CN115263225B

CN115263225B - Well head increases abrasionproof energy-saving sealing system

Info

Publication number: CN115263225B
Application number: CN202211139092.2A
Authority: CN
Inventors: 丁蕾
Original assignee: Qingdao Xinsheng Petroleum Machinery Co ltd; Daqing Yongjin Petroleum Technology Co ltd
Current assignee: Daqing Yongjin Petroleum Technology Co ltd; Qingdao Xinsheng Petroleum Machinery Co ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2023-03-24
Anticipated expiration: 2042-09-19
Also published as: CN115263225A

Abstract

The wellhead synergistic anti-abrasion energy-saving sealing system adopts a structure and a principle of self-sealing of oil fluid, compared with the traditional mode that a polished rod sealer is only arranged outside a wellhead, the wellhead synergistic anti-abrasion energy-saving sealing system can effectively seal oil pumped in a well, can reduce leakage, particularly can reduce the pressure of the leaked oil on the polished rod sealer, and is matched with a pressure relief mechanism, so that the oil leakage of the polished rod sealer outside the wellhead can be greatly weakened, and the workload of wellhead maintenance is reduced; therefore, more comfortable working conditions are brought to the polish rod sealer, so that the polish rod sealer can meet lower design requirements on execution, the service life of the polish rod sealer can be prolonged, the production efficiency of the whole set of equipment is further improved, and the environmental pollution is reduced; meanwhile, the efficiency of the whole oil pumping system can be improved, and particularly the pumping efficiency of an oil well can be improved by 20-30%.

Description

Well head increases abrasionproof energy-saving sealing system

Technical Field

The invention relates to the field of oil exploitation equipment, in particular to a wellhead sealing system, and particularly relates to a wellhead synergistic anti-abrasion energy-saving sealing system.

Background

The existing oil well is provided with a sealer at the position of a well head so as to prevent oil from being sprayed out of the well head; most of wellhead sealing devices mainly use a polish rod sealer, the polish rod sealer is installed on a gland flange fixed on a wellhead and is positioned on the upper portion of the gland flange of the wellhead, and when a rod moves up and down, a gap between the movable rod and a fixed part is sealed through the polish rod sealer. Specifically, the polished rod sealer comprises a packing, the packing is matched with the rod to form a sealing pair, the packing is used for directly plugging underground oil, namely the packing is designed based on the underground oil state to realize a sealing structure and a sealing method.

However, because the state of the underground oil is very complex, parameters such as the components, the temperature, the pressure, the oil content and the gas content of the oil are in a changing state and are unstable, so that a fixedly arranged packing cannot adapt to and match the oil condition in various states, the sealing failure is often caused to occur frequently, and the oil is leaked to cause resource waste and environmental pollution.

Meanwhile, because the pumping unit is difficult to be completely concentric with the wellhead and keeps concentric for a long time, the installation of the pumping unit is aligned more difficultly, so that the rod and the packing of the polished rod sealer cannot be aligned, and eccentric wear is easily generated on the packing in the rod running process, thereby causing abrasion and even failure of the packing structure, further causing oil leakage and environmental pollution.

Under the conditions, oil extraction workers need to frequently maintain the wellhead sealing device, regularly check and clean the wellhead and regularly replace the packing and the rod, so that huge maintenance is brought to production; more seriously, the whole set of equipment can not be used continuously due to the damage of the sealing part, so that the utilization rate of the equipment, the production efficiency and huge economic loss are caused.

It is therefore desirable to develop a wellhead sealing system that is effective in preventing oil leakage and has long life with reduced maintenance.

Disclosure of Invention

To solve the above technical problems, the present invention provides a wellhead synergistic wear-resistant energy-saving sealing system for coupling with a rod of an oil well, characterized in that the sealing system comprises a first pipe, a sealing member and a leakage fluid discharge pipe, wherein the first pipe is located below a wellhead sealing flange, the first pipe is arranged in a third pipe of the oil well, the diameter of the first pipe is smaller than that of the third pipe, thereby forming an annular leakage discharge channel between the first pipe and the third pipe, a leakage discharge hole is provided at one end of the first pipe located at the wellhead sealing flange, so that the inside of the first pipe can be in fluid communication with the leakage discharge channel via the leakage discharge hole; the sealing component and the rod are fixed in a relatively fixed or relatively slidable manner, and the sealing component and the rod are arranged inside the first pipe and can move in the longitudinal direction of the first pipe in the first pipe; a leakage fluid discharge pipe provided on the third pipe and capable of being in fluid communication with the leakage discharge passage to discharge fluid in the oil well that has passed through the seal member to leak to an upper portion of the seal member; the sealing part is of a cylindrical structure, the first pipe is a cylindrical pipe body, the outer diameter of the sealing part is smaller than the inner diameter of the inner wall of the first pipe, and a gap is formed between the sealing part and the inner wall of the first pipe.

Further, sealing system still includes sealed top tube, and sealed top tube setting is between well head sealing flange and first pipe and well head sealing flange is connected to one end and the first pipe is connected to the other end, and sealed top tube is provided with sealed top tube end plate at the tip that is located first pipe side, and wherein, sealed top tube end plate can be with the inside of first pipe and the inside mutual isolation of sealed top tube.

Further, the sealing component comprises a first part, a first groove and a second part which are sequentially arranged from top to bottom, wherein the first part is disc-shaped, the first groove extends along the circumferential direction of the sealing component, the radius of the bottom of the first groove is smaller than that of the first part, rib parts and second grooves which are distributed at intervals are arranged on the outer peripheral surface of the second part, the second groove extends along the axial direction of the sealing component, one end of the second groove is communicated with the first groove, and the other end of the second groove extends to the lower end of the second part, so that oil in the oil well can flow to the first groove through the second groove.

Further, the radius of the rib is the same as the radius of the first portion, and the depth of the groove bottom of the second groove is the same as the depth of the first groove.

Further, the number of ribs and second grooves is 4, 5, 6 or 8, respectively.

Further, a concave portion is provided at an end portion of the seal member on the second portion side, the concave portion being a portion of a sphere or a portion of an ellipsoid, an axis of the concave portion coinciding with an axis of the seal member; wherein a rod hole is provided in the sealing member along an axis of the sealing member, the rod hole being fitted with the rod to effect coupling of the sealing member with the rod.

Further, a fluid inlet is arranged in the concave part, a fluid outlet is arranged in the first groove, a fluid channel is arranged inside the sealing part to communicate the fluid inlet with the fluid outlet, and the fluid outlet is formed into a tapered nozzle; preferably, the cross-sectional area of the fluid outlet is smaller than the cross-sectional area of the fluid inlet.

Further, the axis of the tapered nozzle is provided offset toward the second portion with respect to the radial direction of the seal member, or the axis of the tapered nozzle is provided extending along the radial direction of the seal member.

Further, the number of fluid inlets and the number of fluid outlets are the same as the number of second grooves, and the fluid outlets are provided at the intersection of the second grooves and the first grooves.

Further, a relief valve, preferably a plurality of relief valves, whose set pressure can be set to different relief pressures, is provided on the leaking fluid discharge pipe.

Furthermore, the sealing system also comprises a supporting pipe section, wherein the supporting pipe section is arranged and fixed on the inner wall of a second pipe of the oil well, the second pipe is positioned on the outer side of a third pipe, and the pipe diameter of the second pipe is larger than that of the third pipe; the supporting pipe section is located below the first pipe and the third pipe and used for supporting the first pipe and the third pipe, and a channel located between the second pipe and the third pipe is arranged in the radial direction of the supporting pipe section, so that oil extracted from an oil well can be conveyed to an oil discharge pipe at a wellhead through an annular channel between the second pipe and the third pipe through the channel of the supporting pipe section.

The implementation of the invention has the following beneficial effects: the wellhead sealing system adopts the structure and the principle of self-sealing of oil fluid, compared with the traditional mode that the polish rod sealer is only arranged outside the wellhead, the wellhead sealing system can effectively seal oil pumped in a well, can reduce leakage, particularly can reduce the pressure of the leaked oil on the polish rod sealer, and is matched with a pressure relief mechanism, so that the oil leakage of the polish rod sealer outside the wellhead can be greatly weakened, and the workload of wellhead maintenance is reduced; therefore, more comfortable working conditions are brought to the polish rod sealer, so that the polish rod sealer can meet lower design requirements on execution, the service life of the polish rod sealer can be prolonged, the production efficiency of the whole set of equipment is further improved, and the environmental pollution is reduced; meanwhile, the efficiency of the whole oil pumping system can be improved, and particularly the pumping efficiency of an oil well can be improved by 20-30%.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a diagram of a wellhead seal configuration of the present invention.

Fig. 2 is a structural view of the seal member of the present invention.

Fig. 3 is a structural view of the seal member of the present invention.

Figure 4 is one embodiment of a cross-sectional view of a seal member of the present invention.

Fig. 5 is another embodiment of a cross-sectional view of the sealing member of the present invention.

Reference numerals: 1. a first tube; 2. a rod; 3. a wellhead sealing flange; 4, a polish rod sealer; 5. a sealing member; 6. a leakage fluid discharge pipe; 7. a first pressure relief valve; 8. a second pressure relief valve; 9. a second tube; 10. supporting the pipe section; 11. a gap; 12. a third tube; 13. a leakage discharge passage; 14. a leakage vent hole; 15. an oil well pump; 16. an oil discharge pipe; 101. sealing the upper pipe; 102. sealing the upper tube end plate; 51. a first portion; 52. a first trench; 53. a rib portion; 54. a second trench; 55. a recess; 56. a fluid inlet; 57. a fluid outlet; 58. a fluid channel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

In the traditional wellhead structure of the oil well, a rod drives an oil pump in the oil well to pump underground oil, and the high-pressure oil in the oil well reaches the wellhead position of the oil well; and a wellhead sealing flange and a polish rod sealer are usually arranged at the wellhead position, wherein the wellhead sealing flange is installed at the wellhead, and the polish rod sealer is usually installed at the upper part of the wellhead sealing flange and is usually positioned at the uppermost part of a wellhead device so as to seal oil in an oil well and prevent the oil from leaking into the external environment. At this time, the high-pressure oil is applied to the polish rod sealer along the rod, and the high-pressure oil is leaked from the gap between the polish rod sealer and the rod due to the abrasion of the rod and the polish rod sealer in the up-and-down reciprocating motion.

In order to solve the technical problems, the invention provides a wellhead synergistic anti-abrasion energy-saving sealing system which is arranged at a position close to a wellhead in an oil well; and a wellhead sealing flange 3 and a polish rod sealer 4 are provided at the wellhead, wherein the wellhead sealing flange 3 is used for sealing the wellhead, and the polish rod sealer 4 is provided at an upper portion of the wellhead sealing flange 3, and preferably the polish rod sealer 4 is mounted on the wellhead sealing flange 3. A packing is provided in the rod packing 4, which cooperates in a contact manner with the rod 2 for sealing a gap between the rod 2 and the rod packing 4, for preventing oil in the oil well from leaking into the external environment through the gap between the rod 2 and the rod packing 4.

As shown in fig. 1, the sealing system is coupled to a rod 2 of an oil well, in particular, a second pipe 9 and a third pipe 12 are arranged in the oil well, the third pipe 12 being arranged inside the second pipe 9, in particular in a centered manner, i.e. the pipe diameter of the second pipe 9 is larger than the pipe diameter of the third pipe 12, where the second pipe 9 is the oil pipe of the oil well. The rod 2 is arranged in the second tube 9 and in the third tube 12, preferably on the axis of the second tube 9 and the third tube 12. An oil well pump 15 is arranged in the second pipe 9, the oil well pump 15 can be driven by the rod 2, the oil well pump 15 is driven by the up-and-down reciprocating motion of the rod 2 to extract oil from the ground, the oil is pumped upwards along the second pipe 9, the oil is conveyed to a wellhead through an annular channel between the second pipe 9 and the third pipe 12, and the oil is discharged from an oil discharge pipe 16 arranged near the wellhead.

The sealing system, as shown in fig. 1, comprises a first pipe 1, a supporting pipe section 10, a sealing part 5 and a leakage fluid discharge pipe 6. The first tube 1 is arranged in a third tube 12, the inner diameter of the first tube 1 being smaller than the inner diameter of the third tube 12, the first tube 1 being arranged in particular coaxially with the third tube 12. The support tube section 10 serves here to support the first tube 1 and the third tube 12. Preferably, the support tube segment 10 is sealingly connected with the first tube 1 and the third tube 12, so that oil cannot enter the third pipe 12 through the connection between the support pipe segment 10 and the first and

third pipes

1, 12. Wherein the support tube section 10 is arranged inside the second tube 9 and can be fixed to the inner wall of the second tube 9, thereby enabling the third tube 12 as well as the first tube 1 to be supported on the second tube 9 by the support tube section 10. Also, the support pipe section 10 is provided with a passage in the radial direction between the second pipe 9 and the third pipe 12, for example with a plurality of spaced through holes in the circumferential direction, but these through holes are arranged in the radial direction between the second pipe 9 and the third pipe 12, whereby oil extracted from the oil well can be conveyed via the passage of the support pipe section 10 through the annular passage between the second pipe 9 and the third pipe 12 to the oil drain pipe 16 near the wellhead.

As shown in fig. 1, the sealing system additionally comprises an upper sealing pipe 101, the upper sealing pipe 101 being arranged between the wellhead sealing flange 3 and the first pipe 1 for connecting the wellhead sealing flange 3 with the first pipe 1. The sealing upper tube 101 has a hollow tubular shape, and the rod 2 can move up and down freely in the sealing upper tube 101. The sealing upper pipe 101 has a sealing upper pipe end plate 102 positioned on the first pipe 1 side, and thus the internal space of the first pipe 1 can be isolated from the internal space of the sealing upper pipe 101.

In this embodiment, the sealing member 5 and the rod 2 are connected in a mutually fixed manner, that is, the sealing member 5 can reciprocate up and down with the rod 2; of course, in other embodiments, the sealing member 5 and the rod 2 may be fixedly connected in a relatively sliding manner, and the sealing member 5 may be fixed relative to the first pipe 1. The sealing element 5 and the rod 2 are arranged in the first pipe 1, in particular the sealing element 5 and the rod 2 are arranged centrally to the first pipe 1, i.e. the axes of the sealing element 5 and the rod 2 coincide with the axis of the first pipe 1. In this way, it is possible to keep the seal member 5 centered as much as possible with the first pipe 1 when the seal member 5 reciprocates up and down with the rod 2.

Here, the sealing member 5 is a cylinder, and the first tube 1 is a cylindrical tube. However, since the sealing member 5 is located below the wellhead sealing flange 3, i.e. the sealing member 5 is located inside the well during use, it is impossible to perform maintenance and service of the sealing member 5 at a high frequency. In order to prevent the sealing member 5 from being worn due to friction between the sealing member 5 and the first pipe 1 during the vertical reciprocating motion of the sealing member 5, thereby affecting the sealing effect of the sealing member 5, the outer diameter of the sealing member 5 is set smaller than the inner diameter of the inner wall of the first pipe 1, and thus, a gap 11 is formed between the sealing member 5 and the inner wall of the first pipe 1. Since the sealing member 5 is disposed in a centered manner with respect to the first pipe 1, the sealing member 5 maintains a relatively stable gap 11 with the inner wall of the first pipe 1 during the up-and-down reciprocating movement of the sealing member 5.

Due to the gap 11, high-pressure oil under the seal member 5 in the oil well inevitably flows to the upper side of the seal member 5 through the gap 11. Oil leaking above the sealing element 5 must be drained to avoid affecting the normal operation of the well. Here, as shown in fig. 1, since there is the sealed upper tube end plate 102, in order to discharge oil leaked above the sealing member 5, a leakage discharge hole 14 is provided at an upper portion of the first tube 1, the number of the leakage discharge holes 14 may be plural, and the plural leakage discharge holes 14 are arranged, particularly uniformly, in a circumferential direction of the first tube 1; the leakage bleed holes 14 are preferably provided in the first pipe 1 at a location close to the sealed upper pipe end plate 102. And the first pipe 1 is disposed in the third pipe 12, and the inner diameter of the first pipe 1 is smaller than that of the third pipe 12, thereby forming an annular leak discharge passage 13 between the first pipe 1 and the third pipe 12, so that the oil leaked above the sealing member 5 can be discharged into the leak discharge passage 13 via the leak discharge hole 14 and further, discharged through the leaked fluid discharge pipe 6.

Through the structure mode, in the process that the rod 2 drives the oil well pump 15 to move up and down to pump oil, even if high-pressure oil can enter the first pipe 1 along the rod 2, the leaked high-pressure oil can be discharged to the upper part of the sealing part 5 through the sealing and pressure reducing effects of the sealing part 5, so that only a small amount of oil can be leaked to the upper part of the sealing part 5, and the oil leaked to the upper part of the sealing part 5 can be discharged to the leakage discharge channel 13 through the leakage discharge hole 14 and further discharged through the leakage fluid discharge pipe 6, so that only a small amount of oil or even no oil can further reach the polish rod sealer 4 up along the rod 2, and the oil leakage condition at the polish rod sealer 4 is greatly reduced. From this, through arranging such sealing system below the well head, compare in traditional oil well, can reduce the fluid leakage condition of well head widely, reduce simultaneously to polished rod sealing ware's sealed requirement for polished rod sealing ware need not to possess very high sealed effect, just so can reduce the maintenance frequency and the change frequency of fastening packing and change packing, thereby can reduce the work load that the well head was maintained widely. Meanwhile, the oil extracted from the oil well is conveyed out through another channel and is independently arranged and not communicated with a leakage discharge channel of the sealing system, so that the normal oil extracting work of the oil well can be ensured, and the normal operation of the sealing system can also be ensured.

According to the sealing structure, the sealing system is additionally arranged on the basis of the traditional oil well pump, the sealing part 5 of the sealing system can reciprocate up and down along with the rod 2, and the up and down reciprocating movement of the sealing part 5 enables the sealing part to function in a suction pump mode, so that the efficiency of the whole oil well pump can be improved, and particularly, the efficiency of the underground oil well pump can be improved by 20% -30%.

In order to further ensure that the area of the first pipe 1 above the sealing element 5 is kept at a low pressure, a pressure relief valve is preferably provided in the leakage fluid discharge pipe 6, preferably an automatic pressure relief valve, so that when the pressure of the oil in the area above the sealing element 5 reaches a set pressure, the automatic pressure relief valve will automatically open and discharge the leakage fluid discharge pipe 6 through the automatic pressure relief valve, thereby reducing the pressure of the oil in the area above the sealing element 5. The number of the pressure relief valves may be one or more. Here, the set pressures of the respective relief valves may be set to be the same or preferably different. As shown in fig. 1, two pressure relief valves, a first pressure relief valve 7 and a second pressure relief valve 8, are exemplarily shown, and in other embodiments, the number of the pressure relief valves may be one, or may be 3, 5, or 6. Automatic pressure relief valves are selected for use in the first pressure relief valve 7 and the second pressure relief valve 8, and the pipe diameters of the first pressure relief valve 7 and the second pressure relief valve 8 can be selected for use at will. The set pressure of the first pressure release valve 7 and the set pressure of the second pressure release valve 8 can be set to be different, for example, the set pressure of the first pressure release valve 7 can be set to be 0.050MPa, and the set pressure of the second pressure release valve 8 can be set to be 0.058MPa, so that on one hand, when one of the first pressure release valve 7 and the second pressure release valve 8 fails to perform pressure release, the other one can perform overpressure discharge on the oil liquid in the leakage fluid discharge pipe 6; on the other hand, when the oil pressure in the leaking fluid discharge pipe 6 rises rapidly, especially when the set pressure of the first relief valve 7 and the second relief valve 8 is exceeded rapidly, the first relief valve 7 and the second relief valve 8 can be opened simultaneously, the overpressure discharge capacity of the leaking fluid discharge pipe 6 is increased, so that the steep rise of the oil pressure in the leaking fluid discharge pipe 6 can be effectively suppressed, and further, no oil is leaked out at the polished rod sealer 4.

As shown in fig. 1, the present invention selects the gap 11 between the sealing member 5 and the inner wall of the first pipe 1, and thus high-pressure oil under the sealing member 5 inevitably leaks to the upper side of the sealing member 5 through the gap 11, and in order to effectively suppress the occurrence of the leakage state, the present invention achieves the effect of sealing the gap 11 by providing the sealing member 5 in a structure in which the gap 11 is accurately set, for example, 0.5cm, 0.8cm, or 1 cm.

As shown in fig. 2 to 3, the sealing member 5 has a substantially cylindrical shape, and specifically includes a first portion 51, a first groove 52, and a second portion arranged in this order from top to bottom. The first portion 51 is located at the uppermost portion, the first portion 51 has a substantially disk shape or a cylindrical shape with a thickness, and a gap 11 is defined between the first portion 51 and the inner wall of the first pipe 1.

And the first groove 52 is located below the first portion 51 and adjacent to the first portion 51, the first groove 52 being provided on the outer periphery of the seal member 5 and extending in the circumferential direction of the seal member 5. The cross-section of the first groove 52 may be square or arc-shaped. The radius of the groove bottom of the first groove 52 is smaller than the radius of the first portion 51; the bottom of the first groove 52 may be a circumferential line of the same radius, as shown in fig. 2-3; it may also be a curve with varying radius, such as a wavy circumference with a periodically varying radius.

And a second portion is provided at a lower portion of the sealing member 5, the second portion being located below the first groove 52 and adjacent to the first groove 52. As shown in fig. 2-3, a rib 53 and a second groove 54 are provided on the outer periphery of the second portion, the rib 53 and the second groove 54 being provided in a spaced manner; here, as shown in fig. 3, the number of the ribs 53 is 6, and the number of the second grooves 54 is also 6, but other numbers may be adopted. As can be seen from fig. 2 to 3, the rib 53 extends in the axial direction of the seal member 5, and the second groove 54 also extends in the axial direction of the seal member 5. One end (i.e., an upper end) of the second groove 54 meets and communicates with the first groove 52, and the other end (i.e., a lower end) of the second groove 54 extends to the lower end surface of the sealing member 5, so that the high-pressure oil in the first pipe 1 below the sealing member 5 can flow into the second groove 54 from the lower end surface of the sealing member 5 and flow upward along the second groove 54 to be immersed in the first groove 52. Wherein the radius of the rib 53 is the same as the radius of the first portion 51, that is, the space between the rib 53 and the inner wall of the first pipe 1 is the gap 11; while the groove bottom depth of the second grooves 54 is preferably set to be the same as the depth of the first grooves 52.

Then, with the sealing member 5, in the region of the first portion 51, the first portion 51 is spaced from the inner wall of the first tube 1 by the gap 11; in the region of the first groove 52, the distance between the groove base of the first groove 52 and the inner wall of the first tube 1 is greater than the gap 11; in the region of the second section, the rib 53 is spaced from the inner wall of the first tube 1 by the gap 11, while the groove base of the second groove 54 is spaced from the inner wall of the first tube 1 by a greater distance than the gap 11. When the high-pressure oil below the sealing member 5 flows to the space above the sealing member 5 along the gap between the sealing member 5 and the inner wall of the first pipe 1, because the oil generally has a large viscosity, the resistance to the flow of the oil in the rib 53 and the section of the inner wall of the first pipe 1 is greater than the resistance to the flow of the oil in the second groove 54 and the section of the inner wall of the first pipe 1, and the oil mainly flows upward extending the second groove 54; here, the rib 53 and the second groove 54 will generate a combing and rectifying effect on the oil.

Further, in order to be able to enhance and achieve the sealing effect of the seal member 5, as shown in fig. 3 to 4, a recess 55 is provided on the lower end surface, i.e., the second portion-side end portion, of the seal member 5, the recess 55 being provided in a centered manner with respect to the seal member 5, that is, the center of the recess 55 is located on the axis of the seal member 5. The recess 55 is preferably a portion of a sphere (e.g., a hemisphere) or a portion of an ellipsoid; wherein a rod hole 21 is provided in the sealing member 5 along the axis of the sealing member 5, the rod hole 21 being fitted with the rod 2 to achieve coupling of the sealing member 5 with the rod 2. A plurality of fluid inlets 56 are provided in the recess 55, while a plurality of fluid outlets 57 are provided in the first groove 52, one fluid inlet 56 being in fluid communication with one fluid outlet 57, in particular one fluid channel 58 being in communication with one fluid outlet 57 via a fluid channel 58 provided inside the sealing member 5. The number of fluid inlets 56, fluid outlets 57 and fluid channels 58 is the same as the number of second grooves 54, all 6 in this embodiment.

As shown in fig. 4, the rod bore 21 is located in the center of the recess 55, while the plurality of fluid inlets 56 are distributed around the rod bore 21, in particular uniformly distributed in the circumferential direction. The fluid outlet 57 is located in the first channel 52, preferably as shown in figure 3, the fluid outlet 57 being provided at the intersection of the second channel 54 and the first channel 52.

In order to generate a fluid resistance to the oil flowing through the second groove 54 to achieve a high flow resistance state, thereby achieving a sealing effect, as shown in fig. 4, the fluid outlet 57 is configured as a tapered nozzle, that is, the cross-sectional area of the fluid passage of the fluid outlet 57 portion is gradually reduced in the direction toward the outlet, and the cross-sectional area of the fluid outlet 57 is smaller than the cross-sectional area of the fluid inlet 56 and/or the fluid passage 58.

Since the gap region between the first portion 51 and the inner wall of the first pipe 1 is at a low pressure, the fluid inlet 56, the fluid passage 58 and the fluid outlet 57 of the present invention are configured like a laval nozzle, and the oil enters from the fluid inlet 56, flows through the fluid passage 58, and then flows through the fluid outlet 57 configured as a tapered nozzle, the flow velocity of the oil is significantly increased, that is, the velocity of the oil ejected from the fluid outlet 57 is significantly increased compared to the flow velocity of the oil in the fluid inlet 56 or the gap 11.

In order to further enhance the fluid resistance effect at the fluid outlet 57, as shown in fig. 4, the axis of the tapered nozzle of the fluid outlet 57 is disposed to be offset toward the second portion with respect to the radial direction of the seal member, that is, the axis of the tapered nozzle as shown in fig. 4 is extended downward. With this arrangement, when high-speed oil ejected from the fluid outlet 57 enters the intersection of the first groove 52 and the second groove 54, the high-speed oil ejected at the fluid outlet 57 moves in a direction opposite to the direction of movement of the oil in the second groove 54, and the high-speed oil ejected from the fluid outlet 57 collides with the oil in the second groove 54, and a high-speed oil ejected through the fluid outlet 57 is blocked by the kinetic energy and a static pressure, so that a high-resistance region in terms of fluid is generated in the vicinity of the fluid outlet 57, which hinders the movement of the oil between the seal member 5 and the inner wall of the first pipe 1 toward the upper side of the seal member 5, and particularly hinders the movement of the oil along the second groove 54 toward the upper side of the seal member 5.

Still further, since the plurality of fluid outlets are arranged in the first grooves 52, the high resistance region in terms of fluid as shown above will be generated over the entire circumferential extent of the first grooves 52, which will generate a fluid resistance effect not only on the oil flowing through the second grooves 54 but also on the oil flowing through the ribs 53, thereby significantly reducing the amount of high-pressure oil in the oil well below the seal member 5 leaking through the clearance 11. The sealing effect is achieved through a non-contact sealing structure, the oil liquid achieves the effect of fluid sealing, mechanical friction cannot be generated between the sealing part 5 and the inner wall of the first pipe 1, abrasion cannot be generated on the sealing part 5 and/or the first pipe 1, and therefore the sealing part 5 can achieve the long-acting sealing effect.

In another embodiment, as shown in fig. 5, the axis of the tapered nozzle of the fluid outlet 57 may also be arranged to extend in the radial direction of the sealing member 5, i.e., in the horizontal direction in fig. 5.

Further, as shown in fig. 1, the sealing system further includes a second pipe 9 and a support pipe section 10, the second pipe 9 and the support pipe section 10 are disposed at a lower portion of the first pipe 1, an inner diameter of the second pipe 9 is larger than an inner diameter of the first pipe 1, and the support pipe section 10 is disposed between the first pipe 1 and the second pipe 9 and communicates the first pipe 1 with the second pipe 9. The support tube section 10 can also be in fluid communication with the flow of oil. By the action of the support tube segment 10 and the configuration of the sealing member 5, oil leakage through the sealing member 5 and the inner wall of the first tube 1 can be greatly reduced.

The implementation of the invention has the following beneficial effects: the wellhead sealing system adopts the structure and the principle of self-sealing of oil fluid, compared with the traditional mode that the polish rod sealer is only arranged outside the wellhead, the wellhead sealing system can effectively seal oil pumped in a well, can reduce leakage, particularly can reduce the pressure of the leaked oil on the polish rod sealer, and is matched with a pressure relief mechanism, so that the oil leakage of the polish rod sealer outside the wellhead can be greatly weakened, and the workload of wellhead maintenance is reduced; therefore, more comfortable working conditions are brought to the polish rod sealer, so that the execution of the polish rod sealer can meet lower design requirements, the service life of the polish rod sealer can be prolonged, the production efficiency of the whole set of equipment is further improved, and the environmental pollution is reduced; meanwhile, the efficiency of the whole oil pumping system can be improved, and particularly the pumping efficiency of an oil well can be improved by 20-30%.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An efficient, wear-resistant and energy-saving sealing system for a wellhead, intended to be coupled to the rod of an oil well, characterized in that it comprises a first pipe, a sealing member and a discharge pipe for leaking fluid,

wherein the first pipe is located below the wellhead sealing flange, the first pipe is arranged in a third pipe of the oil well, the first pipe has a diameter smaller than that of the third pipe, thereby forming an annular leakage discharge channel between the first pipe and the third pipe, a leakage discharge hole is provided at an end of the first pipe located at the wellhead sealing flange, such that the interior of the first pipe is fluidly communicable with the leakage discharge channel via the leakage discharge hole;

the sealing component and the rod are fixed in a relatively fixed or relatively slidable manner, and the sealing component and the rod are arranged inside the first pipe and can move in the longitudinal direction of the first pipe in the first pipe;

a leakage fluid discharge pipe provided on the third pipe and capable of being in fluid communication with the leakage discharge passage to discharge fluid in the oil well that has passed through the seal member to leak to an upper portion of the seal member; the sealing part is of a cylindrical structure, the first pipe is a cylindrical pipe body, the outer diameter of the sealing part is smaller than the inner diameter of the inner wall of the first pipe, and a gap is formed between the sealing part and the inner wall of the first pipe; the sealing system further comprises a sealing upper pipe, the sealing upper pipe is arranged between the wellhead sealing flange and the first pipe, one end of the sealing upper pipe is connected with the wellhead sealing flange, the other end of the sealing upper pipe is connected with the first pipe, and a sealing upper pipe end plate is arranged at the end part of the sealing upper pipe positioned on the first pipe side, wherein the sealing upper pipe end plate can isolate the inside of the first pipe from the inside of the sealing upper pipe; the sealing part comprises a first part, a first groove and a second part which are sequentially arranged from top to bottom, wherein the first part is disc-shaped, the first groove extends along the circumferential direction of the sealing part, the radius of the bottom of the first groove is smaller than that of the first part, rib parts and second grooves which are distributed at intervals are arranged on the outer peripheral surface of the second part, the second groove extends along the axial direction of the sealing part, one end of the second groove is communicated with the first groove, and the other end of the second groove extends to the lower end of the second part, so that oil in the oil well can flow to the first groove through the second groove.

2. The wellhead synergistic wear-resistant energy-saving sealing system according to claim 1, wherein the radius of the rib is the same as that of the first part, and the depth of the bottom of the second groove is the same as that of the first groove; the number of the ribs and the number of the second grooves are 4, 5, 6 or 8.

3. A wellhead efficiency enhancing, wear preventing and energy saving sealing system according to any one of claims 1 to 2, wherein a concave part is provided at the end part of the sealing component on the second part side, the concave part is a part of a sphere or a part of an ellipsoid, and the axis of the concave part is coincident with the axis of the sealing component; wherein a rod hole is provided in the sealing member along an axis of the sealing member, the rod hole being fitted with the rod to effect coupling of the sealing member with the rod.

4. A wellhead efficiency enhancing, wear preventing and energy saving sealing system according to claim 3, wherein a fluid inlet is provided in the recess, a fluid outlet is provided in the first groove, a fluid passage is provided inside the sealing member to communicate the fluid inlet with the fluid outlet, wherein the fluid outlet is formed as a tapered nozzle; the cross-sectional area of the fluid outlet is smaller than the cross-sectional area of the fluid inlet.

5. A wellhead efficiency, wear and energy saving sealing system according to claim 4, wherein the axis of the tapered nozzle is arranged to be offset towards the second section relative to the radial direction of the sealing member or the axis of the tapered nozzle is arranged to extend in the radial direction of the sealing member.

6. A wellhead efficiency, wear prevention and energy saving sealing system according to claim 4 or 5, characterized in that the number of fluid inlets and the number of fluid outlets are the same as the number of the second grooves, and the fluid outlets are arranged at the intersection of the second grooves and the first grooves.

7. A wellhead efficiency-enhancing wear-resistant energy-saving sealing system according to claim 1, wherein a plurality of pressure relief valves are provided on the leakage fluid discharge pipe, and the set pressure of each pressure relief valve is set to be different pressure relief pressure.

8. The wellhead efficiency-improving wear-resisting energy-saving sealing system according to claim 1, characterized in that the sealing system further comprises a supporting pipe section which is fixed on the inner wall of a second pipe of the oil well, wherein the second pipe is positioned on the outer side of the third pipe, and the pipe diameter of the second pipe is larger than that of the third pipe; the supporting pipe section is located below the first pipe and the third pipe and used for supporting the first pipe and the third pipe, and a channel located between the second pipe and the third pipe is arranged in the radial direction of the supporting pipe section, so that oil extracted from an oil well can be conveyed to an oil discharge pipe at a wellhead through an annular channel between the second pipe and the third pipe through the channel of the supporting pipe section.