Nano paraffin inhibitor

Abstract

The invention belongs to the technical field of compositions for treating wells, and particularly relates to a nano paraffin inhibitor. The nano paraffin inhibitor provided by the invention is prepared by the following method: carrying out ultrasonic reaction on fatty alcohol-polyoxyethylene ether (3) monoester disodium sulfosuccinate, dicyclohexylamine and nano aluminum oxide powder in a solvent, carrying out solid-liquid separation, and drying. The nano Al2O3 endows the nano paraffin inhibitor with extremely strong surface activity, can penetrate into paraffin in the early stage of paraffin precipitation formation, and is combined with wax crystals through chemical bonds to cause loose paraffin precipitation, and meanwhile, the nano paraffin inhibitor covers the pipe wall to change the surface property of the pipe wall, so that the surface is hydrophilic, the paraffin on the surface of the pipe wall is promoted to fall off, and the paraffin on the surface of the pipe wall is prevented from falling off. The paraffin inhibition performance is further enhanced; in addition, the S = O bond and the wax crystal can inhibit the growth of the wax crystal through the bonding effect, and the S = O bond and the steric effect of the six-membered ring have a synergistic effect, so that the molecular structure of the nano paraffin inhibitor has better scale inhibition performance.

Description

Technical Field

[0001] This invention relates to the field of composition technology for treating wells, and more specifically to a nano-anti-wax agent. Background Technology

[0002] During oil and gas field development, changes in temperature, pressure, and flow rate can cause wax deposition in the wellbore or surface flow path, affecting normal production. Adding wax inhibitors is a common method to prevent wax deposition. Effective wax inhibitors fall into three categories: 1) Polycyclic aromatic hydrocarbon (PAH) type wax inhibitors, which participate in the formation of crystal nuclei, causing nucleus distortion and preventing further wax crystal growth; 2) Surfactant type wax inhibitors, divided into oil-soluble and water-soluble types, which mainly work by altering the surface properties of wax crystals; 3) Polymer type wax inhibitors, whose non-polar and non-polar segments can co-crystallize with wax, while the polar segments distort the crystal structure of the wax crystals, hindering further growth and the formation of a network structure, resulting in better wax deposition prevention.

[0003] CN 110157400A discloses an environmentally friendly, high-efficiency water-based wax remover and its preparation method for oil wells. Modified graphene oxide is added to the traditional wax remover and its agent, acrylamide, methacrylic acid, and allyl sulfonate, significantly improving the wax dissolution rate. CN 115466607B discloses a microemulsion wax remover and its preparation method and application. The microemulsion wax remover and its agent includes fatty alcohol ether salts, fatty alcohol polyethers, fatty acid amide betaine, etc., and has high wax prevention rates and surface activity. These wax removers generally have a certain wax prevention effect in the early stages of wax crystal formation.

[0004] There are many types of wax inhibitors, which generally provide good protection when wax crystals are just forming. However, these inhibitors are less effective at preventing wax buildup in the early stages or when wax has already formed. For cases where wax has already formed, a wax remover is needed. However, adding a wax remover increases costs, disrupts production, and most currently used wax removers are highly toxic. Therefore, current wax inhibitors cannot penetrate deep into the already formed wax layer, resulting in poor protection against wax buildup in the early stages or when wax has already formed. Summary of the Invention

[0005] This invention provides a nano-anti-wax agent, which solves the problem of poor anti-wax effect of existing anti-wax agents.

[0006] To solve the above-mentioned technical problems, the technical solution of the nano-wax inhibitor of the present invention is as follows:

[0007] A nano-wax inhibitor, wherein the nano-wax inhibitor is prepared by the following method: sodium disodium sulfosuccinate monoester of fatty alcohol polyoxyethylene ether (3), dicyclohexylamine and nano alumina powder are subjected to ultrasonic reaction in a solvent, and then dried after solid-liquid separation.

[0008] This invention improves upon existing technology and provides a nano-wax inhibitor. This agent is produced by ultrasonically reacting fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium, dicyclohexylamine, and nano-alumina powder in a solvent. The reaction equation is shown below:

[0009] Nano-Al2O3 endows the nano-wax inhibitor with extremely strong surface activity. In the early stage of wax formation, it can penetrate into the interior of paraffin wax and combine with wax crystals through chemical bonds, resulting in loose wax formation. At the same time, the nano-wax inhibitor covers the pipe wall, causing the surface properties of the pipe wall to change and become hydrophilic, which promotes the shedding of paraffin wax from the pipe wall surface and further enhances the wax inhibitor performance. In addition, the S=O bond can also inhibit the growth of wax crystals through bonding, and the synergistic effect with the steric hindrance effect of the six-membered ring gives the nano-wax inhibitor a good scale inhibition performance.

[0010] The nano-anti-wax agent provided by this invention, as a nanomaterial, has strong interfacial activity, which promotes the penetration of the anti-wax agent into the interior of wax crystals, reduces the binding of wax crystals, effectively inhibits the growth of wax crystals, and improves the anti-wax efficiency from the source. Furthermore, the bonding effect between the S=O bond and the wax crystal and the steric hindrance effect of the six-membered ring synergistically improve the anti-wax performance.

[0011] In order to further improve the bonding effect between nano alumina powder and fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium ester, and to improve the interfacial properties of nano anti-wax agent, preferably, the crystal form of the nano alumina powder is γ-Al2O3, and the particle size of the nano alumina powder is 30-100nm.

[0012] To further enhance the synergistic effect of the S=O bond bonding and steric hindrance of the nano-wax inhibitor, preferably, the mass ratio of the fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium, dicyclohexylamine, and nano-alumina powder is 1:(0.2-0.6):(0.1-0.3).

[0013] To further improve the compatibility of the nano-anti-wax agent with crude oil and enhance the dispersibility of paraffin in crude oil, preferably, the structural formula of the fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium ester is shown in Formula I:

[0014]

[0015] Where R is C 10 ~C 20 The long-chain alkane structure in the nano-alkanes improves the compatibility of the anti-wax agent with crude oil. Furthermore, the long alkyl chains increase the dispersibility of paraffin in crude oil, thus improving the dispersion of wax crystals in crude oil. Paraffin is less likely to bind, thereby playing an anti-wax role.

[0016] To further enhance the bonding effect of the three raw materials, preferably, the ultrasonic reaction time is 60–90 min, and the ultrasonic power during the ultrasonic reaction is 60–120 W·cm. -2 The ultrasonic frequency is 20–30 kHz.

[0017] To further enhance the ability of the nano-anti-wax agent to penetrate the interior of paraffin and bond with the wax crystals through chemical bonds, preferably, the particle size of the nano-anti-wax agent is 50-100 nm. Detailed Implementation

[0018] The technical concept of the nano-anti-wax agent provided by this invention is as follows:

[0019] A nano-wax inhibitor, wherein the nano-wax inhibitor is prepared by the following method: sodium disodium sulfosuccinate monoester of fatty alcohol polyoxyethylene ether (3), dicyclohexylamine and nano alumina powder are subjected to ultrasonic reaction in a solvent, and then dried after solid-liquid separation.

[0020] In recent years, nanomaterials have been gradually applied in the field of oilfield chemical additives, and their application in the field of wax and scale prevention in oil and gas fields has also become increasingly in-depth. Traditional wax inhibitors and scale inhibitors are prepared at the nanoscale, and the strong interfacial activity of nanomaterials can significantly improve the effectiveness of the agents. The nano wax inhibitor provided by this invention is prepared by ultrasonic reaction of fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium, dicyclohexylamine, and nano alumina powder in a solvent. The reaction equation is shown below:

[0021]

[0022] Nano-Al2O3 endows the nano-wax inhibitor with extremely strong surface activity. In the early stage of wax formation, it can penetrate into the interior of paraffin wax and combine with wax crystals through chemical bonds (mainly through ether bonds and carbonyl groups), resulting in loose wax formation. At the same time, the nano-wax inhibitor covers the pipe wall. The nanomaterials in the nano-wax inhibitor and the functional groups grafted onto it work together to change the surface properties of the pipe wall, making the surface hydrophilic, which promotes the shedding of paraffin wax from the pipe wall surface and further enhances the anti-wax performance. In addition, the S=O bond with nano-alumina has a weak bond force and is in a multi-ring state, which is not very stable. When the external environment changes, the alumina can be removed, and the reformed S=O bond can also inhibit the growth of wax crystals through bonding. The synergistic effect with the steric hindrance effect of the six-membered ring makes the molecular structure of the nano-wax inhibitor have good scale inhibition performance.

[0023] In a specific embodiment, the solvent is water.

[0024] In a specific embodiment, the solid-liquid separation is filtration, and the solid obtained after filtration is washed with water at least three times.

[0025] In a specific embodiment, the filtered material is dried. After drying, the nano-anti-wax agent may clump together, requiring further grinding to disperse the clumps and form nano-anti-wax agent powder.

[0026] The embodiments of the present invention will be further described below with reference to specific examples. Unless otherwise specified, the chemical reagents involved in the following examples are all commercially available conventional products.

[0027] I. Specific Embodiments of the Nano-Wax Resistant Agent of the Present Invention

[0028] The nano-wax inhibitor of the present invention is prepared by the following method:

[0029] Add fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium, dicyclohexylamine, and nano-alumina powder (γ-Al2O3, particle size 30-100nm) to a beaker containing 500mL of deionized water. Sonicate the mixture for a certain time, setting the ultrasonic power and frequency. After the reaction, filter the mixture. Wash the filtered solid three times with water, dry it, and grind it to obtain nano-wax inhibitor powder (particle size 50-100nm). The parameter settings in different embodiments are shown in Table 1.

[0030] Table 1 Parameter settings in different embodiments

[0031]

[0032] II. Comparative Example

[0033] Comparative Example 1

[0034] The nano-anti-wax agent provided in this comparative example differs from that in Example 1 in that nano-alumina powder is replaced with nano-silica powder. After the ultrasonic reaction is completed, the mixed solution exhibits stratification and cannot form a stable and uniform suspension system, indicating that nano-silica powder cannot participate in the reaction in the ultrasonic system.

[0035] Comparative Example 2

[0036] The nano-anti-wax agent provided in this comparative example differs from that in Example 1 in that nano-alumina powder is replaced with nano-titanium dioxide powder. After the ultrasonic reaction is completed, the mixed solution exhibits stratification and cannot form a stable and uniform suspension system, indicating that nano-titanium dioxide powder also cannot participate in the reaction in the ultrasonic system.

[0037] III. Experimental Examples

[0038] This experiment, referring to standard SYT6300-2009 "Technical Conditions for Wax Inhibitors and Cleaners in Oil Production," tested the wax inhibition rate of the wax inhibitor powders obtained in each example. The nano-wax inhibitor powders from Examples 1-10 were applied to produced fluids from unconventional gas fields containing condensate oil. The addition amount was gradually increased from low to high, starting at 0 ppm, then 100 ppm, 150 ppm, and finally 200 ppm. The wax inhibition rate test results of the nano-wax inhibitor powders in each example are shown in Table 2. Using the same experimental conditions as above, the wax inhibition rate of five commonly used field wax inhibitors (Comparative Examples 3-7) was tested. Comparative Examples 3-5 were WRQ-1, WRQ-4, and WRQ-8 provided by Henan Hereda Petroleum Engineering Technology Co., Ltd.; Comparative Examples 6-7 were H-311 and H-323 provided by Puyang Keli Chemical Co., Ltd.

[0039] Table 2. Wax-preventing rate test results of nano-wax-preventing powders in each embodiment.

[0040]

[0041] As can be seen from Table 2, the anti-wax agent powder provided by the present invention can achieve an anti-wax rate of over 82% when the addition amount is 100 ppm, with a maximum of 85.7%. As the addition amount increases, the anti-wax rate gradually increases. The anti-wax rate can reach over 83% when the addition amount is 150 ppm, with a maximum of 89.1%, and the anti-wax rate can reach over 85% when the addition amount is 200 ppm, with a maximum of 91.7%. Moreover, under the same test conditions, the anti-wax rate of commonly used anti-wax agents in the field is below 70%, which is significantly lower than that of the nano anti-wax agent powder of the present invention.

[0042] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A nano-anti-wax agent, characterized in that, The nano-anti-wax agent is prepared by the following method: sodium sulfosuccinate monoester of fatty alcohol polyoxyethylene ether (3), dicyclohexylamine and nano alumina powder are subjected to ultrasonic reaction in a solvent, and then dried after solid-liquid separation.

2. The nano-anti-wax agent as described in claim 1, characterized in that, The nano-alumina powder has a crystal form of γ-Al2O3 and a particle size of 30–100 nm.

3. The nano-anti-wax agent as described in claim 1 or 2, characterized in that, The mass ratio of the fatty alcohol polyoxyethylene ether (3) sulfosuccinate disodium ester, dicyclohexylamine, and nano alumina powder is 1:(0.2-0.6):(0.1-0.3).

4. The nano-wax inhibitor as described in claim 1, characterized in that, The structural formula of the fatty alcohol polyoxyethylene ether (3) sulfosuccinic acid disodium ester is shown in Formula I: Where R is C 10 ~C 20 saturated alkanes.

5. The nano-anti-wax agent as described in claim 1, characterized in that, The ultrasonic response time is 60–90 min, and the ultrasonic power during the ultrasonic response is 60–120 W·cm. -2 The ultrasonic frequency is 20–30 kHz.

6. The nano-anti-wax agent as described in claim 1, characterized in that, The particle size of the nano-anti-wax agent is 50-100 nm.

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