Anticorrosion sucker rod containing POK polyketone material and oil pipe

Abstract

The invention belongs to the technical field of petroleum equipment, and particularly relates to an anti-corrosion sucker rod containing a POK polyketone material and an oil pipe. The invention aims to solve the problems of low wear resistance, low tensile strength and low frictional resistance of the existing anti-corrosion sucker rod and oil pipe. According to the anti-corrosion sucker rod and the oil pipe, a POK-containing polyketone material is sprayed on the surfaces of the anti-corrosion sucker rod and the oil pipe, and the POK-containing polyketone material comprises the following components in parts by mass: 50-60 parts of POK; 20-30 parts by mass of a reinforcing agent; 10 to 15 parts by mass of nano silicon dioxide; 5-10 parts by mass of barium sulfate; and 0.2-1 part by mass of an antioxidant 1010. The sucker rod and the oil pipe have the advantages of being high in tensile strength, small in frictional resistance and high in abrasive resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum equipment, and in particular relates to an anti-corrosion sucker rod and oil pipe containing POK polyketone material. Background Art

[0002] In the oil production process, with the increasing proportion of directional, horizontal, and highly deviated wells, and the continued deepening of waterflood development, the working environment of pipes and tubing has become increasingly harsh. Well fluid salinity continues to rise, and corrosive media (such as H2S, CO2, Cl⁻, and brine) are increasing. Sucker rods and tubing are exposed to high temperatures, high pressures, and a high concentration of corrosive media in the downhole environment. Long-term use can easily lead to corrosion, eccentric wear, and breakage. This not only reduces the strength of the sucker rod, causing it to break, but also wears through the tubing wall, causing tubing leaks. This shortens equipment life, increases maintenance costs, and impacts normal oil well production.

[0003] It is becoming increasingly important to treat sucker rods and oil pipes with wear resistance and corrosion resistance.

[0004] The use of chemical corrosion inhibitors is a commonly used anti-corrosion method. Corrosion inhibitors are added to the wellhead to form a dense protective film on the sucker rod and oil pipe to delay corrosion. However, this method has limited effect and can only delay but not fundamentally eliminate corrosion.

[0005] In recent years, spraying anti-corrosion materials on the surface of sucker rods and oil pipes has become the mainstream process for eliminating corrosion. The technical core of this process is the selection and optimization of anti-corrosion materials.

[0006] Polyethylene (PE) / polypropylene (PP) composite coating has good damage resistance, impact resistance, and waterproof properties, but the material has poor bonding with the metal surface and is easy to fall off.

[0007] Polytetrafluoroethylene (PTFE): It has excellent corrosion resistance and friction resistance, but has low mechanical strength and cannot withstand high pressure loads underground.

[0008] Modified nylon: low cost, but poor high temperature resistance, easy to soften and deform in high temperature oil wells.

[0009] Epoxy powder: insufficient flexibility, high brittleness, limited impact resistance, and prone to peeling under impact loads.

[0010] Polyketone (POK), an engineering plastic with exceptionally high comprehensive performance, offers a new opportunity to address these challenges. POK, a polymer composed of CO, ethylene, and propylene, possesses numerous excellent properties. Applying POK to the development of corrosion-resistant sucker rods and tubing promises to overcome the shortcomings of existing technologies, fundamentally addressing the corrosion and eccentric wear issues faced by sucker rods and tubing in complex oil well environments, extending their service life and reducing oil production costs. This material holds significant practical significance and broad application prospects. Currently, POK is being used effectively and efficiently in the corrosion-resistant manufacturing of sucker rods and tubing, but its wear resistance, tensile strength, and frictional resistance require further improvement. Summary of the Invention

[0011] The present invention addresses the deficiencies of the prior art and provides an anti-corrosion sucker rod and oil pipe containing POK polyketone material. The sucker rod and oil pipe of the present invention have the advantages of high tensile strength, low friction resistance and high wear resistance.

[0012] The present invention discloses an anti-corrosion sucker rod and oil pipe containing POK polyketone material. The surface of the anti-corrosion sucker rod and oil pipe is sprayed with the POK polyketone material. The composition and mass components of the POK polyketone material are as follows: POK 50-60 parts by mass; 20-30 parts by weight of a reinforcing agent; 10-15 parts by mass of nano-silicon dioxide; 5-10 parts by mass of barium sulfate; Antioxidant 1010 0.2-1 parts by mass

[0013] The molecular structure of the enhancer is as follows: Wherein, m is an integer from 500 to 5000; n is an integer from 300 to 3000.

[0014] Preferably, the viscosity average molecular weight of the reinforcing agent is 500,000-1,000,000.

[0015] The specific steps of the preparation method of the POK-containing polyketone material are as follows: (1) Add enhancer monomer, OP-10, K12, sodium dihydrogen phosphate, and deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 5-10 minutes, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) Rapidly stir the mixture, add the initiator, raise the temperature to 60-70°C, keep the temperature for 2-8 hours to obtain a viscous mixture, cool it to below 50°C, add ethanol, separate the layers, settle, filter, wash with ethanol 2-3 times, dry and granulate the filtered solid to obtain a reinforcing agent; (3) POK, reinforcing agent, nano-silica, barium sulfate and antioxidant 1010 are mixed evenly in proportion, melted at 260-280°C, and granulated to obtain a product containing POK polyketone material.

[0016] Preferably, the reinforcing agent monomer is a mixture of 2-allylcyclohexanone and allylpentafluorobenzene, with a mass ratio of (2-8): (8-2).

[0017] Preferably, in step (1), the mass ratio of OP-10, K12, sodium dihydrogen phosphate, deionized water and the reinforcing agent monomer is 0.01-0.02:0.005-0.01:0.005-0.01:3-5:1.

[0018] Preferably, in step (2), the initiator is one of potassium persulfate, ammonium persulfate, and sodium persulfate, and the mass ratio of the initiator to the reinforcing agent monomer is 0.01-0.03:1.

[0019] Preferably, the mass ratio of the POK, reinforcing agent, nano-silica, barium sulfate, and antioxidant 1010 is 50-60:20-30:10-15:5-10:0.2-1.

[0020] The POK polyketone material used in the present invention is sprayed on the sucker rod and the oil pipe base according to the following A certain process flow, the specific steps of the process flow are as follows: (1) Preprocessing Clean the sucker rod surface and the oil pipe surface with an alkaline aqueous solution to remove oil stains, clean the sucker rod surface and the oil pipe surface with an acidic aqueous solution to remove rust, sandblast the cleaned surface, and then clean it again with acetone after sandblasting; (2) Anti-corrosion treatment of sucker rods The sucker rod is passed through an extruder, and the POK-containing polyketone material is melted and extruded and then coated on the entire surface of the sucker rod; Preferably, the coating thickness of the POK-containing polyketone material is 1000-2500 μm; more preferably, the coating thickness of the POK-containing polyketone material is 1500-2000 μm.

[0021] (3) Oil pipe anti-corrosion treatment The oil pipe is sprayed with POK polyketone material using an electrostatic spraying process.

[0022] Preferably, the POK-containing polyketone material is sprayed with a thickness of 200-1000 μm; more preferably, the POK-containing polyketone material is sprayed with a thickness of 300-500 μm.

[0023] The POK polyketone material sprayed on the surface of the anti-corrosion sucker rod and oil pipe of the present invention is selected from South Korea's Hyosung 730R and exhibits excellent high-temperature resistance, corrosion resistance, and wax resistance. The reinforcing agent contains a rigid ring, which significantly increases the material's strength; a high molecular weight, which increases toughness; fluorobenzene, which is chemically stable and significantly reduces the coefficient of friction, resulting in excellent wear resistance; and polyketone functional groups, which allow for excellent integration with the POK polyketone material. Nano-silica enhances impact resistance. Barium sulfate increases the coating's thickness and hiding power, improving its smoothness. Antioxidant 1010 prevents oxidation.

[0024] Compared with the prior art, the present invention has the following beneficial effects and advantages: (1) The anti-corrosion sucker rod and oil pipe of the present invention have a high tensile yield stress, which reaches 60 MPa or above; (2) The anti-corrosion sucker rod and oil pipe of the present invention have a low friction coefficient, with a static friction coefficient of 0.1 or less and a dynamic friction coefficient of 0.09 or less; (3) The anti-corrosion sucker rod and oil pipe of the present invention have low sliding mass wear, and the mass wear reaches 0.0012g or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attachment Figure 1 This is the reaction equation for synthesizing the reinforcing agent in the POK polyketone material sprayed on the surface of the anti-corrosion sucker rod and oil pipe of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below with reference to specific embodiments: Example 1 (1) Add 80 g of 2-allylcyclohexanone, 20 g of allyl pentafluorobenzene, 1 g of OP-10, 0.5 g of K12, 0.5 g of sodium dihydrogen phosphate, and 300 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 5 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1 g of potassium persulfate was added, the temperature was raised to 70 °C, and the mixture was kept warm for 2 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol twice. The filtered solid was dried and granulated to obtain the enhancer J1.

[0027] (3) 60 g of POK, 20 g of J1, 10 g of nano-silicon dioxide, 9.8 g of barium sulfate, and 0.2 g of antioxidant were mixed evenly, melted at 260 °C, and granulated to obtain a POK-containing polyketone material.

[0028] Example 2 (1) Add 70 g of 2-allylcyclohexanone, 30 g of allyl pentafluorobenzene, 1 g of OP-10, 0.5 g of K12, 0.6 g of sodium dihydrogen phosphate, and 350 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 6 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1.5 g of potassium persulfate was added, the temperature was raised to 68 °C, and the mixture was kept warm for 2 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol twice. The filtered solid was dried and granulated to obtain the enhancer J2.

[0029] (3) 60 g of POK, 23 g of J2, 10.6 g of nano-silicon dioxide, 6 g of barium sulfate, and 0.4 g of antioxidant were mixed evenly, melted at 260 °C, and granulated to obtain a POK-containing polyketone material.

[0030] Example 3 (1) Add 60 g of 2-allylcyclohexanone, 40 g of allyl pentafluorobenzene, 1.5 g of OP-10, 0.8 g of K12, 0.8 g of sodium dihydrogen phosphate, and 500 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 10 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 2 g of potassium persulfate was added, the temperature was raised to 68 °C, and the mixture was kept warm for 2 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol three times. The filtered solid was dried and granulated to obtain the enhancer J3.

[0031] (3) 56 g of POK, 23 g of J3, 15 g of nano-silicon dioxide, 5 g of barium sulfate, and 1 g of antioxidant were mixed evenly, melted at 260 °C, and granulated to obtain a POK-containing polyketone material.

[0032] Example 4 (1) Add 50 g of 2-allylcyclohexanone, 50 g of allyl pentafluorobenzene, 1.5 g of OP-10, 0.7 g of K12, 0.8 g of sodium dihydrogen phosphate, and 323 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 8 minutes, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1 g of sodium persulfate was added, the temperature was raised to 65 °C, and the mixture was kept warm for 4 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol three times. The filtered solid was dried and granulated to obtain the enhancer J4.

[0033] (3) 56 g of POK, 25 g of J4, 11.5 g of nano-silicon dioxide, 7 g of barium sulfate, and 0.5 g of antioxidant were mixed evenly, melted at 270 °C, and granulated to obtain a POK-containing polyketone material.

[0034] Example 5 (1) Add 40 g of 2-allylcyclohexanone, 60 g of allyl pentafluorobenzene, 2 g of OP-10, 0.8 g of K12, 1 g of sodium dihydrogen phosphate, and 455 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 7 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1.5 g of sodium persulfate was added, the temperature was raised to 65 °C, and the mixture was kept warm for 6 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol twice. The filtered solid was dried and granulated to obtain the enhancer J5.

[0035] (3) 53 g of POK, 25 g of J5, 11 g of nano-silicon dioxide, 10 g of barium sulfate, and 1 g of antioxidant were mixed evenly, melted at 275 °C, and granulated to obtain a POK-containing polyketone material.

[0036] Example 6 (1) Add 30 g of 2-allylcyclohexanone, 70 g of allyl pentafluorobenzene, 2 g of OP-10, 1 g of K12, 0.6 g of sodium dihydrogen phosphate, and 385 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 10 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1.2 g of ammonium persulfate was added, the temperature was raised to 62 °C, and the mixture was kept warm for 4 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated into layers, settled, filtered, and washed with ethanol three times. The filtered solid was dried and granulated to obtain the enhancer J6.

[0037] (3) 51 g of POK, 28 g of J6, 12 g of nano-silicon dioxide, 8.3 g of barium sulfate, and 0.7 g of antioxidant were mixed evenly, melted at 280 °C, and granulated to obtain a POK-containing polyketone material.

[0038] Example 7 (1) Add 20 g of 2-allylcyclohexanone, 80 g of allyl pentafluorobenzene, 2 g of OP-10, 1 g of K12, 0.5 g of sodium dihydrogen phosphate, and 400 g of deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 6 min, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) The mixture was stirred rapidly, 1.2 g of ammonium persulfate was added, the temperature was raised to 60 °C, and the mixture was kept warm for 8 h to obtain a viscous mixture. The mixture was cooled to below 50 °C, ethanol was added, the mixture was separated, settled, filtered, and washed with ethanol twice. The filtered solid was dried and granulated to obtain the enhancer J7.

[0039] (3) 50 g of POK, 30 g of J7, 10 g of nano-silicon dioxide, 9 g of barium sulfate, and 1 g of antioxidant were mixed evenly, melted at 280 °C, and granulated to obtain a POK-containing polyketone material.

[0040] Comparative Example 1 The same as step (3) of Example 6, except that 51g POK and 28g J5 were replaced with 79g POK.

[0041] Test Example 1 Tensile Yield Stress Performance Test The tensile yield stress of the POK-containing polyketone materials (Examples 1-7) of the present invention was tested with reference to GB / T 1040 "Test for Tensile Properties of Plastics." The test results are shown in Table 1.

[0042] From Table 1 we can see that: The POK-containing polyketone materials of the present invention (Examples 1-7) have relatively high tensile yield stress, reaching 60 MPa and above, with a maximum of 64 MPa; while the tensile yield stress of Comparative Example 1 is 49 MPa, which is significantly lower than that of the present invention.

[0043] Test Example 2 Static Friction Coefficient and Dynamic Friction Coefficient Test The static and dynamic coefficients of friction of the POK-containing polyketone materials (Examples 1-7) of the present invention were tested with reference to ASTM D1894, "Standard Test Method for Static and Dynamic Coefficients of Friction of Plastic Film and Sheeting." The specific testing method is as follows: Test samples were prepared into 120 mm × 120 mm × 2 mm flat plates. Testing was performed using a Universal materials testing machine equipped with a coefficient of friction test accessory at 23 ± 2°C and a relative humidity of 50 ± 5%. Static coefficient of friction was measured using a 200 g load and a pulling speed of 5 mm / min; dynamic coefficient of friction was measured using a 200 g load and a pulling speed of 100 mm / min. The test results are summarized in Table 1.

[0044] From Table 1 we can see that: The POK-containing polyketone material of the present invention (Examples 1-7) has a low friction coefficient, with a static friction coefficient of 0.1 or less, and a minimum of 0.08; a dynamic friction coefficient of 0.09 or less, and a minimum of 0.07; while the comparative example 1 is 0.12, which is significantly higher than the present invention.

[0045] Test Example 3 Sliding Friction and Wear Test The mass wear of the POK-containing polyketone materials (Examples 1-7) of the present invention was tested in accordance with GB / T 3960, "Test Methods for Sliding Friction and Wear of Plastics." The specific test parameters were as follows: the test ring rotated at 200 r / min, the test lasted 6 hours, and the load was 196 N. The test results are shown in Table 1.

[0046] Table 1 Tensile yield stress, friction coefficient, sliding friction and wear test Tensile yield stress, MPa Static friction coefficient Dynamic friction coefficient Mass wear, g Example 1 60 0.10 0.09 0.0012 Example 2 62 0.10 0.09 0.0010 Example 3 63 0.09 0.08 0.0009 Example 4 63 0.10 0.09 0.0009 Example 5 64 0.09 0.08 0.0007 Example 6 64 0.09 0.08 0.0008 Example 7 63 0.08 0.07 0.0009 Comparative Example 1 49 0.15 0.12 0.0025 From Table 1 we can see that: The POK-containing polyketone materials of the present invention (Examples 1-7) have lower sliding mass wear, with mass wear reaching 0.0012 g or less, and the lowest reaching 0.0007; while the mass wear of Comparative Example 1 is 0.0025, which is significantly higher than that of the present invention.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An anti-corrosion sucker rod and oil pipe containing POK polyketone material, characterized in that: The surface of the anti-corrosion sucker rod and oil pipe is sprayed with a POK-containing polyketone material, wherein the composition and mass components of the POK-containing polyketone material are as follows: POK 50-60 parts by mass; 20-30 parts by weight of a reinforcing agent; 10-15 parts by mass of nano-silicon dioxide; 5-10 parts by mass of barium sulfate; Antioxidant 1010 0.2-1 parts by mass; The molecular structure of the enhancer is as follows: Wherein, m is an integer from 500 to 5000; n is an integer from 300 to 3000; The viscosity average molecular weight of the reinforcing agent is 500,000-1,000,000.

2. The anti-corrosion sucker rod and oil pipe containing POK polyketone material as claimed in claim 1, characterized in that: The specific steps of the preparation method of the POK-containing polyketone material are as follows: (1) Add enhancer monomer, OP-10, K12, sodium dihydrogen phosphate, and deionized water to the reactor in sequence, purge the reactor and pipeline with nitrogen for 5-10 minutes, stir, and adjust the pH to 7-8 with sodium hydroxide solution; (2) Rapidly stir the mixture, add the initiator, raise the temperature to 60-70°C, keep the temperature for 2-8 hours to obtain a viscous mixture, cool it to below 50°C, add ethanol, separate the layers, settle, filter, wash with ethanol 2-3 times, dry and granulate the filtered solid to obtain a reinforcing agent; (3) POK, reinforcing agent, nano-silica, barium sulfate and antioxidant 1010 are mixed uniformly in proportion, melted at 260-280°C, and granulated to obtain a product containing POK polyketone material; The reinforcing agent monomer is a mixture of 2-allylcyclohexanone and allylpentafluorobenzene, with a mass ratio of (2-8): (8-2).

3. The anti-corrosion sucker rod and oil pipe containing POK polyketone material as claimed in claim 2, characterized in that: In step (1), the mass ratio of OP-10, K12, sodium dihydrogen phosphate, deionized water and the reinforcing agent monomer is 0.01-0.02:0.005-0.01:0.005-0.01:3-5:

1.

4. The anti-corrosion sucker rod and oil pipe containing POK polyketone material as claimed in claim 2, characterized in that: In step (2), the initiator is one of potassium persulfate, ammonium persulfate, and sodium persulfate, and the mass ratio of the initiator to the reinforcing agent monomer is 0.01-0.03:

1.

5. The anti-corrosion sucker rod and oil pipe containing POK polyketone material as claimed in claim 2, characterized in that: The mass ratio of the POK, reinforcing agent, nano-silica, barium sulfate and antioxidant 1010 is 50-60:20-30:10-15:5-10:0.2-1.

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