Self-lubricating high-pressure plunger pump sealing ring

Abstract

The utility model relates to a self-lubricating high-pressure plunger pump sealing ring which comprises a head ring, a pressure ring and an isolating ring which are sequentially arranged on a plunger in a sleeving mode. The top of the head ring is provided with a herringbone protruding structure protruding outwards. A herringbone groove structure matched with the herringbone protrusion structure is arranged at the bottom of the pressure ring. The top of the pressure ring is provided with a cambered surface structure protruding outwards. And the cambered surface structure is matched with an arc-shaped groove formed in the bottom of the isolating ring. The head ring is suitable for extreme working conditions of high-pressure and high-hardness sand abrasion and high-acidity, low-viscosity and poor-self-lubricating fracturing fluid and cement paste corrosion, the performance of the head ring is remarkably improved, the service life of a fracturing packing assembly is prolonged, the operation cost and risk are reduced, and the oil and gas exploitation efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas well operation technology, specifically to a self-lubricating high-pressure plunger pump sealing ring and its manufacturing method. Background Technology

[0002] Oilfield fracturing trucks are key equipment in oil and gas well production enhancement operations. They primarily use hydraulic fracturing technology to induce fractures in oil and gas formations, optimizing underground oil and gas flow and thus increasing well production. On the other hand, oilfield cementing trucks play a crucial role in oil and gas drilling operations. Their high-pressure pumping systems deliver cement slurry to the annular space between the casing and the wellbore, securing the casing and sealing unwanted oil, gas, or water zones to ensure safe well production. As core components of these vehicles, the performance of fracturing pumps and cementing pumps directly impacts the overall operational effectiveness of the equipment.

[0003] In the hydraulic end section of fracturing pumps and cementing pumps, the packing assembly is a key component to ensure continuous power supply, and its lifespan is an important indicator for measuring pump performance.

[0004] The shortcomings of existing technology are:

[0005] 1. Because fracturing pumps and cementing pumps operate in extremely harsh environments, they face high pressure, abrasion from high-hardness sand particles, and corrosion from fracturing fluids or cement slurries that are highly acidic, have low viscosity, and poor self-lubricating properties. This causes packing components, especially the rubber head rings, to be extremely prone to wear and corrosion, thus shortening their service life. Frequent replacements not only increase operating costs and risks but also affect oil production efficiency.

[0006] 2. To improve the wear resistance and corrosion resistance of rubber end rings, some improvements have been made to existing technologies, such as replacing the material of the rubber end ring from NBR to HNBR. HNBR material, due to its superior temperature resistance and chemical corrosion resistance, can effectively reduce the coefficient of friction and wear, extending the service life of the end ring. However, existing pure rubber end rings still lag significantly behind fabric-reinforced rubber end rings in terms of wear resistance, tear resistance, and corrosion resistance, which limits their application performance and durability under extreme working conditions. Summary of the Invention

[0007] This invention addresses the aforementioned problems by providing a self-lubricating high-pressure plunger pump sealing ring and its manufacturing method. The purpose is to provide a novel packing head ring, which is particularly suitable for extreme working conditions such as high pressure, high-hardness sand abrasion, and corrosion from fracturing fluids and cement slurries with high acidity, low viscosity, and poor self-lubrication. This significantly improves the performance of the head ring, extends the service life of fracturing packing components, reduces operating costs and risks, and improves oil and gas extraction efficiency.

[0008] To solve the above problems, the technical solution provided by this utility model is as follows:

[0009] A self-lubricating high-pressure plunger pump sealing ring comprises a head ring, a pressure ring, and an isolation ring sequentially fitted onto the plunger, wherein:

[0010] The top of the head ring has an outwardly protruding herringbone-shaped protrusion; the bottom of the pressure ring has a herringbone-shaped groove structure that matches the herringbone-shaped protrusion; the top of the pressure ring has an outwardly protruding arc-shaped surface structure; the arc-shaped surface structure matches the arc-shaped groove at the bottom of the isolation ring.

[0011] Preferably, the outer diameter of the annular outer surface of the head ring is smaller than the inner diameter of the packing box; the inner surface of the head ring includes an annular protrusion structure with an arc cross-section and an annular step located below the annular protrusion structure; the inner diameter of the annular protrusion structure is smaller than the outer diameter of the plunger.

[0012] Preferably, the headband comprises a uniformly distributed fabric-reinforced elastic material; the surface of the headband is uniformly coated with a self-lubricating protective film.

[0013] Preferably, the rubber material content of the headband is in the range of 35% to 75%.

[0014] Preferably, the sealing ring is used in the cementing packing assembly of the cementing truck, comprising a head ring, a pressure ring, and an isolation ring sequentially fitted onto the plunger.

[0015] Preferably, the sealing ring is used in the fracturing packing assembly of the fracturing truck, comprising a head ring and two pressure rings sequentially fitted onto the plunger.

[0016] Compared with the prior art, this utility model has the following advantages:

[0017] 1. Because the packing head ring of this patent is made of fully fabric-reinforced rubber, its unique manufacturing process ensures that the fiber direction of the fabric reinforcement material is radially perpendicular to the movement axis of the plunger, which significantly enhances the shear strength of the contact area on the inner surface of the head ring.

[0018] 2. Because the aramid fabric material used in this patent has excellent wear resistance, tear resistance and corrosion resistance, it effectively improves the tear strength of the headband, while reducing the coefficient of friction and reducing the risk of leakage.

[0019] 3. Because the aramid fabric used in this patent is treated with liquid or low-viscosity flowable rubber, it has good adhesive properties, avoiding the problem of interlayer delamination or peeling.

[0020] 4. Because this patent makes full use of the elastic deformation characteristics of the aramid fabric bevel structure, the overall performance of the headband is enhanced.

[0021] 5. Since this patent is applicable to various models and specifications of fracturing and cementing head rings, it is easy to operate and requires no special equipment or process conditions, thereby improving its practicality and convenience. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view of the cementing packing assembly arrangement of this utility model;

[0023] Figure 2 This is a schematic cross-sectional view of the arrangement of the fracturing packing assembly of this utility model;

[0024] Figure 3 This is a schematic diagram of the cross-section of the head ring of this utility model, cut along a plane parallel to the plunger axis.

[0025] Figure 4 This is a schematic diagram of the head ring blank of this utility model;

[0026] Figure 5 This is a schematic diagram of the parting surface of the headband molding die of this utility model;

[0027] Figure 6 This is a cross-sectional view of the headband of this utility model after it has been molded and treated with protective measures.

[0028] Among them: 1. Head ring, 2. Pressure ring, 3. Isolation ring, 110. Herringbone protrusion structure, 120. Annular outer surface, 130. Inner surface, 131. Annular protrusion structure, 132. Annular step, 210. Herringbone groove structure, 220. Arc surface structure, 310. Arc groove Detailed Implementation

[0029] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0030] like Figure 1 , 2 As shown in Figure 3, a self-lubricating high-pressure plunger pump sealing ring comprises a head ring 1, a pressure ring 2, and an isolation ring 3 sequentially fitted onto the plunger, wherein:

[0031] The top of the head ring 1 is provided with an outwardly protruding herringbone-shaped protrusion structure 110; the bottom of the pressure ring 2 is provided with a herringbone-shaped groove structure 210 that matches the herringbone-shaped protrusion structure 110; the top of the pressure ring 2 is provided with an outwardly protruding arc surface structure 220; the arc surface structure 220 matches the arc groove 310 located at the bottom of the isolation ring 3.

[0032] It should be noted that the outer diameter of the annular outer surface 120 of the head ring 1 is smaller than the inner diameter of the packing box to facilitate installation; the inner surface 130 of the head ring 1 includes an annular protrusion structure 131 with an arc-shaped cross section and an annular step 132 located below the annular protrusion structure 131; the inner diameter of the annular protrusion structure 131 is smaller than the outer diameter of the plunger, thereby ensuring close contact with the plunger, improving sealing, and avoiding unnecessary shaking.

[0033] It should be further explained that the herringbone-shaped protrusion 110 at the upper end of the head ring 1 has a protrusion along the center line, which fits tightly with the herringbone-shaped groove 210 at the bottom of the pressure ring 2, reducing relative movement; the annular step 132 at the lower end of the head ring 1 fits against the packing seat. This structure not only ensures the overall tightness of the packing assembly, but also effectively prevents high-hardness sand particles from penetrating into the assembly, thereby reducing wear.

[0034] It should be further noted that the head ring 1 has greater elasticity than the pressure ring 2, enabling it to maintain a constant force on the pressure ring 2 during assembly. When the packing nut is connected to the sleeve thread, the elasticity of the head ring 1 can compensate for minor compression fluctuations, maintaining a constant axial force on the pressure ring 2 and ensuring a sealing effect.

[0035] It should be further noted that the headband 1 contains a uniformly distributed fabric-reinforced elastic material; the surface of the headband 1 is uniformly coated with a layer of self-lubricating material protective film.

[0036] In this specific embodiment, the rubber material content of the head ring 1 is in the range of 35% to 75%, and preferably 55% to 65%.

[0037] like Figure 1 As shown, it should be noted that the sealing ring is used in the cementing packing assembly of the cementing truck, which includes a head ring 1, a pressure ring 2, and an isolation ring 3 sequentially fitted onto the plunger.

[0038] like Figure 2 As shown, it should be noted that the sealing ring is also used in the fracturing packing assembly of the fracturing truck, which includes a head ring 1 and two pressure rings 2 sequentially fitted onto the plunger.

[0039] A method for manufacturing a self-lubricating high-pressure plunger pump sealing ring includes the following steps:

[0040] S100. Rubber material and fabric material are mixed in a predetermined ratio to form fabric-reinforced rubber with fabric fibers.

[0041] S200. The fabric-reinforced rubber is beveled into thin sheets, so that the fabric fibers form an artificially preset angle.

[0042] S300. Join sheets of fabric-reinforced rubber, and then cut the joined sheets into strips.

[0043] S400. Stacking or winding strip materials into preforms.

[0044] S500. Place the preformed part in the mold cavity of the compression mold, set the vulcanization conditions: vulcanization temperature 170℃, vulcanization pressure 15MPa, vulcanization time 20min, and push it into the flat vulcanizing machine according to the process requirements to vulcanize the preformed part to form head ring 1.

[0045] S600. Trim the edges of the vulcanized head ring 1, and then uniformly spray a layer of self-lubricating material protective film onto the surface of the head ring 1.

[0046] It should be noted that, as Figure 4 The headband blank 1 shown is made of fabric-reinforced rubber and is composed entirely of uniformly distributed fabric-reinforced elastic material, without containing any other types of embedded or added materials; the mixing process of rubber material and fabric material in step S100 is as follows: the rubber material and fabric material are calendered together by a calender.

[0047] It should be further explained that in order to make the fabric-reinforced rubber head ring 1, the rubber material needs to be mixed with the fabric material; the rubber material includes hydrogenated nitrile rubber. The rubber material and the fabric material can be smoothed and thinned together by using rollers in a calender; thereby enabling the rubber content of the head ring 1 blank to reach the specification requirement of 35% to 75%; the optimal range of rubber content for the head ring 1 blank is 55% to 65%.

[0048] It should be further explained that the mixing process of the rubber material and the fabric material in step S100 is as follows:

[0049] Sa100. Dissolves rubber materials in solvents suitable for specific rubber chemistry, or uses organic solvents or plasticizers to convert rubber materials into a liquid or low-viscosity flowable state.

[0050] Sa200. Apply liquid rubber material to fabric material.

[0051] Sa300 heats the fabric material and the liquid rubber material, causing the rubber material to penetrate into the fabric material, thereby generating solid fabric-reinforced rubber.

[0052] It should be further explained that the method for applying the liquid rubber material to the fabric material in step Sa200 is as follows: the liquid rubber material is sprayed onto the fabric material using a pneumatic spraying device or an airless spraying machine; or a transfer roller mechanism is used, where the liquid rubber material is applied to a roller, and then transferred to the fabric material through contact between the roller and the fabric material. When using a roller, the coating weight can be controlled by changing the relationship between the roller speed and the fabric speed.

[0053] It should be further explained that after the coating in step Sa300 is completed, the solvent is removed in an oven or the rubber is gelled, thereby producing solid fabric-reinforced rubber.

[0054] like Figure 5 As shown, it should be noted that the compression mold in step S500 includes a first mold assembly A, a second mold assembly B, and a third mold assembly C, which together define the shape of the mold cavity. By applying pressure to the first mold assembly A, the second mold assembly B, and the third mold assembly C, the fabric-reinforced rubber is forced into close contact with all areas within the mold cavity. The fabric-reinforced rubber is molded into the finished product shape, forming the headband 1.

[0055] like Figure 6 As shown, it should be noted that in step S600, the vulcanized head ring 1 is subjected to quality inspection. The head ring 1 that meets the specifications is coated with a self-lubricating material protective film with a thickness of 40-100μm to provide additional protection.

[0056] The headband 1, after being treated with a protective film of self-lubricating material, has the following advantages:

[0057] 1. The surface is smooth, without defects, bubbles, or cracks.

[0058] 2. The dimensions meet the requirements, and there is no deformation or delamination.

[0059] 3. The bonding strength reaches 12MPa or above, with good adhesion and is not easy to peel or slip.

[0060] 4. The coefficient of friction is reduced, while tear strength and corrosion resistance are improved.

[0061] It should be noted that the technical problem addressed by this invention is to improve the wear resistance, tear resistance, and corrosion resistance of packing head rings in fracturing pumps and cementing pumps used in oil and gas extraction equipment. During fracturing and cementing operations in oil and gas wells, the packing head rings in the pumping system need to withstand the abrasion of high-hardness sand particles under high-pressure environments, as well as the corrosion and abrasion from fracturing fluids that are highly acidic, have low viscosity, and poor self-lubricating properties. Therefore, the technical field of this invention also includes providing a packing head ring that can maintain better wear resistance, tear resistance, and corrosion resistance under the aforementioned harsh operating conditions, thereby extending the service life of packing components, reducing equipment maintenance and replacement frequency, and improving oil and gas extraction efficiency and economic benefits.

[0062] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the present invention is in a state with fewer features than all of the disclosed individual embodiments. Therefore, the appended claims are hereby clearly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the present invention.

[0063] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use this invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the widest scope of the principles and novel features disclosed in this application.

[0064] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0065] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A self-lubricating high-pressure plunger pump sealing ring, characterized in that: It includes a head ring (1), a pressure ring (2), and a separator ring (3) sequentially fitted onto the plunger, wherein: The top of the head ring (1) is provided with an outwardly protruding herringbone-shaped protrusion structure (110); the bottom of the pressure ring (2) is provided with a herringbone-shaped groove structure (210) that matches the herringbone-shaped protrusion structure (110); the top of the pressure ring (2) is provided with an outwardly protruding arc surface structure (220); the arc surface structure (220) matches the arc-shaped groove (310) at the bottom of the isolation ring (3).

2. The self-lubricating high-pressure plunger pump sealing ring according to claim 1, characterized in that: The outer diameter of the annular outer surface (120) of the head ring (1) is smaller than the inner diameter of the packing box; the inner surface (130) of the head ring (1) includes an annular protrusion structure (131) with an arc-shaped cross section and an annular step (132) located below the annular protrusion structure (131); the inner diameter of the annular protrusion structure (131) is smaller than the outer diameter of the plunger.

3. The self-lubricating high-pressure plunger pump sealing ring according to claim 1, characterized in that: The headband (1) contains a uniformly distributed fabric-reinforced elastic material; the surface of the headband (1) is uniformly coated with a self-lubricating protective film.

4. The self-lubricating high-pressure plunger pump sealing ring according to claim 3, characterized in that: The rubber material content of the head ring (1) ranges from 35% to 75%.

5. The self-lubricating high-pressure plunger pump sealing ring according to any one of claims 1 to 4, characterized in that: The sealing ring is used for the cementing packing assembly of the cementing truck and includes a head ring (1), a pressure ring (2), and an isolation ring (3) sequentially fitted onto the plunger.

6. The self-lubricating high-pressure plunger pump sealing ring according to any one of claims 1 to 4, characterized in that: The sealing ring is used for the fracturing packing assembly of the fracturing truck and includes a head ring (1) and two pressure rings (2) sequentially mounted on the plunger.

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