An oil production wellhead device with automatic flow regulation

Abstract

The present invention relates to the technical field of oil production wellhead devices, and discloses an oil production wellhead device with automatic flow regulation, which includes a casing head, a tubing head, a Christmas tree and a controller sequentially installed on the top of the wellhead. The Christmas tree includes an adjustable throttle valve. The adjustable throttle valve includes a valve body and a valve cover. A valve seat is installed inside the valve body, and a sealing packing is installed inside the valve body. A valve stem is slidably connected inside the valve cover, and a valve core is fixedly connected to the bottom of the valve stem. An annular groove is formed in the middle of the sealing packing, and a fat-absorbing sponge sleeve is arranged inside the annular groove. An L-shaped fat-adding pipe is symmetrically arranged outside the fat-absorbing sponge sleeve, and a fat-adding mechanism is arranged inside the valve cover. When the valve stem in the present invention moves linearly up and down to change the opening degree between the valve core and the valve seat, the annular piston can move downward to squeeze the grease inside the annular grease storage cavity to achieve self-lubrication of the valve stem, thereby reducing the dynamic friction between the valve stem and the sealing packing.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production wellhead devices, and particularly to an oil production wellhead device with automatic flow regulation. Background Art

[0002] An oil production wellhead device is a series of equipment installed at the wellhead of an oil well during the oil production process. It is used to control and manage the flow of fluids (including crude oil, natural gas, and associated water) from underground to the surface, and is crucial for ensuring safe and efficient oil production. The oil production wellhead device mainly consists of components such as a casing head, a tubing head, and a Christmas tree. The casing head is mainly used to support the tubing head and the Christmas tree. The tubing head is mainly used to suspend the tubing. The Christmas tree is mainly used to control the reservoir pressure and regulate the oil flow rate. Each component is connected using a sealing structure to ensure the safety and reliability of the oil production operation.

[0003] After retrieval, the Chinese invention patent with the publication number CN 101644149 A discloses an integral horizontal oil production wellhead device, which consists of a wellhead body, a tubing hanger, a gas-liquid dynamic safety valve, a throttle valve, a flat valve, a WD casing hanger slip housing, a back slip, a front slip, a sealing baffle, a double C-shaped sealing ring, a BT sealing ring, a plug, an intermediate casing hanger, a completion casing hanger, a steel ring, a reducing flange, a paraffin removal valve, and a Christmas tree cap. The wellhead body is cylindrical, and there are an upper cavity, a middle cavity, and a lower cavity inside the wellhead body. Compared with the prior art, the Chinese invention patent with the publication number CN 101644149 A adopts an integral triple-hanging integral suspension structure, which reduces the height of the wellhead and simplifies the installation procedure. For subsequent workover operations, there is no need to remove the Christmas tree and related connecting pipelines, thus simplifying the subsequent workover operations.

[0004] During the oil production process of the above-mentioned integral horizontal oil production wellhead device, although the throttle valve included in the Christmas tree valve body can automatically adjust the output flow rate of oil according to downhole conditions or production requirements, when adjusting the position of the valve core in the throttle valve, dynamic friction will occur between the valve stem and the packing, that is, frequent adjustment of the valve core position will lead to increased wear between the valve stem and the packing, thereby increasing the risk of device leakage. Therefore, an oil production wellhead device with automatic flow regulation that can reduce dynamic friction (between the valve stem and the packing) is needed. Summary of the Invention

[0005] The purpose of the present invention is to solve the defect that frequent adjustment of the valve core position in the prior art will lead to increased wear between the valve stem and the packing, and to propose an oil production wellhead device with automatic flow regulation.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] An oil production wellhead device with automatic flow regulation, comprising a casing head, a tubing head, a Christmas tree, and a controller connected to the Christmas tree, which are sequentially installed on the top of the wellhead. The Christmas tree includes an adjustable throttle valve for automatically regulating the oil production flow rate. The adjustable throttle valve includes a valve body for encapsulation and a valve cover installed on its top. The side and bottom of the valve body are respectively fixedly connected with an inlet pipe and an outlet pipe. A sensor group is installed inside the inlet pipe. A valve seat extending to the upper part inside the outlet pipe is installed inside the valve body. A sealing packing is installed inside the valve body near the valve cover. A valve stem that slides through the sealing packing and extends into the valve body is slidably connected inside the valve cover. A valve core for sealing the valve seat is fixedly connected to the bottom of the valve stem. An actuator for performing linear motion of the valve stem is arranged outside the valve body;

[0008] An annular groove is formed in the middle of the sealing packing. A suction sponge sleeve sleeved outside the valve stem is arranged inside the annular groove. Symmetrically arranged L-shaped grease filling pipes extending above the sealing packing are arranged outside the suction sponge sleeve. A grease filling mechanism for adding grease into the symmetrically arranged L-shaped grease filling pipes is arranged inside the valve cover. A linkage mechanism linked to the actuator and the grease filling mechanism is arranged on the top of the valve cover.

[0009] The above technical solution further includes:

[0010] The sensor group is connected to the controller and is used to monitor the flow rate, pressure, and temperature inside the inlet pipe. The controller calculates based on a preset algorithm and issues commands to the actuator to work; the flow rate, pressure, and temperature data inside the inlet pipe are the basis for realizing automatic regulation of the oil production flow rate.

[0011] The actuator includes a sealing bearing installed on the top of the valve cover and an actuator motor installed on the top of the valve cover through a mounting bracket. The input end of the actuator motor is connected to the controller, and the output end of the actuator motor is fixedly connected with a rotating threaded rod passing through the sealing bearing;

[0012] The actuator further includes two vertical sliding grooves formed inside the valve cover. Sliders fixedly connected to the valve stem are slidably connected inside the two vertical sliding grooves. A cylindrical groove extending to the top of the valve stem is formed inside the valve stem. An internal thread sleeve threadedly connected to the outside of the rotating threaded rod is fixedly connected inside the cylindrical groove;

[0013] When the actuator motor starts, it can drive the rotating threaded rod to rotate, so that the internal thread sleeve drives the valve stem to move up and down to change the opening degree between the valve core and the valve seat. The linearly moving valve stem can reduce the dynamic friction between the valve stem and the sealing packing when realizing the adjustment of the valve core opening degree.

[0014] The greasing mechanism includes an annular grease storage cavity opened inside the valve cover. An oil injection pipe extending outside the valve cover is arranged outside the annular grease storage cavity. A conical grease injection pipe capable of being inserted into the inside of the L-shaped grease injection pipe is fixedly communicated with the bottom of the annular grease storage cavity in an axisymmetric manner. An annular piston is arranged inside the annular grease storage cavity. A connecting rod passing through the valve cover is fixedly connected to the top of the annular piston in an axisymmetric manner. A connecting ring is fixedly connected to the tops of the axisymmetric connecting rods together; when the connecting ring drives the annular piston to move downward through the axisymmetric connecting rods, the grease inside the annular grease storage cavity can be squeezed into the conical grease injection pipe and the L-shaped grease injection pipe.

[0015] The linkage mechanism includes an inverted U-shaped air pressure pipe and a regular U-shaped air pressure pipe symmetrically and fixedly connected to the top of the valve cover. An annular air pressure pipe is fixedly communicated between the middle of the symmetric inverted U-shaped air pressure pipes and the top of the symmetric regular U-shaped air pressure pipes. Two one-way valves A close to the corresponding inverted U-shaped air pressure pipes are symmetrically installed outside the annular air pressure pipe. One-way valves B are installed outside the symmetric inverted U-shaped air pressure pipes close to the annular air pressure pipe. A piston connecting rod passing through the valve cover is arranged inside one end of each of the symmetric inverted U-shaped air pressure pipes. The two piston connecting rods are respectively fixedly connected to the tops of the two sliders. A piston expansion rod A fixedly connected to the top of the connecting ring is arranged inside the other end of each of the symmetric inverted U-shaped air pressure pipes. A piston expansion rod B fixedly connected to the bottom of the connecting ring is arranged inside one end of each of the symmetric regular U-shaped air pressure pipes far from the annular air pressure pipe; when the valve stem moves up and down to change the opening degree between the valve core and the valve seat, the inside of the inverted U-shaped air pressure pipe can be pressurized with gas and the inside of the annular air pressure pipe and the regular U-shaped air pressure pipe can be decompressed with gas through the piston connecting rod.

[0016] The opposite one-way valves A are all used to allow the air flow inside the annular air pressure pipe to pass in the direction of approaching each other. The one-way valve B is used to allow the air flow inside the corresponding inverted U-shaped air pressure pipe to pass upward; the gas below inside the inverted U-shaped air pressure pipe can pass through the blockage of the opposite one-way valves A and enter the upper part inside the inverted U-shaped air pressure pipe through the one-way valve B. The gas inside the annular air pressure pipe and the regular U-shaped air pressure pipe can pass through the blockage of the one-way valve B and enter the lower part inside the inverted U-shaped air pressure pipe through the opposite one-way valves A.

[0017] The piston expansion rod A and the piston expansion rod B both include a piston outer sleeve and a telescopic inner connecting rod slidably connected inside the piston outer sleeve. The piston outer sleeve is disposed inside the corresponding inverted U-shaped air pressure pipe or inside the corresponding regular U-shaped air pressure pipe. The telescopic inner connecting rod is fixedly connected to the top or the bottom of the connecting ring. Symmetrically arranged driving torque grooves are formed on the inner side of the piston outer sleeve, and symmetrically arranged built-in torque grooves are formed on the outer side of the telescopic inner connecting rod. A connecting spring is fixedly connected inside the built-in torque groove, and a driving torque block fixedly connected to the connecting spring is slidably connected inside the built-in torque groove. The driving torque block can enter the inside of the driving torque groove, and the bottom surface of the driving torque block is set as an abutting inclined surface. The piston outer sleeve included in the piston expansion rod A can drive the torque block to move downward through the driving torque groove, and the telescopic inner connecting rod can be extended through the driving torque groove, the abutting inclined surface, and the driving torque block. The piston outer sleeve included in the piston expansion rod B can drive the torque block to move downward through the driving torque groove and the driving torque block, and the telescopic inner connecting rod can be shortened through the driving torque groove, the abutting inclined surface, and the driving torque block.

[0018] The symmetric piston expansion rod A can drive the connecting ring to move downward and can drive the piston expansion rod B to shorten. The symmetric piston expansion rod B can drive the connecting ring to move downward and can drive the piston expansion rod A to extend. That is, when the valve stem moves up and down to change the opening degree between the valve core and the valve seat, the annular piston can be driven to move downward to squeeze the lubricating grease inside the annular grease storage cavity, so as to realize the self-lubrication of the valve stem.

[0019] The present invention has the following beneficial effects:

[0020] 1. In the present invention, a sensor group installed inside the oil inlet pipe is used to monitor the flow rate, pressure, and temperature of the internal oil body. The controller receives data from the sensor group and can calculate the optimal opening degree of the valve core based on a preset algorithm to send an instruction to the actuating motor, so that the actuating motor drives the rotating threaded rod to rotate, so that the valve stem performs linear up and down movement, thereby changing the opening degree between the valve core and the valve seat. In this way, the function of automatically adjusting the oil production flow rate according to downhole conditions or production requirements can be realized.

[0021] 2. In the present invention, the rotational movement of the rotating threaded rod is converted into the linear movement of the valve stem, avoiding the need for the valve stem to overcome the linear friction and rotational friction with the sealing packing when the rotating threaded rod is directly connected to the valve stem to adjust the opening degree of the valve core. That is, the linear movement of the valve stem to realize the adjustment of the opening degree of the valve core can reduce the dynamic friction between the valve stem and the sealing packing, thereby reducing the risk of device leakage. Moreover, the self-locking effect between the rotating threaded rod and the internal thread sleeve can ensure the stability of the valve core position, so as to avoid fluctuations of the valve core affecting the sealing performance of the device.

[0022] 3. When the valve stem moves upward in the present invention to increase the opening degree between the valve core and the valve seat, the piston expansion rod A can drive the annular piston to move downward to extrude the grease inside the annular grease storage cavity. At the same time, the piston expansion rod B shortens. When the valve stem moves downward to reduce the opening degree between the valve core and the valve seat, the piston expansion rod B can drive the annular piston to move downward to extrude the grease inside the annular grease storage cavity. At the same time, the piston expansion rod A elongates. That is, when the valve stem makes a linear up-and-down movement to change the opening degree between the valve core and the valve seat, it can make the annular piston move downward to extrude the grease inside the annular grease storage cavity to achieve self-lubrication of the valve stem, thereby reducing the dynamic friction between the valve stem and the packing. Brief Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of an oil production wellhead device with automatic flow regulation proposed by the present invention;

[0024] Figure 2 is Figure 1 the external structural schematic diagram of the adjustable throttle valve in

[0025] Figure 3 is Figure 1 the internal structural schematic diagram of the adjustable throttle valve in

[0026] Figure 4 is a schematic structural diagram of the valve body and the valve cover in the present invention;

[0027] Figure 5 is a schematic structural diagram of the linkage mechanism in the present invention;

[0028] Figure 6 is a schematic structural diagram of the piston expansion rod A and the piston expansion rod B in the present invention;

[0029] Figure 7 is Figure 6 the enlarged schematic diagram of the structure at position A in

[0030] Figure 8 is Figure 6 the enlarged schematic diagram of the structure at position B in

[0031] Figure 9 is a schematic structural diagram of the adjustable throttle valve in the present invention in a semi-open state;

[0032] Figure 10 is Figure 9 the enlarged schematic diagram of the structure at position C in

[0033] In the figure: 100, wellhead; 200, casing head; 300, tubing head; 400, Christmas tree; 410, adjustable throttle valve; 411, valve body; 412, valve cover; 413, inlet pipe; 414, outlet pipe; 415, sensor group; 416, valve seat; 417, sealing packing; 418, valve stem; 419, valve core; 420, actuator; 421, sealing bearing; 422, mounting bracket; 423, actuator motor; 424, rotating threaded rod; 425, vertical chute; 426, slider; 427, cylindrical groove; 428, internal thread sleeve; 430, annular groove; 440, fat-absorbing sponge sleeve; 450, L-shaped fat-adding pipe; 460, fat-adding mechanism; 461, annular grease storage cavity; 462, grease injection pipe; 463, conical fat-adding pipe; 464, annular piston; 465, connecting rod; 466, connecting ring; 470, linkage mechanism; 471, inverted U-shaped air pressure pipe; 472, regular U-shaped air pressure pipe; 473, annular air pressure pipe; 474, check valve A; 475, check valve B; 476, piston connecting rod; 477, piston expansion rod A; 478, piston expansion rod B; 479, piston outer sleeve; 480, telescopic inner connecting rod; 481, driving torque groove; 482, built-in torque groove; 483, connecting spring; 484, driving torque block; 485, abutting inclined surface. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention. Embodiment

[0035] Such as Figures 1-4 And Figures 9-10As shown in the figure, an oil production wellhead device with automatic flow regulation proposed by the present invention includes a casing head 200, a tubing head 300, a Christmas tree 400, and a controller connected to the Christmas tree 400, which are sequentially installed on the top of the wellhead 100. The casing head 200 is mainly used to support the tubing head 300 and the Christmas tree 400. The tubing head 300 is mainly used to suspend the tubing. The Christmas tree 400 is mainly used to control the reservoir pressure and regulate the oil flow rate. The wellhead 100, the casing head 200, the tubing head 300, and the Christmas tree 400 are connected by a sealing structure to ensure the safety and reliability of the oil production operation. The controller calculates based on a preset algorithm and can issue commands to the actuator 420 to work. The controller can calculate the optimal opening of the adjustable throttle valve 410 based on a preset algorithm (such as PID control). The specific structures and connection methods of the wellhead 100, the casing head 200, the tubing head 300, the Christmas tree 400, and the controller all adopt existing technologies. Therefore, they are not elaborated in this embodiment;

[0036] The Christmas tree 400 includes an adjustable throttle valve 410 for automatically regulating the oil production flow rate. The adjustable throttle valve 410 includes a valve body 411 for encapsulation and a valve cover 412 installed on its top. A feed pipe 413 and a discharge pipe 414 are respectively fixedly connected to the side and bottom of the valve body 411. A sensor group 415 is installed inside the feed pipe 413, and the sensor group 415 is connected to the controller and used to monitor the flow rate, pressure, and temperature inside the feed pipe 413. The flow rate, pressure, and temperature data inside the feed pipe 413 are the basis for realizing the automatic regulation of the oil production flow rate. A valve seat 416 extending to the upper part inside the discharge pipe 414 is installed inside the valve body 411. A sealing packing 417 close to the valve cover 412 is installed inside the valve body 411. The sealing packing 417 needs to have good temperature resistance, pressure resistance, and corrosion resistance. A valve stem 418 that slides through the sealing packing 417 and extends into the inside of the valve body 411 is slidably connected inside the valve cover 412. The valve stem 418 can perform linear motion inside the sealing packing 417, thereby reducing the dynamic friction between the valve stem 418 and the sealing packing 417. A valve core 419 for sealing the valve seat 416 is fixedly connected to the bottom of the sealing valve stem 418. The larger the opening between the valve core 419 and the valve seat 416, the greater the oil flow rate through the discharge pipe 414. Conversely, the smaller the oil flow rate through the discharge pipe 414;

[0037] An actuator 420 for performing linear motion of the valve stem 418 is provided outside the valve body 411. The actuator 420 includes a sealing bearing 421 installed on the top of the valve cover 412 and an actuator motor 423 installed on the top of the valve cover 412 through a mounting bracket 422. The input end of the actuator motor 423 is connected to the controller. After receiving data from the sensor group 415, the controller can calculate the optimal opening degree of the valve core 419 based on a preset algorithm and issue an instruction to the actuator motor 423. The output end of the actuator motor 423 is fixedly connected to a rotating threaded rod 424 passing through the sealing bearing 421. The actuator 420 further includes two vertical chutes 425 opened inside the valve cover 412. A slider 426 fixedly connected to the valve stem 418 is slidably connected inside the two vertical chutes 425. A cylindrical groove 427 extending to the top of the valve stem 418 is opened inside the valve stem 418. An internal thread sleeve 428 threadedly connected to the outside of the rotating threaded rod 424 is fixedly connected inside the cylindrical groove 427. The self-locking effect between the rotating threaded rod 424 and the internal thread sleeve 428 can ensure the stability of the position of the valve core 419 and prevent the valve core 419 from fluctuating and affecting the sealing performance. When the actuator motor 423 is started, it can drive the rotating threaded rod 424 to rotate, so that the internal thread sleeve 428 drives the valve stem 418 to move up and down linearly, thereby changing the opening degree between the valve core 419 and the valve seat 416.

[0038] The working principle of this embodiment is as follows: As Figure 9 shown, when the valve core 419 in the adjustable throttle valve 410 is in a semi-open state, the sensor group 415 installed inside the oil inlet pipe 413 can monitor the flow rate, pressure and temperature of the oil body inside the oil inlet pipe 413 and transmit the data information to the controller. After receiving the data from the sensor group 415, the controller can calculate the optimal opening degree of the valve core 419 based on a preset algorithm and issue an instruction to the actuator motor 423. The actuator motor 423 drives the rotating threaded rod 424 to rotate after receiving the instruction, so that the internal thread sleeve 428 drives the valve stem 418 to perform linear up and down motion (during this process, the two sliders 426 connected to the outside of the valve stem 418 slide inside the two vertical chutes 425 respectively), thereby changing the opening degree between the valve core 419 and the valve seat 416. The larger the opening degree between the valve core 419 and the valve seat 416, the larger the oil body flow rate through the oil outlet pipe 414, and vice versa, the smaller the oil body flow rate through the oil outlet pipe 414. In this way, the function of automatically adjusting the oil production flow rate according to downhole conditions or production requirements can be realized.

[0039] The main difference between this embodiment and the prior art is that in this embodiment, the rotational motion of the rotating threaded rod 424 is converted into the linear motion of the valve stem 418, avoiding the need for the valve stem 418 to overcome the linear friction and rotational friction between it and the packing 417 to adjust the opening degree of the valve core 419 when the rotating threaded rod 424 is directly connected to the valve stem 418. That is, the linear motion of the valve stem 418 to achieve the adjustment of the opening degree of the valve core 419 can reduce the dynamic friction between the valve stem 418 and the packing 417, thereby reducing the risk of device leakage. Moreover, the self-locking effect between the rotating threaded rod 424 and the internal thread sleeve 428 can ensure the stability of the position of the valve core 419, avoiding fluctuations of the valve core 419 and affecting the sealing performance of the device. Embodiment

[0040] As Figures 1-10 shown, based on Embodiment 1, an annular groove 430 is formed in the middle of the packing 417. An oil-absorbing sponge sleeve 440 sleeved outside the valve stem 418 is arranged inside the annular groove 430. An L-shaped grease adding pipe 450 extending above the packing 417 is symmetrically arranged outside the oil-absorbing sponge sleeve 440. The oil-absorbing sponge sleeve 440 can absorb the grease extruded from the end of the L-shaped grease adding pipe 450. When the valve stem 418 moves linearly to adjust the oil production flow rate, the oil-absorbing sponge sleeve 440 can apply the absorbed grease to the outer surface of the valve stem 418 to reduce the dynamic friction between the valve stem 418 and the packing 417;

[0041] An oil adding mechanism 460 for adding grease into the axially symmetric L-shaped grease adding pipe 450 is arranged inside the valve cover 412. The oil adding mechanism 460 includes an annular grease storage cavity 461 formed inside the valve cover 412. A grease injection pipe 462 extending outside the valve cover 412 is arranged outside the annular grease storage cavity 461. A conical grease adding pipe 463 that can be inserted into the inside of the L-shaped grease adding pipe 450 is axially symmetrically and fixedly communicated with the bottom of the annular grease storage cavity 461. An annular piston 464 is arranged inside the annular grease storage cavity 461. The top of the annular piston 464 is axially symmetrically and fixedly connected with a connecting rod 465 passing through the valve cover 412. When the axially symmetric connecting rods 465 drive the annular piston 464 to move downward together at the top, the grease inside the annular grease storage cavity 461 can be extruded into the inside of the conical grease adding pipe 463 and the L-shaped grease adding pipe 450 to achieve self-lubrication of the valve stem 418;

[0042] At the top of the valve cover 412, there is a linkage mechanism 470 that is linked to the actuator 420 and the lubricating grease adding mechanism 460. The linkage mechanism 470 includes an inverted U-shaped air pressure pipe 471 and a regular U-shaped air pressure pipe 472 that are symmetrically and fixedly connected to the top of the valve cover 412. Between the middle of the symmetric inverted U-shaped air pressure pipes 471 and the top of the symmetric regular U-shaped air pressure pipes 472, there is a circular air pressure pipe 473 fixedly connected in common. On the outside of the circular air pressure pipe 473, there are two one-way valves A474 symmetrically installed near the corresponding inverted U-shaped air pressure pipes 471. On the outside of the symmetric inverted U-shaped air pressure pipes 471, there are one-way valves B475 installed near the circular air pressure pipe 473. The opposite one-way valves A474 are all used to allow the air flow inside the circular air pressure pipe 473 to pass in the direction of approaching each other. The one-way valve B475 is used to allow the air flow inside the corresponding inverted U-shaped air pressure pipe 471 to pass upward. That is, the gas below the inside of the inverted U-shaped air pressure pipe 471 can pass through the block of the opposite one-way valves A474 and enter the upper part of the inside of the inverted U-shaped air pressure pipe 471 through the one-way valve B475. The gas inside the circular air pressure pipe 473 and the regular U-shaped air pressure pipe 472 can pass through the block of the one-way valve B475 and enter the lower part of the inside of the inverted U-shaped air pressure pipe 471 through the opposite one-way valves A474;

[0043] Inside one end of each of the symmetric inverted U-shaped air pressure pipes 471, there is a piston connecting rod 476 that passes through the valve cover 412. The two piston connecting rods 476 are respectively fixedly connected to the tops of the two sliders 426. That is, when the valve stem 418 moves up and down to change the opening between the valve core 419 and the valve seat 416, it can pressurize the gas inside the inverted U-shaped air pressure pipe 471 and decompress the gas inside the circular air pressure pipe 473 and the regular U-shaped air pressure pipe 472 through the piston connecting rod 476. Inside the other end of each of the symmetric inverted U-shaped air pressure pipes 471, there is a piston expansion rod A477 fixedly connected to the top of the connecting ring 466. Inside one end of each of the symmetric regular U-shaped air pressure pipes 472 away from the circular air pressure pipe 473, there is a piston expansion rod B478 fixedly connected to the bottom of the connecting ring 466. The symmetric piston expansion rods A477 can drive the connecting ring 466 to move downward and can drive the piston expansion rod B478 to shorten. The symmetric piston expansion rods B478 can drive the connecting ring 466 to move downward and can drive the piston expansion rod A477 to elongate;

[0044] The piston expansion rod A477 and the piston expansion rod B478 both include a piston outer sleeve 479 and a telescopic inner connecting rod 480 slidably connected inside the piston outer sleeve 479. The piston outer sleeve 479 is disposed inside the corresponding inverted U-shaped air pressure tube 471 or inside the corresponding upright U-shaped air pressure tube 472. The telescopic inner connecting rod 480 is fixedly connected to the top or the bottom of the connecting ring 466. Driving torque grooves 481 are symmetrically formed on the inner side of the piston outer sleeve 479. Built-in torque grooves 482 are symmetrically formed on the outer side of the telescopic inner connecting rod 480. A connecting spring 483 is fixedly connected inside the built-in torque groove 482. A driving torque block 484 fixedly connected to the connecting spring 483 is slidably connected inside the built-in torque groove 482. The driving torque block 484 can enter the inside of the driving torque groove 481. The bottom surface of the driving torque block 484 is provided with an abutting inclined surface 485. That is, the piston outer sleeve 479 included in the piston expansion rod A477 can move downward through the driving torque groove 481 and the driving torque block 484, and the telescopic inner connecting rod 480 can be extended through the driving torque groove 481, the abutting inclined surface 485 and the driving torque block 484. The piston outer sleeve 479 included in the piston expansion rod B478 can move downward through the driving torque groove 481 and the driving torque block 484, and the telescopic inner connecting rod 480 can be shortened through the driving torque groove 481, the abutting inclined surface 485 and the driving torque block 484.

[0045] The working principle of this embodiment is as follows: As Figure 9 shown, when the valve core 419 in the adjustable throttle valve 410 is in a semi-open state and the valve stem 418 moves upward to increase the opening between the valve core 419 and the valve seat 416, the valve stem 418 can drive the piston connecting rod 476 to move upward through the slider 426 to pressurize the lower part inside the inverted U-shaped air pressure tube 471, so that the gas in the lower part inside the inverted U-shaped air pressure tube 471 can pass through the blocking of the check valve A474 and enter the upper part inside the inverted U-shaped air pressure tube 471 through the check valve B475. Thus, the piston expansion rod A477 drives the connecting ring 466 to move downward, so that the connecting ring 466 drives the annular piston 464 to move downward through the axially symmetric connecting rod 465, so as to squeeze the lubricating grease inside the annular grease storage cavity 461 into the inside of the conical grease adding tube 463 and extrude it through the L-shaped grease adding tube 450. The grease absorbing sponge sleeve 440 can absorb the lubricating grease extruded from the end of the L-shaped grease adding tube 450 and apply the absorbed lubricating grease to the outer surface of the upper part of the valve stem 418 to reduce the dynamic friction between the valve stem 418 and the upper sealing packing 417.

[0046] During the process of the piston expansion rod A477 driving the connecting ring 466 to move downward, the telescopic inner connecting rod 480 of the piston expansion rod B478 can be shortened through the driving torque groove 481, the abutting inclined surface 485 and the driving torque block 484.

[0047] When the valve stem 418 moves downward to reduce the opening between the valve core 419 and the valve seat 416, the valve stem 418 can drive the piston connecting rod 476 downward through the slider 426 to decompress the inside of the annular pneumatic tube 473 and the positive U-shaped pneumatic tube 472, so that the gas inside the annular pneumatic tube 473 and the positive U-shaped pneumatic tube 472 can pass through the block of the one-way valve B475 and enter the lower part inside the inverted U-shaped pneumatic tube 471 through the relative one-way valve A474, thereby enabling the piston expansion rod B478 to drive the connecting ring 466 downward to perform self-lubrication of the valve stem 418;

[0048] During the process of the piston expansion rod B478 driving the connecting ring 466 downward, the telescopic inner connecting rod 480 of the piston expansion rod A477 can be elongated through the driving torque groove 481, the abutting inclined surface 485 and the driving torque block 484.

[0049] The main difference between this embodiment and the prior art is that when the valve stem 418 moves upward to increase the opening between the valve core 419 and the valve seat 416 in this embodiment, the piston expansion rod A477 can drive the annular piston 464 downward to squeeze the grease inside the annular grease storage cavity 461, and at the same time the piston expansion rod B478 is shortened. When the valve stem 418 moves downward to reduce the opening between the valve core 419 and the valve seat 416, the piston expansion rod B478 can drive the annular piston 464 downward to squeeze the grease inside the annular grease storage cavity 461, and at the same time the piston expansion rod A477 is elongated. That is, when the valve stem 418 performs linear up and down movement to change the opening between the valve core 419 and the valve seat 416, it can enable the annular piston 464 to move downward to squeeze the grease inside the annular grease storage cavity 461 to achieve self-lubrication of the valve stem 418, thereby being able to reduce the dynamic friction between the valve stem 418 and the packing 417.

[0050] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An oil production wellhead device with automatic flow regulation, comprising a casing head (200), a tubing head (300), a Christmas tree (400) sequentially installed on the top of the wellhead (100), and a controller connected to the Christmas tree (400), characterized in that: The Christmas tree (400) includes an adjustable throttle valve (410) for automatically regulating the oil production flow rate. The adjustable throttle valve (410) includes a valve body (411) for encapsulation and a valve cover (412) installed on its top. A fuel inlet pipe (413) and a fuel outlet pipe (414) are fixedly connected to the side and bottom of the valve body (411) respectively. A sensor group (415) is installed inside the fuel inlet pipe (413). A valve seat (416) extending to the upper part inside the fuel outlet pipe (414) is installed inside the valve body (411). A sealing packing (417) close to the valve cover (412) is installed inside the valve body (411). A valve stem (418) that slides through the sealing packing (417) and extends into the inside of the valve body (411) is slidably connected inside the valve cover (412). A valve core (419) for sealing the valve seat (416) is fixedly connected to the bottom of the valve stem (418). An actuator (420) for performing linear motion of the valve stem (418) is provided outside the valve body (411). An annular groove (430) is formed in the middle of the sealing packing (417). A fat-absorbing sponge sleeve (440) sleeved outside the valve stem (418) is arranged inside the annular groove (430). An L-shaped fat-adding pipe (450) extending above the sealing packing (417) is symmetrically arranged outside the fat-absorbing sponge sleeve (440). A fat-adding mechanism (460) for adding grease into the axially symmetric L-shaped fat-adding pipes (450) is arranged inside the valve cover (412). A linkage mechanism (470) linked with the actuator (420) and the fat-adding mechanism (460) is arranged on the top of the valve cover (412).

2. The oil production wellhead device with automatic flow regulation according to claim 1, characterized in that: The sensor group (415) is connected to the controller and is used for monitoring the flow rate, pressure and temperature inside the fuel inlet pipe (413). The controller calculates based on a preset algorithm and issues an instruction for the actuator (420) to work.

3. The oil production wellhead device with automatic flow regulation according to claim 1, characterized in that: The actuator (420) includes a sealing bearing (421) installed on the top of the valve cover (412) and an actuator motor (423) installed on the top of the valve cover (412) through a mounting bracket (422). The input end of the actuator motor (423) is connected to the controller. A rotating threaded rod (424) passing through the sealing bearing (421) is fixedly connected to the output end of the actuator motor (423). The actuator (420) further includes two vertical sliding grooves (425) formed inside the valve cover (412). A slider (426) fixedly connected to the valve stem (418) is slidably connected inside the two vertical sliding grooves (425). A cylindrical groove (427) extending to the top of the valve stem (418) is formed inside the valve stem (418). An internal thread sleeve (428) threadedly connected to the outside of the rotating threaded rod (424) is fixedly connected inside the cylindrical groove (427).

4. The oil production wellhead device with automatic flow regulation according to claim 3, characterized in that: The fat adding mechanism (460) includes an annular grease storage cavity (461) opened inside the valve cover (412). An oil injection pipe (462) extending outside the valve cover (412) is arranged outside the annular grease storage cavity (461). A conical grease adding pipe (463) that can be inserted into the inside of the L-shaped grease adding pipe (450) is axially symmetrically and fixedly communicated at the bottom of the annular grease storage cavity (461). An annular piston (464) is arranged inside the annular grease storage cavity (461). A connecting rod (465) passing through the valve cover (412) is axially symmetrically and fixedly connected to the top of the annular piston (464). A connecting ring (466) is fixedly connected to the top of the axially symmetric connecting rods (465).

5. The oil production wellhead device with automatic flow regulation according to claim 4, characterized in that: The linkage mechanism (470) includes an inverted U-shaped air pressure pipe (471) and a regular U-shaped air pressure pipe (472) symmetrically and fixedly connected to the top of the valve cover (412). An annular air pressure pipe (473) is fixedly communicated between the middle of the symmetrically arranged inverted U-shaped air pressure pipes (471) and the top of the symmetrically arranged regular U-shaped air pressure pipes (472). Two one-way valves A (474) close to the corresponding inverted U-shaped air pressure pipes (471) are symmetrically installed outside the annular air pressure pipe (473). One-way valves B (475) close to the annular air pressure pipe (473) are installed outside the symmetrically arranged inverted U-shaped air pressure pipes (471). Piston connecting rods (476) passing through the valve cover (412) are arranged inside one ends of the symmetrically arranged inverted U-shaped air pressure pipes (471). The two piston connecting rods (476) are respectively fixedly connected to the tops of the two sliders (426). Piston telescopic rods A (477) fixedly connected to the top of the connecting ring (466) are arranged inside the other ends of the symmetrically arranged inverted U-shaped air pressure pipes (471). Piston telescopic rods B (478) fixedly connected to the bottom of the connecting ring (466) are arranged inside the other ends of the symmetrically arranged regular U-shaped air pressure pipes (472) far from the annular air pressure pipe (473).

6. The oil production wellhead device with automatic flow regulation according to claim 5, characterized in that: The opposite one-way valves A (474) are both used to allow the air flow inside the annular air pressure pipe (473) to pass in the direction of approaching each other. The one-way valve B (475) is used to allow the air flow inside the corresponding inverted U-shaped air pressure pipe (471) to pass upward.

7. An oil production wellhead device with automatic flow regulation according to claim 5, characterized in that: The piston telescopic rod A (477) and the piston telescopic rod B (478) both include a piston outer sleeve (479) and a telescopic inner connecting rod (480) slidably connected inside the piston outer sleeve (479). The piston outer sleeve (479) is disposed inside the corresponding inverted U-shaped air pressure tube (471) or inside the corresponding upright U-shaped air pressure tube (472). The telescopic inner connecting rod (480) is fixedly connected to the top or the bottom of the connecting ring (466). Driving torque grooves (481) are symmetrically formed on the inner side of the piston outer sleeve (479). Built-in torque grooves (482) are symmetrically formed on the outer side of the telescopic inner connecting rod (480). A connecting spring (483) is fixedly connected inside the built-in torque groove (482). A driving torque block (484) fixedly connected to the connecting spring (483) is slidably connected inside the built-in torque groove (482). The driving torque block (484) can enter the inside of the driving torque groove (481), and the bottom surface of the driving torque block (484) is provided as an abutting inclined surface (485).

8. An oil production wellhead device with automatic flow regulation according to claim 5, characterized in that: The symmetric piston telescopic rod A (477) can drive the connecting ring (466) to move downward and can drive the piston telescopic rod B (478) to shorten. The symmetric piston telescopic rod B (478) can drive the connecting ring (466) to move downward and can drive the piston telescopic rod A (477) to elongate.

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