CN117605909A - Wax-proof coating oil pipe and processing method and application thereof - Google Patents

Abstract

The invention discloses a wax-proof coating oil pipe, a processing method and application thereof, comprising a pipe body, wherein the pipe body comprises a bottom coating and a surface coating, and the processing method comprises the following steps: the bottom coating comprises special modified epoxy resin, and has good acid resistance and temperature resistance, and diethylenetriamine; the special modified epoxy resin is modified nano phenolic resin formed by phenol and formaldehyde through polycondensation; the surface coating comprises a metal oxide nano material and modified graphene, wherein the metal oxide nano material comprises titanium dioxide, aluminum oxide and zinc powder; the process adopts nano materials such as modified phenolic resin, modified graphene, titanium dioxide and the like; after spraying and curing, the coating obtains comprehensive mechanical functions, and the aluminum oxide and the titanium dioxide greatly reduce the surface stress of the coating; the coating has better ductility; the material has better hydrophobicity by adjusting the proportion of graphene oxide to titanium dioxide.

Description

Wax-proof coating oil pipe and processing method and application thereof

Technical Field

The invention belongs to the technical field of petroleum and mechanical engineering surface treatment, and particularly relates to a wax-proof coating oil pipe and a processing method and application thereof.

Background

In the production process of oil and gas fields, the following problems generally exist, so that the oil extraction cost is increased, and the economic benefit is restrained from being improved. Firstly, for a mechanical production well, the eccentric wear problem between rod pipes is serious, and particularly for a horizontal well and a directional well, the problem is more remarkable, so that the damage speed of an oil pipe and a sucker rod is increased, and the mechanical energy consumption of the mechanical production well is increased; secondly, for oil wells, water injection wells and gas wells adopting chemical flooding exploitation modes, the problems of corrosion and scaling of production pipe columns are increasingly serious due to the fact that produced liquid, injection liquid, produced gas and the like are rich in corrosive media or impurities; thirdly, for a dilute oil well, the problem of wax deposition of the oil well is more remarkable. The causes of oil well paraffin deposition are mainly divided into an internal cause and an external cause, wherein the internal cause is the physical property of crude oil, the external cause is the exploitation condition of an oil well, and the oil transportation temperature inside an oil pipe and the surface energy of the oil pipe are main factors influencing the oil pipe paraffin deposition cause. The common oil pipe is directly contacted with corrosive medium, which is easy to cause oil pipe corrosion. The rust wall surface provides a deposition point for precipitated wax, forms a laminar boundary layer, promotes wax particles/scale particles to migrate to the boundary and adhere, and when the temperature is reduced below the wax deposition point, the wax is precipitated from crude oil in a crystalline form; the temperature and the pressure are continuously reduced, gas is separated out, and the crystallized wax is gathered and grown to form wax crystals; wax crystals are deposited on the surfaces of pipe bars and equipment and the like.

The prior wax-proof coating oil pipe is easy to have the following problems: 1. in the conveying medium, the medium with too high temperature is not suitable to be conveyed; the coating with too high temperature is easy to bulge and fall off to block the pump. 2. The hydrophobicity of the coated oil pipe is relatively poor, and in the oil extraction and transportation process, along with the reduction of temperature and pressure and the precipitation of gas, when the temperature, pressure and gas precipitation reach certain conditions, paraffin dissolved in crude oil is crystallized and precipitated. The crystals thereof accumulate and precipitate on the inner wall of the coated tubing, a phenomenon known as waxing. The wax precipitation causes the inner diameter of the oil outlet channel to be gradually reduced, thus increasing the oil flow resistance, reducing the oil well productivity, and sometimes even sealing the shaft channel, causing the production stoppage and maintenance to affect the normal production and greatly reducing the oil field development benefit.

In the prior art, a titanium nano coating technology is adopted, the smell is large in the batching process, an oil pipe must continuously rotate in a curing furnace in the spraying process, and the coating in the pipe can flow to form a nodulation when a little is stopped, so that a certain part is too thick, and the coating is cracked; the plating adopts electrochemistry to deposit a compact metal plating layer (such as nickel-copper-nickel composite plating layer, nickel-tungsten plating layer, zinc plating layer and the like) on the surface of the oil pipe so as to protect the oil pipe from being corroded rapidly and provide a certain finish degree to prevent wax precipitation, but the plating layer is always not thick, the thickness of the plating layer is always thick, in the pretreatment process of plating layer processing, the depth of anchor lines exists on the inner wall of the oil pipe after shot blasting, the plating layer is not smooth after processing, the wax prevention effect is lower than the coating, as mentioned above, the corrosion problems exist on the wax prevention coating oil pipe in different degrees in the prior art, thus leading to oil well shutdown maintenance, and the method has great significance to further research on the oil pipe technology of oil field coating

Disclosure of Invention

The invention aims to provide a wax-proof coating oil pipe, a processing method and application thereof, and the wax-proof coating oil pipe has the characteristics of wear resistance, temperature resistance, permeation resistance and the like, and is used for achieving remarkable effects in the application of long-day oil fields and Xinjiang oil fields in the petrochemical industry field so as to solve the problem of corrosion in the background technology.

In order to achieve the above purpose, the present invention provides the following technical solutions: a wax-resistant coated tubing comprising a tubing body comprising a primer coating and a topcoat coating, wherein:

the bottom coating comprises special modified epoxy resin, and has good acid resistance and temperature resistance, and diethylenetriamine; the special modified epoxy resin is modified nano phenolic resin formed by phenol and formaldehyde through polycondensation;

the surface coating comprises a metal oxide nano material and modified graphene, wherein the metal oxide nano material comprises titanium dioxide, aluminum oxide and zinc powder.

As a preferable technical scheme in the invention, the roughness of the pipe body is 0.132-0.334 um; the hydrophobicity of the pipe body is 83-92 degrees; the wear resistance of the pipe body has a wear resistance value of 4.5L/um, and the pH value resistant and wax-proof coating of the pipe body is soaked in 10% hydrochloric acid and 10% sodium hydroxide for 90 hours, so that the coating is perfect; and the coating of the pipe body is good after the pipe body is boiled at the temperature of 100 ℃ for 148 hours with high temperature, and the coating of the downhole fluid of the high-temperature autoclave oil field is good after the pipe body is boiled at the temperature of 148 ℃ for 24 hours under the pressure of 70 MPa.

The invention also discloses a processing method of the wax-proof coating oil pipe, which comprises a pipe body and specifically comprises the following steps:

step one: and (3) primer spraying: transferring the tube body which is qualified to be tested to a spraying workshop for spraying; air gun is used for blowing and dedusting in the pipe body before spraying, and the first liquid primer spraying is started after dedusting; before starting spraying, adjusting the air pressure of a spray gun system to be kept at 0.2-0.6 MPa, keeping the feeding pressure to be 0.2-0.6 MPa, reducing the frequency to be 20-40 Hz, and spraying after adjusting parameters; a special tool is arranged at the coupling end of the pipe body, so that the J value of the coupling can be uniformly coated, the thickness of a primer wet film is 100-150 mu m, thickness measurement is carried out by using a wet film gauge every time one primer wet film is sprayed, the coating of a measured point is repaired by using the wet film gauge after the measurement is finished, and the quality of products is ensured; after the spraying is finished, carrying out heat preservation and solidification for the first time, heating a solidification furnace to 150-200 ℃ in advance, solidifying in the furnace for 30-60 min, discharging from the furnace, measuring the dry film thickness, and keeping the dry film thickness at 50-100 mu m;

step two: and (3) spraying finishing paint: before spraying, the vulcanizing equipment is opened, the air supply pressure is checked to be 0.2-0.6 MPa, the powder supply pressure is 0.2-0.5 MPa, and the frequency of the rotating roller is 20-50 Hz; after the first spraying and curing process, measuring the temperature of the pipe body by a temperature measuring gun, placing the pipe body on a rotary roller when the temperature of the pipe body reaches 120-150 ℃, carrying a special tool on the end of a coupling, ensuring that 3-5 threads can be uniformly coated on the J value part, starting to spray finish paint, and opening the rotary roller of the pipe body to start to spray finish paint when the spray gun moves to the other end of the pipe body and the spray gun head is exposed, wherein the thickness of a wet film of the finish paint is 280-300 mu m; after finishing the spraying of the finish paint, carrying out secondary heat preservation and solidification, wherein the solidification temperature is 200-220 ℃ and the solidification time is 50-90 min; and (5) discharging the finish paint after the finish paint is sufficiently baked, and detecting after the pipe body is cooled.

As a preferable technical scheme in the invention, the primer in the first step is a mixture of an A component and a B component; the weight ratio of the component A is 5:0.042; before spraying, mixing the component A to obtain a mixture, and uniformly stirring the component A for 20-40 minutes by using a stirrer after preparing the component A until bubbles above the paint surface completely disappear.

As a preferable technical scheme in the invention, the component A in the step one comprises modified epoxy resin and curing agent which is at least one of diethylenetriamine and dichloramine; the spraying weight ratio of the epoxy resin to the curing agent is 5:0.042; the epoxy resin of the component A is modified nano phenolic resin formed by polycondensation of modified phenol and formaldehyde; the phenolic resin has good acid resistance and temperature resistance, and the weight ratio of the phenolic resin to the monomeric phenol to the formaldehyde is 180-220: 320-360 parts by weight: 1, phenolic resin has a weight average molecular weight of 124.137, acid resistance and temperature resistance parameters of 10% hydrochloric acid and sodium hydroxide, is soaked for 90 hours at room temperature, is boiled in water in a water bath kettle at 100 ℃ for 148 hours, and has a nanometer particle size of 50-100 nm;

the component B in the step one comprises modified epoxy resin, metal oxide and modified graphene; the metal oxide is a nano material with the particle size of 20-50 nm; the metal oxide comprises at least one of titanium dioxide and aluminum oxide, preferably titanium dioxide and aluminum oxide; the mass ratio of the titanium dioxide to the aluminum oxide is 35-45: 20-30 g of each part; the mass ratio of the metal oxide to the modified graphene is 1-3: 2-5 g per serving.

As a preferred technical scheme in the invention, the oil pipe is subjected to pretreatment cleaning before the step one, wherein the pretreatment cleaning comprises oil removal and/or rust removal treatment, and the oil removal treatment and the rust removal treatment can adopt methods known in the art, and the oil removal treatment method comprises at least one of chemical oil removal and physical oil removal methods;

the oil removing method comprises the following steps:

s1, primarily degreasing oil pipe threads by using diesel oil, after cleaning most oil blocks, dissolving degreasing powder by using 40-60 ℃ water, and secondarily degreasing, wherein the degreasing is performed by using a manual scrubbing method, and after the degreasing is completed, performing high-temperature sintering on the oil pipe;

s2, loading the oil pipe into a heat treatment furnace, setting the temperature to be 200-300 ℃ and sintering for 3-4 hours at the temperature; and (5) fully baking the greasy dirt on the inner wall of the oil pipe and the greasy dirt on the screw thread.

As a preferable technical scheme in the invention, the rust removing method comprises the following steps:

s1, performing rust removal in the oil pipe after sintering, and transferring the oil pipe to a rust removal workshop;

s2, respectively carrying special tools on the male buckle and the female buckle end of the oil pipe, namely carrying a nylon protector on the male buckle end, carrying an iron tool on the female buckle end, and protecting the male buckle end from being damaged by threads, wherein the J value of the female buckle coupling is the J value of the coupling after the oil pipes are connected in pairs, the middle gap part of the coupling is 3-5 threads under the action of the special tools and has a certain anchor line depth of 25-75 mu m;

s3, rust removal in the oil pipe is carried out by mixing 10-14 mesh steel sand and 18-25 mesh brown alumina, gun-withdrawal type shot blasting is carried out, and the anchor grain depth reaches 25-75 mu m; checking by using a surface roughness meter, checking the surface roughness meter once every 50 times, checking the oxide skin and oil stain in the pipe, and checking the surface roughness meter by each time by adopting a flashlight with the lumen of more than 100-500 lumens and a pipeline endoscope;

s4, entering the next working procedure after the test is qualified.

The invention also discloses application of the wax-proof coating oil pipe obtained by the processing method in an oil and gas field.

Compared with the prior art, the invention has the beneficial effects that:

1. the process adopts nano materials such as modified phenolic resin, modified graphene, titanium dioxide and the like; after spraying and curing, the coating obtains comprehensive mechanical functions, and the aluminum oxide and the titanium dioxide greatly reduce the surface stress of the coating; the coating has better ductility; the material has better hydrophobicity by adjusting the proportion of graphene oxide to titanium dioxide; the phenolic resin can enable the coating to have higher temperature resistance and acid resistance;

2. the process can be used for preventing scaling and waxing of the coating, reducing the number of times of waxing, saving the cost, and improving the yield and efficiency.

Drawings

FIG. 1 is a schematic view of the structure of the pipe body of the present invention.

In the figure: 100. a tube body; 100a, a bottom coating; 100b, surface layer coating.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Referring to fig. 1, the present invention provides a technical solution: a wax-coated tubing comprising a tubular body 100, the tubular body 100 comprising a base coat 100a and a top coat 100b, wherein:

the primer coating 100a comprises special modified epoxy resin, and has good acid resistance, temperature resistance and diethylenetriamine overall; the special modified epoxy resin is modified nano phenolic resin formed by phenol and formaldehyde polycondensation;

the top coat 100b comprises a metal oxide nanomaterial, modified graphene, wherein the metal oxide nanomaterial comprises titanium dioxide, aluminum oxide, zinc powder.

In the present embodiment, the roughness of the tube body 100 is 0.132-0.334 um; the hydrophobicity of the tube body 100 is 83-92 degrees; the wear resistance of the pipe body 100 has a wear resistance value of 4.5L/um, while the pH value resistant and wax-proof coating of the pipe body 100 is soaked in 10% hydrochloric acid and 10% sodium hydroxide for 90 hours, and the coating is perfect; and the heat-resistant performance of the pipe body 100 is that the coating is good after the pipe body is boiled at 100 ℃ for 148 hours with high temperature, and the coating is good after the downhole fluid of the high-temperature autoclave oil field is 70MPa, 148 ℃ and 24 hours.

The invention also discloses a processing method of the wax-proof coating oil pipe, which comprises a pipe body 100 and specifically comprises the following steps:

step one: and (3) primer spraying: transferring the tube body 100 which is qualified to be tested to a spraying workshop for spraying; air blowing and dedusting are carried out in the spraying front pipe body 100 by an air gun, and the first liquid primer spraying is started after dedusting; before starting spraying, adjusting the air pressure of a spray gun system to be kept at 0.2-0.6 MPa, keeping the feeding pressure to be 0.2-0.6 MPa, reducing the frequency to be 20-40 Hz, and spraying after adjusting parameters; a special fixture is arranged on the end band of the pipe body 100 coupling, so that the coupling J value can be uniformly coated, the thickness of a primer wet film is 100-150 mu m, thickness measurement is carried out by using a wet film gauge every time one primer wet film is sprayed, the measured point coating is repaired by using the wet film gauge after the measurement is finished, and the product quality is ensured; after the spraying is finished, carrying out heat preservation and solidification for the first time, heating a solidification furnace to 150-200 ℃ in advance, solidifying in the furnace for 30-60 min, discharging from the furnace, measuring the dry film thickness, and keeping the dry film thickness at 50-100 mu m;

step two: and (3) spraying finishing paint: before spraying, the vulcanizing equipment is opened, the air supply pressure is checked to be 0.2-0.6 MPa, the powder supply pressure is 0.2-0.5 MPa, and the frequency of the rotating roller is 20-50 Hz; after the first spraying and curing are carried out, measuring the temperature of the pipe body 100 by using a temperature measuring gun, when the temperature of the pipe body 100 reaches 120-150 ℃, placing the pipe body 100 on a rotary roller, and carrying out special tooling on the end of a coupling to ensure that 3-5 threads can be uniformly coated on the J value part, starting to spray finish paint, and when the spray gun moves to the other end of the pipe body 100 and exposes out of a spray gun head, opening the rotary roller of the pipe body 100 to start to spray finish paint, wherein the thickness of a wet film of the finish paint is 280-300 mu m; after finishing the spraying of the finish paint, carrying out secondary heat preservation and solidification, wherein the solidification temperature is 200-220 ℃ and the solidification time is 50-90 min; and taking the finish paint out of the furnace after being sufficiently baked, and detecting after the pipe body 100 is cooled.

And (3) dry film inspection: the flashlights with the lumens of more than 100-500 lumens are used for appearance inspection one by one, so that smoothness, no flow and no orange peel in the oil pipe are ensured; measuring the thickness by using a coating thickness gauge, wherein the dry film thickness is 180-220 mu m; the whole length of the oil pipe is checked by a wet sponge pinhole leak detector, and no leak is qualified; the oil pipe after being inspected to be qualified is provided with a thread protector and is transported into a finished product, and then is packed and shipped;

the roughness is measured after the instrument is calibrated to zero, and the roughness of the wax-proof coating is between 0.132um and 0.334um;

the hydrophobicity adopts an angular contact measuring instrument and adopts a method of 83-92 degrees of underground oil-water mixed liquid;

pouring a certain volume of quartz sand into a funnel of a shakeout tester by adopting a shakeout tester instrument, opening a shakeout plugboard, adjusting the opening to control the time of the quartz sand with the flow of 2L to 21-23.5 s, placing a test piece on a test frame, forming 45 degrees with a vertical guide pipe, adjusting the vertical distance of the surface of the test piece at the center of the guide pipe opening to 25mm, pouring one liter of quartz sand into the funnel of the tester, pulling the plugboard to a position with the opening calibrated to enable the shakeout to impact the surface of the test piece, marking a circular impact area with the diameter of about 20-30 mm by using a pen, measuring the thickness of the impact area by using a magnetic thickness gauge, and obtaining an average value of more than five points to represent the thickness before abrasion; pouring the quartz sand with the weighed volume into a funnel, opening an inserting plate to a calibration position, enabling the quartz sand to impact on the surface of a test piece, and continuously supplementing the quartz sand until the accumulated volume reaches 400L; taking out the test piece, measuring the thinnest point of the residual thickness of the coating in the impact area by using a magnetic thickness gauge, drawing a circle with the diameter of 4mm by taking the changed point as the center, uniformly measuring 5 points in the circle, and obtaining an average value which represents the thickness of the worn test piece; finally, calculating a method according to a formula;

acid and alkali resistance is soaked for 90 hours at room temperature by adopting 10% hydrochloric acid and sodium hydroxide of a beaker soaking instrument;

the temperature resistance is achieved by adopting a constant-temperature water bath dynamic high-temperature high-pressure kettle instrument which is boiled at 100 ℃ for 148 hours with a perfect coating, and the high-temperature high-pressure kettle adopts an oilfield downhole fluid 70MPa and 148 ℃ and 24 hours later with a perfect coating parameter particle size instrument.

In the embodiment, the primer in the first step is a mixture of an A component and a B component; the weight ratio of the component A is 5:0.042; before spraying, mixing the component A to obtain a mixture, and uniformly stirring the component A for 20-40 minutes by using a stirrer after preparing the component A until bubbles above the paint surface completely disappear.

In the embodiment, the component A in the first step comprises modified epoxy resin and curing agent which is at least one of diethylenetriamine and dichloramine; the spraying weight ratio of the epoxy resin to the curing agent is 5:0.042; the A component epoxy resin is modified nano phenolic resin formed by polycondensation of modified phenol and formaldehyde; the phenolic resin has good acid resistance and temperature resistance, and the weight ratio of phenolic resin, monomer phenol and formaldehyde is 180-220: 320-360 parts by weight: 1, phenolic resin has a weight average molecular weight of 124.137, acid resistance and temperature resistance parameters of 10% hydrochloric acid and sodium hydroxide, is soaked for 90 hours at room temperature, is boiled in water in a water bath kettle at 100 ℃ for 148 hours, and has a nanometer particle size of 50-100 nm;

the component B in the first step comprises modified epoxy resin, metal oxide and modified graphene; the metal oxide is a nano material with the grain diameter of 20-50 nm; the metal oxide comprises at least one of titanium dioxide and aluminum oxide, preferably titanium dioxide and aluminum oxide; the mass ratio of the titanium dioxide to the aluminum oxide is 35-45: 20-30 g of each part; the mass ratio of the metal oxide to the modified graphene is 1-3: 2-5 g per serving.

In this embodiment, the oil pipe is subjected to pretreatment cleaning before the first step, where the pretreatment cleaning includes degreasing and/or derusting treatment, and the degreasing treatment and the derusting treatment may be performed by methods known in the art, where the degreasing treatment includes at least one of chemical degreasing and physical degreasing;

the oil removing method comprises the following steps:

s1, primarily degreasing oil pipe threads by using diesel oil, after cleaning most oil blocks, dissolving degreasing powder by using 40-60 ℃ water, and secondarily degreasing, wherein the degreasing is performed by using a manual scrubbing method, and after the degreasing is completed, performing high-temperature sintering on the oil pipe;

s2, loading the oil pipe into a heat treatment furnace, setting the temperature to be 200-300 ℃ and sintering for 3-4 hours at the temperature; and (5) fully baking the greasy dirt on the inner wall of the oil pipe and the greasy dirt on the screw thread.

In this embodiment, the method for rust removal includes the steps of:

s1, performing rust removal in the oil pipe after sintering, and transferring the oil pipe to a rust removal workshop;

s2, respectively carrying special tools on the male buckle and the female buckle end of the oil pipe, namely carrying a nylon protector on the male buckle end, carrying an iron tool on the female buckle end, and protecting the male buckle end from being damaged by threads, wherein the J value of the female buckle coupling is the J value of the coupling after the oil pipes are connected in pairs, the middle gap part of the coupling is 3-5 threads under the action of the special tools and has a certain anchor line depth of 25-75 mu m;

s3, rust removal in the oil pipe is carried out by mixing 10-14 mesh steel sand and 18-25 mesh brown alumina, gun-withdrawal type shot blasting is carried out, and the anchor grain depth reaches 25-75 mu m; checking by using a surface roughness meter, checking the surface roughness meter once every 50 times, checking the oxide skin and oil stain in the pipe, and checking the surface roughness meter by each time by adopting a flashlight with the lumen of more than 100-500 lumens and a pipeline endoscope;

s4, entering the next working procedure after the test is qualified.

The invention also discloses application of the wax-proof coating oil pipe obtained by the processing method in an oil and gas field.

Example 2

The difference from this embodiment 1 is that: the A component of the coating and the weight ratio thereof are as follows: phenolic epoxy resin: 55%, color: 25% of auxiliary agent: 3% of curing agent: 8% of organic solvent: 10%.

Example 3

The difference from the above embodiment is that: the coating comprises the following components in parts by weight: titanium dioxide: 45% aluminum oxide: 30% of modified graphene 25%.

Although embodiments of the present invention have been shown and described in detail with reference to the foregoing detailed description, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations may be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (8)

1. A wax control coated oil pipe comprising a pipe body (100), characterized in that: the pipe body (100) comprises a primer coating (100 a) and a topcoat coating (100 b), wherein:

the primer coating (100 a) comprises special modified epoxy resin and diethylenetriamine; the special modified epoxy resin is modified nano phenolic resin formed by phenol and formaldehyde through polycondensation;

the surface layer coating (100 b) comprises a metal oxide nano material and modified graphene, wherein the metal oxide nano material comprises titanium dioxide, aluminum oxide and zinc powder.

2. A wax control coated oil pipe as in claim 1, wherein: the roughness of the pipe body (100) is 0.132-0.334 um; the hydrophobicity of the pipe body (100) is 83-92 degrees; the wear resistance of the pipe body (100) has a wear resistance value of 4.5L/um, and the acid-base resistance and wax-proof coating of the pipe body (100) is soaked in 10% hydrochloric acid and 10% sodium hydroxide for 90 hours, so that the coating is perfect; and the heat-resistant performance of the pipe body (100) is good after being boiled at 100 ℃ for 148 hours with high temperature, and the coating is good after the downhole fluid of the high-temperature high-pressure kettle oil field is 70MPa, 148 ℃ and 24 hours.

3. A method of processing a wax-resistant coated oil pipe, comprising the pipe body (100) of any one of claims 1 and 2, characterized in that: the method specifically comprises the following steps:

step one: and (3) primer spraying: transferring the tube body (100) which is qualified to be inspected to a spraying workshop for spraying; air blowing and dust removing are carried out in the spraying front pipe body (100) by an air gun, and liquid priming paint spraying is started for the first time after dust removing; before starting spraying, adjusting the air pressure of a spray gun system to be kept at 0.2-0.6 MPa, keeping the feeding pressure to be 0.2-0.6 MPa, reducing the frequency to be 20-40 Hz, and spraying after adjusting parameters; a special tool is arranged on the end of a coupling of a pipe body (100), so that the J value of the coupling can be uniformly coated, the thickness of a primer wet film is 100-150 mu m, each spray of the primer wet film is subjected to thickness measurement by a wet film gauge, and after the measurement is finished, the coating of a measured point is repaired by the wet film gauge, so that the quality of a product is ensured; after the spraying is finished, carrying out heat preservation and solidification for the first time, heating a solidification furnace to 150-200 ℃ in advance, solidifying in the furnace for 30-60 min, discharging from the furnace, measuring the dry film thickness, and keeping the dry film thickness at 50-100 mu m;

step two: and (3) spraying finishing paint: before spraying, the vulcanizing equipment is opened, the air supply pressure (0.2-0.6 MPa) is checked, the powder supply pressure (0.2-0.5 MPa) and the frequency of the rotary roller (20-50 Hz) are controlled; after the first spraying and curing are carried out, measuring the temperature of a pipe body (100) by a temperature measuring gun, when the temperature of the pipe body (100) reaches 120-150 ℃, placing the pipe body (100) on a rotary roller, carrying a special tool on the end of a coupling, ensuring that 3-5 threads can be uniformly coated on the J value part, starting to spray finish paint, and when the spray gun moves to the other end of the pipe body (100) and exposes out of a spray gun head, opening the rotary roller of the pipe body (100) to start to spray finish paint, wherein the thickness of a wet finish paint film is 280-300 mu m; after finishing the spraying of the finish paint, carrying out secondary heat preservation and solidification, wherein the solidification temperature is 200-220 ℃ and the solidification time is 50-90 min; and (5) discharging the finish paint after the finish paint is sufficiently baked, and detecting after the pipe body (100) is cooled.

4. A method of processing a wax-resistant coated tubing as claimed in claim 3, wherein: the primer in the first step is a mixture of an A component and a B component; the weight ratio of the component A is 5:0.042; before spraying, mixing the component A to obtain a mixture, and uniformly stirring the component A for 20-40 minutes by using a stirrer after preparing the component A until bubbles above the paint surface completely disappear.

5. The method for processing the wax-proof coated oil pipe according to claim 4, wherein the method comprises the following steps: the component A in the step one comprises modified epoxy resin and curing agent which is at least one of diethylenetriamine and dichloramine; the spraying weight ratio of the epoxy resin to the curing agent is 5:0.042; the epoxy resin of the component A is modified nano phenolic resin formed by polycondensation of modified phenol and formaldehyde; the weight ratio of the phenolic resin, the monomer phenol and the formaldehyde is 180-220: 320-360 parts by weight: 1, phenolic resin has a weight average molecular weight of 124.137, acid resistance and temperature resistance parameters of 10% hydrochloric acid and sodium hydroxide, is soaked for 90 hours at room temperature, is boiled in water in a water bath kettle at 100 ℃ for 148 hours, and has a nanometer particle size of 50-100 nm;

the component B in the step one comprises modified epoxy resin, metal oxide and modified graphene; the metal oxide is a nano material with the particle size of 20-50 nm; the metal oxide comprises at least one of titanium dioxide and aluminum oxide; the mass ratio of the titanium dioxide to the aluminum oxide is 35-45: 20-30 g of each part; the mass ratio of the metal oxide to the modified graphene is 1-3: 2-5 g per serving.

6. A method of processing a wax-resistant coated tubing as claimed in claim 3, wherein: the oil pipe is subjected to pretreatment cleaning before the first step, the pretreatment cleaning comprises oil removal and/or rust removal treatment, and the oil removal treatment method comprises at least one of chemical oil removal and physical oil removal methods;

the oil removing method comprises the following steps:

s1, primarily degreasing oil pipe threads by using diesel oil, after cleaning most oil blocks, dissolving degreasing powder by using 40-60 ℃ water, and secondarily degreasing, wherein the degreasing is performed by using a manual scrubbing method, and after the degreasing is completed, performing high-temperature sintering on the oil pipe;

s2, loading the oil pipe into a heat treatment furnace, setting the temperature to be 200-300 ℃ and sintering for 3-4 hours at the temperature; and (5) fully baking the greasy dirt on the inner wall of the oil pipe and the greasy dirt on the screw thread.

7. The method for processing the wax-resistant coated oil pipe according to claim 6, wherein the method comprises the following steps: the rust removing method comprises the following steps:

s1, performing rust removal in the oil pipe after sintering, and transferring the oil pipe to a rust removal workshop;

s2, respectively carrying special tools on the male buckle and the female buckle end of the oil pipe, namely carrying a nylon protector on the male buckle end, carrying an iron tool on the female buckle end, and protecting the male buckle end from being damaged by threads, wherein the J value of the female buckle coupling is the J value of the coupling after the oil pipes are connected in pairs, the middle gap part of the coupling is 3-5 threads under the action of the special tools and has a certain anchor line depth of 25-75 mu m;

s3, rust removal in the oil pipe is carried out by mixing 10-14 mesh steel sand and 18-25 mesh brown alumina, gun-withdrawal type shot blasting is carried out, and the anchor grain depth reaches 25-75 mu m; checking by using a surface roughness meter, checking the surface roughness meter once every 50 times, checking the oxide skin and oil stain in the pipe, and checking the surface roughness meter by each time by adopting a flashlight with the lumen of more than 100-500 lumens and a pipeline endoscope;

s4, entering the next working procedure after the test is qualified.

8. Use of a wax-resistant coated tubing obtained by the process of any one of claims 3 to 7 in oil and gas fields.