High-temperature-resistant and high-pressure-resistant check ring for petroleum well logging and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant and high-pressure-resistant check ring for oil well logging and a preparation method of the check ring. A composite material of the check ring comprises the following components in parts by weight: 70-75 parts of PAEK, 20-25 parts of glass fiber powder, 4-9 parts of a wear-resistant agent and 1 part of a silane coupling agent. Wherein the wear-resistant agent is one of tin disulfide, tungsten disulfide and molybdenum disulfide. The retainer ring produced by the preparation process provided by the invention has the advantages of high temperature resistance, high pressure resistance, hydrogen sulfide corrosion resistance, acid-base corrosion resistance, mechanical wear resistance and the like, is good in high-temperature dimensional stability, has relatively high consistency during batch production, improves the overall production efficiency and the product quality, and meets the strict requirements of the petroleum logging field on high-temperature and high-pressure resistant parts.

Description

Technical Field

[0001] The invention relates to a retaining ring for petroleum logging instruments and equipment, and more specifically, mainly relates to a preparation method of a retaining ring using polyaryletherketone (PAEK) as a raw material and reinforced with glass fiber. Background Art

[0002] As the drilling depth increases, the underground temperature becomes higher and higher, and the working environment becomes very harsh and complex, which undoubtedly poses a severe challenge to the functional stability and safety of logging instruments and equipment. In this context, the reliability of the sealing system has become a decisive factor, which is directly related to whether the instruments and equipment can continue to operate stably in harsh environments.

[0003] Therefore, sealing rings and other components play a vital role as key components of the above-mentioned instruments and equipment. They not only need to withstand extreme physical conditions such as high temperature of 200°C and high pressure of 175MPa, but also need to resist working under multiple conditions such as hydrogen sulfide corrosion, acid and alkali corrosion and mechanical wear. These extreme working conditions put forward more refined requirements on the structural design of seals, and it is necessary to ensure that they can withstand complex stress distribution; in terms of raw material selection, materials with excellent high temperature resistance and corrosion resistance must be selected; the manufacturing process must be refined to ensure the accuracy and reliability of the seals; at the same time, quality control of batch products is also an important part that cannot be ignored, and any minor defects may lead to a decline in overall performance.

[0004] However, existing similar products (generally retaining rings made of pure PEEK, PTFE, POM, PA and other polymer materials and rubber or its modified materials) have frequently exposed problems in actual applications. These retaining rings often loosen or even break during use, which seriously hinders the downhole operation of the system and instruments, and even causes operation failure. Through in-depth failure analysis of failed seals, combined with sampling inspections of currently available imported retaining ring components, we found that the failed retaining rings have obvious deficiencies in strength, toughness and environmental tolerance, and cannot meet the requirements of specific installation locations. In addition, the quality consistency of these retaining rings in the prior art is poor, and some retaining rings have unreasonable designs or defects in the manufacturing process. These problems not only affect the sealing performance, but also directly lead to a significant decrease in the overall sealing reliability of the system and instruments, posing a great hidden danger to the safety and efficiency of drilling operations.

[0005] Therefore, there is an urgent need in the art for a retaining ring that can be used for petroleum logging instruments and equipment in extreme working environments. Summary of the invention

[0006] In order to solve the above problems, the primary purpose of the present invention is to provide a high temperature and high pressure resistant retaining ring for petroleum logging and a preparation method thereof. The retaining ring provided by the present invention can work in extreme working conditions, including high temperature of 200°C, high pressure of 175MPa, hydrogen sulfide corrosion, acid and alkali corrosion, mechanical wear, etc. Therefore, these factors put forward higher requirements on the raw material selection, structure, manufacturing process, quality stability and reliability of the instrument-specific retaining ring.

[0007] The present invention adopts the following technical solution:

[0008] The components and weight ratio of a high temperature and high pressure resistant retaining ring composite material for petroleum logging are: 70-75 parts of PAEK, 20-25 parts of glass fiber powder, 4-9 parts of wear-resistant agent, and 1 part of silane coupling agent. Among them, the silane coupling agent is KH550;

[0009] The wear-resistant agent is one of tin disulfide, tungsten disulfide and molybdenum disulfide.

[0010] Tin disulfide, tungsten disulfide, and molybdenum disulfide all have a layer lattice structure, the atomic layers can easily move relative to each other, the material is soft, has good adhesion to metals, forms a stable lubricating film interface, and has better wear resistance.

[0011] Furthermore, the glass fiber powder needs to be glass fiber treated with a silane coupling agent.

[0012] The present invention also claims protection for a method for preparing a high temperature and high pressure resistant retaining ring for petroleum logging, which specifically comprises the following steps:

[0013] (1) PAEK 70-75 parts is dried before use;

[0014] (2) adding a silane coupling agent to anhydrous ethanol to prepare a coupling agent solution; adding 20-25 parts of glass fiber powder to the silane coupling agent solution and stirring; then filtering and extracting the solution, and finally drying off the residual solvent;

[0015] (3) placing the PAEK, glass fiber powder, and wear-resistant agent powder treated in steps (1) and (2) in a double-motion mixer and mixing them, while introducing negative ion compressed air at one end of the mixer and filtering and discharging at the other end, and mixing to obtain a mixed raw material;

[0016] (4) Place the mixed raw materials into the cavity of the retaining ring mold, apply a pressure of 3-5 MPa through the punch to compact the raw materials and expel the air in the cavity.

[0017] (5) Place the mold in an electromagnetic heating furnace and heat it at 410-420°C for 10-15 minutes;

[0018] (6) Quickly remove the mold and place it on the press, slowly pressurize it to 10-15 MPa, maintain the pressure for 20-30 minutes, and demold and remove the retaining ring;

[0019] (7) Place the retaining ring in a heating furnace and heat it to 200°C for 1 hour to eliminate its internal stress.

[0020] Furthermore, in step (1), the mixture is dried at 150° C. for 4 hours.

[0021] Furthermore, after filtering in step (2), the modified glass fiber powder is dried at 120° C. to remove residual solvent.

[0022] Furthermore, the mixing time in step (3) is 25-30 minutes.

[0023] The preparation method provided by the present invention is a significant improvement over the prior art, and the various steps work synergistically, promote each other, and are closely linked, making the product performance more excellent.

[0024] In the steps (1) to (3), a PAEK material with higher heat resistance is used as the matrix resin, and the glass transition temperature is (240-280°C), wherein the glass transition temperature of PEEK is 143°C. It has better mechanical properties, dimensional stability, friction and wear properties under high temperature and high pressure conditions underground. The glass fiber is treated with a silane coupling agent to improve its compatibility with the resin and improve the material properties.

[0025] The present invention adopts double motion superposition mixing technology to achieve two functions: gravity diffusion type mixing and forced shear type mixing, so that the powder can roll up and down and convect left and right to diffuse and mix evenly. In addition, negative ion compressed air is introduced to eliminate the positive ions generated by material friction and reduce the temperature. The negative ion airflow can improve the mixing effect and thus improve the material performance.

[0026] The steps (4) to (6) are a forming and manufacturing process for the retaining ring, which abandons the method of first performing preliminary processing on the blank and then manufacturing the retaining ring by mechanical processing in the traditional manufacturing process.

[0027] This innovative preparation process exhibits the following significant advantages:

[0028] 1. The retaining ring has good dimensional consistency and high batch stability: Through precise molding technology, the dimensional accuracy and consistency of the prepared retaining ring are ensured, which effectively improves the product stability in batch production.

[0029] 2. The preparation process is streamlined and production efficiency is significantly improved: Compared with traditional processes, this process reduces the intermediate processing links, thereby greatly shortening the production cycle and improving overall production efficiency.

[0030] 3. One-time molding, maximized material utilization: The retaining ring is directly formed in this process without the need for subsequent material removal processing steps. Compared with traditional machining methods based on bar or tube materials, it significantly reduces material loss and achieves higher material utilization.

[0031] The step (7) eliminates the internal stress of the retaining ring product by high-temperature heating, thereby improving the dimensional stability of the retaining ring product and making the retaining ring sealing more reliable.

[0032] The present invention also comprises step (8): cutting a 30° bevel on the retaining ring by using a special cutting device.

[0033] As a preferred embodiment of the present invention, the mass ratio of the raw materials is: 75 parts of PAEK, 20 parts of glass fiber, 4 parts of wear-resistant agent, and 1 part of silane coupling agent (KH550).

[0034] The retaining ring mold in the present invention is composed of a male mold, an outer mold, an inner mold, a female mold and a pad. A columnar inner mold and an outer mold are arranged on the pad, a female mold is arranged on the pad, a male mold is arranged above the female mold, the female mold and the male mold cooperate with each other, the inner mold, the outer mold and the male mold located above form a cavity, and the mixed raw materials of the retaining ring to be formed are placed in the cavity.

[0035] Furthermore, the punch is cylindrical, with a diameter larger than that of the inner mold and smaller than that of the outer mold, and the punch is arranged on the outer ring of the inner mold.

[0036] Furthermore, the shape of the punch located in the cavity is conical, cylindrical, or a curved surface with a smooth transition.

[0037] The present invention also claims protection for the retaining ring prepared by the above method.

[0038] The product of the present invention operates in extremely harsh working conditions, such as facing multiple challenges such as scorching high temperature up to 200°C, severe high pressure up to 175MPa, highly corrosive hydrogen sulfide gas environment, erosion by strong acid and strong alkali solutions, and continuous mechanical wear. All of these factors have put forward extremely stringent and comprehensive requirements on the raw material selection, structural design, manufacturing process, quality stability and reliability of the instrument-specific retaining ring and support ring.

[0039] 1. In terms of raw material selection, materials that can withstand extreme temperature and pressure changes, have excellent corrosion resistance and good mechanical strength must be selected to ensure that the retaining ring and support ring will not deform, break or deteriorate in performance during long-term operation. In terms of structural design, factors such as stress distribution, sealing effect, installation convenience and maintenance cost must be comprehensively considered. Through precise calculation and simulation, a structural solution that meets functional requirements and has high reliability can be designed.

[0040] 2. In terms of manufacturing technology, advanced processing technology and strict quality control procedures are required to ensure that every detail meets the design requirements, so as to produce high-precision, high-performance products. At the same time, stable quality and reliability are the key to ensuring the long-term stable operation of the instrument. Therefore, from raw material inspection, production and processing to finished product testing, every link needs to be strictly controlled to ensure that all products shipped can meet the most stringent working conditions.

[0041] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0042] The retaining ring produced by the preparation process provided by the present invention has the advantages of resistance to high temperature of 200°C, high pressure of 175MPa, hydrogen sulfide corrosion, acid and alkali corrosion, mechanical wear, etc., and has good high-temperature dimensional stability and high consistency during batch production, thereby improving the overall production efficiency and product quality, and meeting the strict requirements of the oil well logging field for high-temperature and high-pressure resistant parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of retaining ring mold structure;

[0044] Figure 2 Photos of the front and back of the PEEK retaining ring;

[0045] Figure 3 Schematic diagram of the PEEK retaining ring structure.

[0046] Among them, 1. punch, 2. outer mold, 3. inner mold, 4. die, 5. pad, 6. cavity, 7. retaining ring. DETAILED DESCRIPTION

[0047] In order to more clearly illustrate the purpose, technical solutions and advantages of the present disclosure, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the following description of the embodiments is intended to explain and illustrate the overall concept of the present invention, and should not be understood as a limitation of the present invention. In the specification and the drawings, the same or similar figure marks refer to the same or similar parts or components. For the sake of clarity, the drawings are not necessarily drawn to scale, and some well-known parts and structures may be omitted in the drawings. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0048] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0050] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] Example 1

[0052] The PAEK was dried at 150°C for 4 hours; the glass fiber powder was placed in the prepared silane coupling agent solution and stirred for 10 minutes, and then the solution was filtered and extracted, and finally the modified glass fiber was baked at 120°C to remove the residual solvent to obtain the modified glass fiber powder. The processed PAEK, glass fiber powder and wear-resistant agent powder are placed together in a double-motion mixer, and negative ion compressed air is introduced at one end of the mixer, filtered and discharged at the other end, and mixed for 30 minutes to obtain a mixed raw material; the mixed raw material is placed in the cavity of the retaining ring mold, and a pressure of 3-5MPa is applied through the punch to compact the raw material and discharge the air in the cavity; the mold is placed in an electromagnetic heating furnace for heating at a temperature of 410-420°C for 10-15 minutes; then the mold is quickly taken out and placed on a press, and the pressure is slowly increased to 10-15MPa, the pressure is maintained for 30 minutes, and the retaining ring is demolded and taken out; the retaining ring is placed in a heating furnace and heated to 200°C, and the temperature is maintained for 1 hour to eliminate its internal stress; the retaining ring is cut with a 30° bevel using a special cutting device.

[0053] The mass ratio of the raw materials described in the above steps is: 75 parts of PEEK, 20 parts of glass fiber, 4 parts of wear-resistant agent tin disulfide powder, and 1 part of silane coupling agent (KH550).

[0054] The retaining ring mold in the present invention is composed of a punch 1, an outer mold 2, an inner mold 3, a die 4, and a pad 5. A columnar inner mold 3 and an outer mold 2 are provided on the pad 5, and a die 4 is provided on the pad 5. A punch 1 is provided above the die 4. The punch 1 is cylindrical, with a diameter larger than that of the inner mold 3 and smaller than that of the outer mold 2. The punch 1 is provided on the outer ring of the inner mold 3.

[0055] The concave die 4 cooperates with the convex die 1 , and the inner die 3 , the outer die 2 and the convex die 1 located above form a cavity 6 , in which the mixed raw materials of the retaining ring 7 to be formed are placed.

[0056] The shape of the punch 1 located in the cavity 6 is conical, cylindrical, or a smoothly transitioned curved surface.

[0057] Example 2

[0058] The PAEK was dried at 150°C for 4 hours; the glass fiber powder was placed in the prepared silane coupling agent solution and stirred for 10 minutes, and then the solution was filtered and extracted, and finally the modified glass fiber was baked at 120°C to remove the residual solvent to obtain the modified glass fiber powder. The processed PAEK, glass fiber powder and wear-resistant agent powder are placed together in a double-motion mixer, and negative ion compressed air is introduced at one end of the mixer, filtered and discharged at the other end, and mixed for 30 minutes to obtain a mixed raw material; the mixed raw material is placed in the cavity of the retaining ring mold, and a pressure of 3-5MPa is applied through the punch to compact the raw material and discharge the air in the cavity; the mold is placed in an electromagnetic heating furnace for heating at a temperature of 410-420°C for 10-15 minutes; then the mold is quickly taken out and placed on a press, and the pressure is slowly increased to 10-15MPa, the pressure is maintained for 30 minutes, and the retaining ring is demolded and taken out; the retaining ring is placed in a heating furnace and heated to 200°C, and the temperature is maintained for 1 hour to eliminate its internal stress; the retaining ring is cut with a 30° bevel using a special cutting device.

[0059] The mass ratio of the raw materials described in the above steps is: 70 parts of PEEK, 25 parts of glass fiber, 4 parts of wear-resistant agent tungsten disulfide powder, and 1 part of silane coupling agent (KH550).

[0060] Comparative Example 1

[0061] In this comparative example, the retaining ring is made of pure PEEK as a control, and the experimental data are shown in Table 1.

[0062] Comparative Example 2

[0063] In this comparative example, the retaining ring is prepared by the method described in Example 1, and the raw materials are PTFE+15wt% glass fiber.

[0064] Comparative Example 3

[0065] In this comparative example, the retaining ring was prepared by the method described in Example 1, and the raw material was pure PA66.

[0066] Comparative Example 4

[0067] In this comparative example, the retaining ring is prepared by the method described in Example 1, and the raw material is pure POM.

[0068] Table 1 Retaining ring performance test data

[0069]

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high temperature and high pressure resistant retaining ring composite material for petroleum well logging, characterized in that: The components and their weight ratios are: PAEK 70-75 parts, glass fiber powder 20-25 parts, wear-resistant agent 4-9 parts, silane coupling agent 1 part; The wear-resistant agent is one of tin disulfide, tungsten disulfide and molybdenum disulfide.

2. The method for preparing a retaining ring composite material according to claim 1, characterized in that the steps include: (1) 70-75 parts of PAEK are dried before use; (2) adding a silane coupling agent to anhydrous ethanol to prepare a coupling agent solution; adding 20-25 parts of glass fiber powder to the silane coupling agent solution and stirring; then filtering and extracting the solution, and finally drying off the residual solvent; (3) placing the PAEK, glass fiber powder, and wear-resistant agent powder treated in steps (1) and (2) in a double-motion mixer and mixing them, while introducing negative ion compressed air at one end of the mixer and filtering and discharging at the other end, and mixing to obtain a mixed raw material; (4) Place the mixed raw materials into the cavity of the retaining ring mold, apply a pressure of 3-5 MPa through the punch to compact the raw materials and expel the air in the cavity; (5) Place the mold in an electromagnetic heating furnace and heat it at 410-420°C for 10-15 minutes; (6) Quickly remove the mold and place it on the press, slowly pressurize it to 10-15 MPa, maintain the pressure for 20-30 minutes, and demold and remove the retaining ring; (7) Place the retaining ring in a heating furnace and heat it to 200°C for 1 hour to eliminate its internal stress.

3. The method according to claim 2, characterized in that In step (1), the mixture is dried at 150° C. for 4 hours.

4. The method according to claim 2, characterized in that: After filtering in step (2), the modified glass fiber powder is dried at 120° C. to remove the residual solvent.

5. The method according to claim 2, characterized in that: The mixing time of step (3) is 25-30 minutes.

6. A high temperature and high pressure retaining ring for petroleum logging, characterized in that: Prepared by the method of claim 2.

7. A mold for preparing a high temperature and high pressure retaining ring for petroleum logging, characterized in that: The invention comprises a male mold (1), an outer mold (2), an inner mold (3), a female mold (4) and a backing plate (5). A columnar inner mold (3) and an outer mold (2) are arranged on the backing plate (5). A female mold (4) is arranged on the backing plate (5). A male mold (1) is arranged above the female mold (4). The female mold (4) cooperates with the male mold (1). The inner mold (3), the outer mold (2) and the male mold (1) located above form a cavity (6). A mixed raw material of a retaining ring (7) to be formed is placed in the cavity (6).

8. The mold according to claim 7, characterized in that: The punch (1) is cylindrical, with a diameter greater than that of the inner mold (3) and smaller than that of the outer mold (2), and the punch (1) is arranged on the outer ring of the inner mold (3).

9. The mold according to claim 7, characterized in that: The shape of the punch (1) located in the mold cavity (6) is conical, cylindrical, or a curved surface with a smooth transition.

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