Control pipeline interface sealing device for 175MPa gas production wellhead

Abstract

The utility model relates to a control pipeline interface sealing device for a 175MPa gas production wellhead, which comprises a drilling and production integrated four-way body, the drilling and production integrated four-way body is provided with a channel for installing an oil pipe hanger, and the inner wall of the channel is fit with the side surface of the oil pipe hanger. The oil pipe hanger is provided with a first through hole for a control pipeline to penetrate through, the drilling and production integrated four-way body is further provided with a second through hole communicated with the channel, each through hole is provided with a plug used for plugging a gap between the control pipeline and the through hole, and each plug is provided with a metal sealing structure used for plugging the gap. The metal sealing structure comprises a metal sealing ring in interference fit. The sealing structure has the advantages of high strength and reliable sealing under high-temperature and high-pressure conditions; and meanwhile, stable shock resistance and impact resistance are achieved so as to adapt to the working conditions of ultra-deep well gas production operation.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of gas production well accessory, especially to a 175MPa gas production wellhead control pipeline interface sealing device. BACKGROUND

[0002] With the improvement of oil and gas exploration and development, more and more ultra-deep wells and other risk exploration wells will be deployed in China. These wells have the characteristics of deep burial, high pressure coefficient, high single-well design production, high wellhead fluid temperature, and even the completion depth exceeding 10000 meters, the formation pressure reaching 175MPa, the formation temperature exceeding 121℃, and the predicted shut-in pressure exceeding 135MPa of ultra-high pressure wells.

[0003] The downhole safety valve is the most critical well control equipment in the entire gas production wellhead equipment, and is also the last line of defense for controlling wellhead safety accidents. In actual operation, the downhole safety valve needs to be controlled by ground hydraulic control equipment, which requires a stable and reliable control pipeline interface sealing device to achieve hydraulic control. The control pipeline interface sealing device in the current domestic gas production wellhead equipment cannot meet the production safety needs of these ultra-deep wells. At the same time, the number of ultra-high pressure, ultra-high temperature, and high impact gas production conditions is also increasing, which can easily cause internal and external sealing failure of the control pipeline interface sealing device, and easily cause well control risks. In order to solve the above problems, it is necessary to develop and design a new control pipeline interface sealing device for gas production wellhead to adapt to the above-mentioned ultra-deep wells. SUMMARY

[0004] The utility model solves the problem of developing and designing a new control pipeline interface sealing device for gas production wellhead to adapt to the ultra-deep well gas production conditions, and provides a 175MPa control pipeline interface sealing device for gas production wellhead to solve the technical problem. The plug and metal sealing structure are configured at the interface position of the control pipeline to adapt to the working conditions of ultra-deep well gas production.

[0005] To solve the above technical problems, the technical scheme of the utility model is as follows:

[0006] A 175MPa control pipeline interface sealing device for gas production wellhead, comprising a drilling and production integrated cross body, the drilling and production integrated cross body is provided with a channel for installing a tubing hanger, the inner wall of the channel is adaptively fitted with the side surface of the tubing hanger, the tubing hanger is provided with a first through hole for the control pipeline to pass through, the drilling and production integrated cross body is also provided with a second through hole communicating with the channel, each through hole is provided with a plug for plugging the gap between the control pipeline and the through hole, the plug is provided with a metal sealing structure for plugging the gap, and the metal sealing structure comprises an interference fit metal sealing ring.

[0007] Preferably, the metal sealing ring is provided with an annular taper surface, and abuts against the plug and / or the through-hole wall through the taper surface.

[0008] Preferably, the taper surface of the metal sealing ring is provided with a counterbore.

[0009] Preferably, the plug in the first through-hole is defined as a first plug, the plug in the second through-hole is defined as a second plug, and a combined sealing packing is further provided between the second plug and the sidewall of the second through-hole, the combined sealing packing comprising polytetrafluoroethylene and a metal compression ring.

[0010] Preferably, the polytetrafluoroethylene of the combined sealing packing is filled with at least five layers, and the metal compression ring is arranged at the pressure-bearing end of the combined sealing packing.

[0011] Preferably, the material of the plug is 718 nickel-based alloy or 925 nickel-based alloy.

[0012] Preferably, the material of the metal sealing ring is 825 nickel-based alloy.

[0013] The beneficial technical effects of the technical scheme of the utility model are as follows:

[0014] (1) The position control pipeline interface and the drilling and production integrated four-way control pipeline interface are both provided with plugs, and the gap at the plug is sealed by a metal sealing ring in an interference fit, which has the advantages of high strength and reliable sealing under high temperature and high pressure, and also has stable anti-shock and impact resistance.

[0015] Thanks to the above technical scheme, the pipeline interface sealing device can adapt to the working conditions of super-deep well gas production, and can realize a pressure-bearing capacity of 175 MPa of the control pipeline interface sealing device, has high strength and reliable sealing under high temperature and high pressure, and also has stable anti-shock and impact resistance, so as to adapt to the working conditions of super-deep well gas production.

[0016] (2) The metal sealing ring is provided with a taper surface, and a counterbore for easy metal deformation is arranged in the taper surface. This design can ensure more reliable metal sealing, and has small installation torque and is convenient for field installation.

[0017] (Three) combined sealing packing is the most important sealing member for preventing leakage of wellhead control pipeline position, and is mainly made of polytetrafluoroethylene and metal compression ring, has high pressure resistance, high temperature resistance and high corrosion resistance, and can work at a pressure of 37500 PSI and a temperature of-29 DEG C to 180 DEG C. The main body is made of high-performance filled polytetrafluoroethylene, the sealing packing is 5-seal, and the sealing reliability of the control pipeline interface position is ensured. The high-performance metal compression ring at the pressure-bearing end can adapt to the impact of superhigh pressure. The initial compression elastic compensation provided by the continuous hand-tightening mode can maintain the pre-compression elastic force in the severe temperature difference and high pressure and high corrosive medium to adapt to the complex working conditions.

[0018] (Four) the plug material is selected from high-strength nickel-based alloy material, and the mechanical property reaches 120K, so that the threaded connection strength requirement under high pressure and high temperature is met. The material has excellent corrosion resistance and high temperature strength. At the same time, it has very good low temperature impact ability, which is far superior to ordinary alloy steel and stainless steel, and is very suitable for use in the working condition under high H2S and CO2 content. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The structure schematic view of the control pipeline interface sealing device for 175MPa gas production wellhead is shown.

[0020] Markings in the drawings:

[0021] 1-drilling and production integrated four-way body; 11-second plug; 111-plug body; 112-sealing plug; 2-tubing hanger; 21-first plug; 3-control pipeline; 4-metal sealing ring; 5-combined sealing packing. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the utility model more clear, the following will make further detailed description of the control pipeline interface sealing device for 175MPa gas production wellhead of the utility model combining with the drawings and specific implementation. According to the following description, the advantages and features of the utility model will be more clear. It should be noted that the drawings are very simplified and all use non-precise proportions, only to facilitate, clear and assist the purpose of explaining the implementation mode of the utility model. In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, please refer to the drawings. It should be known that the structure, proportion, size, etc. shown in the drawings attached to the specification are only used to cooperate with the content disclosed in the specification, so that people skilled in the art can understand and read, and are not used to limit the conditions of the implementation of the utility model, so they do not have the technical essence, any modification of structure, change of proportion relationship or adjustment of size, as long as it does not affect the effect and purpose that can be produced by the utility model, it should still fall within the scope of the technical content disclosed by the utility model.

[0023] The utility model discloses a kind of 175MPa gas production wellhead control pipeline interface sealing devices, which will be described in detail below in conjunction with the drawings of the accompanying Figure 1 And specific embodiment to the technical scheme of the utility model of a kind of 175MPa gas production wellhead control pipeline interface sealing devices.

[0024] Embodiment

[0025] As Figure 1 As shown in the drawing, the utility model discloses a kind of 175MPa gas production wellhead control pipeline interface sealing devices, which will be described in detail below in conjunction with the drawings of the accompanying

[0026] Each of the through holes is provided with a plug for plugging the gap between the control pipeline 3 and the through hole, and each plug is provided with a central hole for the pipeline to pass through. The plug in the first through hole is defined as the first plug 21, and the plug in the second through hole is defined as the second plug 11. Each plug is provided with a metal sealing structure for plugging the gap. The metal sealing structure includes a metal sealing ring 4 that is interference-fitted between the plug and the through hole. The second plug 11 and the side wall of the second through hole are further provided with a combined sealing packing 5, which includes polytetrafluoroethylene and a metal compression ring.

[0027] Specifically, the metal sealing ring 4 of the first plug 21 is sleeved outside the control pipeline 3 and sealed between the first plug 21 and the hole wall of the first through hole. The second plug 11 further includes a plug body 111 for plugging the second through hole and a sealing plug 112 for plugging the gap between the control pipeline 3 and the plug body 111. The metal sealing ring 4 of the second plug 11 is sleeved outside the control pipeline 3 and sealed between the sealing plug 112 and the hole wall of the plug body 111.

[0028] Further, the metal sealing ring 4 is machined with an annular taper surface (not shown in the drawing), which is tightly fitted against the plug and / or the hole wall of the through hole. The taper surface of the metal sealing ring 4 is provided with a counterbore to facilitate deformation of the metal sealing ring 4. This design can ensure more reliable metal sealing, with small installation torque and convenient on-site installation.

[0029] Specifically, the polytetrafluoroethylene of the combined sealing packing 5 is filled with at least five metal compression rings, which are arranged at the pressure-bearing end of the combined sealing packing 5. The combined sealing packing 5 is the most important sealing member for preventing leakage of the wellhead control pipeline 3, and is mainly made of polytetrafluoroethylene and metal compression rings, and has the properties of high pressure resistance, high temperature resistance and high corrosion resistance, and can work at a pressure of up to 37500 PSI and a temperature of up to -29℃ to 180℃. The main body is made of high-performance filled polytetrafluoroethylene, the sealing packing is 5-seal, and the reliability of the sealing of the control pipeline 3 interface position is ensured. The sealing pressure-bearing end adopts a high-performance metal compression ring to adapt to the impact of super-high pressure; and the initial compression elastic compensation provided by the continuous hand-tightening mode can maintain the pre-compression elastic force to adapt to complex working conditions in the case of severe temperature difference and high-pressure and high-corrosion medium.

[0030] The material of the plug is 718 nickel-based alloy or 925 nickel-based alloy, and the material of the metal sealing ring 4 is 825 nickel-based alloy. The control pipeline 3 interface sealing of the tubing hanger 2 adopts a metal sealing form; the control pipeline 3 interface position of the integrated drilling and production four-way body 1 adopts a high-temperature and high-pressure impact-resistant combined sealing packing 5 and a metal seal. The plugs at each interface position are made of 718 or 925 high-strength corrosion-resistant nickel-based alloy material; the metal sealing ring 4 is made of 825 material, and the control pipeline 3 interface sealing device not only has the advantages of high strength and reliable sealing under high temperature and high pressure conditions; but also has stable anti-shock and impact resistance. The above scheme realizes the sealing of the control pipeline 3 and the four-way body, improves the overall compression strength and sealing performance of the product, makes the control pipeline 3 interface sealing device suitable for more severe geological exploration environment, and at the same time ensures safety and reliability during use and easy operation, thereby greatly reducing the well control risk. The control pipeline 3 interface sealing device can be used with a 175MPa gas wellhead, and can meet the use conditions of an ultra-high pressure well with a completion depth of more than 10000 meters, a formation pressure of 175MPa, a formation temperature of more than 121℃, and a predicted shut-in pressure of more than 135MPa.

[0031] The tubing hanger 2 position adopts pure metal sealing, and sufficient metal sealing interference amount needs to be set according to the sealing size. The metal sealing ring 4 adopts a tapered seal.

[0032] The material of the plug is selected from high-strength nickel-based alloy material, and the mechanical property reaches 120K, which meets the screw connection strength requirement under high pressure and high temperature. The material has excellent corrosion resistance and high temperature strength, and also has very good low temperature impact capacity, which is much better than ordinary alloy steel and stainless steel. It is very suitable for use in high H2S and CO2 conditions.

[0033] The two sealing positions of the high-temperature-resistant and impact-resistant control pipeline 3 interface sealing device in the scheme are composed of six parts, the structure is simple, the anti-seismic ability of the control pipeline 3 interface sealing device can be greatly improved, and the device failure caused by wellhead vibration can be reduced. The simple structure is convenient for on-site installation personnel to understand, and convenient for on-site personnel to install, maintain and replace.

[0034] The technical features of the above-described embodiments can be combined in any manner, and to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0035] The above-described embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but it cannot be understood as the limitation of the scope of the utility model patent. It should be pointed out that for ordinary skilled persons in the art, on the premise of not departing from the concept of the utility model, a number of modifications and improvements can be made, which belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A control line interface seal for 175 MPa gas wellheads, characterized by, The drilling and production integrated cross body is provided with a channel for installing a tubing hanger, the inner wall of the channel is adapted to the side of the tubing hanger, the tubing hanger is provided with a first through hole for the control pipeline, the drilling and production integrated cross body is also provided with a second through hole communicating with the channel, each through hole is provided with a plug for plugging the gap between the control pipeline and the through hole, the plug is provided with a metal sealing structure for plugging the gap, and the metal sealing structure comprises an interference fit metal sealing ring.

2. A 175 MPa gas wellhead control line interface seal as defined in claim 1, wherein, The metal sealing ring is provided with an annular taper surface, and the taper surface is adapted to abut against the plug and / or the through hole wall.

3. A 175 MPa gas wellhead control line interface seal as defined in claim 2, wherein, The taper surface of the metal sealing ring is provided with a counterbore.

4. A 175 MPa gas wellhead control line interface seal as defined in claim 1, wherein, The plug in the first through hole is defined as a first plug, and the plug in the second through hole is defined as a second plug, and a combined sealing packing is further arranged between the second plug and the side wall of the second through hole, the combined sealing packing comprises polytetrafluoroethylene and a metal pressing ring.

5. A 175 MPa gas wellhead control line interface seal as defined in claim 4, wherein, The polytetrafluoroethylene of the combined sealing packing is filled with at least five, and the metal pressing ring is arranged at the pressure receiving end of the combined sealing packing.

6. A 175 MPa gas wellhead control line interface seal as defined in claim 1, wherein, The material of the plug is 718 nickel-based alloy or 925 nickel-based alloy.

7. A 175 MPa gas wellhead control line interface seal as defined in claim 1, wherein, The material of the metal sealing ring is 825 nickel-based alloy.

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