A connection structure between a Christmas tree and an oil pipe hanger and an installation method thereof

Abstract

The present invention relates to a connection structure between a Christmas tree and a tubing hanger and an installation method thereof, wherein the connection structure comprises a Christmas tree body, a tubing hanger, an oil pipe, a first connector and a second connector; a vertical production channel, a horizontal production channel and an installation channel for the tubing hanger are arranged in the Christmas tree body; one end of the tubing hanger extends into the installation channel for the tubing hanger and is connected to the Christmas tree body through the first connector, and the other end of the tubing hanger extends into the high-pressure wellhead of the oil production well; the second connector is sleeved at the joint between the Christmas tree body and the high-pressure wellhead and is used to connect the Christmas tree body and the high-pressure wellhead. The present invention solves the problem that the traditional tubing hanger needs to be put into the water twice to install the tubing hanger and the Christmas tree body respectively because it is fixed on the oil production well, thereby effectively simplifying the Christmas tree installation process, improving installation efficiency and reducing installation costs.

Description

Technical Field

[0001] The invention relates to the field of underwater natural gas drilling equipment, and in particular to a connection structure of a Christmas tree and an oil pipe hanger and an installation method thereof. Background Art

[0002] The underwater Christmas tree is the core equipment for offshore oil and gas field production and downhole operations. It is mainly used to hang the oil pipe string in the well, seal the annular space of the oil casing, control and adjust the oil well production, ensure the operation, oil extraction, casing pressure, testing and wax removal and other daily production management work. The underwater Christmas tree is an important hub connecting the oil and gas production pipe string thousands of meters below the seabed and the tens of kilometers of submarine oil and gas transportation pipelines. It is like an intelligent "faucet" at the wellhead, controlling the oil and gas production speed, and real-time monitoring and adjustment of the production situation. Therefore, the structure of the underwater Christmas tree is of great significance to oil production.

[0003] According to the installation position of the production main valve, the underwater Christmas tree can be divided into horizontal Christmas tree and vertical Christmas tree. The production main valve of the horizontal Christmas tree is installed in the horizontal production channel, while the production main valve of the vertical Christmas tree is installed in the vertical production channel. When the tubing hanger is used in conjunction with the vertical Christmas tree, it is generally installed in the oil well to hang the tubing and support the weight of the tubing. After the top of the tubing is connected to the tubing hanger, the bottom of the tubing extends downward to the production layer of the oil well; and the channel of the tubing is connected to the vertical production channel of the vertical Christmas tree, forming a part of the production channel of the Christmas tree, improving the pressure control and sealing guarantee capabilities of the Christmas tree, and effectively isolating the well fluid from the external environment.

[0004] During the installation process, the tubing hanger is usually installed in the underwater high-pressure wellhead first and locked by the locking mechanism; then the tubing is plugged and the blowout preventer is removed before the Christmas tree and the underwater high-pressure wellhead can be connected. At the same time, since the tubing hanger is installed on the production casing hanger of the underwater high-pressure wellhead, a special tool needs to be lowered before installing the tubing hanger to check whether the production casing hanger is installed in place, so as to ensure that after the tubing hanger is installed on the inner casing, its locking mechanism can be locked to the locking groove of the inner cavity of the high-pressure wellhead. When operating in deep-sea oil and gas fields, the lowering and recovery of the inspection tool consumes a lot of operating time, thereby increasing the operating cost. Therefore, installing the tubing hanger and the Christmas tree separately makes the installation process very complicated, the installation efficiency is extremely low, and the installation cost is also high. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a connection structure between a Christmas tree and a tubing hanger and an installation method thereof, so as to simplify the installation process and improve the installation efficiency.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A connection structure between a Christmas tree and an oil pipe hanger, comprising:

[0008] A Christmas tree body, wherein a vertical production channel, a horizontal production channel and a tubing hanger installation channel are provided in the Christmas tree body, wherein the horizontal production channel is communicated with the vertical production channel, and the tubing hanger installation channel is communicated with the vertical production channel;

[0009] A tubing hanger and a tubing, wherein the tubing hanger is provided with a tubing hanger production channel, and the tubing is installed at the bottom of the tubing hanger and connected to the tubing hanger production channel;

[0010] a first connector, wherein one end of the tubing hanger extends into the tubing hanger installation channel and is connected to the Christmas tree body through the first connector, and the other end of the tubing hanger extends into the high-pressure wellhead of the oil production well, so that one end of the oil pipe is connected to the vertical production channel and the other end extends into the oil production well;

[0011] The second connector is sleeved at the joint between the Christmas tree body and the high-pressure wellhead, and is used to connect the Christmas tree body and the high-pressure wellhead.

[0012] In one embodiment, the first connector includes an inner connector and an outer connector, the inner connector is provided with a connecting hole, the tubing hanger is passed through the connecting hole and is connected to the inner connector, the outer connector is sleeved on the inner connector and is connected to the inner connector, and the outer connector is threadedly connected to the inner wall of the tubing hanger mounting channel.

[0013] In one of the embodiments, the connecting hole of the inner connector includes a first connecting hole, a second connecting hole and a third connecting hole whose diameters decrease from top to bottom, and the oil pipe hanger includes a first shaft segment, a second shaft segment and a third shaft segment whose diameters decrease from top to bottom, and the first shaft segment, the second shaft segment and the third shaft segment are respectively matched and connected with the first connecting hole, the second connecting hole and the third connecting hole, and a first sealing ring is provided between the first connecting hole and the first shaft segment.

[0014] In one embodiment, the third connecting hole is a tapered hole with a gradually decreasing diameter, and the third shaft segment is a tapered shaft segment that matches the third connecting hole.

[0015] In one of the embodiments, a tubing hanger positioning protrusion is provided on the outer surface of the first shaft segment, a tubing hanger positioning groove is provided on the first connecting hole, and the tubing hanger positioning groove is provided with an opening on the end surface of the inner connector so that the tubing hanger positioning protrusion can be inserted into the tubing hanger positioning groove from top to bottom.

[0016] In one embodiment, the tubing hanger installation channel includes a first installation hole, a second installation hole and a third installation hole with increasing apertures from top to bottom, one end of the first shaft section is matched and connected with the first installation hole, the other end of the first shaft section is matched and connected with the first connecting hole, and a second sealing ring is provided between the first shaft section and the first installation hole;

[0017] The inner connector includes a shoulder section and a fixed section connected from top to bottom, the shoulder section is cooperatively connected with the second mounting hole, a third sealing ring is provided between the shoulder section and the second mounting hole, and the outer connector is sleeved on the fixed section and cooperatively connected with the third mounting hole.

[0018] In one of the embodiments, the shoulder section is provided with a connector positioning protrusion, the second mounting hole is provided with a connector positioning groove, and the connector positioning groove is provided with an opening on the side facing the third mounting hole, so that the connector positioning protrusion can be inserted into the connector positioning groove from bottom to top.

[0019] In one embodiment, a first annular channel parallel to the vertical production channel is provided in the Christmas tree body, the first annular channel is communicated with the horizontal production channel, and a second annular channel is provided in the tubing hanger, the second annular channel is communicated with the first annular channel.

[0020] In one embodiment, one end of the Christmas tree body away from the tubing hanger is connected in sequence to a completion and workover riser assembly and an emergency release assembly, and the completion and workover riser assembly is used to communicate with the riser.

[0021] A method for installing a connection structure between a Christmas tree and a tubing hanger comprises the following steps:

[0022] S10: installing a plurality of packers at the bottom of the oil well;

[0023] S20: Dismantle the blowout preventer connected to the wellhead of the oil production well;

[0024] S30: Connect the tubing and the tubing hanger;

[0025] S40: Connecting the tubing hanger and the Christmas tree body through a first connector to form a connection structure between the Christmas tree and the tubing hanger;

[0026] S50: lowering the connection structure between the Christmas tree and the tubing hanger so that the tubing hanger extends into the wellbore of the oil production well, and connecting the Christmas tree body and the high-pressure wellhead of the oil production well through the second connector;

[0027] S60: Recover the plurality of packers.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The above-mentioned connection structure between the Christmas tree and the tubing hanger has a first connector for connecting the Christmas tree body and the tubing hanger, and a second connector for connecting the Christmas tree body and the high-pressure wellhead. Therefore, during the installation process, the tubing hanger can be first inserted into the tubing hanger installation channel to connect the tubing hanger and the Christmas tree body into a whole, and then the whole connection structure is lowered together, and the second connector is used to connect the Christmas tree body to the high-pressure wellhead of the oil well. At this time, one end of the tubing hanger is inserted into the tubing hanger installation channel, and the other end is inserted into the wellbore of the oil well. However, the tubing hanger is mainly fixed to the Christmas tree body by the first connector, and the Christmas tree is then fixed to the oil well by the second connector. Therefore, the Christmas tree body and the tubing hanger can be installed on the drilling platform, and then the Christmas tree body and the oil well can be installed in the water, which solves the problem that the traditional tubing hanger needs to be lowered twice to install the tubing hanger and the Christmas tree body respectively because the tubing hanger is fixed on the oil well, effectively simplifies the Christmas tree installation process, and improves the installation efficiency.

[0030] 2. The first connector is provided with an inner connector and an outer connector. First, the rotational freedom of the tubing hanger is fixed by connecting the inner connector with the tubing hanger, and then the outer connector is sleeved on the inner connector, and the outer connector is threadedly connected to the Christmas tree body to fix the axial freedom of the tubing hanger. During the installation process, the inner connector and the tubing hanger are first installed, and then the inner connector and the tubing hanger are installed in the tubing hanger installation channel, and finally the inner connector is sleeved on the outer connector, thereby realizing the installation of the tubing hanger and the Christmas tree body, with stable connection and high installation efficiency.

[0031] 3. The inner connector is matched with a plurality of shaft sections of the tubing hanger whose diameters decrease from top to bottom through a connecting hole whose diameters decrease from top to bottom, so that the inner connector is connected to the tubing hanger, and the tubing hanger is fixed in its axial downward movement freedom relative to the inner connector. At the same time, a tubing hanger positioning groove is provided on the inner connector, and a tubing hanger positioning protrusion is provided on the tubing hanger. When the tubing hanger positioning protrusion is inserted into the tubing hanger positioning groove from top to bottom, not only the rotational freedom of the tubing hanger relative to the inner connector is fixed, but also the axial downward movement freedom of the tubing hanger relative to the inner connector is further fixed. In addition, the tubing hanger positioning protrusion and the tubing hanger positioning groove make the positioning of the inner connector and the tubing hanger during installation more convenient, thereby improving the installation efficiency.

[0032] 4. The tubing hanger installation channel of the Christmas tree body is provided with a plurality of installation holes with apertures increasing from top to bottom. A portion of the first shaft section of the tubing hanger extends into the first installation hole of the Christmas tree body. Meanwhile, a second sealing ring is provided between the first shaft section and the first installation hole, and a third sealing ring is provided between the inner connector and the second installation hole of the Christmas tree body, which is beneficial to ensure that the tubing in the tubing hanger is completely connected with the vertical production channel of the Christmas tree body, thereby improving the sealing performance of the connection between the tubing hanger and the Christmas tree body.

[0033] 5. Furthermore, the connector positioning protrusion and the connector positioning groove can be used for installation and positioning of the tubing hanger, limiting the rotational freedom of the tubing hanger relative to the Christmas tree body, which is convenient for installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the connection structure between the Christmas tree and the tubing hanger in the present invention.

[0035] Figure 2 It is a structural schematic diagram of the connection structure between the Christmas tree and the oil pipe hanger and the oil production well in the present invention.

[0036] Figure 3 It is a partial enlarged view of the connection structure between the Christmas tree and the tubing hanger in the present invention.

[0037] Figure 4 It is a schematic structural diagram of the Christmas tree body in the present invention.

[0038] Figure 5 It is a structural schematic diagram of the oil pipe hanger in the present invention.

[0039] Figure 6 It is a schematic structural diagram of the first connector in the present invention.

[0040] Figure 7 The figure is a flow chart of the method for installing the connection structure between the Christmas tree and the tubing hanger in the present invention.

[0041] Figure 8 It is a schematic diagram of installing multiple packers at the bottom of the oil well in the present invention.

[0042] Fig. 9 This is a schematic diagram of the connection structure between the Christmas tree lowered into the drilling platform and the tubing hanger in the present invention.

[0043] Fig.10 It is a schematic diagram of installing the Christmas tree and the oil pipe hanger connection structure to the oil production wellhead in the present invention.

[0044] 1. The Christmas tree and the tubing hanger connection structure; 2. The Christmas tree body; 3. The vertical production channel; 4. The production main valve; 5. The first wax cleaning valve; 6. The horizontal production channel; 7. The production wing valve; 8. The tubing hanger installation channel; 9. The first installation hole; 10. The second installation hole; 11. The connector positioning groove; 12. The third installation hole; 13. The first annular space channel; 14. The second wax cleaning valve; 14. The annular space main valve; 14. The annular space wing valve; 14. The conversion valve; 15. The emergency release assembly; 16. The completion and workover riser assembly; 17. The riser; 18. The outer tree cap; 20. The tubing hanger; 21. The tubing hanger production channel; 22. The second annular space channel; 23. The first Shaft section; 231, tubing hanger positioning protrusion; 24, second shaft section; 25, third shaft section; 26, first sealing ring; 27, second sealing ring; 28, third sealing ring; 30, tubing; 40, first connector; 41, inner connector; 411, first connecting hole; 4111, tubing hanger positioning groove; 412, second connecting hole; 413, third connecting hole; 414, shaft shoulder section; 4141, connector positioning protrusion; 415, fixing section; 42, outer connector; 50, oil production well; 51, guide tube head; 52, high-pressure wellhead; 53, casing hanger; 54, guide tube; 55, surface casing; 56, technical casing; 60, second connector; 70, drilling platform; 71, riser; 72, blowout preventer; 73, packer. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0046] A connection structure 100 between a Christmas tree and a tubing hanger and an installation method thereof will be described in detail below with reference to the accompanying drawings.

[0047] like Figures 1 to 6 In one embodiment, a connection structure 100 of a Christmas tree and a tubing hanger is provided, comprising: a Christmas tree body 10, a tubing hanger 20 and a tubing 30, a first connector 40 and a second connector 60;

[0048] The Christmas tree body 10 is provided with a vertical production channel 11, a horizontal production channel 12 and a tubing hanger installation channel 13. The horizontal production channel 12 is connected to the vertical production channel 11, and the tubing hanger installation channel 13 is connected to the vertical production channel 11. The tubing hanger 20 is provided with a tubing hanger production channel 21. The tubing 30 is installed at the bottom of the tubing hanger 20 and connected to the tubing hanger production channel 21.

[0049] One end of the tubing hanger 20 extends into the tubing hanger installation channel 13 and is connected to the Christmas tree body 10 through the first connector 40. The other end of the tubing hanger 20 extends into the high-pressure wellhead 52 of the oil production well 50, so that one end of the oil pipe 30 is connected to the vertical production channel 11 and the other end extends into the oil production well 50.

[0050] The second connector 60 is sleeved at the joint between the Christmas tree body 10 and the high-pressure wellhead 52 , and is used to connect the Christmas tree body 10 and the high-pressure wellhead 52 .

[0051] In the connection structure between the Christmas tree and the tubing hanger 20, since the first connector 40 is provided to connect the Christmas tree body 10 and the tubing hanger 20, and the second connector 60 is provided to connect the Christmas tree body 10 and the high-pressure wellhead 52, during the installation process, the tubing hanger 20 can be first inserted into the tubing hanger installation channel 13 to connect the tubing hanger 20 and the Christmas tree body 10 into a whole, and then the whole connection structure is lowered together, and the second connector 60 is used to connect the Christmas tree body 10 to the high-pressure wellhead 52 of the oil production well 50. At this time, one end of the tubing hanger 20 is inserted into the tubing hanger installation channel 13, so that the tubing hanger 20 and the Christmas tree body 10 are connected into a whole. The first connector 40 is used to fix the Christmas tree body 10 to the oil well 50, and the second connector 60 is used to fix the Christmas tree body 10 to the oil well 50. Therefore, the Christmas tree body 10 and the tubing hanger 20 can be installed on the drilling platform 70, and then the Christmas tree body 10 and the oil well 50 can be installed in the water. This solves the problem that the traditional tubing hanger 20 is fixed on the oil well 50, so that the tubing hanger 20 and the Christmas tree body 10 need to be installed in the water twice, which effectively simplifies the Christmas tree installation process and improves the installation efficiency.

[0052] Specifically, in one embodiment, the second connector 60 is a claw-type connector, a clamp-type connector, or a bolt flange-type connector.

[0053] Specifically, Figure 5 and Figure 6 As shown, in one embodiment, the first connector 40 includes an inner connector 41 and an outer connector 42. The inner connector 41 is provided with a connecting hole. The tubing hanger 20 is passed through the connecting hole and connected to the inner connector 41. The outer connector 42 is sleeved on the inner connector 41 and connected to the inner connector 41. The outer connector 42 is threadedly connected to the inner wall of the tubing hanger mounting channel 13.

[0054] The first connector 40 is provided with an inner connector 41 and an outer connector 42. Firstly, the inner connector 41 is connected to the tubing hanger 20 to fix the rotational freedom of the tubing hanger 20, and then the outer connector 42 is sleeved on the inner connector 41, and the outer connector 42 is threadedly connected to the Christmas tree body 10 to fix the axial freedom of the tubing hanger 20. During the installation process, the inner connector 41 and the tubing hanger 20 are first installed, and then the inner connector 41 and the tubing hanger 20 are installed in the tubing hanger installation channel 13, and finally the inner connector 41 is sleeved on the outer connector 42, so that the installation of the tubing hanger 20 and the Christmas tree body 10 is realized, and the connection is stable and the installation efficiency is high.

[0055] Furthermore, if Figure 3 , Figure 5 and Figure 6 As shown, in one embodiment, the connecting holes of the inner connector 41 include a first connecting hole 411, a second connecting hole 412 and a third connecting hole 413 whose diameters decrease from top to bottom, and the tubing hanger 20 includes a first shaft segment 23, a second shaft segment 24 and a third shaft segment 25 whose diameters decrease from top to bottom, and the first shaft segment 23, the second shaft segment 24 and the third shaft segment 25 are respectively matched and connected with the first connecting hole 411, the second connecting hole 412 and the third connecting hole 413, and a first sealing ring 26 is provided between the first connecting hole 411 and the first shaft segment 23.

[0056] The inner connector 41 cooperates with multiple shaft sections of the tubing hanger 20 with diameters decreasing from top to bottom through connecting holes with diameters decreasing from top to bottom, so that the inner connector 41 is connected to the tubing hanger 20, and the freedom of the tubing hanger 20 to move axially downward relative to the inner connector 41 is fixed.

[0057] In this specific embodiment, the third connecting hole 413 is a tapered hole with a gradually decreasing diameter, and the third shaft section 25 is a tapered shaft section that matches the third connecting hole 413. The tapered hole and the tapered shaft section make the connection between the inner connector 41 and the tubing hanger 20 more stable and reliable, and more tolerant to errors.

[0058] Furthermore, if Figure 3 , Figure 5 and Figure 6As shown, in one embodiment, a tubing hanger positioning protrusion 231 is provided on the outer surface of the first shaft section 23, a tubing hanger positioning groove 4111 is provided on the first connecting hole 411, and the tubing hanger positioning groove 4111 is provided with an opening on the end surface of the inner connector 41, so that the tubing hanger positioning protrusion 231 can be inserted into the tubing hanger positioning groove 4111 from top to bottom. A tubing hanger positioning groove 4111 is provided on the inner connector 41, and a tubing hanger positioning protrusion 231 is provided on the tubing hanger 20. When the tubing hanger positioning protrusion 231 is inserted into the tubing hanger positioning groove 4111 from top to bottom, not only the rotational freedom of the tubing hanger 20 relative to the inner connector 41 is fixed, but also the freedom of the tubing hanger 20 to move axially downward relative to the inner connector 41 is further fixed. In addition, the tubing hanger positioning protrusion 231 and the tubing hanger positioning groove 4111 make the positioning of the inner connector 41 and the tubing hanger 20 during the installation process more convenient, thereby improving the installation efficiency.

[0059] Furthermore, if Figure 3 , Figure 4 and Figure 6 As shown, in one embodiment, the tubing hanger installation channel 13 includes a first installation hole 131, a second installation hole 132 and a third installation hole 133 with increasing apertures from top to bottom, a portion of the first shaft section 23 is matched and connected with the first installation hole 131, another portion of the first shaft section 23 is matched and connected with the first connecting hole 411, and a second sealing ring 27 is provided between the first shaft section 23 and the first installation hole 131;

[0060] In addition, the inner connector 41 includes a shoulder section 414 and a fixed section 415 connected from top to bottom, the shoulder section 414 is cooperatively connected to the second mounting hole 132, a third sealing ring 28 is provided between the shoulder section 414 and the second mounting hole 132, and the outer connector 42 is sleeved on the fixed section 415 and cooperatively connected to the third mounting hole 133.

[0061] The tubing hanger installation passage 13 is provided with a plurality of installation holes with apertures increasing from top to bottom. A portion of the first shaft section 23 of the tubing hanger 20 extends into the first installation hole 131 of the Christmas tree body 10. Meanwhile, a second sealing ring 27 is provided between the first shaft section 23 of the tubing hanger 20 and the first installation hole 131 of the Christmas tree body 10, and a third sealing ring 28 is provided between the inner connector 41 and the second installation hole 132, which is conducive to ensuring that the tubing 30 in the tubing hanger 20 is completely connected with the vertical production passage 11 of the Christmas tree body 10, thereby improving the sealing performance of the connection between the tubing hanger 20 and the Christmas tree body 10.

[0062] Furthermore, if Figure 3 , Figure 4 and Figure 6As shown, in one embodiment, the shaft shoulder section 414 is provided with a connector positioning protrusion 4141, the second mounting hole 132 is provided with a connector positioning groove 1321, and the connector positioning groove 1321 is provided with an opening on a side facing the third mounting hole 133, so that the connector positioning protrusion 4141 can be inserted into the connector positioning groove 1321 from bottom to top. The connector positioning protrusion 4141 and the connector positioning groove 1321 can be used for installation and positioning of the tubing hanger 20, limiting the rotational freedom of the tubing hanger 20 relative to the Christmas tree body 10, and facilitating installation.

[0063] Specifically, Figure 1 As shown, in one embodiment, one end of the Christmas tree body 10 away from the tubing hanger 20 is connected in sequence to the completion and workover riser assembly 16 and the emergency release assembly 15 , and the completion and workover riser assembly 16 is used to communicate with the riser 17 .

[0064] The completion and workover riser assembly 16 provides a well control safety function by means of the blowout preventer inside it; the emergency release assembly 15 provides a function of quickly releasing the riser by means of the connector inside it when an emergency event requires emergency release.

[0065] Generally speaking, in the process of lowering and installing the Christmas tree body 10 into the production well 50, the end of the Christmas tree body 10 away from the tubing hanger 20 is connected to the completion and workover riser assembly 16 and the emergency release assembly 15 in sequence, and the completion and workover riser assembly 16 is used to communicate with the riser 17. After the Christmas tree body 10 is installed, the Christmas tree body 10 needs to be provided with an outer tree cap 18, which is used to close the vertical production channel 11 and the first annular channel 14, so as to prevent the top sealing surface of the mandrel of the Christmas tree body and the vertical production channel 11 from being damaged by erosion, marine organisms and external mechanical loads.

[0066] Specifically, Figure 1 and Figure 2 As shown, in one embodiment, a main production valve 111 and a first wax removal valve 112 are provided on the vertical production channel 11 . The main production valve 111 is provided on the lower side of the horizontal production channel 12 , and the first wax removal valve 112 is provided on the upper side of the horizontal production channel 12 .

[0067] Specifically, Figure 1 and Figure 2 As shown, in one embodiment, a first annular passage 14 parallel to the vertical production passage is provided in the Christmas tree body 10, and the first annular passage 14 is communicated with the horizontal production passage 12. A second annular passage 22 is provided in the tubing hanger 20, and the second annular passage 22 is communicated with the first annular passage 14.

[0068] Furthermore, if Figure 1 and Figure 2As shown, in one embodiment, a production wing valve 121 is provided on the horizontal production channel 12 , and the connection between the first annular channel 14 and the horizontal production channel 12 is located on a side of the production wing valve 121 close to the vertical production channel 11 .

[0069] Furthermore, if Figure 1 and Figure 2 As shown, in one embodiment, the first annular space channel 14 is provided with a second wax removal valve 141 and an annular space main valve 142 from top to bottom, and an annular space wing valve 143 and a conversion valve 144 are provided between the first annular space channel 14 and the horizontal production channel 12. When there is gas leakage during the production process, the annular space main valve 142, the annular space wing valve 143 and the conversion valve 144 can be opened to allow the gas to enter the horizontal production channel 12 through the first environmental control channel 14 to ensure production safety.

[0070] Specifically, Figure 1 and Figure 2 As shown, in one embodiment, the oil production well 50 includes a guide tube head 51, a high-pressure well head 52 and a casing hanger 53 arranged in sequence from the outer layer to the inner layer; wherein the high-pressure well head 52 is higher than the guide tube head 51 and the casing hanger 53, and is used to connect with the Christmas tree body 10. The guide tube head 51, the high-pressure well head 52 and the casing hanger 53 are used to connect the guide tube 54 below, the surface casing 55 and the technical casing 56 respectively.

[0071] like Figures 7 to 10 As shown, in one embodiment, a method for installing a connection structure 100 between a Christmas tree and a tubing hanger is provided, comprising the following steps:

[0072] S10: installing a plurality of packers 73 at the bottom of the oil production well 50;

[0073] S20: disassembling the blowout preventer 72 connected to the wellhead of the oil production well 50;

[0074] S30: Connect the tubing 30 and the tubing hanger 20;

[0075] S40: Connecting the tubing hanger 20 and the Christmas tree body 10 through the first connector 40 to form a Christmas tree and tubing hanger connection structure 100;

[0076] S50: lowering the connection structure between the Christmas tree and the tubing hanger 20, so that the tubing hanger 20 extends into the wellbore of the oil production well 50, and connecting the Christmas tree body 10 and the high-pressure wellhead 52 of the oil production well 50 through the second connector 60;

[0077] S60: Recover the plurality of packers 73 .

[0078] In the above installation method, during operation, the tubing hanger 20 and the Christmas tree body 10 are first connected into a whole, and then the whole connection structure is lowered together, and the Christmas tree body 10 is connected to the high-pressure wellhead 52 of the oil well 50 by using the second connector 60. At this time, one end of the tubing hanger 20 extends into the tubing hanger installation channel 13, and the other end extends into the wellbore of the oil well 50. However, the tubing hanger 20 is mainly fixed to the Christmas tree body 10 by the first connector 40, and the Christmas tree is then fixed to the oil well 50 by the second connector 60. Therefore, the Christmas tree body 10 and the tubing hanger 20 can be installed on the drilling platform, and then the Christmas tree body 10 and the oil well 50 can be installed in the water. This solves the problem that the traditional tubing hanger 20 needs to be lowered twice to install the tubing hanger 20 and the Christmas tree body 10 respectively because the tubing hanger 20 is fixed on the oil well 50, effectively simplifies the Christmas tree installation process, and improves the installation efficiency.

[0079] In one embodiment, before step S50, the following steps are also included:

[0080] An emergency release assembly 15 and a completion and workover riser assembly 16 are connected to one end of the Christmas tree body 10 away from the tubing hanger 20 , and the completion and workover riser assembly 16 is connected to a riser 17 .

[0081] In one embodiment, step S40 includes the following specific steps:

[0082] Connecting the inner connector 41 and the tubing hanger 20 to form a first mounting body;

[0083] Connecting the first mounting body to the Christmas tree body 10;

[0084] The outer connector 42 is sleeved on the inner connector 41 , and the outer connector 42 is threadedly connected to the inner wall of the tubing hanger installation passage 13 .

[0085] Generally speaking, the Christmas tree and tubing hanger connection structure 100 is hoisted into the water from the drilling platform 70 by the staff. Before the connection structure 100 is installed, the drilling platform is provided with a riser 71 connected to a blowout preventer 72 to prevent gas from erupting from the bottom of the well during the well digging process and improve production safety.

[0086] In one embodiment, before step S10, the following steps are also included:

[0087] The first drilling was to drill a 36” wellbore;

[0088] The catheter 54 is inserted and fixed, and then waited for solidification;

[0089] The second drilling, drilling 17 1 / 2” borehole;

[0090] The surface casing 55 is lowered and fixed, and then waits for solidification;

[0091] Run the BOP 72 and install it, and test the well pressure;

[0092] The third drilling borehole;

[0093] The technical casing 56 is lowered and fixed, and then waited for solidification.

[0094] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0095] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0096] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0097] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0098] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0099] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A connection structure between a Christmas tree and a tubing hanger, characterized in that: include: A Christmas tree body (10), wherein a vertical production channel (11), a horizontal production channel (12) and a tubing hanger installation channel (13) are provided in the Christmas tree body (10), wherein the horizontal production channel (12) is communicated with the vertical production channel (11), and the tubing hanger installation channel (13) is communicated with the vertical production channel (11); A tubing hanger (20) and a tubing (30), wherein a tubing hanger production channel (21) is provided in the tubing hanger (20), and the tubing (30) is installed at the bottom of the tubing hanger (20) and connected to the tubing hanger production channel (21); A first connector (40), one end of the tubing hanger (20) extends into the tubing hanger installation channel (13), and is connected to the Christmas tree body (10) through the first connector (40), and the other end of the tubing hanger (20) extends into the high-pressure wellhead (52) of the oil production well (50), so that one end of the oil pipe (30) is connected to the vertical production channel (11), and the other end extends into the oil production well (50); The second connector (60) is sleeved at the joint between the Christmas tree body (10) and the high-pressure wellhead (52) and is used to connect the Christmas tree body (10) and the high-pressure wellhead (52).

2. The connection structure between a Christmas tree and a tubing hanger according to claim 1, characterized in that: The first connector (40) comprises an inner connector (41) and an outer connector (42), wherein a connecting hole is provided in the inner connector (41), the tubing hanger (20) is passed through the connecting hole and is connected to the inner connector (41), the outer connector (42) is sleeved on the inner connector (41) and is connected to the inner connector (41), and the outer connector (42) is threadedly connected to the inner wall of the tubing hanger mounting channel (13).

3. The connection structure between a Christmas tree and a tubing hanger according to claim 2, characterized in that: The connection holes of the inner connector (41) include a first connection hole (411), a second connection hole (412) and a third connection hole (413) whose diameters decrease from top to bottom, and the tubing hanger (20) includes a first shaft section (23), a second shaft section (24) and a third shaft section (25) whose diameters decrease from top to bottom, and the first shaft section (23), the second shaft section (24) and the third shaft section (25) are respectively connected to the first connection hole (411), the second connection hole (412) and the third connection hole (413), and a first sealing ring (26) is provided between the first connection hole (411) and the first shaft section (23).

4. The connection structure between a Christmas tree and a tubing hanger according to claim 3, characterized in that: The third connecting hole (413) is a tapered hole with a gradually decreasing diameter, and the third shaft segment (25) is a tapered shaft segment that matches the third connecting hole (413).

5. The connection structure between a Christmas tree and a tubing hanger according to claim 3, characterized in that: The outer surface of the first shaft section (23) is provided with a tubing hanger positioning protrusion (231), and the first connecting hole (411) is provided with a tubing hanger positioning groove (4111), and the tubing hanger positioning groove (4111) is provided with an opening on the end surface of the inner connector (41), so that the tubing hanger positioning protrusion (231) can be inserted into the tubing hanger positioning groove (4111) from top to bottom.

6. The connection structure between a Christmas tree and a tubing hanger according to claim 3, characterized in that: The tubing hanger mounting channel (13) comprises a first mounting hole (131), a second mounting hole (132) and a third mounting hole (133) whose apertures increase in sequence from top to bottom; one end of the first shaft section (23) is cooperatively connected to the first mounting hole (131); the other end of the first shaft section (23) is cooperatively connected to the first connecting hole (411); and a second sealing ring (27) is provided between the first shaft section (23) and the first mounting hole (131); The inner connector (41) comprises a shoulder section (414) and a fixing section (415) connected from top to bottom, the shoulder section (414) is connected in cooperation with the second mounting hole (132), a third sealing ring (28) is provided between the shoulder section (414) and the second mounting hole (132), and the outer connector (42) is sleeved on the fixing section (415) and connected in cooperation with the third mounting hole (133).

7. The connection structure between a Christmas tree and a tubing hanger according to claim 6, characterized in that: The shoulder section (414) is provided with a connector positioning protrusion (4141), the second mounting hole (132) is provided with a connector positioning groove (1321), and the connector positioning groove (1321) is provided with an opening on a side facing the third mounting hole (133), so that the connector positioning protrusion (4141) can be inserted into the connector positioning groove (1321) from bottom to top.

8. The connection structure between a Christmas tree and a tubing hanger according to claim 1, characterized in that: A first annular passage (14) parallel to the vertical production passage is provided in the Christmas tree body (10), and the first annular passage (14) is communicated with the horizontal production passage (12). A second annular passage (22) is provided in the tubing hanger (20), and the second annular passage (22) is communicated with the first annular passage (14).

9. The connection structure between a Christmas tree and a tubing hanger according to claim 1, characterized in that: One end of the Christmas tree body (10) away from the tubing hanger (20) is connected in sequence to a completion and workover riser assembly (16) and an emergency release assembly (15), and the completion and workover riser assembly (16) is used to communicate with a riser (17).

10. A method for installing a connection structure between a Christmas tree and a tubing hanger, characterized in that: The steps include: S10: installing a plurality of packers (73) at the bottom of the oil production well (50); S20: disassembling the blowout preventer (72) connected to the wellhead of the oil production well (50); S30: Connecting the oil pipe (30) and the oil pipe hanger (20); S40: Connecting the tubing hanger (20) and the Christmas tree body (10) via the first connector (40) to form a connection structure between the Christmas tree and the tubing hanger (20); S50: lowering the connection structure between the Christmas tree and the tubing hanger (20) so that the tubing hanger (20) extends into the wellbore of the oil production well (50), and connecting the Christmas tree body (10) and the high-pressure wellhead (52) of the oil production well (50) via the second connector (60); S60: Recover the plurality of packers (73).

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