Christmas tree and tubing hanger connecting structure

Abstract

The utility model relates to a Christmas tree and tubing hanger connecting structure. The connecting structure comprises a Christmas tree body, a tubing hanger, a tubing, a first connector and a second connector. A vertical production channel, a horizontal production channel and a tubing hanger mounting channel are arranged in the Christmas tree body; one end of the oil pipe hanger extends into the oil pipe hanger mounting channel and is connected with the Christmas tree body through a first connector, and the other end of the oil pipe hanger extends into a high-pressure well head of the producing well; the second connector is arranged at the butt joint of the Christmas tree body and the high-pressure well head in a sleeving mode and used for connecting the Christmas tree body and the high-pressure well head. The utility model solves the problem that the traditional tubing hanger is fixed on the producing well, and the tubing hanger and the Christmas tree body need to be respectively installed by entering water twice, thereby effectively simplifying the installation process of the Christmas tree, improving the installation efficiency and reducing the installation cost.

Description

Technical Field

[0001] The utility model relates to the field of underwater natural gas drilling equipment, in particular to a connecting structure between a Christmas tree and a tubing hanger. Background Technique

[0002] The underwater Christmas tree is the core equipment for the production and downhole operations of offshore oil and gas fields. It is mainly used to suspend the tubing string lowered into the well, seal the annular space between the tubing and the casing, control and regulate the production of oil wells, ensure operations, oil extraction, casing pressure, testing, paraffin removal and other daily production management work. The underwater Christmas tree is an important hub connecting the oil and gas production tubing string thousands of meters below the seabed and the offshore oil and gas transportation pipeline dozens of kilometers long. Just like the intelligent "water faucet" at the wellhead, it controls the oil and gas production rate and monitors and adjusts the production situation in real time. Therefore, the structure of the underwater Christmas tree is of great significance to oil extraction.

[0003] According to the installation position of the production master valve, the underwater Christmas tree can be divided into a horizontal Christmas tree and a vertical Christmas tree. The production master valve of the horizontal Christmas tree is installed in the horizontal production channel, while the production master valve of the vertical Christmas tree is installed in the vertical production channel. When the tubing hanger is used in cooperation with the vertical Christmas tree, it is generally installed in the production well to suspend 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 oil well production layer; and the channel of the tubing is communicated with the vertical production channel of the vertical Christmas tree to form a part of the production channel of the Christmas tree, improving the pressure control and sealing guarantee ability of the Christmas tree and effectively separating the well fluid from the external environment.

[0004] During the installation process, usually the tubing hanger is first installed into the underwater high-pressure wellhead 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 to check whether the production casing hanger is installed in place before installing the tubing hanger, so as to ensure that after the tubing hanger is installed on the inner casing, its locking mechanism can be locked into the locking groove in 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 consume a large amount of operation time, thus increasing the operation cost. Therefore, installing the tubing hanger and the Christmas tree separately results in a very complex installation process, extremely low installation efficiency, and high installation costs. Content of the Utility Model

[0005] The purpose of the utility model is to overcome the defects of the above-mentioned existing technologies and provide a connecting structure between a Christmas tree and a tubing hanger, which simplifies the installation process and improves the installation efficiency.

[0006] The purpose of the utility model can be realized by the following technical solutions:

[0007] An oil production tree and tubing hanger connection structure, comprising:

[0008] An oil production tree body, in which a vertical production channel, a horizontal production channel and a tubing hanger installation channel are provided. The horizontal production channel communicates with the vertical production channel, and the tubing hanger installation channel communicates with the vertical production channel;

[0009] A tubing hanger and a tubing. A tubing hanger production channel is provided in the tubing hanger. The tubing is installed at the bottom of the tubing hanger and connected to the tubing hanger production channel;

[0010] A first connector. One end of the tubing hanger extends into the tubing hanger installation channel and is connected to the oil production tree body through the first connector. The other end of the tubing hanger extends into the high-pressure wellhead of the oil production well, so that one end of the tubing communicates with the vertical production channel and the other end extends into the oil production well;

[0011] A second connector. The second connector is sleeved at the docking part of the oil production tree body and the high-pressure wellhead for connecting the oil production tree body and the high-pressure wellhead.

[0012] In one embodiment, the first connector includes an inner connector and an outer connector. A connection hole is provided in the inner connector. The tubing hanger passes through the connection hole and is connected to the inner connector. The outer connector is sleeved on the inner connector and connected to the inner connector. The outer connector is threadedly connected to the inner wall of the tubing hanger installation channel.

[0013] In one embodiment, the connection hole of the inner connector includes a first connection hole, a second connection hole and a third connection hole with diameters decreasing sequentially from top to bottom. The tubing hanger includes a first shaft section, a second shaft section and a third shaft section with diameters decreasing sequentially from top to bottom. The first shaft section, the second shaft section and the third shaft section are respectively connected in cooperation with the first connection hole, the second connection hole and the third connection hole. A first sealing ring is provided between the first connection hole and the first shaft section.

[0014] In one embodiment, the third connection hole is a tapered hole with a gradually decreasing diameter, and the third shaft section is a tapered shaft section that cooperates with the third connection hole.

[0015] In one embodiment, a tubing hanger positioning protrusion is provided on the outer surface of the first shaft section, and a tubing hanger positioning groove is provided on the first connection hole. The tubing hanger positioning groove has an opening on the end face 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 diameters increasing sequentially from top to bottom. One end of the first shaft section is fitted and connected to the first installation hole, and the other end of the first shaft section is fitted and connected to the first connection hole. 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 fitted and connected to the second installation hole, and a third sealing ring is provided between the shoulder section and the second installation hole. The outer connector is sleeved on the fixed section and is fitted and connected to the third installation hole.

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

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

[0020] In one embodiment, a production wing valve (121) is provided on the horizontal production channel (12). The connection point of the first annulus channel (14) and the horizontal production channel (12) is located on the side of the production wing valve (121) close to the vertical production channel (11).

[0021] In one embodiment, a completion and workover riser assembly and an emergency release assembly are sequentially connected to one end of the Christmas tree body away from the tubing hanger. The completion and workover riser assembly is used to communicate with the riser.

[0022] Compared with the prior art, the present utility model has the following advantages:

[0023] 1. For the connection structure between the above Christmas tree and the tubing hanger, since the first connector is provided to connect the Christmas tree body and the tubing hanger, and the second connector is provided to connect the Christmas tree body and the high-pressure wellhead, during the installation process, the tubing hanger can be first inserted into the tubing hanger installation channel, so that the tubing hanger and the Christmas tree body are connected into a whole, and then this whole connection structure is lowered together, and the second connector is used to connect the Christmas tree body with the high-pressure wellhead of the oil production well. At this time, one end of the tubing hanger extends into the tubing hanger installation channel, and the other end extends into the wellbore of the oil production well. However, the tubing hanger is mainly fixed on the Christmas tree body by the first connector, and the Christmas tree is fixed on the oil production well by the second connector. Therefore, the Christmas tree body and the tubing hanger can be installed on the drilling platform and then lowered into the water to install the Christmas tree body and the oil production well, solving the problem that the traditional tubing hanger needs to be lowered into the water twice to install the tubing hanger and the Christmas tree body respectively because it is fixed on the oil production well, effectively simplifying the installation process of the Christmas tree and improving the installation efficiency.

[0024] 2. The first connector is provided with an inner connector and an outer connector. First, by connecting the inner connector with the tubing hanger, the rotational degree of freedom of the tubing hanger is fixed. Then, the outer connector is sleeved on the inner connector, and the outer connector is threadedly connected with the Christmas tree body to fix the axial degree of freedom of the tubing hanger. During the installation process, the inner connector and the tubing hanger are installed first, 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, realizing the installation of the tubing hanger and the Christmas tree body, with stable connection and high installation efficiency.

[0025] 3. The inner connector is matched with multiple shaft sections of the tubing hanger with diameters decreasing from top to bottom through connection holes with diameters decreasing from top to bottom, so that the inner connector is connected with the tubing hanger, and the degree of freedom of the tubing hanger moving axially downward relative to the inner connector is fixed. 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. After the tubing hanger positioning protrusion is inserted into the tubing hanger positioning groove from top to bottom, not only the rotational degree of freedom of the tubing hanger relative to the inner connector is fixed, but also the degree of freedom of the tubing hanger moving axially downward relative to the inner connector is further fixed. Moreover, the tubing hanger positioning protrusion and the tubing hanger positioning groove make the positioning during the installation process of the inner connector and the tubing hanger more convenient, improving the installation efficiency.

[0026] 4. The tubing hanger installation channel of the Christmas tree body is provided with multiple installation holes with gradually increasing diameters from top to bottom. A part of the first shaft section of the tubing hanger extends into the first installation hole of the Christmas tree body. At the same time, 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 ensuring the complete butt joint of the tubing inside the tubing hanger and the vertical production channel of the Christmas tree body, and improving the sealing performance of the connection between the tubing hanger and the Christmas tree body.

[0027] 5. Further, the connector positioning protrusion and the connector positioning groove can be used for the installation positioning of the tubing hanger, restricting the rotational freedom of the tubing hanger relative to the Christmas tree body, which is convenient for installation. Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the connection structure between the Christmas tree and the tubing hanger in the present utility model.

[0029] Figure 2 It is a schematic structural diagram of the connection structure between the Christmas tree and the tubing hanger and the oil production well in the present utility model.

[0030] Figure 3 It is a partial enlarged view of the connection structure between the Christmas tree and the tubing hanger in the present utility model.

[0031] Figure 4 It is a schematic structural diagram of the Christmas tree body in the present utility model.

[0032] Figure 5 It is a schematic structural diagram of the tubing hanger in the present utility model.

[0033] Figure 6 It is a schematic structural diagram of the first connector in the present utility model.

[0034] Figure 7 It is a schematic flow diagram of the installation method of the connection structure between the Christmas tree and the tubing hanger in the present invention.

[0035] Figure 8 It is a schematic diagram of installing multiple packers at the bottom of the oil production well in the present invention.

[0036] Figure 9 It is a schematic diagram of using a drilling platform to lower the connection structure between the Christmas tree and the tubing hanger in the present invention.

[0037] Figure 10Schematic diagram of installing the connection structure between the Christmas tree and the tubing hanger to the oil production wellhead in the present invention. Reference numerals: 100, connection structure between the Christmas tree and the tubing hanger; 10, Christmas tree body; 11, vertical production channel; 111, production main valve; 112, first paraffin removal valve; 12, horizontal production channel; 121, production wing valve; 13, tubing hanger installation channel; 131, first installation hole; 132, second installation hole; 1321, connector positioning groove; 133, third installation hole; 14, first annulus channel; 141, second paraffin removal valve; 142, annulus main valve; 143, annulus wing valve; 144, switching valve; 15, emergency release assembly; 16, completion and workover riser assembly; 17, riser; 18, outer tree cap; 20, tubing hanger; 21, tubing hanger production channel; 22, second annulus channel; 23, first shaft section; 231, tubing hanger positioning projection; 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 connection hole; 4111, tubing hanger positioning groove; 412, second connection hole; 413, third connection hole; 414, shoulder section; 4141, connector positioning projection; 415, fixed section; 42, outer connector; 50, oil production well; 51, conductor head; 52, high-pressure wellhead; 53, casing hanger; 54, conductor; 55, surface casing; 56, technical casing; 60, second connector; 70, drilling platform; 71, riser; 72, blowout preventer; 73, packer. Detailed implementation manners

[0038] The following combines the drawings and specific embodiments to describe the present utility model in detail. This embodiment is implemented on the premise of the technical solution of the present utility model, and gives the detailed implementation manners and specific operation processes, but the protection scope of the present utility model is not limited to the following embodiments.

[0039] The following combines the drawings to specifically describe a connection structure 100 between a Christmas tree and a tubing hanger.

[0040] As Figures 1 to 6 , in an embodiment, a connection structure 100 between a Christmas tree and a tubing hanger is provided, including: a Christmas tree body 10, a tubing hanger 20, a tubing 30, a first connector 40, and a second connector 60;

[0041] Among them, a vertical production channel 11, a horizontal production channel 12, and a tubing hanger installation channel 13 are provided inside the Christmas tree body 10. The horizontal production channel 12 communicates with the vertical production channel 11, and the tubing hanger installation channel 13 communicates with the vertical production channel 11; a tubing hanger production channel 21 is provided inside 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;

[0042] 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 a first connector 40. The other end of the tubing hanger 20 extends into the high-pressure wellhead 52 of the production well 50, so that one end of the tubing 30 communicates with the vertical production channel 11 and the other end extends into the production well 50;

[0043] The second connector 60 is sleeved at the docking portion of the Christmas tree body 10 and the high-pressure wellhead 52 for connecting the Christmas tree body 10 and the high-pressure wellhead 52.

[0044] In the above 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 extended into the tubing hanger installation channel 13 to connect the tubing hanger 20 and the Christmas tree body 10 into a whole, and then this whole connection structure is lowered together, and the second connector 60 is used to connect the Christmas tree body 10 and the high-pressure wellhead 52 of the production well 50. 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 production well 50. However, the tubing hanger 20 is mainly fixed on the Christmas tree body 10 by the first connector 40, and the Christmas tree is fixed on the production 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 70 and then lowered into the water to install the Christmas tree body 10 and the production well 50, solving the problem that the traditional tubing hanger 20 needs to be lowered into the water twice to install the tubing hanger 20 and the Christmas tree body 10 respectively, effectively simplifying the installation process of the Christmas tree and improving the installation efficiency.

[0045] Specifically, in one embodiment, the second connector 60 is a claw-type connector, a clamp-type connector, or a bolt-flange connector.

[0046] Specifically, as Figure 5 and Figure 6As shown, in one embodiment, the first connector 40 includes an inner connector 41 and an outer connector 42. A connection hole is provided in the inner connector 41. The tubing hanger 20 passes through the connection 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. The outer connector 42 is threadedly connected to the inner wall of the tubing hanger installation channel 13.

[0047] The first connector 40 is provided with an inner connector 41 and an outer connector 42. First, by connecting the inner connector 41 to the tubing hanger 20, the rotational degree of freedom of the tubing hanger 20 is fixed. 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 degree of freedom of the tubing hanger 20. During the installation process, the inner connector 41 and the tubing hanger 20 are first installed, 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, realizing the installation of the tubing hanger 20 and the Christmas tree body 10, with stable connection and high installation efficiency.

[0048] Further, as Figure 3 , Figure 5 and Figure 6 shown, in one embodiment, the connection hole of the inner connector 41 includes a first connection hole 411, a second connection hole 412, and a third connection hole 413 with diameters decreasing sequentially from top to bottom. The tubing hanger 20 includes a first shaft section 23, a second shaft section 24, and a third shaft section 25 with diameters decreasing sequentially from top to bottom. The first shaft section 23, the second shaft section 24, and the third shaft section 25 are respectively in mating connection with the first connection hole 411, the second connection hole 412, and the third connection hole 413. A first sealing ring 26 is provided between the first connection hole 411 and the first shaft section 23.

[0049] The inner connector 41 is connected to the tubing hanger 20 by means of connection holes with diameters decreasing sequentially from top to bottom and multiple shaft sections of the tubing hanger 20 with diameters decreasing sequentially from top to bottom, so that the connection between the inner connector 41 and the tubing hanger 20 is achieved, and the degree of freedom of the tubing hanger 20 to move axially downward relative to the inner connector 41 is fixed.

[0050] In this specific embodiment, the third connection hole 413 is a tapered hole with a gradually decreasing diameter, and the third shaft section 25 is a tapered shaft section that mates with the third connection 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 of errors.

[0051] Further, as 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, and a tubing hanger positioning groove 4111 is provided on the first connection hole 411. The tubing hanger positioning groove 4111 has an opening on the end face of the inner connector 41, such that the tubing hanger positioning protrusion 231 can be inserted into the tubing hanger positioning groove 4111 from top to bottom. The tubing hanger positioning groove 4111 is provided on the inner connector 41, and the tubing hanger positioning protrusion 231 is provided on the tubing hanger 20. After 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. Moreover, the tubing hanger positioning protrusion 231 and the tubing hanger positioning groove 4111 make the positioning during the installation process of the inner connector 41 and the tubing hanger 20 more convenient, improving the installation efficiency.

[0052] Further, as Figure 3 , Figure 4 and Figure 6 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 diameters gradually increasing from top to bottom. A part of the first shaft section 23 is connected in cooperation with the first installation hole 131, another part of the first shaft section 23 is connected in cooperation with the first connection hole 411, and a second sealing ring 27 is provided between the first shaft section 23 and the first installation hole 131;

[0053] Moreover, the inner connector 41 includes a shoulder section 414 and a fixed section 415 connected from top to bottom. The shoulder section 414 is connected in cooperation with the second installation hole 132, a third sealing ring 28 is provided between the shoulder section 414 and the second installation hole 132, and the outer connector 42 is sleeved on the fixed section 415 and is connected in cooperation with the third installation hole 133.

[0054] The tubing hanger installation channel 13 is provided with a plurality of installation holes with diameters gradually increasing from top to bottom. A part of the first shaft section 23 of the tubing hanger 20 extends into the first installation hole 131 of the Christmas tree body 10. At the same time, 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 beneficial to ensuring the complete butt joint of the tubing 30 inside the tubing hanger 20 and the vertical production channel 11 of the Christmas tree body 10, and improving the sealing performance of the connection between the tubing hanger 20 and the Christmas tree body 10.

[0055] Further, as Figure 3 , Figure 4 and Figure 6As shown, in one embodiment, the shoulder section 414 is provided with a connector positioning protrusion 4141, and the second mounting hole 132 is provided with a connector positioning groove 1321. An opening is provided on one side of the connector positioning groove 1321 facing the third mounting hole 133, such 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 the installation and positioning of the tubing hanger 20, restricting the rotational freedom of the tubing hanger 20 relative to the christmas tree body 10, facilitating installation.

[0056] Specifically, as Figure 1 shown, in one embodiment, one end of the christmas tree body 10 away from the tubing hanger 20 is successively connected with a completion and workover riser assembly 16 and an emergency release assembly 15. The completion and workover riser assembly 16 is used for communicating with the riser 17.

[0057] The completion and workover riser assembly 16 relies on the blowout preventer inside it to provide well control safety functions; the emergency release assembly 15, when emergency release is required in case of emergencies, relies on the connector inside it to provide the function of quickly releasing the riser.

[0058] Generally, during the process of lowering and installing the christmas tree body 10 into the production well 50, one end of the christmas tree body 10 away from the tubing hanger 20 is successively connected with a completion and workover riser assembly 16 and an emergency release assembly 15. The completion and workover riser assembly 16 is used for communicating with the riser 17. After the installation of the christmas tree body 10 is completed, an outer tree cap 18 needs to be set on the christmas tree body 10, which is used to seal the vertical production channel 11 and the first annulus channel 14, preventing 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.

[0059] Specifically, as Figure 1 and Figure 2 shown, in one embodiment, a production main valve 111 and a first paraffin removal valve 112 are provided on the vertical production channel 11. The production main valve 111 is arranged on the lower side of the horizontal production channel 12, and the first paraffin removal valve 112 is arranged on the upper side of the horizontal production channel 12.

[0060] Specifically, as Figure 1 and Figure 2 shown, in one embodiment, a first annulus channel 14 parallel to the vertical production channel is provided inside the christmas tree body 10. The first annulus channel 14 is communicated with the horizontal production channel 12. A second annulus channel 22 is provided inside the tubing hanger 20, and the second annulus channel 22 is communicated with the first annulus channel 14.

[0061] Furthermore, as 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 annulus channel 14 and the horizontal production channel 12 is located on the side of the production wing valve 121 close to the vertical production channel 11.

[0062] Further, as Figure 1 and Figure 2 shown, in one embodiment, the first annulus channel 14 is successively provided with a second paraffin removal valve 141 and an annulus main valve 142 from top to bottom, and an annulus wing valve 143 and a conversion valve 144 are successively provided between the first annulus channel 14 and the horizontal production channel 12. When there is gas leakage during production, the annulus main valve 142, the annulus 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 annulus control channel 14 to ensure production safety.

[0063] Specifically, as Figure 1 and Figure 2 shown, in one embodiment, the oil production well 50 includes a conductor head 51, a high-pressure wellhead 52 and a casing hanger 53 arranged in sequence from the outer layer to the inner layer; wherein the height of the high-pressure wellhead 52 is greater than that of the conductor head 51 and the casing hanger 53 and is used for connecting with the production tree body 10. The conductor head 51, the high-pressure wellhead 52 and the casing hanger 53 are respectively used for connecting the lower conduit 54, surface casing 55 and technical casing 56.

[0064] As Figures 7 to 10 shown, in one embodiment, a method for installing a connection structure 100 between a production tree and a tubing hanger is provided, including the following steps:

[0065] S10: Install a plurality of packers 73 at the bottom of the oil production well 50;

[0066] S20: Dismantle the blowout preventer 72 connected to the wellhead of the oil production well 50;

[0067] S30: Connect the tubing 30 and the tubing hanger 20;

[0068] S40: Connect the tubing hanger 20 and the production tree body 10 through the first connector 40 to form a connection structure 100 between the production tree and the tubing hanger;

[0069] S50: Lower the connection structure between the production tree and the tubing hanger 20 so that the tubing hanger 20 extends into the wellbore of the oil production well 50, and connect the production tree body 10 and the high-pressure wellhead 52 of the oil production well 50 through the second connector 60;

[0070] S60: Recover a plurality of packers 73.

[0071] In the above installation method, during the operation process, first, the tubing hanger 20 and the Christmas tree body 10 are connected into a whole, and then this whole connection structure is lowered together. The Christmas tree body 10 is connected to the high-pressure wellhead 52 of the oil production 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 production well 50. However, the tubing hanger 20 is mainly fixed on the Christmas tree body 10 by the first connector 40, and the Christmas tree is fixed on the oil production 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 lowered into the water to install the Christmas tree body 10 and the oil production well 50, solving the problem that the traditional tubing hanger 20 needs to be lowered into the water twice to install the tubing hanger 20 and the Christmas tree body 10 respectively because it is fixed on the oil production well 50, effectively simplifying the installation process of the Christmas tree and improving the installation efficiency.

[0072] In one embodiment, before step S50, the following steps are further included:

[0073] 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 the riser 17.

[0074] In one embodiment, in step S40, the following specific steps are included:

[0075] Connect the inner connector 41 to the tubing hanger 20 to form a first installation body;

[0076] Connect the first installation body to the Christmas tree body 10;

[0077] Sheath the outer connector 42 on the inner connector 41, and thread-connect the outer connector 42 to the inner wall of the tubing hanger installation channel 13.

[0078] Generally, the connection structure 100 between the Christmas tree and the tubing hanger is lifted into the water by the staff from the drilling platform 70. Before the connection structure 100 is installed, the drilling platform is provided with a riser 71 connected to the blowout preventer 72 to prevent the bottom hole gas from erupting during the well-digging process and improve production safety.

[0079] In one embodiment, before step S10, the following steps are further included:

[0080] Drill the 36” wellbore for the first time;

[0081] Lower the conductor 54 and fix it, and wait for it to solidify;

[0082] Drill the 17 1 / 2” wellbore for the second time;

[0083] Run in the surface casing 55 and fix it, then wait for it to solidify;

[0084] Run in the blowout preventer 72 and install it, then test the well pressure;

[0085] For the third drilling, drill the wellbore;

[0086] Run in the technical casing 56 and fix it, then wait for it to solidify.

[0087] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 construed as a limitation to the present invention.

[0088] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0089] In the present invention, unless otherwise clearly specified and defined, the terms "install", "connect", "couple", "fix", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0090] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the 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, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0091] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0092] The preferred specific embodiments of the present utility model have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present utility model without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present utility model through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A connection structure between a Christmas tree and a tubing hanger, characterized in that, Comprising: A Christmas tree body (10), within which a vertical production channel (11), a horizontal production channel (12) and a tubing hanger installation channel (13) are provided. The horizontal production channel (12) communicates with the vertical production channel (11), and the tubing hanger installation channel (13) communicates with the vertical production channel (11); A tubing hanger (20) and a tubing (30). A tubing hanger production channel (21) is provided within the tubing hanger (20). The tubing (30) is installed at the bottom of the tubing hanger (20) and is 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). The other end of the tubing hanger (20) extends into the high-pressure wellhead (52) of an oil production well (50), such that one end of the tubing (30) communicates with the vertical production channel (11) and the other end extends into the oil production well (50); A second connector (60). The second connector (60) is sleeved at the docking position between the Christmas tree body (10) and the high-pressure wellhead (52) for connecting the Christmas tree body (10) and the high-pressure wellhead (52).

2. The connecting structure between a Christmas tree and a tubing hanger according to claim 1, characterized in that, The first connector (40) includes an inner connector (41) and an outer connector (42). A connection hole is provided within the inner connector (41). The tubing hanger (20) passes through the connection 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). The outer connector (42) is threadedly connected to the inner wall of the tubing hanger installation channel (13).

3. The connecting structure between a Christmas tree and a tubing hanger according to claim 2, wherein, The connection hole of the inner connector (41) includes a first connection hole (411), a second connection hole (412) and a third connection hole (413) with diameters decreasing successively from top to bottom. The tubing hanger (20) includes a first shaft section (23), a second shaft section (24) and a third shaft section (25) with diameters decreasing successively from top to bottom. The first shaft section (23), the second shaft section (24) and the third shaft section (25) are respectively in mating connection with the first connection hole (411), the second connection hole (412) and the third connection hole (413). A first sealing ring (26) is provided between the first connection hole (411) and the first shaft section (23).

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

5. The connecting 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 connection hole (411) is provided with a tubing hanger positioning groove (4111). The tubing hanger positioning groove (4111) has an opening on the end face 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 connecting structure between a Christmas tree and a tubing hanger according to claim 3, characterized in that The tubing hanger installation channel (13) includes a first installation hole (131), a second installation hole (132), and a third installation hole (133) with diameters gradually increasing from top to bottom. One end of the first shaft section (23) is connected to the first installation hole (131) in a matching manner, and the other end of the first shaft section (23) is connected to the first connection hole (411) in a matching manner. A second sealing ring (27) is provided between the first shaft section (23) and the first installation hole (131); The inner connector (41) includes a shoulder section (414) and a fixed section (415) connected from top to bottom. The shoulder section (414) is connected to the second installation hole (132) in a matching manner, and a third sealing ring (28) is provided between the shoulder section (414) and the second installation hole (132). The outer connector (42) is sleeved on the fixed section (415) and is connected to the third installation hole (133) in a matching manner.

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

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

9. A connection structure between a Christmas tree and a tubing hanger according to claim 8, characterized in that, A production wing valve (121) is provided on the horizontal production channel (12). The connection point between the first annulus channel (14) and the horizontal production channel (12) is located on the side of the production wing valve (121) close to the vertical production channel (11).

10. A 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 sequentially connected to a completion and workover riser assembly (16) and an emergency release assembly (15). The completion and workover riser assembly (16) is used to communicate with the riser (17).

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