Four-way structure of ultrahigh-pressure tubing head

Abstract

The utility model relates to an ultrahigh pressure tubing head four-way structure, which belongs to the technical field of petroleum drilling wellhead devices and comprises a tubing head four-way body and a tubing hanger mounted inside the tubing head four-way body. A welding flux containing groove is machined in the tubing head four-way joint body, a nickel base alloy layer is arranged in the welding flux containing groove in a surfacing mode, and a 45-degree bearing shoulder is machined on the upper surface of the nickel base alloy layer. An upper flange is installed on the upper portion of the tubing head four-way body. Annular metal sealing pieces are installed between the outer side wall of the tubing hanger and the upper flange and between the outer side wall of the tubing hanger and the inner wall of the tubing head four-way body. The bearing requirement under the working condition of the ultrahigh pressure of 175 MPa can be met, high-performance alloy surfacing is only carried out on the core bearing area, and the manufacturing cost is reduced; the interference self-tightening sealing structure of the metal sealing piece solves the problem that a conventional O-shaped ring and rubber seal are insufficient in pressure resistance, leakage points caused by multiple sealing pieces and a jackscrew structure are reduced, and the sealing reliability under the ultrahigh pressure working condition is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of ultra-high pressure tubing head four-way structure, belong to petroleum drilling wellhead device technical field. BACKGROUND

[0002] In petroleum and natural gas drilling engineering, 6000-8000 meters above deep well exploitation needs to use 175MPa grade ultra-high pressure wellhead device, tubing head four-way as the core component of wellhead device, mainly bear the weight load of tubing hanger and thousands of meters tubing underground, while sealing under ultra-high pressure working condition needs to be realized, to prevent well medium leakage.

[0003] In prior art, conventional tubing head four-way has following two defects:

[0004] 1, tubing head four-way's bearing shoulder is integrally machined from base material, and the mechanical properties of base material are difficult to meet the ultra-large weight bearing requirements of tubing hanger+deep well tubing under 175MPa ultra-high pressure working condition, and the shoulder is prone to deformation and damage, and the use of high-performance alloy for the whole tubing head four-way will lead to a substantial increase in cost, which is difficult to be industrialized.

[0005] 2, the sealing structure of tubing head four-way is mostly O-ring or ordinary rubber seal, and the pressure resistance of such sealing element is limited, which cannot withstand 175MPa ultra-high pressure, and is prone to leakage, and some use multiple sealing element combination or top screw sealing mode, which not only increases the complexity of sealing structure, but also produces multiple leakage points, further reducing the sealing reliability under ultra-high pressure working condition. UTILITY MODEL CONTENTS

[0006] According to the deficiencies in the above prior art, the technical problem to be solved by the utility model is to provide a kind of ultra-high pressure tubing head four-way structure, to realize reliable bearing and sealing under 175Mpa ultra-high pressure, while controlling manufacturing cost.

[0007] The ultra-high pressure tubing head four-way structure, including tubing head four-way body and tubing hanger, tubing hanger is installed in the inside of tubing head four-way body;Welding material containing groove is machined at the bearing position of tubing head four-way body, nickel-based alloy layer is built up welding in welding material containing groove, and 45 ° bearing shoulder cooperating with tubing hanger is machined on the upper surface of nickel-based alloy layer;Annular metal sealing element is installed between the outer wall of tubing hanger and the inner wall of upper flange and tubing head four-way body.

[0008] Preferably, the welding material containing groove is arranged in the shoulder area of tubing head four-way body and tubing hanger cooperation.

[0009] Preferably, the build-up thickness of the nickel-based alloy layer is adapted to the depth of the solder accommodating groove, ensuring the dimensional accuracy and fit of the shoulder.

[0010] Preferably, the metal seal has an H-shaped longitudinal section, with notches on the upper and lower sides, and the notches gradually widen from the middle to the upper and lower ends; the metal seal is in interference fit with the outer wall of the upper end of the tubing hanger, the inner wall of the upper flange, and the inner wall of the tubing head cross body in the initial state; when the pressure between the upper flange and the tubing head cross body gradually increases, the metal seal is elastically deformed and further expanded under high pressure, realizing the close fit of the sealing surface and forming a self-tightening seal; the tubing hanger can realize full sealing through a single metal seal, eliminating the traditional top screw fastening structure, simplifying the sealing structure and reducing leakage points.

[0011] Preferably, the nickel-based alloy layer is an Inconel 625 nickel-based alloy layer, which is a high-performance nickel-based high-temperature alloy with excellent corrosion resistance, oxidation resistance, and high strength, and is widely used in high-end manufacturing fields such as aerospace, chemical industry, and ocean engineering.

[0012] The utility model has the beneficial effects compared with prior art:

[0013] 1、The utility model discloses a welding filler metal accommodating groove is set up in the shoulder area of the tubing head cross body, and a nickel-based alloy layer is locally built up, which improves the mechanical properties of the bearing shoulder, meets the bearing requirements of super large weight under 175MPa super high pressure working condition, and only builds up high-performance alloy in the core bearing area, so that the whole is not made of precious alloy, the manufacturing cost is greatly reduced, and performance and economy are considered.

[0014] 2、The utility model discloses a self-tightening sealing structure of annular metal seal, which realizes sealing in the initial state, and the sealing performance is enhanced with the increase of pressure, can stably meet the sealing requirements of 175MPa super high pressure, and solves the problem of insufficient pressure resistance of conventional O-ring and rubber seal.

[0015] 3、The utility model discloses a tubing hanger that realizes sealing through a single metal seal, cancels the top screw fastening structure, not only simplifies the overall structure of the tubing head, but also completely reduces the leakage points caused by multiple seals and top screw structures, and improves the sealing reliability under super high pressure working condition. DRAWINGS

[0016] Figure 1 It is the structure schematic diagram of the utility model;

[0017] Figure 2 It is the sectional view of the utility model;

[0018] Figure 3is the sectional view of the tubing head cross body without welding nickel-based alloy layer;

[0019] Figure 4 is the structural schematic diagram of the annular metal seal;

[0020] Figure 5 is the structural schematic diagram of the tubing hanger.

[0021] In the figure: 1, upper flange; 2, tubing head cross body; 21, solder accommodating groove; 3, metal seal; 31, notch; 4, tubing hanger; 5, nickel-based alloy layer. DETAILED DESCRIPTION

[0022] The utility model is further explained below in combination with specific embodiments.

[0023] As Figures 1-5 shown, the embodiment is realized by the following technical scheme: including tubing head cross body 2 and tubing hanger 4, tubing hanger 4 is installed inside tubing head cross body 2, the load bearing position of tubing head cross body 2 is processed with solder accommodating groove 21, the outer diameter of solder accommodating groove 21 is 25mm, and the depth is 18mm, nickel-based alloy layer 5 is built up welding in solder accommodating groove 21, the upper surface of nickel-based alloy layer 5 is processed with 45 ° load bearing shoulder that cooperates with tubing hanger 4, the upper portion of tubing head cross body 2 is installed with upper flange 1, and the outer side wall of tubing hanger 4 is installed with annular metal seal 3 between upper flange 1 and the inner wall of tubing head cross body 2.

[0024] In the embodiment, the solder accommodating groove 21 is arranged in the shoulder area of the cooperation of the tubing head cross body 2 and the tubing hanger 4. The build-up welding thickness of the nickel-based alloy layer 5 is adapted to the depth of the solder accommodating groove 21, so as to ensure the dimensional accuracy and the cooperation degree of the shoulder.

[0025] The longitudinal section of the metal seal 3 is H-shaped, the upper and lower sides are provided with notches 31, and the notches 31 gradually widen from the middle to the upper and lower ends; the metal seal 3 is in interference fit with the outer wall of the upper end of the tubing hanger 4, the inner wall of the upper flange 1 and the inner wall of the tubing head cross body 2 in the initial state; when the pressure between the upper flange 1 and the tubing head cross body 2 gradually increases, the metal seal 3 is elastically deformed and further expanded under high pressure, realizing the close fit of the sealing surface and forming a self-tightening seal; the tubing hanger 4 can realize full sealing only through a single metal seal 3, eliminating the traditional top screw fastening structure, simplifying the sealing structure and reducing the leakage points.

[0026] The nickel-based alloy layer 5 is an Inconel 625 nickel-based alloy layer, which is a high-performance nickel-based high-temperature alloy with excellent corrosion resistance, oxidation resistance and high strength, and is widely used in aerospace, chemical industry, marine engineering and other high-end manufacturing fields.

[0027] The manufacturing method of the utility model is:

[0028] In the shoulder area of the tubing head cross body 2 and the tubing hanger 4 cooperation, first processing car out the outer diameter is 25mm, the depth is 18mm's solder accommodation groove 21, then at solder accommodation groove 21 place cladding inconel 625 nickel base alloy layer 5;Again in proper order install tubing hanger 4, metal sealing element 3 and upper flange 1;

[0029] Through nickel base alloy layer 5 carries overweight tubing hanger 4 and its tubing, need not all use high material, can maximum degree reduce cost;When installing, metal sealing element 3 is extruded and is further enlarged by high pressure and occurs elastic deformation, realize and the close fit of the sealing surface between upper flange 1 and tubing head cross body 2, form self-tight type seal, solved the problem of conventional O ring, rubber seal pressure deficiency.

Claims

1. An ultra-high pressure tubing head four-way structure, characterized in that, The oil pipe head cross body (2) and the oil pipe hanger (4) are included, and the oil pipe hanger (4) is installed inside the oil pipe head cross body (2); the bearing position of the oil pipe head cross body (2) is processed with the solder accommodating groove (21), the nickel-based alloy layer (5) is built up welded in the solder accommodating groove (21), and the upper surface of the nickel-based alloy layer (5) is processed with the 45° bearing shoulder matched with the oil pipe hanger (4); the upper flange (1) is installed on the upper part of the oil pipe head cross body (2), and the annular metal sealing element (3) is installed between the outer wall of the oil pipe hanger (4) and the inner wall of the oil pipe head cross body (2) and the upper flange (1); the solder accommodating groove (21) is arranged in the shoulder area matched with the oil pipe hanger (4) of the oil pipe head cross body (2).

2. The ultra-high pressure tubing head four-way structure of claim 1, wherein, The build-up welding thickness of the nickel-based alloy layer (5) is matched with the depth of the solder accommodating groove (21).

3. The ultra-high pressure tubing head four-way structure of claim 1, wherein, The longitudinal section of the metal sealing element (3) is H-shaped, the upper and lower sides are provided with notches (31), and the notches (31) are gradually widened from the middle to the upper and lower ends; the metal sealing element (3) is in interference fit with the outer wall of the upper end of the oil pipe hanger (4), the inner wall of the upper flange (1) and the inner wall of the oil pipe head cross body (2) in the initial state.

4. The ultra-high pressure tubing head four-way structure of claim 1, wherein, The nickel-based alloy layer (5) is the Inconel 625 nickel-based alloy layer.

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