CN118206973A

CN118206973A - In-situ self-generated super-hydrophobic interface layer drag reducer and preparation method thereof

Info

Publication number: CN118206973A
Application number: CN202410638934.1A
Authority: CN
Inventors: 杨洋; 刘毅恒; 杨杰元; 梁克胜; 钟颖; 张�浩; 杨波
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2024-05-22
Filing date: 2024-05-22
Publication date: 2024-06-18

Abstract

The application relates to the technical field of oilfield chemical reagents, in particular to an in-situ self-generated super-hydrophobic interface layer drag reducer and a preparation method thereof; the drag reducer comprises, in mass fraction: catalytic emulsifier: 0.5 to 3.0 percent of nucleating agent: 1.0 to 10 percent of cross-linking agent: 0.2 to 1.0 percent of adhesion reinforcing agent: 0.1 to 1.0 percent of hydrophobic reinforcing agent: 0.1 to 2.0 percent of activator: 0.3 to 1.0 percent, and the balance of water and unavoidable impurities; wherein the activator comprises a mixture of urotropine and ammonium chloride; the drag reducer can be injected into a stratum in a liquid phase form, has good injectability and no risk of reservoir damage, and can greatly reduce the water flooding pressure of a hypotonic oil reservoir; meanwhile, the drag reducer is not required to be carried by oil phases such as diesel oil, kerosene and the like, and can be carried by water phases, so that the drag reducer is low in cost, safe and environment-friendly.

Description

In-situ self-generated super-hydrophobic interface layer drag reducer and preparation method thereof

Technical Field

The application relates to the technical field of oilfield chemical reagents, in particular to an in-situ self-generated super-hydrophobic interfacial layer drag reducer and a preparation method thereof.

Background

Along with the gradual exhaustion of the medium-high permeability reservoir resources, the low permeability reservoir resources gradually become the main resource types of crude oil stable production; aiming at the problems of poor adaptability, high injection pressure, insufficient water injection quantity, difficult oil reservoir energy supplementation and the like of a low-permeability oil reservoir, the water injection pressure maintaining technology mainly aims at the exploitation of oil reservoir resources, and therefore, a new exploitation technology suitable for the low-permeability oil reservoir needs to be developed at present. The nanometer drag reduction technology is to inject nanometer fluid into stratum, and nanometer particles in the nanometer fluid can form a hydrophobic layer after being adsorbed on the surface of rock, and the hydrophobic layer can reduce the attraction and adhesion force of the surface of rock to water molecules, so that the water injection pressure of oil reservoirs can be greatly reduced through the surface sliding effect, and the water injection quantity and the oil reservoir energy supplementing effect can be improved.

The existing nano drag reduction technology comprises the following steps: (1) The depressurization and injection-increasing nano drag reducer mainly comprises hydrophobic nano particles, a composite surfactant, an auxiliary agent and water, wherein the hydrophobic nano particles are silica nano hollow spheres with fluorine-containing groups and long-chain alkyl chains loaded on the surfaces, and the depressurization and injection-increasing agent has the advantages of small dosage, good stability, strong timeliness, small adsorption capacity and the like, and can effectively reduce the injection pressure of a hypotonic oil reservoir; (2) super-hydrophobic nanometer drag reducer, which comprises the following preparation processes: under the vacuum condition, the nano silicon dioxide is dried to remove adsorbed water, then heptadecafluorodecyl trimethoxy silane is modified to obtain the super-hydrophobic nano particles, the contact angle of water drops in the air of the super-hydrophobic nano particles reaches 165 degrees, the super-hydrophobic nano particles can be promoted to be excellent in the aspect of pressure reduction and injection increase of a hypotonic oil reservoir, and the drag reduction rate of the super-hydrophobic nano drag reducer reaches more than 1.35 times of that of a conventional nano material. However, these nanodrag reducers also present some bottlenecks that greatly limit the large-scale use of nanodrag reducers in oil reservoirs.

Disclosure of Invention

The application provides an in-situ self-generated super-hydrophobic interface layer drag reducer and a preparation method thereof, which are used for solving the following problems: how to increase the application scale of the nanometer drag reducer in oil reservoirs.

In a first aspect, the present application provides an in-situ self-generated superhydrophobic interfacial layer drag reducer comprising, in mass fraction:

Catalytic emulsifier: 0.5 to 3.0 percent of nucleating agent: 1.0 to 10 percent of cross-linking agent: 0.2 to 1.0 percent of adhesion reinforcing agent: 0.1 to 1.0 percent of hydrophobic reinforcing agent: 0.1 to 2.0 percent of activator: 0.3 to 1.0 percent, and the balance of water and unavoidable impurities;

wherein the activator comprises a mixture of urotropine and ammonium chloride.

Optionally, the mass ratio of urotropine to ammonium chloride is 1:1-1:2.

Optionally, the catalytic emulsifier comprises sodium dodecyl benzene sulfonate and/or sodium petroleum sulfonate.

Optionally, the nucleating agent comprises octamethyl cyclotetrasiloxane and/or hexamethylcyclotrisiloxane.

Optionally, the cross-linking agent comprises ethyl orthosilicate and/or methyl orthosilicate.

Optionally, the adhesion enhancer comprises gamma-aminopropyl methyl diethoxysilane and/or gamma-aminopropyl triethoxysilane.

Optionally, the hydrophobic enhancer comprises at least one of:

Dodecyl trimethoxy silane, cetyl triethoxy silane and stearyl methyl dimethoxy silane.

In a second aspect, the present application provides a method of making the drag reducer of the first aspect, the method comprising:

mixing a catalytic emulsifier and an activator, and then adding water into the mixture to obtain a mixed aqueous solution;

Mixing a nucleating agent, a cross-linking agent, an adhesion enhancer and a hydrophobic enhancer to obtain mixed oil;

And mixing the mixed oil liquid and the mixed aqueous solution to enable the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement and the catalytic emulsifier to perform catalytic reaction and emulsion to form an oil-in-water emulsion, and then to perform in-situ autogenous reaction with the activating agent to obtain the drag reducer.

Optionally, the mixing of the mixed oil and the mixed aqueous solution causes an in-situ autogenous reaction between the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement and the catalytic emulsifier after catalytic reaction and emulsification to form an oil-in-water emulsion and the activating agent to obtain the drag reducer, and the method comprises the following steps:

Dropwise adding the mixed oil liquid into the mixed aqueous solution, stirring and mixing the mixed oil liquid to enable the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement and the catalytic emulsifier to respectively perform catalytic reaction and emulsification to form oil-in-water emulsion, and then performing in-situ autogenous reaction with the activating agent to obtain a drag reducer;

wherein the rotation speed of stirring and mixing is 300 r/min-500 r/min.

Optionally, the stirring and mixing time is the same as the dripping time of the mixed oil, and the dripping time is 30-60 min.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

The embodiment of the application provides an in-situ self-generated super-hydrophobic interface layer drag reducer, which comprises the following components: catalytic emulsifier: 0.5 to 3.0 percent of nucleating agent: 1.0 to 10 percent of cross-linking agent: 0.2 to 1.0 percent of adhesion reinforcing agent: 0.1 to 1.0 percent of hydrophobic reinforcing agent: 0.1 to 2.0 percent of activator: 0.3 to 1.0 percent, and the balance of water and unavoidable impurities; the activator can comprise a mixture of urotropine and ammonium chloride, when the superhydrophobic interface drag reducer enters an underground reservoir in a liquid phase form, a stable oil-in-water emulsion is formed among the catalytic emulsifier, the nucleating agent, the cross-linking agent, the adhesion enhancer and the hydrophobic enhancer, and the activator can slowly release acidic components containing hydrochloric acid, when the content of the acidic components is enough, sufficient hydrochloric acid can promote the catalytic emulsifier to activate to generate cationic catalysis, the activated catalytic emulsifier can cause the nucleating agent to open loops, the nucleating agent after the loops can react with the hydrolyzed cross-linking agent in a polycondensation way to form solid cross-linked silicone oil nano particles, in addition, the hydrophobic enhancer can participate in the polycondensation way after the hydrolysis and improve the hydrophobicity of the solid silicone oil nano particles, and the adhesion enhancer can participate in the polycondensation way and form a certain amount of amino groups on the surface of the solid silicone oil nano particles, so that the amino groups can show cationic groups under the water environment and temperature condition of the underground reservoir, the adhesiveness of the solid silicone oil nano particles and the surface of the underground reservoir can be improved, the water-flooding effect can be improved by the mutual water injection effect of the catalyst, the cross-linking agent and the water-linking agent can be greatly enhanced, the water-flooding effect can be greatly improved, and the interface drag reducer can be formed by the interface-absorbing effect can be greatly improved, and the water-flooding effect can be further improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic flow chart of a method for preparing an in-situ self-generated super-hydrophobic interfacial layer drag reducer according to an embodiment of the present application;

FIG. 2 is a detailed flow chart of a method for preparing an in-situ self-generated super-hydrophobic interfacial layer drag reducer according to an embodiment of the present application;

FIG. 3 is a scanning electron microscope image of solid silicone oil nanoparticles in an in-situ self-generated super-hydrophobic interfacial layer drag reducer provided by an embodiment of the application;

FIG. 4 is a schematic diagram of the forming reaction of a drag reducer provided by an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present application are commercially available or may be prepared by existing methods.

It should be noted that, with respect to the prior arts (1) and (2) in the background art, the inventors found through a large number of experiments that: (1) The hydrophobic nano particles adopted by the nano drag reduction technology can be injected into an underground reservoir only by adopting oil phases such as diesel oil, kerosene and the like as carrying liquid, and the injection of the oil phases greatly improves construction cost and safety risks; (2) Hydrophobic nanoparticles are easy to agglomerate after meeting water in an underground reservoir, and can block pore throats of the underground reservoir, so that the bottleneck problems greatly limit the application scale of the nano drag reducer in an oil reservoir.

The embodiment of the application provides an in-situ self-generated super-hydrophobic interface layer drag reducer, which comprises the following components in percentage by mass:

Wherein the activator comprises a mixture of urotropine and ammonium chloride;

In these embodiments, the mass fraction of the catalytic emulsifier may be 0.5% to 3.0%, and the catalytic emulsifier may be promoted to sufficiently promote the ring opening and polymerization of the nucleating agent, so that solid silicone oil nanoparticles with better adsorptivity may be conveniently formed in an in-situ formation manner, and may be adsorbed on the rock surface to form a superhydrophobic interface layer.

The mass fraction of the nucleating agent can be 1.0% -10%, the nucleating agent after ring opening can be fully copolymerized with the cross-linking agent, the adhesion enhancer and the hydrophobic enhancer in the polymerization stage in a ring opening and polymerization mode of the nucleating agent, so that solid silicone oil nano particles with better adsorptivity can be formed in an in-situ generation mode, and the solid silicone oil nano particles can be adsorbed on the surface of rock and form a sufficient superhydrophobic interface layer.

The mass fraction of the cross-linking agent can be 0.2-1.0%, the mass fraction of the adhesion enhancer can be 0.1-1.0%, and the mass fraction of the hydrophobic enhancer can be 0.1-2.0%, so that the cross-linking agent, the adhesion enhancer and the hydrophobic enhancer can be fully copolymerized with the nucleating agent after ring opening in a polymerization stage, the water injection energy supplementing effect of a hypotonic oil reservoir can be improved, and the application scale of the nano drag reducer in an oil reservoir can be improved by using the drag reducer.

The activator can comprise a mixture of urotropine and ammonium chloride, and can promote the urotropine to slowly release formaldehyde and react with the ammonium chloride under the action of formation temperature to generate an acidic component containing hydrochloric acid, and the reaction can be slowly carried out under normal temperature conditions so as to ensure that the oil-in-water emulsion can migrate to the deep part of an underground reservoir; when the hydrochloric acid content of the underground reservoir is enough, the sufficient hydrochloric acid and the catalytic emulsifier together generate cation catalysis, so that the nucleating agent is promoted to carry out ring-opening polymerization, and simultaneously, the nucleating agent and the hydrolyzed crosslinking agent are subjected to polycondensation reaction to generate crosslinked solid silicone oil nano particles.

The mass fraction of the activator may be 0.3% to 1.0%, which may cause the activator to slowly release a sufficient amount of an acidic component comprising hydrochloric acid, which may cause the catalytic emulsifier to activate, which may cause the nucleating agent to open and polymerize. In some alternative embodiments, the mass ratio of urotropin to ammonium chloride is 1:1 to 1:2;

In the embodiments, the mass ratio of urotropine to ammonium chloride can be 1:1-1:2, so that the activator can be further promoted to slowly release enough acid components containing hydrochloric acid, the acid components can further promote the activation of the catalytic emulsifier, solid silicone oil nano particles with better adsorptivity can be formed through an in-situ generation mode, the solid silicone oil nano particles can be adsorbed on the rock surface of an underground reservoir and form a super-hydrophobic interface layer, the super-hydrophobic interface layer can greatly reduce the water injection resistance of a low-permeability reservoir by relying on the interface sliding effect, the water injection energy supplementing effect of the low-permeability reservoir can be further improved, and the application scale of the nano drag reducer in the low-permeability reservoir can be further effectively improved by using the drag reducer.

The mass ratio of urotropin to ammonium chloride may be 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2.0.

In some alternative embodiments, the catalytic emulsifier comprises sodium dodecyl benzene sulfonate and/or sodium petroleum sulfonate;

in these embodiments, the catalytic emulsifier may include sodium dodecyl benzene sulfonate and/or sodium petroleum sulfonate, and the catalytic emulsifier may be used to sufficiently promote the ring opening and polymerization of the nucleating agent, so that sufficient solid silicone oil nanoparticles may be formed conveniently by in situ formation, and the sufficient solid silicone oil nanoparticles may be adsorbed on the rock surface of the underground reservoir to form a superhydrophobic interface layer, so that the water injection and energy supplementing effect of the hypotonic reservoir may be further improved.

In some alternative embodiments, the nucleating agent comprises octamethyl cyclotetrasiloxane and/or hexamethylcyclotrisiloxane;

In the embodiments, the nucleating agent can comprise octamethyl cyclotetrasiloxane and/or hexamethylcyclotrisiloxane, and the nucleating agent after ring opening can be fully copolymerized with the cross-linking agent, the adhesion enhancer and the hydrophobic enhancer in the polymerization stage through ring opening and polymerization of the nucleating agent, so that solid silicone oil nano particles with better adsorptivity can be formed through an in-situ generation mode, and can be adsorbed on the rock surface of an underground reservoir and form a sufficient amount of super-hydrophobic interface layer.

In some alternative embodiments, the cross-linking agent comprises ethyl orthosilicate and/or methyl orthosilicate;

in some alternative embodiments, the adhesion enhancer comprises gamma-aminopropyl methyldiethoxysilane and/or gamma-aminopropyl triethoxysilane;

In some alternative embodiments, the hydrophobic enhancer comprises at least one of the following:

Dodecyl trimethoxy silane, cetyl triethoxy silane and stearyl methyl dimethoxy silane;

In these embodiments, the cross-linking agent may comprise ethyl orthosilicate, and the adhesion enhancing agent may comprise gamma-aminopropyl methyldiethoxysilane and/or gamma-aminopropyl triethoxysilane, and the hydrophobic enhancing agent comprises at least one of dodecyl trimethoxysilane, cetyl triethoxysilane, and stearyl methyldimethoxysilane, which may facilitate sufficient copolymerization of the cross-linking agent, adhesion enhancing agent, and hydrophobic enhancing agent with the ring-opened nucleating agent during the polymerization stage, thereby enhancing the water injection and energy replenishment effects of the hypotonic reservoir, and which may be used to enhance the scale of application of the nano drag reducer in the reservoir.

FIG. 4 schematically illustrates a schematic of the shaping reaction of a drag reducer provided by an embodiment of the present application;

where desired, the tetraethyl orthosilicate or methyl orthosilicate of the crosslinker may be hydrolyzed to produce silicic acid according to the reaction shown in FIG. 4.

FIG. 1 schematically illustrates a process flow diagram for preparing an in situ self-generated superhydrophobic interfacial layer drag reducer according to an embodiment of the application;

based on one general inventive concept, as shown in FIG. 1, an embodiment of the present application provides a method of preparing the drag reducer, the method comprising:

s1, mixing a catalytic emulsifier and an activator, and then adding water into the mixture to obtain a mixed aqueous solution;

s2, mixing a nucleating agent, a cross-linking agent, an adhesion enhancer and a hydrophobic enhancer to obtain mixed oil;

S3, mixing the mixed oil liquid and the mixed aqueous solution, and enabling the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement and the catalytic emulsifier to react and emulsify to form an oil-in-water emulsion, and then enabling the oil-in-water emulsion and the activating agent to perform in-situ autogenous reaction so as to obtain the drag reducer.

The method is directed to the preparation method of the drag reducer, and the specific composition of the drag reducer can refer to the above embodiment, and because the method adopts part or all of the technical solutions of the above embodiment, the method at least has all the beneficial effects brought by the technical solutions of the above embodiment, and the detailed description is omitted herein.

FIG. 2 schematically illustrates a detailed flow diagram of one method of preparing an in situ self-generated superhydrophobic interfacial layer drag reducer according to an embodiment of the application;

In some alternative embodiments, as shown in fig. 2, the mixing of the mixed oil and the mixed aqueous solution results in an in situ autogenous reaction between the nucleating agent, the cross-linking agent, the adhesion enhancing agent, the hydrophobic enhancing agent and the catalytic emulsifier after catalytic reaction and emulsification to form an oil-in-water emulsion and the activating agent to obtain a drag reducing agent, comprising the steps of:

S301, dropwise adding the mixed oil liquid into the mixed aqueous solution, stirring and mixing the mixed oil liquid to enable the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement and the catalytic emulsifier to respectively perform catalytic reaction and emulsification to form oil-in-water emulsion, and then performing in-situ self-generating reaction with the activating agent to obtain a drag reducer;

wherein the rotation speed of stirring and mixing is 300 r/min-500 r/min;

In these embodiments, the rotational speed of the stirring and mixing may be 300r/min to 500r/min, which may promote the formation of a stable oil-in-water emulsion between the catalytic emulsifier, the nucleating agent, the cross-linking agent, the adhesion enhancer and the hydrophobic enhancer, and in addition, through the interaction between the catalytic emulsifier, the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancer and the activator, solid silicone oil nanoparticles with better adsorptivity may be formed in situ, and may be adsorbed on the rock surface of the underground reservoir and form a superhydrophobic interface layer, which may greatly reduce the water injection resistance of the low-permeability reservoir by virtue of the interface sliding effect, so as to improve the water injection energy supplementing effect of the low-permeability reservoir, and further, may use the drag reducer to improve the application scale of the nano drag reducer in the reservoir.

The rotational speed of the stirring and mixing can be 300r/min, 350r/min, 400r/min, 450r/min or 500r/min.

In some embodiments, the stirring and mixing time is the same as the dripping time of the mixed oil, and the dripping time is 30-60 min;

In the embodiments, the stirring and mixing time can be the same as the mixed oil dripping time, and the dripping time can be 30-60 min, and the full reaction between the mixed oil and the mixed aqueous solution can be promoted by a slow dripping mode, so that solid-phase nano particles with better adsorptivity can be formed by an in-situ generation mode, the solid-phase nano particles can be adsorbed on the surface of rock and form a super-hydrophobic interface layer, the super-hydrophobic interface layer can greatly reduce the water injection resistance of a hypotonic oil reservoir by relying on the interface sliding effect, so that the water injection energy supplementing effect of the hypotonic oil reservoir can be improved, and the application scale of the nano drag reducer in the oil reservoir can be further improved by using the drag reducer.

The dripping time can be 30min, 35min, 40min, 45min, 50min, 55min or 60min.

It should be noted that, after the completion of the dropping, stirring is continued for a while to promote complete mixing of the materials.

The application will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. The experimental procedures, which are not specified in the following examples, are generally determined according to industry standards. If there is no corresponding industry standard, it is carried out according to the general international standard, the conventional conditions, or according to the conditions recommended by the manufacturer.

Example 1

The in-situ self-generated super-hydrophobic interface layer drag reducer comprises the following components in percentage by mass, 100g of drag reducer:

Catalytic emulsifier: 0.5%, nucleating agent: 1.0% of a crosslinking agent: 0.2%, adhesion enhancer: 0.1%, hydrophobic enhancer: 0.1 percent of activator: 0.3% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is octadecyl methyl dimethoxy silane.

As shown in fig. 2, a method of making the drag reducer, the method comprising:

S301, dropwise adding the mixed oil liquid into the mixed aqueous solution, and stirring and mixing the mixed oil liquid to enable the nucleating agent, the cross-linking agent, the adhesion enhancer, the hydrophobic enhancement, the catalytic emulsifier and the activating agent to generate in-situ autogenous reaction and generate a super-hydrophobic interface layer so as to obtain a drag reducer;

Wherein the rotation speed of stirring and mixing is 400r/min.

The stirring and mixing time is the same as the dripping time of the mixed oil, and the dripping time is 60min.

Example 2

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

catalytic emulsifier: 3.0% of nucleating agent: 10%, cross-linking agent: 1.0% adhesion enhancer: 1.0%, hydrophobic enhancer: 2.0% of activator: 1.0%, the balance being water and unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is dodecyl trimethoxy silane.

Example 3

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

catalytic emulsifier: 1.5%, nucleating agent: 4%, cross-linking agent: 0.5% adhesion enhancer: 0.3%, hydrophobic enhancer: 0.4% of an activator: 0.6% of water and the balance of unavoidable impurities;

wherein the activator comprises a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:2.

The catalytic emulsifier is sodium petroleum sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl triethoxysilane.

The hydrophobic enhancer is hexadecyl trimethoxy silane.

Example 4

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

Catalytic emulsifier: 2.0%, nucleating agent: 6.0% of a crosslinking agent: 0.4% adhesion enhancer: 0.5%, hydrophobic enhancer: 0.2% of an activator: 0.6% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl triethoxysilane.

The hydrophobic enhancer is hexadecyltriethoxysilane.

Comparative example 1

On the disclosure of example 1, the following modifications were further made:

The traditional nanometer drag reducer is used, and the components of the nanometer drag reducer are as follows in mass percent: hydrophobic nanosilica: 0.1%, dispersant Tween80:0.5% and the balance of water.

Comparative example 2

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

catalytic emulsifier: 3.0% of nucleating agent: 10.0% of a crosslinking agent: 1.0% adhesion enhancer: 1.0%, hydrophobic enhancer: 2.0% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is dodecyl trimethoxy silane.

Comparative example 3

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

catalytic emulsifier: 3.0% of nucleating agent: 10.0% of a crosslinking agent: 1.0%, hydrophobic enhancer: 2.0% of activator: 1.0%, the balance being water and unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The hydrophobic enhancer is dodecyl trimethoxy silane.

Comparative example 4

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

Catalytic emulsifier: 3.0% of nucleating agent: 10.0% of a crosslinking agent: 1.0% adhesion enhancer: 1.0% of an activator: 1.0%, the balance being water and unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is dodecyl trimethoxy silane.

Comparative example 5

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

Catalytic emulsifier: 0.5%, nucleating agent: 1.0% of a crosslinking agent: 0.2%, adhesion enhancer: 0.1%, hydrophobic enhancer: 0.1 percent of activator: 2.0% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is octadecyl methyl dimethoxy silane.

Comparative example 6

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

Catalytic emulsifier: 0.5%, nucleating agent: 1.0% of a crosslinking agent: 0.2%, adhesion enhancer: 2.0%, hydrophobic enhancer: 0.1 percent of activator: 0.3% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is octadecyl methyl dimethoxy silane.

Comparative example 7

On the disclosure of example 1, the following modifications were further made:

100g of drag reducer comprises, in mass fraction:

Catalytic emulsifier: 0.5%, nucleating agent: 1.0% of a crosslinking agent: 0.2%, adhesion enhancer: 0.1%, hydrophobic enhancer: 3.0% of activator: 0.3% of water and the balance of unavoidable impurities;

wherein the activator is a mixture of urotropine and ammonium chloride.

The mass ratio of urotropine to ammonium chloride is 1:1.

The catalytic emulsifier is sodium dodecyl benzene sulfonate.

The nucleating agent is octamethyl cyclotetrasiloxane.

The cross-linking agent is ethyl orthosilicate.

The adhesion enhancer is gamma-aminopropyl methyl diethoxy silane.

The hydrophobic enhancer is octadecyl methyl dimethoxy silane.

Related experiment and effect data:

1. The influence of different samples on the wettability of the surface of the core piece is tested by using sandstone core pieces, and the contact angle of water drops on the surface of the core piece is measured by using a Kruss contact angle measuring instrument (DSA), and the specific steps are as follows:

The drag reducers obtained in examples 1 to 4 and comparative examples 1 to 6 were immersed in the sandstone core sheet 15d at 70 ^o C, and then the sandstone core sheet was taken out and dried in a constant temperature oven at 40 ^o C, and then subjected to a water drop contact angle test, and the results are shown in table 1.

Table 1 surface oil drop contact angle data for sandstone core pieces after immersion with drag reducer obtained in each example and comparative example

As can be seen from table 1, the contact angle of the water drop in the blank group is 21.6 ^o, which indicates that the surface of the sandstone core sheet has hydrophilicity, and the contact angle of the water drop on the surface of the sandstone core sheet changes after being soaked by different drag reducing agents, wherein the contact angle of the water drop corresponding to the drag reducing agents in each embodiment is greater than 150 ^o, which indicates that the sandstone core soaked by the drag reducing agents in the embodiments forms a superhydrophobic surface.

In addition, the drop contact angles for the drag reducers of comparative examples 1,2,3, 4 and 7 were 131.6 ^o 、56.2^o、133.4^o、116.7^o and 102.8 ^o, respectively, and were less than 150 ^o, indicating that the surfaces of the sandstone core pieces were not in a superhydrophobic state, while the drop contact angles for the drag reducers of comparative examples 5 and 6 were 150.4 ^o and 153.7 ^o, respectively, indicating that the surfaces of the core pieces were in a superhydrophobic state.

In addition, the drag reducer obtained in the comparative example 1 is a conventional nano polysilicone drag reducer, and mainly comprises hydrophobic nano silicon dioxide and a dispersing agent TWEEN80, and is influenced by the adsorption of the dispersing agent TWEEN80, a small amount of TWEEN80 hydrophilic head groups exist on the surface of the core, and the surface of the core cannot reach a super-hydrophobic state; compared with example 1, the drag reducer of comparative example 5 contains an excessive amount of activator, which shortens the time of in-situ generation of solid phase particles of the drag reducer, but does not affect the performance of the drag reducer particles, so that the surface of the core still reaches the super-hydrophobic state; compared with example 1, the drag reducer of comparative example 6 contains excessive adhesion enhancer, which increases the adsorption amount of solid particles generated in situ by the drag reducer on the surface of the core, so that the surface of the core still reaches the super-hydrophobic state; compared with example 1, comparative example 7 contains excessive hydrophobic enhancer, the in-situ generated solid particles of drag reducer are too hydrophobic to be stably dispersed in water and part of the particles are suspended on water surface after being formed, and can not be effectively adsorbed on rock surface, so that the rock core surface can only reach weak hydrophobic state.

Compared with example 1, the drag reducer of comparative example 3 has no adhesion enhancer added, but the adsorption density of the drag reducer without the adhesion enhancer component on the surface of the sandstone core is relatively low, and in addition, the roughness of the adsorption layer formed by the drag reducer of comparative example 3 is relatively small, so that the superhydrophobic state cannot be formed on the surface of the sandstone core; based on the same principle, compared with example 2, the drag reducer of comparative example 4 is not added with a hydrophobic enhancer, but the drag reducer without the action of the hydrophobic enhancer can only form a hydrophobic interface on the surface of the sandstone core, so that the drag reducer cannot be promoted to reach a super-hydrophobic state; in contrast to example 2, the drag reducer of comparative example 2 was not added with an activator, which caused other components of the drag reducer to fail to transform from a liquid phase morphology to solid phase nanoparticles, and in addition, the drag reducer of comparative example 2 only slightly increased the surface hydrophobicity of the sandstone core, which may be associated with spreading of the oil phase components of the drag reducer on the surface of the sandstone core, while the surface of the sandstone core remains hydrophilic.

2. And (3) evaluating the performance of depressurization and injection enhancement:

the method comprises the steps of measuring the pressure reduction and injection enhancement performances of different drag reducing agents by using a core displacement experiment, wherein cores used in the test are artificial cores (phi 2.5cm multiplied by 10cm, the porosity is 10 percent, and the permeability is 0.4 mD), the displacement speed is always kept at 0.05mL/min in the test process, the temperature is 70 ^o C in the test process, and if water is driven to be stable in pressure, the stable pressure is recorded as P1; the drag reducer of the examples and the comparative examples are used for displacement of 1PV respectively, then standing is carried out for 72 hours, the subsequent water flooding is carried out until the pressure is stable, the stable pressure is recorded as P2, the drag reduction performance of the drag reducer is quantitatively evaluated by adopting a drag reduction rate E, and the drag reduction rate E has a calculation formula as follows:

E=[(P1-P2)/P1]*100%。

drag reduction rates for the different drag reducers are shown in table 2.

TABLE 2 drag reduction ratio conditions for different drag reducers

As can be seen from table 2, the pressure reduction rate of the drag reducer of each embodiment reaches more than 44%, which indicates that the drag reducer of the embodiment of the application can form a superhydrophobic interface on the surface of a sandstone core, and the sliding effect of the superhydrophobic interface is remarkable, so that the seepage resistance of a water phase can be reduced, and the subsequent water driving pressure is greatly reduced compared with that of a water driving pressure; the drag reducers of the comparative examples 1, 2,3 and 4 cannot form a super-hydrophobic state on the rock surface, and can only reach a general hydrophobic state or still be in a hydrophilic state, so that the maximum drag reduction rate is only 31.6%; the drag reducer of comparative example 5 has too high addition of the activator, so that in-situ autogenous solid phase nano particles are formed prematurely, a large number of solid phase nano particles are formed without injection, partial pores of the core are blocked, and the blocking rate is negative; the drag reducer of comparative example 6 contains excessive adhesion enhancer, and although the surface of the core can be converted into a super-hydrophobic state, the adsorption amount at the injection end of the core is too high, so that the adsorption at the middle and rear ends of the core is insufficient, and the drag reduction rate is relatively low to 19.3%; the drag reducer of comparative example 7 has too high addition, too many hydrophobic groups weaken the electrostatic attraction between cations on the adsorption enhancer and the rock surface of the underground reservoir, the adsorption capacity in the core is insufficient, and the drag reduction rate is only 8.8%.

In summary, the drag reducer with the in-situ self-generated super-hydrophobic interface layer provided by the embodiment of the application can be injected into a stratum in a liquid phase form, has good injectability and no risk of reservoir damage, and in addition, as shown in fig. 3, the drag reducer has good deep migration performance, can generate solid silicone oil nano particles in situ in the water phase environment of the stratum, and the solid silicone oil nano particles can spontaneously form the super-hydrophobic interface layer on the surface of rock so as to improve the drag reduction efficiency of the drag reducer to more than 44%, so that the drag reducer can greatly reduce the water flooding pressure of a hypotonic oil reservoir. Meanwhile, the drag reducer is not required to be carried by oil phases such as diesel oil, kerosene and the like, and can be carried by water phases, so that the drag reducer is low in cost, safe and environment-friendly.

Various embodiments of the application may exist in a range of forms; it should be understood that the description in a range format is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the application; it is therefore to be understood that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that a description of a range from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1,2, 3, 4,5, and 6, wherever applicable. In addition, whenever a numerical range is referred to herein, it is meant to include any reference number (fractional or integer) within the indicated range.

In the description of the present specification, the terms "include," "comprising," and the like are intended to mean "include, but are not limited to. Herein, "and/or" describing an association relationship of an association object means that there may be three relationships, for example, a and/or B, may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. Herein, "at least one" means one or more, and "a plurality" means two or more. "at least one", "at least one" or the like refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

The foregoing is only a specific embodiment of the application to enable those skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An in situ self-generating superhydrophobic interfacial layer drag reducer, comprising, in mass fraction:

wherein the activator comprises a mixture of urotropine and ammonium chloride.

2. The drag reducer of claim 1, wherein the mass ratio of urotropin to ammonium chloride is 1:1-1:2.

3. The drag reducer of claim 1, wherein the catalytic emulsifier comprises sodium dodecylbenzene sulfonate and/or sodium petroleum sulfonate.

4. The drag reducer of claim 1, wherein the nucleating agent comprises octamethyl cyclotetrasiloxane and/or hexamethylcyclotrisiloxane.

5. The drag reducer of claim 1, wherein the cross-linking agent comprises ethyl orthosilicate and/or methyl orthosilicate.

6. The drag reducer of claim 1, wherein the adhesion enhancer comprises gamma-aminopropyl methyldiethoxysilane and/or gamma-aminopropyl triethoxysilane.

7. The drag reducer of claim 1, wherein the hydrophobicity-enhancing agent comprises at least one of:

8. A method of preparing the drag reducer of any of claims 1-7, said method comprising:

9. The method of claim 8, wherein said mixing said mixed oil and said mixed aqueous solution results in an in situ autogenous reaction between said nucleating agent, said cross-linking agent, said adhesion enhancing agent, said hydrophobic enhancing agent and said catalytic emulsifier after catalytic reaction and emulsification to form an oil-in-water emulsion and said activating agent to yield a drag reducing agent, comprising the steps of:

wherein the rotation speed of stirring and mixing is 300 r/min-500 r/min.

10. The method according to claim 9, wherein the stirring and mixing time is the same as the mixed oil dripping time, and the dripping time is 30-60 min.