阅读说明：本技术 一种双亲氧化石墨烯稠油降粘剂的制备方法和应用 (Preparation method and application of amphiphilic graphene oxide heavy oil viscosity reducer ) 是由 陶震 田玉芹 赵凤鸣 黄顼 吴文炜 陈士勇 吴志连 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种双亲氧化石墨烯稠油降粘剂的制备方法和应用,将含有氧化石墨烯、疏水改性剂、偶联剂和模板剂的混合物,反应,得到双亲氧化石墨烯稠油降粘剂。所述双亲氧化石墨烯稠油降粘剂由疏水改性剂改性氧化石墨烯制备得到,使其一面亲水、一面亲油,同时具有油溶性降粘剂和水溶性降粘剂的优点,同时又克服了他们的缺点,应用更加广泛。(The invention discloses a preparation method and application of an amphiphilic graphene oxide thick oil viscosity reducer. The amphiphilic graphene oxide thick oil viscosity reducer is prepared by modifying graphene oxide with a hydrophobic modifier, so that one surface of the graphene oxide thick oil viscosity reducer is hydrophilic, the other surface of the graphene oxide thick oil viscosity reducer is oleophilic, the graphene oxide thick oil viscosity reducer has the advantages of an oil-soluble viscosity reducer and a water-soluble viscosity reducer, the defects of the graphene oxide thick oil viscosity reducer and the water-soluble viscosity reducer are overcome, and the application is wider.)

1. The preparation method of the amphiphilic graphene oxide thick oil viscosity reducer is characterized by reacting a mixture containing graphene oxide, a hydrophobic modifier, a coupling agent and a template agent to obtain the amphiphilic graphene oxide thick oil viscosity reducer.

2. The method of claim 1, wherein the hydrophobic modifier comprises C₁₀～C₂₀At least one of alkyl amines;

preferably, the hydrophobic modifier is selected from at least one of octadecylamine, dodecylamine;

preferably, the coupling agent comprises a silane coupling agent;

preferably, the silane coupling agent is selected from at least one of KH550, KH560 and KH 570;

preferably, the template is selected from at least one of kerosene, heptane and n-hexane;

preferably, the mass ratio of the graphene oxide to the hydrophobic modifier to the coupling agent is 1: 0.02-0.04: 0.02 to 0.04;

preferably, the mass-to-volume ratio of the graphene oxide to the template is: 1g, 100-300 mL;

preferably, the mass-to-volume ratio of the graphene oxide to the template is: 1g:100 mL.

3. The method according to claim 1, wherein the reaction conditions are as follows: the reaction temperature is 60-80 ℃, and the reaction time is 1.5-2.5 h.

4. The method of claim 1, comprising:

(1) obtaining graphene oxide dispersion liquid;

(2) mixing a hydrophobic modifier with a template agent to obtain a mixed solution;

(3) and (3) mixing the graphene oxide dispersion liquid with a coupling agent II, adding the mixed solution obtained in the step (2), and reacting to obtain the amphiphilic graphene oxide thick oil viscosity reducer.

5. The method of claim 4, wherein the conditions of mixing I are: stirring at 15-30 ℃ for 5-12 min; the stirring speed is 200-400 rpm;

preferably, the conditions of the mixing II are as follows: stirring at 50-80 ℃ for 1-3 h; the stirring speed is 200-400 rpm.

6. The preparation method according to claim 1, wherein the particle size of the graphene oxide is 50 to 300 nm.

7. The amphiphilic graphene oxide thick oil viscosity reducer prepared by the preparation method of any one of claims 1 to 6.

8. A viscosity reducer comprising at least one of the amphipathic graphene oxide thick oil viscosity reducer of claim 7 and the amphipathic graphene oxide thick oil viscosity reducer obtained by the preparation method of any one of claims 1 to 6.

9. The viscosity reducer of claim 8 is used for reducing viscosity of thick oil.

10. The use of claim 9, wherein the viscosity reduction of heavy oil is huff and puff, flooding, viscosity reduction of heavy oil in a wellbore.

Technical Field

The invention relates to a preparation method and application of an amphiphilic graphene oxide heavy oil viscosity reducer, and belongs to the field of oil and gas field development.

Background

The viscosity reduction of the thick oil is an effective crude oil exploitation yield-increasing technology, and has very important significance for improving the crude oil recovery efficiency and reducing the exploitation cost. At present, the viscosity reducer for thick oil is widely applied to a plurality of oil fields at home and abroad and plays a key role in a plurality of links. The viscosity reducer for thick oil is divided into oil-soluble viscosity reducer and water-soluble viscosity reducer. The oil-soluble thick oil viscosity reducer mainly breaks the interaction among thick oil macromolecules to dissociate originally crosslinked molecular chains into independent oil drop macromolecules, so that the viscosity of thick oil is reduced, the mobility of the thick oil is enhanced, the swept area in the subsequent water drive and gas drive processes is increased, and more crude oil can be extracted from the stratum. However, the oil-soluble viscosity reducer is generally expensive to use, and the injection process is difficult because the oil-soluble viscosity reducer is insoluble in water. The water-soluble viscosity reducer is mainly used for emulsifying the crude oil in the body driving process through the hydrophilic-lipophilic action of molecular chains of the viscosity reducer, so that an emulsion with the viscosity far lower than that of the crude oil and slightly higher than that of mineralized water is formed. The emulsion has strong interaction with water, and can be quickly carried away from the stratum in the subsequent water flooding process, so that the oil extraction efficiency is improved. The water-soluble viscosity reducer has better adaptability, low cost and wider application range than the oil-soluble viscosity reducer.

The oil-soluble viscosity reducer mainly comprises organic matters containing benzene rings and heteroatoms, the organic matters have poor water solubility but very good solubility in crude oil, and molecular chains of the crude oil can be effectively dispersed through the attraction effect among similar groups. The oil-soluble viscosity reducer for thick oil is generally synthesized by taking a common organic matter as a template through addition reaction and substitution reaction.

The water-soluble viscosity reducer is composed of a plurality of surfactants, and can effectively emulsify the crude oil to form emulsion with lower viscosity. Therefore, the preparation method of the water-soluble viscosity reducer is similar to the synthesis method of the common surfactant, but in consideration of the compatibility problem among various surfactants, the compatibility test of each surfactant is required before the water-soluble viscosity reducer is prepared.

The essence of the oil-soluble viscosity reducer is that some organic matters (such as xylene, kerosene and organic micromolecule synthetic copolymer) similar to the molecular structure of crude oil, the whole viscosity reduction process can be analogized to an oil displacement mode, a large amount of use easily causes influence on the environment, and the oil-soluble viscosity reducer is not an ideal road from the perspective of green development. Meanwhile, the oil-soluble viscosity reducer has high use cost and obvious disadvantages from the economic perspective.

The water-soluble viscosity reducer realizes the viscosity reduction function by virtue of emulsification, but the emulsification process is influenced by a plurality of factors such as temperature, mineralization degree, shearing force and the like, so that the same water-soluble viscosity reducer can show different viscosity reduction effects under different oil field environments, and the universality is not strong. Secondly, in practical environment, the external shearing force is very limited, and the lack of necessary shearing force action hardly promotes the emulsification process, which is why most water-soluble viscosity reducers have good effect in laboratory environment (generally enough shearing force action can be given in experimental environment), but the field application is poor.

Disclosure of Invention

Aiming at a series of problems of the traditional viscosity reducer, the invention aims to provide a novel viscosity reducer which is different from the traditional oil-soluble viscosity reducer, has good water solubility and lower cost; the oil-soluble viscosity reducer is different from a common water-soluble viscosity reducer, is suitable for various oil reservoirs, and can realize the emulsification of crude oil under the action of extremely low shearing force to form emulsion with lower viscosity; finally, the viscosity reducer is based on carbon materials, is green and environment-friendly, and has small environmental pollution pressure when in use.

According to one aspect of the application, a preparation method of an amphiphilic graphene oxide thick oil viscosity reducer is disclosed, and comprises the following steps: and reacting the mixture containing the graphene oxide, the hydrophobic modifier, the coupling agent and the template agent to obtain the amphiphilic graphene oxide thick oil viscosity reducer.

Optionally, the hydrophobic modifier comprises C₁₀～C₂₀At least one of alkyl amines.

Preferably, the hydrophobic modifier is selected from at least one of octadecylamine and dodecylamine.

Preferably, the hydrophobic modifier is selected from octadecylamine and dodecylamine.

Optionally, the coupling agent comprises a silane coupling agent;

preferably, the silane coupling agent is selected from at least one of KH550, KH560 and KH 570.

Optionally, the mass ratio of the graphene oxide to the hydrophobic modifier to the coupling agent is 1: 0.02-0.04: 0.02 to 0.04.

Optionally, the mass ratio of the graphene oxide to the hydrophobic modifier is 1: 0.02, 1: 0.021, 1: 0.022, 1: 0.023, 1: 0.024, 1: 0.025, 1: 0.026, 1: 0.027, 1: 0.028, 1: 0.029, 1: 0.03, 1: 0.031, 1: 0.032, 1: 0.033, 1: 0.034, 1: 0.035, 1: 0.036, 1: 0.037, 1: 0.038, 1: 0.039 or 1: 0.04.

optionally, the mass ratio of the graphene oxide to the coupling agent is 1: 0.02, 1: 0.021, 1: 0.022, 1: 0.023, 1: 0.024, 1: 0.025, 1: 0.026, 1: 0.027, 1: 0.028, 1: 0.029, 1: 0.03, 1: 0.031, 1: 0.032, 1: 0.033, 1: 0.034, 1: 0.035, 1: 0.036, 1: 0.037, 1: 0.038, 1: 0.039 or 1: 0.04.

optionally, the mass-to-volume ratio of the graphene oxide to the template is: 1g is 100-300 mL.

Optionally, the mass-to-volume ratio of the graphene oxide to the template is: 110mL of 1g, 120mL of 1g, 130mL of 1g, 140mL of 1g, 150mL of 1g, 160mL of 1g, 170mL of 1g, 180mL of 1g, 190mL of 1g, 200mL of 1g, 210mL of 1g, 220mL of 1g, 230mL of 1g, 240mL of 1g, 250mL of 1g, 260mL of 1g, 270mL of 1g, 280mL of 1g, 290mL of 1g or 300mL of 1 g.

Preferably, the mass-to-volume ratio of the graphene oxide to the template is: 1g:100 mL.

Optionally, the template is selected from at least one of kerosene, heptane, and n-hexane.

Optionally, the reaction conditions are: the reaction temperature is 60-80 ℃, and the reaction time is 1.5-2.5 h.

Optionally, the preparation method comprises: the method comprises the following steps:

(1) obtaining graphene oxide dispersion liquid;

(2) mixing a hydrophobic modifier with a template agent to obtain a mixed solution;

(3) and (3) mixing the graphene oxide dispersion liquid with a coupling agent II, adding the mixed solution obtained in the step (2), and reacting to obtain the amphiphilic graphene oxide thick oil viscosity reducer.

Optionally, the condition of the mixing I is as follows: stirring at 15-30 ℃ for 5-12 min; the stirring speed is 200-400 rpm.

Preferably, the stirring temperature is 25 ℃, and the stirring time is 10 min; the stirring speed was 300 rpm.

Optionally, the conditions of mixing II are: stirring at 50-80 ℃ for 1-3 h; the stirring speed is 200-400 rpm.

Preferably, the stirring temperature is 70 ℃, and the stirring time is 2 h; the stirring speed was 300 rpm.

Optionally, the particle size of the graphene oxide is 50-300 nm.

Preferably, the particle size of the graphene oxide is 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm or 300 nm.

According to another aspect of the application, the amphiphilic graphene oxide thick oil viscosity reducer obtained by the preparation method is provided.

According to another aspect of the application, a viscosity reducer is provided, which comprises at least one of the amphipathic graphene oxide thick oil viscosity reducer and the amphipathic graphene oxide thick oil viscosity reducer obtained by any preparation method.

Optionally, standing and layering the prepared solution containing the amphiphilic graphene oxide thick oil viscosity reducer, and adjusting the pH of the lower-layer solution to 6-7 to obtain the viscosity reducer.

Optionally, the standing time is 2 h.

Optionally, hydrochloric acid is used to adjust the pH of the lower layer solution.

Optionally, the upper layer solution is precipitated out, leaving a layer solution.

According to another aspect of the application, the application of the viscosity reducer in viscosity reduction of thick oil is provided.

Optionally, the viscosity reduction of the thick oil is huff and puff, oil displacement and viscosity reduction of the thick oil in a shaft.

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

the viscosity reducer provided by the invention has the advantages that one surface of the graphene oxide is hydrophilic and the other surface of the graphene oxide is oleophilic by performing amphiphilic modification on the graphene oxide, and the graphene oxide viscosity reducer has the advantages of an oil-soluble viscosity reducer and a water-soluble viscosity reducer, overcomes the defects of the oil-soluble viscosity reducer and the water-soluble viscosity reducer, and is more widely applied.

2, the viscosity reducer has the advantages of simple preparation method, easily obtained raw materials, environmental protection, green and pollution-free preparation process, mild operation conditions, simple process and low cost.

3 the viscosity reducer has good effect in different crude oils, the viscosity reduction rate can reach more than 93 percent, and the viscosity reduction effect lasts for a long time; even under the condition of low perturbation, the viscosity reducer also has good viscosity reducing effect and has great application prospect.

In a word, the graphene nano material is used as a template, and a brand-new water-soluble nano material thick oil viscosity reducer is prepared through graft modification, is different from the traditional material, can realize the emulsification viscosity reduction process of crude oil under the action of low disturbance, and has a long viscosity reduction effect duration.

Drawings

FIG. 1 is a schematic diagram of the emulsification and viscosity reduction effects of crude oil after mixing the viscosity reducer with crude oil and stirring at 6rpm in example 2 of the present application (the emulsification effect is significant, and no significant stratification occurs).

FIG. 2 is a graph showing viscosity values and viscosity reduction ratios of crude oil and after the use of a viscosity reducer in example 2 of the present application; wherein A is₁Is the instantaneous viscosity of the viscosity reducer after being mixed with crude oil and stirred at 6 rpm; a. the₂The viscosity of the viscosity reducer is kept for 2 hours after the viscosity reducer is stirred with crude oil at 6 rpm.

FIG. 3 is a schematic diagram of the emulsification and viscosity reduction effects of crude oil (poor emulsification effect, significant stratification) after mixing a commercially available common water-soluble viscosity reducer for heavy oil with crude oil and stirring at 6rpm in comparative example 1 of the present application;

FIG. 4 is a graph showing viscosity values and viscosity reduction rates of crude oil and after the use of a viscosity reducer in example 3 of the present application; wherein A is₁Is the instantaneous viscosity of the viscosity reducer after being mixed with crude oil and stirred at 6 rpm; a. the₂The viscosity of the viscosity reducer is kept for 2 hours after the viscosity reducer is stirred with crude oil at 6 rpm.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials and chemicals in the examples of the present application were purchased commercially.

Example 1

(1) Dispersing 1g of Graphene Oxide (GO) in 100mL of deionized water, and then carrying out ultrasonic shearing (30kHz) for 2h to obtain a GO nano dispersion liquid A (the average particle size is 200nm), wherein the average particle size is not more than 300nm, otherwise, precipitation is easy to occur in the subsequent modification process;

(2) weighing 0.01g of octadecylamine and 0.01g of dodecylamine, adding the octadecylamine and the dodecylamine into 100mL of kerosene, and uniformly mixing the octadecylamine and the dodecylamine by using magnetic stirring (300rpm for 10min) to obtain a solution B;

(3) pouring 50mL of the solution A into a beaker, adding 0.01g of silane coupling agent (KH550), uniformly mixing the solution A and the solution B under magnetic stirring at 70 ℃ (300rpm for 2h), then continuously pouring 50mL of the solution B into the beaker, and continuously under magnetic stirring at 70 ℃ (300rpm for 2 h);

(4) standing the mixed solution in the step (3) for 2 hours, and then sucking out the upper layer kerosene by a dropper, and leaving the layer solution for later use;

(5) and (3) adjusting the pH value of the lower layer solution in the step (4) to 6-7 by using hydrochloric acid to obtain an amphiphilic graphene oxide thick oil viscosity reducer solution (the concentration is calculated according to the mass of the graphene oxide nano material, and the concentration of the obtained amphiphilic graphene oxide thick oil viscosity reducer solution is 10 g/L).

Example 2

The viscosity reduction performance of the amphiphilic nano viscosity reducer is tested by taking crude oil of a certain block of the Chinese Shengli oil field as a research object, and the specific crude oil information is shown in table 1.

TABLE 1 crude oil basic information for testing

And (3) crude oil viscosity reduction testing:

(1) 10g of the amphiphilic graphene oxide heavy oil viscosity reducer solution prepared in example 1 (the concentration of the amphiphilic graphene oxide heavy oil viscosity reducer is 10mg/mL) is poured into a 150mL beaker, then 90g of target reservoir mineralized water is poured into the beaker, and the solution and the mineralized water are uniformly mixed after being magnetically stirred (300rpm) for 10 minutes;

(2) taking a clean 250mL beaker, pouring 15g of the solution in the step (1) into the beaker, and then slowly pouring 35g of crude oil into the beaker;

(3) slowly and mechanically stirring the oil-water mixture in the step (2) at the target oil reservoir temperature of 46 ℃ at the speed of 6rpm for 1 h;

(4) after the stirring is finished, an obvious emulsion layer appears between the oil-water interface (as shown in figure 1: it can be seen that after the micro-disturbance, the crude oil is emulsified, and a more obvious emulsion layer is formed between the water layer and the oil layer).

(5) Sucking brown part of the upper and middle layers of the beaker, pouring the brown part into a viscometer for viscosity test to obtain real-time viscosity A₁(ii) a After the test is finished, the temperature is kept in the viscometer for 2 hours, and then the viscosity is measured again to obtain the anti-coalescence viscosity value A₂The results of the performance tests are shown in fig. 2, and it is found that the viscosity of the emulsion layer is significantly reduced to about 47mPa · s compared to the crude oil; after the sucked emulsion layer was removed for 2 hours, the viscosity of the emulsion was maintained at about 50 mPas without increasing the viscosity.

Comparative example 1

For outstanding performance, the viscosity reduction test is carried out by comparing another water-soluble viscosity reducer (viscosity reducer POEM) on the market (Jiangsu Haian petrochemical plant), the viscosity reduction test is carried out by using the method the same as that in the example 2, no obvious emulsion layer appears after stirring, as shown in figure 3, the commercial water-soluble viscosity reducer has poor viscosity reduction effect, oil and water are still obviously layered after micro stirring, no emulsion layer is observed, and the viscosity of crude oil is basically unchanged.

Example 3

The viscosity reduction performance of the amphiphilic nano viscosity reducer is tested by taking crude oil of a certain block of an oil field in Henan China as a research object, and specific crude oil information is shown in Table 2.

TABLE 2 crude oil basic information for testing

The specific test steps are as follows:

(1) 10g of the amphiphilic graphene oxide heavy oil viscosity reducer solution prepared in example 1 (the concentration of the amphiphilic graphene oxide heavy oil viscosity reducer is 10mg/mL) is poured into a 150mL beaker, then 90g of target reservoir mineralized water is poured into the beaker, and the solution and the mineralized water are uniformly mixed after being magnetically stirred (300rpm) for 10 minutes;

(2) taking a clean 250mL beaker, pouring 15g of the solution in the step (1) into the beaker, and then slowly pouring 35g of crude oil into the beaker;

(3) slowly and mechanically stirring the oil-water mixture in the step (2) at the target oil reservoir temperature of 40 ℃ at the speed of 6rpm for 1 h;

(4) after stirring, an obvious emulsifying layer appears between the oil-water interface, and the brown part of the upper middle layer of the beaker is sucked and poured into a viscometer for viscosity test to obtain real-time viscosity A₁25mPa · s; keeping the temperature in the viscometer for 2 hours, and measuring the viscosity again to obtain an anti-coalescence viscosity value A₂The results of the performance tests are shown in fig. 4, and it was found that the viscosity of the emulsion layer was significantly reduced to about 25mPa · s compared to the crude oil; after the sucked-out emulsion layer was removed for 2 hours, the viscosity of the emulsion was maintained at about 45 mPas without increasing the viscosity.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.