Self-lubricating polished rod sealer

Abstract

The invention provides a self-lubricating type polish rod sealer, and relates to the technical field of oil and gas exploitation equipment, the self-lubricating type polish rod sealer comprises a sealing part and a lubricating part communicated with the sealing part, the sealing part comprises a sealing bin and a sealing body filled in the sealing bin, and the lubricating part comprises an oil storage bin and a lubricating medium filled in the oil storage bin; the oil storage bin comprises an inner shell, an oil storage cavity and an outer shell which are sequentially distributed from inside to outside, the oil storage cavity is a sealed space formed by a gap between the inner shell and the outer shell, and the inner shell sleeves the outer wall of the polish rod; a ball lubricating device is arranged at the bottom of the inner shell and comprises a ball bin formed in the wall of the inner shell and a lubricating ball embedded in the ball bin in a rolling mode, and the spherical surface of the lubricating ball makes contact with the oil storage cavity and the polish rod. A ball type lubricating structure is adopted, and liquid lubricating oil is combined, so that the surface of the polish rod can be uniformly and effectively lubricated; lubricating oil is high in utilization efficiency and free of waste, and maintenance frequency is reduced; the device is suitable for high-temperature working environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas production equipment, and particularly relates to a self-lubricating polished rod seal. BACKGROUND

[0002] In the field of oil production engineering, the polished rod seal is the key equipment to ensure that the oil and gas in the well do not leak, and its main function is to maintain good sealing between the polished rod and the sealing filler. However, in the actual production process, due to various challenges, the current polished rod lubrication management has significant problems:

[0003] Firstly, the traditional polished rod maintenance operation relies on the regular inspection of team members and manual application of lubricating grease to the polished rod to reduce the wear between the polished rod and the sealing filler. This method is short-lived and needs to be repeated every day or at fixed intervals, which not only increases the workload of the employees, but also makes it difficult to ensure continuous and effective lubrication.

[0004] Secondly, due to the characteristics of intermittent oil production, high viscosity of crude oil, and easy scaling of the polished rod surface, the lubrication demand is more frequent and urgent. However, in reality, the lubrication operation is often not timely, which leads to insufficient lubrication of the polished rod, and further accelerates the wear rate of the sealing filler, causing the polished rod seal to leak, which not only pollutes the environment, but also forces the team to frequently shut down the well for sealing filler replacement. This process not only affects the normal production rate of the oil well, but also increases material consumption and poses a certain safety and environmental risk.

[0005] Chinese Patent No. CN2289875Y discloses a self-lubricating anti-pollution polished rod seal, which includes two parts of self-lubricating anti-pollution and polished rod seal, and is composed of an upper end cover, a polished rod sealing cover, a polished rod sealing seat, an oil storage cavity, upper and lower overflow oil pipes, a pressure cover, a sealing ring, a pressure pad, a sealing body, and a flange. The patent uses an oil cleaner, an oil storage cavity, and a polished rod seal to complete the wellhead polished rod sealing, lubrication, cooling, and anti-pollution functions.

[0006] However, the shortcomings of this scheme are that it is only suitable for lubricating grease and solid lubricant lubricating media, which can easily melt and quickly lose, or even dilute and fail in high-temperature working environments. In addition, the self-weight lubrication method of the lubricating medium in the patent cannot ensure that the lubricating medium uniformly flows into the gap between the oil storage cavity and the polished rod, and the lubrication of the polished rod is not uniform and sufficient. Furthermore, the self-weight lubrication method of the lubricating medium may also leak lubricating medium from the gap between the oil storage cavity and the polished rod when the polished rod is not working, resulting in waste of lubricating medium and high maintenance frequency. Finally, the self-weight adhesion lubrication method of the lubricating medium will cause the lubricating medium to adhere to the inner wall of the oil storage cavity, resulting in low utilization efficiency and waste of lubricating medium, further increasing the maintenance frequency. SUMMARY

[0007] The self-lubricating polished rod sealer has a ball-type lubricating structure and can uniformly and effectively lubricate the surface of the polished rod in combination with liquid lubricating oil.

[0008] To achieve the above object, the present application is implemented by the following technical scheme:

[0009] The self-lubricating polished rod sealer comprises a sealing part and a lubricating part in communication with the sealing part, the sealing part comprises a sealing chamber and a sealing body filled in the sealing chamber, and the lubricating part comprises an oil storage chamber and a lubricating medium filled in the oil storage chamber.

[0010] The lubricating medium is liquid lubricating oil, and the liquid lubricating oil is filled in the oil storage chamber.

[0011] The inner shell bottom is provided with a ball lubricating device, the ball lubricating device comprises ball chambers opened on the inner shell wall and lubricating balls embedded in the ball chambers, and the spherical surface of the lubricating balls contacts the oil storage chamber and the polished rod.

[0012] Further, the ball lubricating device comprises a plurality of groups of ball chambers and lubricating balls, and each group of ball chambers and lubricating balls is uniformly distributed on the inner shell bottom.

[0013] Further, the ball chamber is provided with a ball snap ring, and the lubricating ball is arranged in the ball snap ring.

[0014] Further, the oil storage chamber is provided with a detachable sealing cover, and the sealing cover seals and isolates the oil storage chamber from the outside space of the oil storage chamber.

[0015] Further, the lubricating part further comprises a follow-up limiting chamber, the follow-up limiting chamber is fixed with the sealing chamber, the oil storage chamber is placed in the follow-up limiting chamber, and the outer diameter of the oil storage chamber is smaller than the inner diameter of the follow-up limiting chamber.

[0016] Further, the outer diameter of the oil storage chamber is 4-6 mm smaller than the inner diameter of the follow-up limiting chamber.

[0017] Further, the follow-up limiting chamber is provided with an openable and closable upper end cover, and the height of the inner cavity of the follow-up limiting chamber is matched with the height of the oil storage chamber.

[0018] Further, the lower end surface of the upper end cover is provided with a sealing gasket. The sealing gasket buffers the vibration in the up-down direction of the oil storage chamber.

[0019] Further, the oil storage chamber is provided with an oil level sensor.

[0020] Further, the oil level sensor comprises a probe head and a signal line, the height of the probe head is higher than the height of the ball center of the lubricating ball, and the signal line leads to the outside of the lubricating part.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] First, the present application is provided with a lubricating ball device at the bottom of the oil storage chamber, which is composed of a ball chamber and lubricating balls, the lubricating balls are embedded in the ball chamber, a part of the lubricating balls is soaked in the lubricating oil in the oil storage chamber, and the other part is in contact with the polished rod. When the lubricating balls rotate, the lubricating oil adsorbed on the surface of the lubricating balls can be applied to the surface of the polished rod, and when the lubricating balls do not rotate, the oil hole of the oil storage chamber is sealed by the lubricating balls, which can simultaneously achieve the purposes of effectively sealing the oil storage chamber and uniformly lubricating the polished rod. Therefore, the above-mentioned lubricating ball lubrication mode realizes the continuous and effective lubrication of the polished rod, greatly prolongs the service life of the sealing filler, and reduces the replacement frequency.

[0023] Second, the oil storage chamber is placed in the follow-up limiting chamber, the outer diameter of the oil storage chamber is smaller than the inner diameter of the follow-up limiting chamber, and the oil storage chamber can be slightly adjusted in position with the movement of the polished rod, so that the lubricating balls at the bottom of the oil storage chamber are always in contact with the polished rod, and the wear of the polished rod surface by the lubricating balls when the polished rod swings is avoided, thereby reducing the vibration and noise of the polished rod during reciprocating motion and improving the stability of the polished rod.

[0024] Third, the oil level sensor is installed in the oil storage chamber, which can monitor the liquid level height of the lubricating oil in the oil storage chamber in real time, supplement the lubricating oil in time, and send an oil level warning signal to remind the addition of lubricating oil when the oil level drops to the low warning line, so as to avoid the failure of the lubricating ball device caused by dry grinding of the lubricating balls.

[0025] Fourth, the lubricating device in the present application is suitable for liquid lubricating oil, which can not only adapt to the high-temperature production environment generated by the up-and-down sliding of the polished rod, but also is not easy to adhere to the inner wall of the oil storage chamber, has high utilization efficiency, and reduces the maintenance frequency. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the state of the device of the present application applied to the polished rod;

[0027] Figure 2 It is a structural schematic diagram of the self-lubricating polished rod seal device of the present application;

[0028] Figure 3 It is a partial sectional schematic diagram of the oil storage chamber;

[0029] In the drawings:

[0030] 1, lubricating part; 1.1, follow-up limiting bin; 1.2, upper end cover; 1.3, oil storage bin; 1.31, inner shell; 1.32, oil storage cavity; 1.33, outer shell; 1.34, lubricating ball; 1.35, snap ring; 2, sealing part; 2.1, sealing bin; 2.2, sealing body; 3, polished rod; 4, oil level sensor; 4.1, probe head; 4.2, signal line. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] As shown in Figure 1

[0034] A self-lubricating polished rod seal device, comprising a sealing part 2 and a lubricating part 1 communicating with the sealing part 2, the sealing part 2 comprising a sealing bin 2.1 and a sealing body 2.2 filled in the sealing bin 2.1, the lubricating part 1 comprising an oil storage bin 1.3 and a lubricating medium filled in the oil storage bin 1.3, the oil storage bin 1.3 comprising an inner shell 1.31, an oil storage cavity 1.32 and an outer shell 1.33 distributed in sequence from inside to outside, the oil storage cavity 1.32 being a sealed space formed by the gap between the inner shell 1.31 and the outer shell 1.33, and the inner shell 1.31 being sleeved on the outer wall of the polished rod 3; the lubricating medium is liquid lubricating oil, which is filled in the oil storage cavity 1.32; the bottom of the inner shell 1.31 is provided with a ball lubricating device, the ball lubricating device comprising a plurality of groups of ball bins opened on the wall of the inner shell 1.31 and lubricating balls 1.34 rollingly embedded in the ball bins, a ball snap ring 1.35 being arranged in each ball bin, and the lubricating balls 1.34 being arranged in the ball snap ring 1.35. The spherical surface of the lubricating balls 1.34 contacts the oil storage cavity 1.32 and the polished rod 3. Each group of ball bins and lubricating balls 1.34 are uniformly distributed at the bottom of the inner shell 1.31.

[0035] ​The oil storage bin 1.3 is provided with a detachable sealing cover which seals and isolates the oil storage cavity 1.32 from the outside space of the oil storage bin 1.3. The lubricating part 1 further comprises a follow-up limiting bin 1.1 which is fixed with the sealing bin 2.1, and the oil storage bin 1.3 is placed in the follow-up limiting bin 1.1, and the outer diameter of the oil storage bin 1.3 is 5mm smaller than the inner diameter of the follow-up limiting bin 1.1. The follow-up limiting bin 1.1 is provided with an openable and closable upper end cover 1.2 which is connected with the bin body of the follow-up limiting bin 1.1 through threaded connection, and the lower end surface of the upper end cover 1.2 is provided with a sealing gasket. The height of the inner cavity of the follow-up limiting bin 1.1 is consistent with the height of the oil storage bin 1.3, and when the upper end cover 1.2 is tightly covered on the follow-up limiting bin 1.1, the upper end cover 1.2 just contacts the upper end surface of the oil storage bin 1.3, but does not press the oil storage bin 1.3 tightly, so as to keep the freedom of the oil storage bin 1.3 in vibration with the polished rod 3. The upper end cover 1.2 simultaneously serves as a sealing cover on the oil storage bin 1.3, and when the upper end cover 1.2 is covered on the follow-up limiting bin 1.1, the oil storage bin 1.3 is simultaneously sealed.

[0036] An oil level sensor 4 is arranged in the oil storage cavity 1.32. The oil level sensor 4 comprises a probe head 4.1 and a signal line 4.2, the height of the probe head 4.1 is consistent with the fixed point height of the spherical surface of the lubricating ball 1.34, and the signal line 4.2 leads to a signal receiving device outside the lubricating part 1, so as to monitor the liquid level height in the oil storage bin 1.3 in real time, and prevent the phenomenon of dry grinding of the lubricating ball 1.34 on the polished rod 3 from occurring when the lubricating oil is insufficient.

[0037] The working principle of the present application is as follows:

[0038] Firstly, initial installation is carried out. Lubricating oil is injected into the oil storage cavity 1.32, and then the oil storage bin 1.3 is placed in the follow-up limiting bin 1.1, and the inner shell 1.31 of the oil storage bin 1.3 is sleeved on the polished rod 3. Then, the upper end cover 1.2 is installed on the follow-up limiting bin 1.1, and the installation of the device of the present application is completed. When the upper end cover 1.2 is tightly covered on the follow-up limiting bin 1.1, the upper end cover 1.2 just contacts the upper end surface of the oil storage bin 1.3, but does not press the oil storage bin 1.3 tightly, so as to keep the freedom of the oil storage bin 1.3 in vibration with the polished rod 3.

[0039] In the operation process of the present polished rod seal, part of the ball is soaked in the lubricating oil in the oil storage cavity 1.32, and part is in contact with the polished rod 3. When the ball rotates, it can smear the surface-adsorbed lubricating oil to the surface of the polished rod 3. When it does not rotate, it can seal the oil hole of the lubricating oil cavity through the ball, which can simultaneously achieve the purposes of effectively sealing the lubricating oil cavity and uniformly lubricating the polished rod 3. At the same time, the oil storage bin 1.3 is placed in the follow-up limiting bin 1.1, the outer diameter of the oil storage bin 1.3 is smaller than the inner diameter of the follow-up limiting bin 1.1, and the oil storage bin 1.3 can fine-tune the position with the movement of the polished rod 3, so that the lubricating ball 1.34 at the bottom of the oil storage bin 1.3 always contacts the polished rod 3, and at the same time, the wear of the lubricating ball 1.34 to the surface of the polished rod 3 is avoided when the polished rod 3 swings, thereby reducing the vibration and noise of the polished rod 3 when reciprocating, and improving the running stability of the polished rod 3.

[0040] In addition, the oil storage bin 1.3 is provided with an oil level sensor 4. When the lubricating oil level in the oil storage cavity 1.32 is lower than the spherical vertex of the lubricating ball 1.34, it means that the lubricating oil cannot completely immerse the lubricating ball 1.34, which may cause the polished rod 3 to be insufficiently lubricated, and the oil temperature sensor 4 will send out an alarm signal. At this time, it is necessary to add lubricating oil to the oil storage cavity 1.32 in time, or replace the oil storage bin 1.3 which has been added with lubricating oil in advance.

[0041] The above-mentioned embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A self-lubricating polished rod seal, comprising a sealing part and a lubricating part in communication with the sealing part, the sealing part comprising a sealing chamber and a sealing body filled in the sealing chamber, and the lubricating part comprising an oil storage chamber and a lubricating medium filled in the oil storage chamber, characterized in that: The oil storage bin comprises an inner shell, an oil storage cavity and an outer shell distributed in sequence from inside to outside, the oil storage cavity is a sealed space formed by the gap between the inner shell and the outer shell, and the inner shell is sleeved on the outer wall of the polished rod; The lubricating medium is liquid lubricating oil, and the liquid lubricating oil is filled in the oil storage cavity; The inner shell bottom is provided with a ball lubricating device, the ball lubricating device comprises ball cartridges opened on the inner shell wall and lubricating balls embedded in the ball cartridges, and the spherical surface of the lubricating balls contacts the oil storage cavity and the polished rod.

2. A self-lubricating polished rod seal as defined in claim 1, wherein: The ball lubricating device comprises several groups of ball cartridges and lubricating balls, and each group of ball cartridges and lubricating balls is uniformly distributed on the inner shell bottom.

3. A self-lubricating polished rod seal as defined in claim 1, wherein: A ball snap ring is arranged in the ball cartridge, and the lubricating ball is arranged in the ball snap ring.

4. The self-lubricating polished rod seal as defined in claim 1, wherein: The oil storage bin is provided with a detachable sealing cover which seals and isolates the oil storage cavity from the outside space of the oil storage bin.

5. The self-lubricating polished rod seal as defined in claim 1, wherein: The lubricating part further comprises a follow-up limiting bin, the follow-up limiting bin is fixed with the sealing bin, the oil storage bin is placed in the follow-up limiting bin, and the outer diameter of the oil storage bin is smaller than the inner diameter of the follow-up limiting bin.

6. A self-lubricating polished rod seal as defined in claim 5 wherein: The outer diameter of the oil storage bin is 4-6mm smaller than the inner diameter of the follow-up limiting bin.

7. A self-lubricating polished rod seal as defined in claim 5 wherein: The follow-up limiting bin is provided with an openable and closable upper end cover, the height of the inner cavity of the follow-up limiting bin is matched with the height of the oil storage bin.

8. A self-lubricating polished rod seal as defined in claim 7, wherein: The lower end surface of the upper end cover is provided with a sealing gasket.

9. The self-lubricating polished rod seal of any of claims 1-8, wherein: An oil level sensor is arranged in the oil storage cavity.

10. A self-lubricating polished rod seal as defined in claim 9, wherein: The oil level sensor comprises a probe head and a signal line, the height of the probe head is higher than the height of the ball center of the lubricating ball, and the signal line leads to the outside of the lubricating part.

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