gas production wellhead

Abstract

The application provides a gas production well head, comprising: a whole valve group having four connection ports in different directions; a main passage having one end connected with one connection port; a tubing head connected with the main passage, the tubing head having a tubing; a connector connected with the tubing head, the central through hole of the connector being divided into a first hole section and a second hole section with different inner diameters, the tubing port being inserted into the second hole section from the opening of the first hole section, and the opening of the second hole section being used for inserting a casing; an adapter ring being replaceably arranged in the second hole section, the adapter ring having an adapter hole with a hole diameter matched with the outer diameters of the tubing and the casing so as to fix the tubing and the casing in the adapter ring; a ring-shaped sealing element abutting against the side of the adapter ring away from the step surface; and a fixing ring arranged on the side of the ring-shaped sealing element away from the adapter ring. The application solves the problem of poor adaptability of the prior art gas production well head and the casing.

Description

Technical Field

[0001] This invention relates to the field of oil and gas development technology, and more specifically, to a gas production wellhead. Background Technology

[0002] In natural gas extraction, a gas production tree (GDK) is typically installed at the wellhead to achieve gas extraction and flow control. The GDK is usually connected to the wellhead by a main pipeline, which has multiple branch lines. These branch lines first connect to the main pipeline, then to the pipeline, and finally transport the natural gas. The main and branch lines of the GDK usually have multiple valves. During maintenance of the GDK, the valves on the main pipeline can be closed, and when maintaining a specific branch line, only the valves on that branch line can be closed. However, current gas production wellheads generally only accommodate a single size of casing to ensure a good seal. Furthermore, existing gas production wellhead structures are relatively large, requiring a separate connection as a section of the wellhead, making them unsuitable for use inside the wellhead.

[0003] In other words, existing technologies suffer from poor compatibility between the gas wellhead and the casing. Summary of the Invention

[0004] The main objective of this invention is to provide a gas production wellhead to solve the problem of poor compatibility between the gas production wellhead and the casing in the prior art.

[0005] To achieve the above objectives, the present invention provides a gas production wellhead, comprising: an integral valve assembly having four connection ports facing different directions, each connection port being equipped with a control valve; a main passage, one end of which is connected to a connection port, and a main control valve being installed on the main passage; a tubing head connected to the other end of the main passage, the tubing head having a tubing extending away from the main passage; and a connector connected to the tubing head, the connector having a central through hole, the central through hole being divided into a first section and a second section with different inner diameters, the wall of the central through hole having a stepped surface to connect the first section and the second section, and the tubing end extending from the opening of the first section into the second section. The second bore section has an opening for inserting a casing to connect it to the tubing. An adapter ring is alternatively disposed within the second bore section, abutting against the stepped surface. The adapter ring has an adapter hole whose diameter matches the outer diameter of the tubing and casing, thus securing them within the adapter ring. An annular seal abuts against the bore wall of the second bore section on its outer surface and against the side of the adapter ring away from the stepped surface. The inner surface of the annular seal abuts against the casing. A retaining ring has its outer surface threaded to the bore wall of the second bore section. The retaining ring is disposed on the side of the annular seal away from the adapter ring, and its inner surface abuts against the casing.

[0006] Furthermore, the gas wellhead also has multiple sealing rings, and the borehole wall of the second section also has multiple spaced annular sealing grooves, with the sealing rings placed inside the annular sealing grooves and matching the size of the annular sealing grooves.

[0007] Furthermore, the adapter ring has an annular notch at one end near the stepped surface, so that an installation space is formed between the outer ring surface of the adapter ring and the connector. The gas wellhead also has an outer ring, which is located within the installation space and abuts against the adapter ring and the connector.

[0008] Furthermore, the gas wellhead also has a sealing sleeve, and the inner ring surface of the outer ring has a sealing groove. The sealing sleeve is set in the sealing groove and matches the size of the sealing groove.

[0009] Furthermore, at least one of the multiple sealing rings abuts against the outer ring to seal the outer ring and the connector.

[0010] Furthermore, the gas wellhead also has multiple sealing rings, and the borehole wall of the adapter hole also has multiple spaced annular sealing grooves. The sealing rings are placed in the annular sealing grooves and match the size of the annular sealing grooves to seal the adapter ring and the casing.

[0011] Furthermore, the adapter ring has an annular flange extending toward the annular seal, and the annular seal has an annular groove at one end facing the adapter ring, with at least a portion of the annular flange extending into and being engaged within the annular groove.

[0012] Furthermore, the retaining ring has an annular protrusion extending toward the annular seal, and the annular seal has an annular recess at one end toward the retaining ring, with at least a portion of the annular protrusion extending into and being engaged within the annular recess.

[0013] Furthermore, the connector has multiple spaced flow channels that extend from the outer wall of the connector along a direction perpendicular to the central axis of the connector. The wellhead also includes multiple pressure testing components, which are arranged one-to-one with the flow channels. The pressure testing components are connected to the end of the flow channel located on the outer wall of the connector to test the sealing performance inside the connector.

[0014] Furthermore, at least one flow channel extends to the outer annular surface of the adapter ring; and / or at least one flow channel extends to the outer annular surface of the annular seal; and / or at least one flow channel extends through the adapter ring via the outer side wall of the connector.

[0015] Applying the technical solution of this invention, the gas wellhead includes an integral valve assembly, a main passage, a tubing head, a connector, an adapter ring, an annular seal, and a fixing ring. The integral valve assembly has four connection ports facing different directions, each equipped with a control valve. One end of the main passage is connected to one connection port, and a main control valve is installed on the main passage. The tubing head is connected to the other end of the main passage, and has tubing extending away from the main passage. The connector is connected to the tubing head and has a central through hole, which is divided into a first section and a second section with different inner diameters. The wall of the central through hole has a stepped surface to connect the first section and the second section. The tubing opening is formed by the first section... An opening extends into the second bore section, the opening of which is used to insert the casing to connect the casing to the tubing. An adapter ring is alternatively disposed within the second bore section, abutting against the stepped surface. The adapter ring has an adapter hole whose diameter matches the outer diameter of the tubing and casing, thus securing the tubing and casing within the adapter ring. The outer ring surface of the annular seal abuts against the bore wall of the second bore section, and the annular seal abuts against the side of the adapter ring away from the stepped surface. The inner ring surface of the annular seal abuts against the casing. The outer ring surface of the retaining ring is threaded to the bore wall of the second bore section. The retaining ring is disposed on the side of the annular seal away from the adapter ring, and the inner ring surface of the retaining ring abuts against the casing.

[0016] The overall valve assembly features four connection ports, enabling multi-path oil and gas delivery. Control valves at these ports control the delivery of oil and gas to each branch. A main passage, connected to one port and equipped with a main control valve, controls whether the produced oil and gas is delivered to other branches. At the other end of the main passage, a tubing head and a connector are sequentially connected. The tubing head contains tubing that extends into the connector and connects to the casing, ensuring unobstructed oil and gas delivery. The connector's central through-hole is divided into a first and second section with different diameters, providing space for an adapter ring and accommodating different outer diameters of tubing and casing. The adapter ring can be interchangeably installed in the second section, with multiple adapter hole diameters available. This means multiple models of adapter rings, each with the same outer diameter but different inner diameters, ensure good compatibility of the gas wellhead with casing of various sizes. By abutting the annular seal against the adapter ring, and simultaneously sleeved over the sleeve, a tight seal between the connector and the sleeve is ensured. Tightening the retaining ring to one end of the annular seal prevents movement between the adapter ring and the annular seal, while also guaranteeing a proper seal. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of the external structure of the gas wellhead according to Embodiment 1 of the present invention is shown;

[0019] Figure 2 It shows Figure 1 A schematic diagram of the internal structure of the connector.

[0020] The above figures include the following reference numerals:

[0021] 10. Integral valve assembly; 11. Connection port; 12. Control valve; 13. Elbow; 14. Branch valve; 20. Main passage; 21. Main control valve; 30. Oil pipe head; 31. Oil pipe; 32. Flat plate valve; 40. Connector; 41. First orifice section; 42. Second orifice section; 43. Stepped surface; 44. Sealing ring; 46. Flow channel; 47. Pressure testing assembly; 50. Adapter ring; 51. Sealing ring; 53. Annular flange; 60. Annular seal; 61. Annular groove; 62. Annular recess; 70. Fixing ring; 71. Annular protrusion; 80. Sleeve; 90. Outer ring; 91. Sealing sleeve. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0024] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0025] To address the problem of poor compatibility between gas wellheads and casings in existing technologies, this invention provides a gas wellhead.

[0026] like Figure 1 and Figure 2As shown, the gas wellhead includes an integral valve assembly 10, a main passage 20, a tubing head 30, a connector 40, an adapter ring 50, an annular seal 60, and a retaining ring 70. The integral valve assembly 10 has four connection ports 11 facing different directions, and each connection port 11 is equipped with a control valve 12. One end of the main passage 20 is connected to one of the connection ports 11, and a main control valve 21 is installed on the main passage 20. The tubing head 30 is connected to the other end of the main passage 20, and the tubing head 30 has a tubing 31 extending away from the main passage 20. The connector 40 is connected to the tubing head 30 and has a central through hole. The central through hole is divided into a first section 41 and a second section 42 with different inner diameters. The wall of the central through hole has a stepped surface 43 to connect the first section 41 and the second section 42. The tubing 31 extends from the opening of the first section 41. The casing 80 is inserted into the second bore section 42, the opening of which is used to extend into the casing 80 so that the casing 80 can be connected to the oil pipe 31. The adapter ring 50 is alternatively disposed in the second bore section 42, abutting against the stepped surface 43. The adapter ring 50 has an adapter hole, the diameter of which is matched with the outer diameter of the oil pipe 31 and the casing 80 so that the oil pipe 31 and the casing 80 are fixed in the adapter ring 50. The outer ring surface of the annular seal 60 abuts against the bore wall surface of the second bore section 42, the annular seal 60 abuts against the side of the adapter ring 50 away from the stepped surface 43, and the inner ring surface of the annular seal 60 abuts against the casing 80. The outer ring surface of the fixing ring 70 is threadedly connected to the bore wall surface of the second bore section 42, the fixing ring 70 is disposed on the side of the annular seal 60 away from the adapter ring 50, and the inner ring surface of the fixing ring 70 abuts against the casing 80.

[0027] The overall valve assembly 10 has four connection ports 11, allowing for multi-channel oil and gas delivery. A control valve 12 is installed at each connection port 11 to control the oil and gas delivery of that branch. A main passage 20 is connected to one connection port 11, and a main control valve 21 is installed on the main passage 20 to control whether the extracted oil and gas is delivered to other branches. At the other end of the main passage 20, an oil pipe head 30 and a connector 40 are sequentially connected. An oil pipe 31 is installed inside the oil pipe head 30, extending into the connector 40 and connecting to the casing 80 to maintain the unobstructed flow of the oil and gas delivery pipeline. By dividing the central through-hole in the connector 40 into a first section 41 and a second section 42 with different diameters, space is provided for the adapter ring 50, which can accommodate different outer diameters of the oil pipe 31 and the casing 80. The adapter ring 50 is replaceably disposed within the second bore section 42, and multiple adapter bore diameters can be provided. In other words, the adapter ring 50 has multiple models, each with the same outer diameter but a different inner diameter, ensuring good compatibility of the gas wellhead with casings 80 of different sizes. By abutting the annular seal 60 against the adapter ring 50 and simultaneously sleeved over the casing 80, the sealing between the connector 40 and the casing 80 is guaranteed. Tightening the retaining ring 70 to one end of the annular seal 60 prevents movement between the adapter ring 50 and the annular seal 60, while also ensuring a good seal.

[0028] It should be noted that in this application, the outer diameter of the oil pipe 31 matches the diameter of the first bore section 41, the outer diameter of the adapter ring 50, the annular seal 60, and the fixing ring 70 matches the diameter of the second bore section 42, the inner diameter of the adapter ring 50, the annular seal 60, and the fixing ring 70 matches the outer diameter of the sleeve 80, the adapter ring 50 abuts against the stepped surface 43, the annular seal 60 abuts against the adapter ring 50, and the fixing ring 70 abuts against the annular seal 60. This can prevent the internal structure from being unstable and causing shaking, and at the same time help to ensure sealing performance.

[0029] Optionally, the annular seal 60 includes one of an H-ring or an O-ring.

[0030] like Figure 1 As shown, the openings of the two connecting ports 11 adjacent to the main passage 20 form an angle greater than 90° with the main passage 20, and each of the two connecting ports 11 adjacent to the main passage 20 is connected to an elbow 13, with the center of the elbow 13 close to the main passage 20. A branch valve 14 is installed at the other end of the elbow 13 to control the flow of oil and gas in that branch. Using the elbow 13 can reduce the direct impact of oil and gas on the pipe wall when flowing from the main passage 20 to other branches while ensuring sealing, thus improving erosion resistance.

[0031] It should be noted that among the control valves 12 on the overall valve assembly 10, the control valve 12 at the connection port 11 connected to the main passage 20 can be a hydraulic valve, while the others are manual valves. The branch valve 14 can be either a hydraulic valve or a manual valve, and the main control valve 21 on the main passage 20 is a manual valve. That is to say, there is at least one manual valve and one hydraulic valve on the vertically or horizontally connected pipelines, so that the oil and gas flow in the passage can be closed by the manual valve when the hydraulic valve fails. Here, the hydraulic valve can be any other automatically controlled valve.

[0032] like Figure 1 As shown, at least two flat valves 32 are provided on each side of the tubing head 30, and both flat valves 32 are manual valves to control the passages connected to both sides of the tubing head 30, thereby improving the safety factor. Generally, double shut-off is required on site, hence the two flat valves 32. The tubing head 30 is symmetrically designed on both sides, allowing relevant on-site operations to be carried out from either the left or right side, facilitating on-site operation.

[0033] It should be noted that both ends of the main passage 20 are connected to the connection port 11 and the oil pipe head 30 via flanges.

[0034] like Figure 2 As shown, the gas wellhead also has multiple sealing rings 44, and the borehole wall of the second section 42 also has multiple spaced annular sealing grooves. The sealing rings 44 are placed in the annular sealing grooves and their dimensions match the annular sealing grooves. The sealing rings 44 can fit against the connector 40 and the adapter ring 50 to ensure their sealing performance.

[0035] Optionally, the sealing ring 44 includes at least one of an H-type metal sealing ring and an O-type sealing ring.

[0036] like Figure 2 As shown, the adapter ring 50 has an annular notch at one end near the stepped surface 43, creating an installation space between the outer annular surface of the adapter ring 50 and the connector 40. The gas wellhead also has an outer ring 90, which is located within the installation space and abuts against the adapter ring 50 and the connector 40. By fitting the outer ring 90 onto the end of the adapter ring 50 near the stepped surface 43, the sealing performance is improved, and minor installation errors are easily adjusted. This avoids difficulties in fully inserting the adapter ring 50 when interference fits are achieved during processing, and also provides a guiding and positioning effect.

[0037] Optionally, the inner ring surface of the outer ring 90 is parallel to the central axis of the second hole segment 42, and the position of the adapter ring 50 mating with the inner ring surface of the outer ring 90 is also parallel to the central axis of the second hole segment 42.

[0038] In a specific embodiment not shown, the inner ring surface of the outer ring 90 is set at an angle to the central axis of the second hole segment 42, so that the inner radial direction of the outer ring 90 gradually decreases towards the step surface 43, and at least a portion of the adapter ring 50 abuts against the step surface 43. At the same time, the adapter ring 50 is also inclined at a certain angle to fit against the inner ring surface of the outer ring 90, so that the two are more convenient to install and connect.

[0039] like Figure 2 As shown, the gas wellhead also has a sealing sleeve 91, and the inner ring surface of the outer ring 90 has a sealing groove. The sealing sleeve 91 is set in the sealing groove and matches the size of the sealing groove. That is to say, the sealing sleeve 91 fits the fitting ring 50 and the outer ring 90 to improve the sealing performance between them.

[0040] It should be noted that the sealing sleeve 91 is relatively small in size to ensure the structural stability of the outer ring 90. Preferably, the length of the sealing sleeve 91 is less than half that of the outer ring 90.

[0041] like Figure 2 As shown, at least one of the plurality of sealing rings 44 abuts against the outer ring 90 to seal the outer ring 90 and the connector 40. The sealing ring 44 can fit against the connector 40 and the outer ring 90 to ensure a tight seal between them.

[0042] like Figure 2 As shown, the gas wellhead also has multiple sealing rings 51, and the wall surface of the adapter hole also has multiple spaced annular sealing grooves. The sealing rings 51 are placed in the annular sealing grooves and match the size of the annular sealing grooves. In other words, the sealing rings 51 are fitted to the adapter rings 50 and the casing 80 to seal the two.

[0043] like Figure 2 As shown, the adapter ring 50 has an annular flange 53 extending into the annular seal 60. The annular seal 60 has an annular groove 61 at one end facing the adapter ring 50. At least a portion of the annular flange 53 extends into and is secured within the annular groove 61. By having the annular flange 53 extend into and be secured within the annular groove 61, movement between the adapter ring 50 and the annular seal 60 is prevented, while also ensuring a tight seal.

[0044] It should be noted that, apart from the part where the annular flange 53 and the annular groove 61 are tightly fitted, the other positions between the adapter ring 50 and the annular seal 60 can be spaced out or fitted together, without affecting the sealing performance between the adapter ring 50 and the annular seal 60.

[0045] like Figure 2As shown, the retaining ring 70 has an annular protrusion 71 extending toward the annular seal 60, and the annular seal 60 has an annular recess 62 at one end facing the retaining ring 70. At least a portion of the annular protrusion 71 extends into and is secured within the annular recess 62. By having the annular protrusion 71 extend into and be secured within the annular recess 62, movement between the retaining ring 70 and the annular seal 60 is prevented, while also ensuring a tight seal.

[0046] It should be noted that, apart from the part where the annular protrusion 71 and the annular recess 62 are tightly pressed together, the other positions between the fixing ring 70 and the annular seal 60 can be spaced out or fitted together, without affecting the sealing performance between the fixing ring 70 and the annular seal 60.

[0047] like Figure 2 As shown, the connector 40 has multiple spaced flow channels 46, which extend from the outer wall of the connector 40 in a direction perpendicular to the central axis of the connector 40. The gas wellhead also includes multiple pressure testing components 47, which are arranged one-to-one with the flow channels 46. The pressure testing components 47 are connected to the end of the flow channel 46 located on the outer wall of the connector 40 to test the sealing performance inside the connector 40. It should be noted that the pressure testing components 47 have good sealing performance and have little to no impact on the sealing performance inside the connector 40, which can be ignored.

[0048] Preferably, at least one flow channel 46 extends to the outer annular surface of the adapter ring 50 in order to test the seal between the adapter ring 50 and the connector 40.

[0049] Preferably, at least one flow channel 46 extends to the outer circumferential surface of the annular seal 60 in order to test the sealing performance between the annular seal 60 and the connector 40.

[0050] Preferably, at least one flow channel 46 extends through the outer wall of the connector 40 to the adapter ring 50, that is, the flow channel 46 extends through the outer wall of the connector 40 to the sleeve 80, so as to test the sealing performance between the sleeve 80, the annular seal 60 and the connector 40.

[0051] It should be noted that both sides of the inwardly extending end of the flow channel 46 have structural components that provide a sealing effect. The pressure testing assembly 47 can test the sealing effect of the structural components that provide a sealing effect adjacent to the flow channel 46. For example, a sealing ring 44 can be provided on each side of the flow channel 46 that extends to the outer annular surface of the adapter ring 50, or a sealing ring 44 and an annular seal 60 can be provided on each side of the flow channel 46; an annular seal 60 can be provided on each side of the flow channel 46 that extends to the outer annular surface of the annular seal 60, or an annular seal 60 and a fixing ring 70 can be provided; a sealing ring 44 can be provided on each side of the flow channel 46 that passes through the adapter ring 50.

[0052] When using the gas wellhead of this application, the matching ring 50 that matches the casing size needs to be installed in place to ensure a sealing effect. Then, the casing is connected and a pressure test is performed. Only after the pressure test is successful can gas production operations be carried out.

[0053] Example 1

[0054] like Figure 1 and Figure 2 As shown, each of the two connectors 40 is provided with two flow channels 46, and the four flow channels 46 have different heights to test the sealing and pressure holding effect at different positions.

[0055] Specifically, a flow channel 46 extends to one end of the outer ring surface of the adapter ring 50 near the outer ring 90, in order to test the sealing effect of the sealing ring 44 on the outer ring 90, the adapter ring 50 and the connector 40.

[0056] Specifically, a flow channel 46 extends to one end of the outer ring surface of the adapter ring 50 near the annular seal 60 in order to test the sealing effect of the sealing ring 44 and the annular seal 60 on the adapter ring 50 and the connector 40.

[0057] Specifically, a flow channel 46 extends through the outer wall of the connector 40 through the adapter ring 50 to test the sealing effect of the sealing ring 44 and the sealing ring 51 on the sleeve 80, the adapter ring 50 and the connector 40.

[0058] Specifically, a flow channel 46 extends to one end of the annular seal 60 near the retaining ring 70 to test the sealing performance between the annular seal 60, the retaining ring 70, and the connector 40.

[0059] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0060] 1. The overall valve group 10 is equipped with four connection ports 11, which can deliver oil and gas in multiple ways. At the same time, a control valve 12 is set at the connection port 11 to control the oil and gas delivery of the branch.

[0061] 2. By connecting the main passage 20 at a connection port 11, and installing a main control valve 21 on the main passage 20, the production oil and gas can be controlled to be transported to other branch lines. At the other end of the main passage 20, an oil pipe head 30 and a connector 40 are connected in sequence. An oil pipe 31 is installed inside the oil pipe head 30 and extends into the connector 40 to connect with the casing 80 to keep the oil and gas transportation pipeline unobstructed.

[0062] 3. By dividing the central through hole in the connector 40 into a first hole section 41 and a second hole section 42 with different diameters, space is provided for the adapter ring 50, and it can also adapt to the different outer diameters of the oil pipe 31 and the casing 80.

[0063] 4. The adapter ring 50 is replaceably disposed within the second bore section 42, and multiple adapter bore diameters can be provided. In other words, the adapter ring 50 has multiple models, each with the same outer diameter but a different inner diameter, ensuring good compatibility of the gas wellhead with casings 80 of different sizes. By abutting the annular seal 60 against the adapter ring 50 and simultaneously sleeved over the casing 80, the sealing between the connector 40 and the casing 80 is guaranteed.

[0064] 5. Tighten the retaining ring 70 to one end of the annular seal 60 to prevent the adapter ring 50 and the annular seal 60 from moving around, while ensuring the sealing effect.

[0065] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0066] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0067] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gas extraction wellhead, characterized in that, include: An integral valve assembly (10) has four connection ports (11) facing four different directions, and each connection port (11) is provided with a control valve (12). A main passage (20) is provided with a main control valve (21) at one end of which is connected to a connection port (11). Oil pipe head (30), the oil pipe head (30) is connected to the other end of the main passage (20), the oil pipe head (30) has an oil pipe (31) extending away from the main passage (20). A connector (40) is connected to the tubing head (30). The connector (40) has a central through hole, which is divided into a first section (41) and a second section (42) with different inner diameters. The wall of the central through hole has a stepped surface (43) to connect the first section (41) and the second section (42). The opening of the tubing (31) extends from the opening of the first section (41) into the second section (42). The opening of the second section (42) is used to insert the casing (80) so that the casing (80) is connected to the tubing (31). An adapter ring (50) is alternatively disposed in the second hole section (42). The adapter ring (50) abuts against the stepped surface (43). The adapter ring (50) has an adapter hole. The diameter of the adapter hole is matched with the outer diameter of the oil pipe (31) and the casing (80) so that the oil pipe (31) and the casing (80) are fixed in the adapter ring (50). The annular seal (60) has an outer ring surface that abuts against the hole wall surface of the second hole segment (42), the annular seal (60) abuts against the side of the adapter ring (50) away from the step surface (43), and the inner ring surface of the annular seal (60) abuts against the sleeve (80). A fixing ring (70) is provided, the outer ring surface of which is threaded to the hole wall of the second hole section (42). The fixing ring (70) is located on the side of the annular seal (60) away from the adapter ring (50). The inner ring surface of the fixing ring (70) abuts against the sleeve (80). The gas wellhead also has multiple sealing rings (44), and the second hole section (42) has multiple spaced annular sealing grooves on its hole wall surface. The sealing rings (44) are placed in the annular sealing grooves and match the size of the annular sealing grooves. The adapter ring (50) has an annular notch at one end near the stepped surface (43) so that an installation space is formed between the outer annular surface of the adapter ring (50) and the connector (40). The gas wellhead also has an outer ring (90), which is located in the installation space and abuts against the adapter ring (50) and the connector (40). The inner ring surface of the outer ring (90) is parallel to the central axis of the second hole segment (42), and the position of the adapter ring (50) mating with the inner ring surface of the outer ring (90) is also parallel to the central axis of the second hole segment (42).

2. The gas wellhead according to claim 1, characterized in that, The gas wellhead also has a sealing sleeve (91), and the inner ring surface of the outer ring (90) also has a sealing groove. The sealing sleeve (91) is set in the sealing groove and matches the size of the sealing groove.

3. The gas wellhead according to claim 1, characterized in that, At least one of the plurality of sealing rings (44) abuts against the outer ring (90) so that the sealing ring (44) seals the outer ring (90) and the connector (40).

4. The gas wellhead according to claim 1, characterized in that, The gas wellhead also has multiple sealing rings (51), and the wall surface of the adapter hole also has multiple spaced annular sealing grooves. The sealing ring (51) is placed in the annular sealing groove and matches the size of the annular sealing groove to seal the adapter ring (50) and the casing (80).

5. The gas wellhead according to claim 1, characterized in that, The adapter ring (50) has an annular flange (53) extending toward the annular seal (60), and the annular seal (60) has an annular groove (61) at one end facing the adapter ring (50), and at least a portion of the annular flange (53) extends into the annular groove (61) and is engaged within the annular groove (61).

6. The gas production wellhead according to any one of claims 1 to 5, characterized in that, The retaining ring (70) has an annular protrusion (71) extending toward the annular seal (60), and the annular seal (60) has an annular recess (62) at one end toward the retaining ring (70). At least a portion of the annular protrusion (71) extends into the annular recess (62) and is engaged within the annular recess (62).

7. The gas wellhead according to any one of claims 1 to 5, characterized in that, The connector (40) has multiple spaced flow channels (46), which extend from the outer side wall of the connector (40) in a direction perpendicular to the central axis of the connector (40). The gas wellhead also includes multiple pressure testing components (47), which are arranged one-to-one with the flow channels (46). The pressure testing components (47) are connected to one end of the flow channel (46) located on the outer side wall of the connector (40) to test the sealing performance inside the connector (40).

8. The gas wellhead according to claim 7, characterized in that, At least one of the flow channels (46) extends to the outer annular surface of the adapter ring (50); and / or At least one of the flow channels (46) extends to the outer annular surface of the annular seal (60); and / or At least one of the flow channels (46) extends through the adapter ring (50) via the outer wall of the connector (40).

Images