowl 7 and the lower leather bowl 9 face the plug 10, and are interference fit and sealed with the inner wall of the outer sleeve 4, and the upper leather bowl 7 and the lower leather bowl 9 are made of non-metallic material.

[0030] As a preferred example, the center tube includes an upper center tube 6 and a lower center tube 8, the first end of the upper center tube 6 is threadedly connected to the second end of the connecting tube 3, the second end of the upper center tube 6 is threadedly connected to the lower center tube 8, the upper leather cup 7 is sleeved on the upper center tube 6, and the lower leather cup 9 is sleeved on the lower center tube 8. The specific center tube is used to fix the upper leather cup 7 and the lower leather cup 9.

[0031] As a preferred example, the upper leather cup 7 includes a first fixing portion and a first leather cup portion, the first fixing portion is sleeved on the upper center tube 6, and the lower leather cup 9 includes a second fixing portion and a second leather cup portion, the second fixing portion is sleeved on the lower center tube 8, the first leather cup portion and the second leather cup portion respectively have openings facing the plug 10, and the diameters of the first fixing portion and the second fixing portion are smaller than the inner diameter of the outer sleeve 4. The roots of the upper leather cup 7 and the lower leather cup 9 are the first fixing portion and the second fixing portion, respectively. Specifically, the first fixing portion can be arranged between the first leather cup portion and the upper center tube 6, and the second fixing portion can be arranged between the second leather cup portion and the lower center tube 8. The upper leather cup 7 and the lower leather cup 9 divide the internal space of the outer sleeve 4 into three spaces. The space between the flow hole 5 and the upper leather cup 7 is the first space, the space between the upper leather cup 7 and the lower leather cup 9 is the second space, and the space between the lower leather cup 9 and the exhaust hole 11 is the third space.

[0032] When in use, the device is placed vertically, with the upper joint 2 facing upwards, the first end of the upper joint 2 is connected to the oil well casing or the logging valve through a pipeline, the logging valve is a valve of the existing oil well casing, the device is vertically inserted into the oil pipe at the tee of the oil well wellhead, and the outer jacket 4 at the lower end of the device is completely immersed in crude oil.

[0033] The working process of this device is as follows:

[0034] like Figure 1As shown, in the actual production process, the device is inserted into the production process, that is, inserted into the crude oil, to achieve the effect of heating and antifreezing. When the casing pressure is greater than the oil pipe pressure, the gas enters the cavity of the connecting pipe 3 through the air inlet 1, and enters the annular space between the outer sleeve 4 and the upper center pipe 6 through the flow hole 5, and first enters the first space. When the gas pressure in the first space reaches the pressure threshold of the upper leather cup 7, the upper leather cup 7 is driven to contract radially, and a first exhaust channel is formed between the upper leather cup 7 and the outer sleeve 4, and the gas enters the second space. When the gas pressure in the second space reaches the pressure threshold of the lower leather cup 9, the lower leather cup 9 is driven to contract radially, and a second exhaust channel is formed between the lower leather cup 9 and the outer sleeve 4. The gas is the casing gas, and enters the production process through the exhaust hole 11 for mixed transportation.

[0035] Since the device is inserted into the process, the produced fluid always flushes the device and keeps it warm, thereby achieving the purpose of preventing the device from freezing and blocking. The produced fluid can be crude oil, and the device can be heated by the heat of the crude oil on site. The double-stage leather cup structure composed of the upper leather cup 7 and the lower leather cup 9 can prevent the crude oil from flowing back into the casing.

[0036] After the upper leather bowl 7 and the lower leather bowl 9 are radially contracted, the flow area of ​​the annular space is larger, which alleviates the heat absorption effect, can recover more gas volume, and has a better anti-freezing effect.

[0037] As a preferred example, the upper leather cup 7 and the lower leather cup 9 are made of non-metallic materials. Non-metallic materials have good elasticity, wear resistance and corrosion resistance, can adapt to different temperature, pressure and medium conditions, and ensure the sensitivity and reliability of the valve core.

[0038] As a preferred example, the non-metallic material may be rubber, plastic or silicone. These materials have a high elastic modulus and a low friction coefficient, and can effectively reduce the wear and deformation of the valve core and extend the service life.

[0039] As a specific example, there are multiple flow holes 5 evenly distributed on the side wall of the second end of the connecting pipe 3. Specifically, four flow holes 5 can be provided.

[0040] As a specific example, the first end of the upper center tube 6 is threadedly connected to the second end of the connecting tube 3, and the second end of the upper center tube 6 is threadedly connected to the lower center tube 8. Specifically, the first end of the upper center tube 6 is provided with an external thread, the second end of the connecting tube 3 is provided with an internal thread, and the second end of the upper center tube 6 is threadedly connected to the lower center tube 8.

[0041] As a preferred example, the plug 10 can be detachable. A detachable plug 10 refers to a plug 10 that can be connected or separated from a pipeline or device by threads, flanges or other connection methods, and is used to easily inspect, clean and replace the device. There are many types of detachable plugs 10, and you can choose according to actual needs, as long as you can achieve a self-sealing effect.

[0042] As a preferred example, the exhaust hole 11 may be adjustable. The adjustable exhaust hole 11 refers to an exhaust hole 11 whose size and number can be changed by rotation, sliding or other means, and is used to adjust the exhaust volume and speed according to different production conditions and requirements. There are many types of adjustable exhaust holes 11, which can be selected according to actual needs.

[0043] As a preferred example, the exhaust hole 11 is provided with a filtering device for preventing foreign matter from entering. Specifically, the filtering device may be a filter net.

[0044] As a preferred example, the outer sleeve 4, the upper joint 2, the connecting pipe 3, the upper central pipe 6, the lower central pipe 8 and the plug 10 are made of metal materials. The metal material has good strength, rigidity and high temperature resistance, and can ensure the structural stability and safety of the device.

[0045] As a preferred example, a pressure sensor is provided on the upper joint 2 for detecting the casing pressure. The pressure sensor can monitor the change of casing pressure in real time and transmit the signal to the control system so as to adjust the opening and closing of the exhaust hole 11 in time.

[0046] As a preferred example, a temperature sensor is provided on the plug 10 to detect the exhaust temperature. The temperature sensor can monitor the change of the exhaust temperature in real time and transmit the signal to the control system so as to timely adjust the opening and closing of the exhaust hole 11 to prevent the occurrence of freezing and blocking.

[0047] like Figure 2 As shown, the present invention also provides a non-metallic valve core casing gas recovery method, comprising the following steps:

[0048] S1. Connect the first end of the upper joint 2 of the device to the oil well casing through a pipeline, and vertically insert the device into the oil pipe at the wellhead tee of the oil well, with the outer jacket 4 completely immersed in crude oil;

[0049] Specifically, the air inlet of the upper joint 2 of the device is connected to the pipeline, and the casing gas in the oil well casing can enter the device through the pipeline and the air inlet.

[0050] S2. When the pressure in the casing is higher than the oil pressure, the casing gas enters the cavity of the connecting pipe 3 through the air inlet 1, and the casing gas enters the annular space between the outer sleeve 4 and the upper center pipe 6 through the flow hole 5. The casing gas drives the upper leather cup 7 to contract radially, and a first exhaust channel is formed between the upper leather cup 7 and the outer sleeve 4. Then, the casing gas drives the lower leather cup 9 to contract radially, and a second exhaust channel is formed between the lower leather cup 9 and the outer sleeve 4. The casing gas enters the production process through the exhaust hole 11 for mixed transportation;

[0051] S3. When the pressure in the casing is lower than the oil pressure, the back pressure drives the upper leather cup 7 and the lower leather cup 9 to open radially, and the exhaust passage is closed to prevent the liquid from flowing back.

[0052] The method can realize the complete recovery of casing gas, improve the utilization rate of oil and gas resources, reduce environmental pollution, and prevent liquid backflow to ensure the safe operation of the oil well.

[0053] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A non-metallic valve core casing gas recovery device, characterized in that: include, An upper joint (2), wherein the upper joint (2) is provided with an air inlet (1) extending therethrough, and a first end of the upper joint (2) is connected to an oil well casing via a pipeline; A connecting pipe (3), wherein a first end of the connecting pipe (3) is detachably connected to a second end of the upper joint (2), the connecting pipe (3) is provided with a cavity, the cavity is communicated with the air inlet (1), and a flow hole (5) is provided at the second end of the connecting pipe (3); A jacket (4), wherein a first end of the jacket (4) is detachably connected to an outer wall of the connecting pipe (3), a second end of the connecting pipe (3) is arranged in an internal space of the jacket (4), the flow hole (5) is in communication with the internal space, a central tube is installed at the center of the internal space of the jacket (4), a plug (10) is connected to the second end of the jacket (4), and an exhaust hole (11) is provided on the plug (10); An upper leather bowl (7) and a lower leather bowl (9), wherein the upper leather bowl (7) and the lower leather bowl (9) are respectively mounted on the central tube, the openings of the upper leather bowl (7) and the lower leather bowl (9) face the plug (10), and are sealed by interference fit with the inner wall of the outer sleeve (4), and the upper leather bowl (7) and the lower leather bowl (9) are made of non-metallic material.

2. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: The non-metallic material is rubber, plastic or silicone.

3. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: The center tube comprises an upper center tube (6) and a lower center tube (8), the first end of the upper center tube (6) is threadedly connected to the second end of the connecting tube (3), the second end of the upper center tube (6) is threadedly connected to the lower center tube (8), the upper leather cup (7) is mounted on the upper center tube (6), and the lower leather cup (9) is mounted on the lower center tube (8).

4. A non-metallic valve core casing gas recovery device according to claim 3, characterized in that: The upper leather cup (7) includes a first fixing portion and a first leather cup portion, the first fixing portion is mounted on the upper center tube (6), and the lower leather cup (9) includes a second fixing portion and a second leather cup portion, the second fixing portion is mounted on the lower center tube (8), the first leather cup portion and the second leather cup portion respectively have openings facing the plug (10), and the diameters of the first fixing portion and the second fixing portion are smaller than the inner diameter of the outer sleeve (4).

5. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: There are a plurality of flow holes (5) which are evenly distributed on the side wall of the second end of the connecting pipe (3).

6. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: The exhaust hole (11) is provided with a filtering device for preventing foreign matter from entering.

7. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: A first sealing ring is provided at the connection between the connecting pipe (3) and the upper joint (2), and a second sealing ring is provided at the connection between the connecting pipe (3) and the outer sleeve (4).

8. The non-metallic valve core casing gas recovery device according to claim 1, characterized in that: The upper joint (2) is provided with a pressure sensor for detecting casing pressure.

9. A non-metallic valve core casing gas recovery device according to claim 1, characterized in that: The plug (10) is provided with a temperature sensor for detecting the exhaust gas temperature.

10. A non-metallic valve core casing gas recovery method based on the non-metallic valve core casing gas recovery device according to any one of claims 1 to 9, characterized in that: The following steps are included: S1. Connect the first end of the upper joint (2) of the device to the casing of the oil well through a pipeline, and vertically insert the device into the oil pipe at the tee of the wellhead of the oil well, so that the outer sleeve (4) is completely immersed in crude oil; S2. When the pressure in the casing is higher than the oil pressure, the casing gas enters the cavity of the connecting pipe (3) through the air inlet (1), and the casing gas enters the annular space between the outer sleeve (4) and the upper center tube (6) through the flow hole (5). The casing gas drives the upper leather bowl (7) to contract radially, and a first exhaust channel is formed between the upper leather bowl (7) and the outer sleeve (4). Then, the casing gas drives the lower leather bowl (9) to contract radially, and a second exhaust channel is formed between the lower leather bowl (9) and the outer sleeve (4). The casing gas enters the production process through the exhaust hole (11) for mixing. S3. When the pressure in the sleeve is lower than the oil pressure, the back pressure drives the upper leather cup (7) and the lower leather cup (9) to open radially, and the exhaust passage is closed to prevent the liquid from flowing back.

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