A hyperbranched polymer paraffin inhibitor and a preparation method thereof

Abstract

The application discloses a kind of hyperbranched polymer paraffin inhibitor and preparation method thereof, belong to the technical field of oil exploitation its technical scheme is: long chain acrylic ester monomer, maleic anhydride, 4-allyl benzyl ether and short chain ester monomer, branched monomer are dissolved in dimethylbenzene, 0.1~1% initiator benzoyl peroxide is added, under the condition of 70~90 ℃, it is obtained hyperbranched polymer paraffin inhibitor that stirring reaction 4~8 hours.The paraffin inhibitor of the application has hyperbranched structure, can destroy the crystal structure of wax crystal, is favorable to change the surface morphology of wax crystal, and weaken the interaction between wax crystal that precipitates, hinder the trend that wax crystal body crosslink forms continuous three-dimensional network structure, effectively prevent wax crystal precipitation deposition, and improve the rheological property of waxy crude oil, with good paraffin resistance.

Description

Technical Field

[0001] This invention discloses a method for preparing a hyperbranched anti-wax agent, belonging to the field of petroleum extraction technology. Background Technology

[0002] Most crude oil is rich in wax. During extraction, as temperature and pressure decrease, the wax in the crude oil gradually precipitates and deposits around the wellbore and inside the production casing, damaging the reservoir. Wax deposition is a common and destructive problem in oil and gas production, and can occur at different locations in the crude oil production system. Wax deposition inside the formation inevitably damages the reservoir, blocks oil and gas channels, significantly reduces its oil phase permeability, and thus leads to reduced well production. Wax deposition on the porous surface of the reservoir alters the wettability of the formation rock, thereby significantly reducing oil recovery. Wax deposition at formation perforations and pump inlets increases oil flow resistance, reduces the effective flow area, and decreases pump efficiency. Wax deposition on the tubing walls reduces oil flow channels, increases back pressure on the formation, reduces the utilization rate of the production tubing, leading to decreased production, and in severe cases, even production shutdowns. Wax deposition between the tubing and sucker rod increases the load on the pumping unit, increases the difficulty of equipment operation and maintenance, and can even cause production failures such as wax jamming of the pump. Wax buildup in oil pipelines increases pump pressure, power consumption, and reduces the pipeline's transport capacity. Simultaneously, as wax accumulates, the wax layer thickens, reducing the pipeline's transport diameter. To maintain production, increased pressure at the pipeline's end is often necessary. If this pressure exceeds the pipeline's maximum capacity, it can lead to rupture, damaging the pipeline and causing significant environmental impact due to crude oil leakage into the ground.

[0003] Using chemical agents to prevent wax deposition in oil wells is a widely used wax-prevention technology in oilfields. Generally, chemical wax prevention is based on two mechanisms: first, one or more agents can form a polar film on the metal surface to affect the wettability of the metal surface, thereby reducing wax deposition; second, one or more agents can be added to change the structure of wax crystals or to disperse the wax crystals, thereby suspending them in the crude oil. Wax inhibitors are developed based on these principles.

[0004] Common anti-wax agents include aromatic hydrocarbon solvents that can dissolve paraffin; polymer wax crystal modifiers that can inhibit or alter wax crystal growth; and wax crystal dispersants that can inhibit particle aggregation and keep wax crystals in a dispersed state.

[0005] The mechanism of action of polymer wax crystal modifiers is that the modifier molecules have side chains of a certain length, with structures and polar groups similar to those of paraffin molecules in the main chain or side chains. At lower temperatures, the paraffin-like structures in their molecules form eutectics with paraffin molecules. Because their molecules also contain polar groups, the resulting crystal nuclei are distorted and deformed, which is not conducive to the continued growth of wax crystals. Summary of the Invention

[0006] The main technical problem solved by this invention is to provide a method for preparing a hyperbranched polymer anti-wax agent, addressing the issues that traditional anti-wax agents cannot further improve their anti-wax effect, require large dosages, and are costly.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] (1) Dissolve long-chain acrylate monomers, maleic anhydride, 4-allyl anisole, short-chain ester monomers, and branched monomers in xylene;

[0009] (2) Add 0.1-1% of the initiator benzoyl peroxide;

[0010] (3) The hyperbranched polymer anti-wax agent is obtained by reacting and stirring at 70-90℃ for 4-8 hours.

[0011] Compared with the prior art, the beneficial effects of this invention are:

[0012] (1) This invention can destroy the original structural arrangement of wax crystals, so that paraffin will not continue to grow and form wax deposits. It can also have a eutectic effect with paraffin molecules to prevent wax crystals from forming a three-dimensional network structure, so that the paraffin crystals dispersed in crude oil can be prevented from sticking and growing, thereby achieving the effect of preventing wax from forming. It has good anti-wax properties.

[0013] (2) The hyperbranched anti-wax agent of the present invention has a small dosage and good anti-wax effect. Compared with conventional anti-wax agents, it can effectively inhibit the precipitation of high carbon number paraffin in crude oil, greatly reduce the blockage of crude oil gathering and transportation pipelines by wax deposition, and has low construction cost and simple on-site construction process.

[0014] (3) The hyperbranched anti-wax agent provided by the present invention has the functions of anti-wax as the main function and decondensation as the auxiliary function. The product is neutral, non-corrosive, stable in storage, convenient to use and simple to prepare.

[0015] (4) The raw materials of the present invention are readily available and have good compatibility with each other, and have the characteristics of wide applicable temperature and significant anti-wax effect. Detailed Implementation

[0016] This invention is not limited to the following embodiments; specific implementation methods can be determined based on the technical solution of this invention and actual circumstances. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are publicly available chemical reagents and chemical products in the prior art.

[0017] Example 1

[0018] Octadecyl acrylate, maleic anhydride, 4-allyl anisole, methyl acrylate, and divinylbenzene were dissolved in xylene, wherein the molar ratio of octadecyl acrylate, maleic anhydride, and divinylbenzene was 1:0.1:0.02. In a nitrogen atmosphere, 0.1% benzoyl peroxide initiator was added, and the mixture was reacted at 70°C for 4 hours to obtain a hyperbranched polymer anti-wax agent.

[0019] Example 2

[0020] Octadecyl acrylate, maleic anhydride, 4-allyl anisole, methyl acrylate, and divinylbenzene were dissolved in xylene, with the molar ratio of octadecyl acrylate, maleic anhydride, and divinylbenzene being 2:0.2:0.04. In a nitrogen atmosphere, 0.3% benzoyl peroxide initiator was added, and the mixture was reacted at 80°C for 6 hours to obtain a hyperbranched polymer anti-wax agent.

[0021] Example 3

[0022] Octadecyl acrylate, maleic anhydride, 4-allyl anisole, methyl acrylate, and divinylbenzene were dissolved in xylene, wherein the molar ratio of octadecyl acrylate, maleic anhydride, and divinylbenzene was 3:0.3:0.06. In a nitrogen atmosphere, 0.5% benzoyl peroxide initiator was added, and the mixture was reacted at 90°C for 8 hours to obtain a hyperbranched polymer anti-wax agent.

[0023] Example 4

[0024] Octadecyl acrylate, maleic anhydride, 4-allyl anisole, methyl acrylate, and divinylbenzene were dissolved in xylene, wherein the molar ratio of octadecyl acrylate, maleic anhydride, and divinylbenzene was 4:0.1:0.08. In a nitrogen atmosphere, 0.7% benzoyl peroxide initiator was added, and the mixture was reacted at 80°C for 8 hours to obtain a hyperbranched polymer anti-wax agent.

[0025] Example 5

[0026] Octadecyl acrylate, maleic anhydride, 4-allyl anisole, methyl acrylate, and divinylbenzene were dissolved in xylene, with the molar ratio of octadecyl acrylate, maleic anhydride, and divinylbenzene being 5:0.2:0.02. In a nitrogen atmosphere, 1% benzoyl peroxide initiator was added, and the mixture was reacted at 80°C for 8 hours to obtain a hyperbranched polymer anti-wax agent.

[0027] The evaluation of wax inhibitors is conducted in accordance with the standard SYT 6300-2009 "Technical Conditions for Wax Inhibitors Used in Oil Production".

[0028] Table 1 Wax Resistance Rate

[0029]

[0030] Experiments have shown that the high carbon number anti-wax depressant of the present invention has a good anti-wax effect on crude oil with high wax content. At an addition of 250 ppm, the highest anti-wax rate can reach 88%.

Claims

1. A polymeric wax inhibitor, prepared from long-chain acrylate monomers, maleic anhydride, 4-allyl anisole, short-chain ester monomers, and branched monomers in a molar ratio of 1~5:0.1~0.3:0.1~0.5:0.1~0.3:0.02~0.08, with the following structural formula: Where R1 is C 12 H 25 ~C 18 H 37 R2 is CH3~C4H9, and R3 is C4H4O4 or C6H6.

2. The polymer anti-wax agent as described in claim 1, its preparation includes the following steps: Long-chain acrylate monomers, maleic anhydride, 4-allyl anisole, short-chain ester monomers, and branched monomers are dissolved in xylene, and 0.1-1% of the initiator benzoyl peroxide is added. The reaction is carried out at 70-90°C with stirring for 4-8 hours to obtain a polymer anti-wax agent.

3. The polymer anti-wax agent as described in claim 2, characterized in that: The long-chain acrylate monomers are at least one of dodecyl acrylate, hexadecyl acrylate, and octadecyl acrylate.

4. The polymer anti-wax agent as described in claim 2, characterized in that: The short-chain ester monomers mentioned are at least one of methyl acrylate, ethyl acrylate, and butyl acrylate.

5. The polymer anti-wax agent as described in claim 2, characterized in that: The branched monomer is at least one of ethylene glycol diacrylate and p-divinylbenzene.

6. The polymer anti-wax agent as described in claim 2, characterized in that: The monomer concentration is 20-50%.

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