Dissoluble light metal paraffin removal ball as well as preparation method and application thereof

Abstract

The invention relates to a dissoluble light metal paraffin removal ball and a preparation method and application thereof, belongs to the technical field of petroleum pipeline paraffin removal, and solves the technical problems of secondary blockage and difficult recovery of paraffin removal balls, the dissoluble light metal paraffin removal ball comprises a dissoluble light metal ball and a dissoluble protective coating. The dissolvable light metal ball comprises 85%-90% of Al, 1%-5% of Zn, 3%-5% of Cu, 1%-3% of Mg, 0.1%-0.5% of Ga, 0.1%-0.5% of In, 0.1%-0.3% of Sn, 1%-3% of Ce and 0.01%-0.1% of Ti, spiral grooves are formed in the surface of the dissolvable light metal ball, and the dissolvable light metal ball is completely wrapped by a dissolvable protective coating. The preparation method comprises the steps of die-casting forming of the dissolvable light metal balls and electrostatic spraying of the dissolvable protective coating. The soluble light metal paraffin removal ball is applied to paraffin removal of a crude oil pipeline. The paraffin remover is used for crude oil pipeline paraffin removal.

Description

Technical Field

[0001] This invention belongs to the field of oil pipeline dewaxing technology, specifically relating to a soluble light metal dewaxing ball, its preparation method, and its application. Background Technology

[0002] The crude oil produced in my country differs from that of most other countries. The wax precipitation point of the crude oil in its pipelines is mainly concentrated between 20-45℃ (the specific value is affected by the crude oil composition, wax content, and environmental conditions), making it easily solidified crude oil, often referred to as "waxy crude oil." In the total produced crude oil, the wax mass fraction exceeds 10%. As hot oil flows along the pipeline, the oil continuously cools and deposits wax, causing difficulties in oil transportation. Wax deposition in oil wells reduces the overall production of the oil field and increases operational energy consumption. The main reason is the wax deposition phenomenon; it reduces the inner diameter of the pipeline, resulting in a decrease in oil delivery and a reduction in oil and gas resource extraction. Wax deposition not only increases pipeline operating energy consumption but can also lead to pipe solidification accidents, posing safety hazards to pipeline operation. When the thickness of the solidified oil layer reaches a certain value, an abnormal phenomenon occurs where the pipeline's oil delivery decreases while friction increases. Under certain vicious cycle conditions, pipeline shutdowns and initial solidification accidents may even occur.

[0003] Traditional dewaxing balls rely on physical friction or chemical dissolution. According to PetroChina statistics in 2022, dewaxing balls accounted for 72% of mechanical dewaxing operations, with an average annual consumption exceeding 500,000 units. However, most traditional dewaxing balls cannot dissolve the wax. When dewaxing long-neglected pipelines for the first time, excessive dewaxing at once can form wax columns (resistance > pump pressure), especially in small-diameter pipelines, leading to secondary blockages. The dewaxing balls cannot be recovered, resulting in direct economic losses.

[0004] In addition, traditional wax cleaning balls are generally collected using manual ball collection equipment. However, manual ball collection equipment requires operators to be familiar with the ball collection process, and the position of the balls cannot be sensed, making collection difficult and resulting in high operating costs. Furthermore, repeated loading and unloading further increases costs. Summary of the Invention

[0005] To overcome the shortcomings of wax removal balls, such as secondary clogging and difficulty in recycling, this invention proposes a soluble light metal wax removal ball, its preparation method, and its application.

[0006] The technical solution adopted by this invention to solve its technical problem is: A soluble light metal dewaxing ball includes a soluble light metal ball and a soluble protective coating.

[0007] The outer surface of the soluble light metal ball is completely covered by the soluble protective coating.

[0008] The soluble light metal spheres are aluminum-based alloys with a density of 2.212 g / cm³-2.813 g / cm³, spherical in shape, and with a diameter of 32 mm-50 mm. They dissolve in crude oil and have spiral grooves on their outer surface. The spheres comprise the following components by weight percentage: Al 85%-90% Zn 1%-5% Cu 3%-5% Mg 1%-3% Ga 0.1%-0.5% In 0.1%-0.5% Sn 0.1%-0.3% Ce 1%-3% Ti 0.01%-0.1% The spiral groove has a depth of 0.5mm-2.0mm, a pitch of 3mm-8mm, and a helix angle of 20°-50°. When used in dewaxing of crude oil pipelines, the crude oil flows through the spiral groove, generating periodic vortices.

[0009] The soluble protective coating is composed of a three-phase blend of polylactide (PLA), paraffin wax, and nano-silica, and is uniformly adhered to the surface of the soluble light metal spheres with a thickness of 1.5mm-2mm. It dissolves in crude oil.

[0010] The aforementioned soluble light metal dewaxing ball is an activated modified aluminum-based alloy. In an environment with a water content ≥5%, it triggers electrochemical corrosion with a dissolution rate of 0.1 mm / h-0.5 mm / h, forming honeycomb-shaped corrosion pits on the surface.

[0011] The aforementioned soluble light metal dewaxing balls are prepared by die casting.

[0012] The aforementioned soluble light metal wax-removing ball, wherein the soluble protective coating comprises the following components by weight percentage: Polylactide (PLA) 80wt%-98wt% Paraffin 5wt%-10wt% Nano-silica 3wt%-5wt%.

[0013] The aforementioned soluble light metal wax removal ball has a soluble protective coating that is uniformly applied to the surface of the soluble light metal ball using an electrostatic spraying method.

[0014] A method for preparing a soluble light metal wax-removing ball includes the following steps: Step 1, die casting Using a die-casting method, soluble light metal spheres are formed.

[0015] Step 2, electrostatic spraying Preheating of soluble light metal balls; An electrostatic spraying method is used to uniformly coat the surface of the soluble light metal spheres with a soluble protective coating.

[0016] In the above-mentioned method for preparing soluble light metal wax balls, in step 2 of the electrostatic spraying process, the preheating temperature of the soluble light metal balls is 60℃; the voltage of the electrostatic spraying is 50kV, the spraying distance is 20cm, and the atomizing pressure is 0.3MPa.

[0017] Application of a soluble light metal dewaxing ball in dewaxing crude oil pipelines.

[0018] The beneficial effects of this invention are: A dewaxing ball capable of dissolving light metals, with a spiral groove shape, can be used as a vortex generator to produce periodic vortices when crude oil flows through it; through fluid-structure interaction design and physical scraping integration, it enhances the turbulence intensity of crude oil and improves the efficiency of dewaxing.

[0019] A soluble light metal dewaxing ball can completely dissolve the metal, and the Al(OH)3 colloid generated by the dissolution has a particle size of ≤500μm. This can prevent the ball from getting stuck at pipeline connections, and it can be applied to oil pipelines of varying complexity. It also solves the problem of secondary blockage caused by traditional dewaxing balls.

[0020] A type of light metal dewaxing ball that can dissolve light metals produces hydrogen as the main gaseous product after electrochemical corrosion, which will not cause harm to the environment or human body.

[0021] A new type of dewaxing ball capable of dissolving light metals reduces the time and cost of handling ball jamming incidents, while also being adaptable to complex dewaxing environments.

[0022] A type of dewaxing ball that can dissolve light metals can be sensed and detected by an external metal detector to understand the dewaxing operation inside the pipeline.

[0023] A soluble light metal dewaxing ball with a spiral groove structure improves physical scraping force; at the same time, both the soluble protective coating on its surface and the soluble light metal ball inside can dissolve in crude oil. After dissolution, it generates small metal fragments and releases hydrogen gas. The small metal fragments are discharged with the crude oil flow in the pipeline and will not be deposited inside the pipeline, thus avoiding secondary blockage problems. Attached Figure Description

[0024] Figure 1 This is a three-dimensional view of the soluble light metal wax ball of Embodiment 1 of the present invention; Figure 2 yes Figure 1 Sectional view of AA in the middle; Figure 3 yes Figure 1 Enlarged view of part B in the middle.

[0025] Reference numerals: 1. Soluble light metal ball, 2. Soluble protective coating, 3. Spiral groove. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] Example 1 A type of light metal-soluble wax-removing ball, such as Figure 1 As shown, it includes a soluble light metal ball 1 and a soluble protective coating 2.

[0028] The soluble light metal sphere 1 is composed of an aluminum-based alloy with the following specific composition ratios: Al (85%-90%), Zn (1%-5%), Cu (3%-5%), Mg (1%-3%), Ga (0.1%-0.5%), In (0.1%-0.5%), Sn (0.1%-0.3%), Ce (1%-3%), and Ti (0.01%-0.1%). When the soluble light metal sphere 1 comes into contact with water, it can undergo electrochemical dissolution. The specific dissolution principle is explained in detail in the specific embodiments. The diameter of the soluble light metal sphere 1 is 32-50 mm, and the density of the aluminum-based alloy is 2.212-2.813 g / cm³.

[0029] Its outer surface is completely covered by a soluble protective coating 2 to prevent the soluble light metal ball 1 from coming into premature contact with crude oil and triggering the dissolution mechanism. The soluble protective coating 2 is composed of high molecular organic matter, the main components of which are PLA (polylactide) (80-98wt%), paraffin (5-10wt%), and nano silica (3-5wt%), with a thickness of 1.5-2mm. The coating can slowly dissolve in crude oil.

[0030] like Figure 3 As shown, the surface of the soluble light metal wax-removing ball is shaped as a spiral groove 3, with a groove depth of 0.5-2.0 mm, a pitch of 3-8 mm, and a helix angle of 20°-50°. The spiral groove 3 can act as a vortex generator, producing periodic vortices when crude oil flows through it, exposing the wax deposition surface to a highly turbulent fluid.

[0031] like Figure 2 As shown, the wax removal ball comprises: Soluble light metal spheres 1 Material: Activated modified aluminum-based alloy.

[0032] Solubility characteristics: In an environment with a water content of ≥5%, it triggers electrochemical corrosion, releases hydrogen gas, and forms honeycomb-like pits (pore size 50-200um) on the surface.

[0033] Soluble protective coating 2 Composite structure: PLA (polylactide) (91.5wt%) / paraffin (5wt%) / nano silica three-phase blend system (3.5wt%).

[0034] Spiral groove 3 Turbulence induction: It can be used as a vortex generator to produce periodic vortices when crude oil flows through it, exposing the wax deposition surface to highly turbulent fluid.

[0035] Example 2 The specific structure and composition of the soluble light metal wax removal balls: This embodiment 1 provides a soluble light metal wax removal ball, such as Figure 1 , 2 As shown in Figure 3, the system includes a soluble light metal sphere 1 and a soluble protective coating 2. The soluble light metal sphere 1 is composed of an aluminum-based alloy with the following specific composition and weight percentages: Al (89.02%), Zn (4.0%), Cu (3.75%), Mg (1.8%), Ga (0.15%), In (0.1%), Sn (0.15%), Ce (1.0%), and Ti (0.03%). The diameter of the soluble light metal sphere 1 is 32-50 mm. The soluble protective coating 2 is composed of PLA (polylactide) (91.5 wt%), paraffin wax (5 wt%), and nano-silica (3.5 wt%), with a thickness of 1.5-2 mm.

[0036] It should be noted that traditional wax removal balls have significant limitations in terms of wax removal efficiency and clogging prevention. This solution significantly improves the efficiency of wax removal operations and avoids clogging by changing the shape and base material of the wax removal balls.

[0037] Specifically, in this embodiment, the solution mainly includes a soluble light metal sphere 1, a soluble protective coating 2, and a spiral groove structure 3. In an environment with a water content ≥5%, the soluble light metal sphere 1 triggers electrochemical corrosion, dissolving at a rate of 0.1-0.5 mm / h, forming honeycomb-like pits on the surface. The soluble protective coating 2 is composed of a three-phase blend system of PLA (polypropylene) lactone / paraffin / nano silica. Since both the soluble protective coating 2 and crude oil are organic materials, they are compatible and slowly dissolve, ultimately exposing the spheres to the crude oil.

[0038] The surface of the soluble light metal wax-removing spheres has a spiral groove structure, and its geometric parameters meet the following requirements: groove depth 0.5-2.0mm, pitch 3-8mm, and helix angle 20°-50°. Figure 3As shown, the spiral groove 3 acts as a vortex generator, producing periodic vortices as crude oil flows through it and inducing turbulent shear forces (increasing wall shear stress to 1.8-2.4 Pa), thus accelerating wax removal and improving wax removal efficiency.

[0039] Example 3 The main mechanism of dissolution of soluble light metal sphere 1: Aluminum readily forms a dense Al2O3 oxide film under normal conditions. This film greatly inhibits corrosion, making aluminum "almost insoluble".

[0040] The addition of In, Ga, and Sn is intended to locally disrupt the Al2O3 film, creating "defects" at the microscopic level, allowing moisture, oxygen, and Cl to pass through. - Ions can quickly penetrate into the metal matrix.

[0041] In the damaged localized area, aluminum undergoes a direct anodic reaction: Al→3e - + Al III At the same time, oxygen and moisture in the environment undergo a cathodic reaction: O2 + H2O + 4e - →4OH - The two reactions form a battery circuit, and the flow of electrons causes aluminum to dissolve rapidly into Al. 3- This causes the soluble light metal ball 1 to dissolve.

[0042] Example 4 Preparation of soluble light metal wax-removing balls: A soluble light metal sphere 1 with spiral grooves 3 is produced using die casting. Then, a soluble protective coating 2 with a thickness of 1.5-2 mm is applied using electrostatic spraying at a voltage of 50kV, a spraying distance of 20cm, an atomizing pressure of 0.3MPa, and a substrate preheated to 60℃. Uniform coating is required, with no missed areas. The purpose is to fill the bottom of the grooves and areas near the spiral angle on the substrate surface, and to increase the adhesion between the substrate and the protective coating.

[0043] Example 5 Simulating pipe dewaxing in a laboratory environment: Pipe specifications: Steel pipe with an inner diameter of 35mm and a length of 10m. Wax layer thickness: A 2mm thick layer of paraffin wax is uniformly coated on the inner wall of the pipe to simulate the actual wax formation.

[0044] The size of the soluble light metal dewaxing ball is 30mm in diameter, ensuring a proper interference fit with the inner wall of the pipe to enhance the scraping effect.

[0045] Propulsion method: The water pressure is used to push the soluble light metal wax removal ball from one end of the pipeline to the other end, with a propulsion pressure of 0.5MPa.

[0046] Dissolution test: After the soluble light metal dewaxing balls pass through the pipeline, collect their residue, place them in crude oil, and observe their dissolution.

[0047] The experimental results are as follows: Wax removal effect: After the wax removal ball that can dissolve light metals passes through the pipe, the paraffin layer on the inner wall is effectively scraped off, with a residual thickness of less than 0.1mm, and the wax removal efficiency is over 95%.

[0048] Example 6 Ball jamming was addressed in a φ50mm oil pipeline at an oilfield in eastern my country. 1. Pipeline foundation parameters The basic parameters of the pipeline are shown in Table 1.

[0049] Table 1 Pipeline foundation parameters 2. Crude oil physical properties The physical properties of crude oil are shown in Table 2.

[0050] Table 2 Crude oil physical properties 3. Wax buildup characteristic parameters The wax buildup characteristic parameters are shown in Table 3.

[0051] Table 3. Characteristic parameters of wax buildup Implementation: The performance parameters of the aluminum-based alloy desiccant ball for dissolving light metals are shown in Table 4.

[0052] Table 4 Performance Parameters As can be seen from Table 4, the soluble light metal dewaxing ball provided by the present invention has a spiral groove 3 structure, which can achieve rapid dewaxing of pipelines. The soluble protective coating 2 and the soluble light metal ball 1 are soluble and decompose into smaller metal fragments, which are discharged with the crude oil in the pipeline and will not be deposited inside the pipeline to form secondary blockage.

[0053] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0054] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A soluble light metal wax-removing ball, characterized in that, Includes soluble light metal spheres (1) and soluble protective coating (2); The outer surface of the soluble light metal ball (1) is completely covered by the soluble protective coating (2); The soluble light metal sphere (1) is an aluminum-based alloy with a density of 2.212 g / cm³-2.813 g / cm³, spherical in shape, and with a diameter of 32 mm-50 mm. It dissolves in crude oil and has spiral grooves (3) on its outer surface. It comprises the following components by weight percentage: Al 85%-90% Zn 1%-5% Cu 3%-5% Mg 1%-3% Ga 0.1%-0.5% In 0.1%-0.5% Sn 0.1%-0.3% Ce 1%-3% Ti 0.01%-0.1% The spiral groove (3) has a groove depth of 0.5mm-2.0mm, a pitch of 3mm-8mm, and a spiral angle of 20°-50°. When used in the dewaxing of crude oil pipelines, the crude oil flows through the spiral groove (3) and generates periodic vortices. The soluble protective coating (2) is composed of a three-phase blend of polylactide PLA, paraffin wax, and nano silica. It is uniformly attached to the surface of the soluble light metal ball (1) with a thickness of 1.5 mm to 2 mm and is soluble in crude oil.

2. The soluble light metal wax-removing ball according to claim 1, characterized in that, The soluble light metal ball (1) is an activated modified aluminum-based alloy. In an environment with a water content ≥5%, it triggers electrochemical corrosion with a dissolution rate of 0.1 mm / h-0.5 mm / h, forming honeycomb-shaped corrosion pits on the surface.

3. The soluble light metal wax removal ball according to claim 1, characterized in that, The soluble light metal ball (1) is prepared by die casting.

4. The soluble light metal wax-removing ball according to claim 1, characterized in that, The soluble protective coating (2) comprises the following components by weight percentage: Polylactide (PLA) 80wt%-98wt% Paraffin 5wt%-10wt% Nano-silica 3wt%-5wt%.

5. The soluble light metal wax-removing ball according to claim 1, characterized in that, The soluble protective coating (2) is uniformly applied to the surface of the soluble light metal ball (1) by electrostatic spraying.

6. A method for preparing a soluble light metal wax-removing ball according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1, die casting Using die casting, soluble light metal balls are formed (1). Step 2, electrostatic spraying Soluble light metal balls (1) preheated; An electrostatic spraying method is used to uniformly coat a soluble protective coating (2) on the surface of the soluble light metal ball (1).

7. The method for preparing soluble light metal wax-removing balls according to claim 6, characterized in that, In step 2, electrostatic spraying... The preheating temperature of the soluble light metal balls (1) is 60℃; The electrostatic spraying voltage is 50kV, the spraying distance is 20cm, and the atomizing pressure is 0.3MPa.

8. The application of the soluble light metal dewaxing balls according to any one of claims 1-5 in the dewaxing of crude oil pipelines.

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