CN119351073B - Salt-resistant foam drainage agent for natural gas exploitation and preparation method thereof - Google Patents

Abstract

The application relates to the technical field of foam drainage agents, and particularly discloses an anti-salt foam drainage agent for natural gas exploitation and a preparation method thereof. Dissolving modified amine oxide, mixing with a silica hollow sphere, decompressing, processing for 0.5-1h, standing at normal pressure to obtain a mixture, marking as M, (2) crushing glass fiber, dispersing chloroform, mixing with No. 58 paraffin, processing for 10-30min at 75-80 ℃, adding a mixed cross-linking agent, stirring for 2-2.5h, keeping the temperature at 60-65 ℃ to obtain a film sealing liquid, filtering M to obtain a precipitate, mixing with the film sealing liquid, standing for 0.5-1h, filtering again to obtain the precipitate, and cooling to obtain the salt-resistant foam water draining agent for natural gas exploitation. The salt-resistant foam drainage agent for natural gas exploitation has the advantages of good foaming effect and long acting time.

Description

Salt-resistant foam drainage agent for natural gas exploitation and preparation method thereof

Technical Field

The application relates to the technical field of foam drainage agents, in particular to an anti-salt foam drainage agent for natural gas exploitation and a preparation method thereof.

Background

Foam drainage refers to a surfactant used to improve the interfacial properties of liquids and gases, and has a molecular structure similar to that of soap molecules, and can reduce the surface tension of the liquid by forming a foam, so that the gas forms a foam on the liquid surface. According to the types, the foam water draining agent can be divided into a liquid foam water draining agent and a solid foam water draining agent, wherein the solid foam water draining agent is more used in the field of oil gas production due to stronger environmental adaptability and better foaming effect.

For natural gas production, in the early stage of gas well production, because the natural gas source is sufficient, underground water in the gas well can be completely discharged out of the gas well through a gas carrying liquid form, and the gas well is not blocked. However, in the late stage of production, because of pressure drop in the gas well and reduction of gas yield, groundwater in the gas well is difficult to be completely removed, and undischarged groundwater is deposited at the bottom of the gas well, thereby generating effusion. Accumulation of liquid products can reduce gas phase permeability of a gas well and inhibit natural gas flow, resulting in rapid gas production drop. Meanwhile, inorganic salts and acid-base substances accumulated in the accumulated liquid can corrode pipelines, so that the service life of equipment is reduced. The problem of effusion can be alleviated by adding the foam drainage agent, and the effusion is easier to drain out of a gas well by reducing the surface activity of the effusion. However, the traditional foam drainage agent has the defects of weak action effect and high consumption speed, and the action effect is not obvious.

The Chinese patent application document with the application publication number of CN117777985A discloses a foam net synergistic solid foam drainage agent and a preparation method thereof, wherein a foam net structure made of a soluble bracket material is introduced, and the surface of the solid foam drainage agent is coated with the foam net structure. When the foam drainage agent is used, the outer-coated foam net structure is dissolved, so that the internal solid foam drainage agent is gradually exposed, the direct and severe action of the foam drainage agent on accumulated liquid is avoided, and the service time of the solid foam drainage agent is prolonged.

Although the consumption rate of the foam drainage agent can be slowed down, the action effect of the foam drainage agent in unit time can be reduced, so that the requirement of searching for a foam drainage agent with slow release effect and enhancing the action of the foam drainage agent still exists.

Disclosure of Invention

The application provides an anti-salt foam drainage agent for natural gas exploitation and a preparation method thereof, in order to obtain a foam drainage agent product which has a slow release function and can enhance the effect of a foam drainage agent.

In a first aspect, the application provides a method for preparing an anti-salt foam drainage agent for natural gas exploitation, comprising the following steps:

(1) Dissolving modified amine oxide, mixing with the hollow silica spheres, decompressing and treating for 0.5-1h, and standing at normal pressure to obtain a mixture, namely M;

(2) Pulverizing glass fiber, dispersing with chloroform, mixing with No. 58 paraffin, treating at 75-80deg.C for 10-30min, adding mixed crosslinking agent, stirring for 2-2.5 hr, maintaining at 60-65deg.C to obtain sealing membrane liquid, filtering M to obtain precipitate, mixing with sealing membrane liquid, standing for 0.5-1 hr, filtering again to obtain precipitate, and cooling to obtain natural gas anti-salt foam drainage agent.

Through adopting above-mentioned technical scheme, have the structure of amine oxide and urea simultaneously in the modified amine oxide, the amine oxide plays the effect of reducing hydrops surface tension in the system, and urea can decompose under gas well temperature environment to produce more bubbles under composite construction effect, the effect of reinforcing foam drainage agent. The silica hollow sphere is a carrier of modified amine oxide, on one hand, a pore channel on the surface is a channel for releasing the modified amine oxide, and the silica hollow sphere is matched with a subsequent glass fiber net grid structure, so that the slow release effect on the modified amine oxide can be realized, and the service life of the modified amine oxide component is prolonged. Meanwhile, the effusion can also be directly reacted with the internal modified amine oxide to generate bubbles through the hollow silica sphere pore canal, and the generated bubbles can form more dense bubble groups after being restrained by the hollow silica sphere pore canal, so that the treatment effect on the effusion is enhanced.

Preferably, in the step (1), the mass ratio of the hollow silica spheres to the injected liquid is 1 (5-7.5).

By adopting the technical scheme, the silica hollow sphere and the injection liquid with the mass ratio can ensure that the injection liquid is filled in the silica hollow sphere after the decompression and normal pressure standing treatment.

Preferably, in the step (1), the pressure of the reduced pressure is 0.01 to 0.03Mpa.

Preferably, in the step (2), the mixed cross-linking agent is formed by mixing diphenylmethane diisocyanate and tricresyl phosphite according to a mass ratio of 5:1.

By adopting the technical scheme, the silicon hydroxyl groups on the surface layer of the glass fiber are subjected to crosslinking reaction with isocyanate groups in the mixed crosslinking agent, the chloroform is mixed with paraffin for dispersion after dissolving the glass fiber chopped fibers, and the glass fiber chopped fibers dispersed in the paraffin are crosslinked with each other and interweaved into a net under the action of the mixed crosslinking agent. And (3) adding the mixture into the M for precipitation, wrapping the silica spheres in the precipitation by paraffin to form a package group structure, taking the glass fiber chopped fibers dispersed in the paraffin as a crosslinking template for continuous reaction, and finally obtaining the glass fiber chopped fiber net grid on the surface of the silica spheres.

In a second aspect, the application provides an anti-salt foam drainage agent for natural gas exploitation, wherein the preparation steps of the modified amine oxide are as follows:

(S01) mixing a bromoalkane source with dipropylamine, dissolving, reacting for 5-8 hours at 55-65 ℃, adding sodium carbonate, stirring, suction filtering to obtain a liquid part, dripping hydrogen peroxide solution, reacting for 1-2 hours at 70-85 ℃, then performing rotary evaporation, collecting a bottom viscous liquid, and washing to obtain bromoamine oxide;

(S02) mixing bromoamine oxide with urea, dissolving the mixture in a mixed solvent, reacting for 5-7 hours at 55-70 ℃, distilling and washing with alcohol to obtain modified amine oxide;

The preparation method of the silica hollow sphere comprises the following steps:

(I) Mixing tetraethoxysilane with the mixed template liquid at 60-65 ℃, stirring, dropwise adding a dilute acid solution, reacting, adding absolute ethyl alcohol, stirring to obtain a sol liquid, dropwise adding the sol liquid into tetrahydrofuran, standing for 8-15 hours at the water bath temperature of 53-60 ℃, filtering, and drying to obtain a silica bead body;

(II) calcining the silica beads and acid etching to obtain the silica hollow spheres.

Preferably, in the step (S01), the bromoalkane source is obtained by mixing 1, 2-dibromododecane, 1, 3-dibromotetradecane and 1, 10-dibromooctadecane according to the mass ratio of 1:1.5 (2.5-3), and the mass ratio of the bromoalkane source to dipropylamine is 1 (0.67-0.8).

By adopting the technical scheme, the bromoalkane source reacts with dipropylamine, so that the tertiary amine intermediate is obtained. The tertiary amine intermediate obtained by using the bromoalkane source and the proportion has the best use effect.

Preferably, in the step (S01), the mass concentration of the hydrogen peroxide solution is 10% -15%.

By adopting the technical scheme, the oxidation reaction of the hydrogen peroxide and the tertiary amine intermediate mainly occurs at tertiary amine sites, and the N atoms of tertiary amine have higher electron cloud density, so that the oxidation reaction is more likely to occur due to attack of nucleophilic reagent hydrogen peroxide, and finally the amine oxide structure is obtained. By regulating the mass concentration of hydrogen peroxide, the situation that the hydrogen peroxide reaction severely damages the bromo-group on the tertiary amine intermediate can be avoided.

Preferably, in the step (S02), the mixed solvent is prepared by mixing (1.5-2) g (1.5-2.5) g (50-100) mL of acetonitrile, potassium carbonate and pyridine according to the mass-volume ratio.

By adopting the technical scheme, acetonitrile is a good solvent for reaction, the reaction in the system is nucleophilic substitution of amino and bromoalkane on urea, the obtained amide structure is simultaneously stripped, and potassium carbonate and pyridine are acid binding agents of the reaction system, so that HBr generated in the reaction can be effectively removed, and forward progress of the reaction is promoted.

Preferably, in the step (I), the mixed template liquid is prepared by mixing (1-2) g (0.2-0.3) mL (1.03-1.25) g (0.5-0.73) g (mass volume ratio) of sodium hexametaphosphate, tween 20, soybean lecithin and carboxymethyl cellulose.

By adopting the technical scheme, the soybean lecithin is an organic vesicle template and is mixed with the ethyl orthosilicate, so that the vesicle template can be distributed among the crosslinking structures during hydrolysis of the ethyl orthosilicate, the soybean lecithin is decomposed to generate gas and carbon residue in the subsequent calcination operation, a cavity and pore canal structure is constructed in the silica beads, tween 20 is a nonionic surfactant, and the surface tension of sol liquid is reduced to assist in forming liquid drops with larger particle sizes.

Preferably, in the step (I), the amount of the absolute ethyl alcohol added is controlled to be 10-20mL.

Preferably, in the step (II), the calcining includes primary calcining, cooling, and secondary calcining, and the following operations are performed:

Primary calcination, namely raising the temperature in a muffle furnace to 300-350 ℃ at the speed of 5-8 ℃ per minute, and preserving heat for 20-30 minutes;

cooling, namely taking out the solid matters from the muffle furnace, and naturally cooling to 45-50 ℃;

And (3) secondary calcination, namely, adding the solid matters into a muffle furnace again at the speed of 10-15 ℃ per minute, heating to 600-750 ℃, and then keeping the temperature for 2-3 hours.

By adopting the technical scheme, the primary calcination aims to promote the decomposition of soybean lecithin on the surface layer of the silica beads, the phospholipids are distributed in the cross-linked network of the silica beads, and the phospholipids on the outer layer of the beads react before the internal phospholipids, so that the primary calcination is carried out, and the pre-pores are left on the surface of the silica beads. The existence of the pre-holes can also relieve the pressure of gas combination and expansion during the decomposition of phospholipid in the silica beads in the secondary calcination process, and avoid the breakage of the silica beads. The silica cavity structure can be obtained by calcination.

Preferably, in the step (II), the acid etching is performed by treating with hydrofluoric acid having a molar concentration of 0.05mol/L for 10-30min.

By adopting the technical scheme, the hydrofluoric acid with the concentration and the treatment time have the best acid etching effect on the silica beads. The pore canal of the hollow silica sphere can be trimmed by acid etching, so that the use effect of the hollow silica sphere is optimal.

In summary, the application has the following beneficial effects:

1. The application adopts the modified amine oxide as the component of the foam drainage agent, can reduce the surface tension of the accumulated liquid, and simultaneously, the modified amine oxide foams by itself, thereby enhancing the action effect of the foam drainage agent. On the one hand, the pore canal on the surface of the silica serving as a carrier of the modified amine oxide in the foam drainage agent component is a channel for releasing the modified amine oxide, and the amine oxide can be slowly released outwards through the channel. Meanwhile, the effusion can also directly react with the internal modified amine oxide through the pore canal to generate bubbles, and the generated bubbles can form more dense bubble groups after being restrained by the pore canal, so that the foaming effect is enhanced.

2. The salt-resistant foam drainage agent for natural gas exploitation, which is prepared by the application, has a longer service cycle, and can effectively isolate the external air through the paraffin sealing film, thereby avoiding the internal modified amine oxide from being exposed to the air and being slowly deliquesced. When the paraffin is put into a gas well, paraffin wrapped outside the paraffin is melted and removed at a higher temperature in the gas well, and the left fiber grid structure is matched with the silica hollow sphere, so that the slow release effect of the product can be enhanced.

3. The salt-resistant foam drainage agent for natural gas exploitation prepared by the application has the advantages that the foaming and drainage performance of the product is reduced by less than or equal to 4.5% before and after ageing, and the product has more stable thermal ageing resistance.

Drawings

FIG. 1 is a TEM image of a hollow silica sphere obtained in example 3 of the present application.

FIG. 2 is an SEM image of a hollow silica sphere prepared in example 3 of the present application.

FIG. 3 is a graph showing the foaming force height data before and after heat aging of examples 1-3 and comparative examples 1-2 according to the present application.

FIG. 4 is a graph showing the liquid carrying amount data before and after heat aging of examples 1-3 and comparative examples 1-2 according to the present application.

Detailed Description

Example 1

The preparation method of the salt-resistant foam drainage agent for natural gas exploitation in the embodiment comprises the following steps:

(1) 25mL of ethylene glycol was added to 45g of modified amine oxide, the temperature was controlled at 45℃and the mixture was homogenized, then 0.1g of monoammonium phosphate and 0.5g of dodecyldimethylamine oxide were added and mixed to obtain a solution for injection. 60g of the injection was mixed with 8g of silica hollow spheres, the vessel was then depressurized to 0.01Mpa, the magnetic stirring speed was adjusted to 50rpm, the normal pressure was recovered after 0.5 hour of treatment, and the mixture was allowed to stand for 10 minutes, and the obtained mixture was designated as M.

(2) 8G of glass fiber is taken and added into a high-speed pulverizer, the rotating speed is controlled to be 1000r/min, and the glass fiber chopped fiber is obtained after pulverizing for 10min. The glass chopped fibers were dispersed using 15mL of chloroform, mixed with 45g of No. 58 paraffin, warmed to 75℃and treated for 10min. Controlling the magnetic stirring speed to 25rpm, continuously stirring for 10min, then adding 3.5g of mixed cross-linking agent, increasing the stirring speed to 75rpm, continuously stirring for 2h, and then reducing the temperature to 60 ℃ and then keeping the temperature constant to obtain the film sealing liquid. And (3) adding the precipitate obtained by filtering M into a film sealing liquid, standing for 0.5h, filtering again to obtain the precipitate, naturally cooling, and removing the adhered paraffin after the paraffin on the surface of the silicon dioxide is solidified to obtain the salt-resistant foam drainage agent for natural gas exploitation.

The modified amine oxide of this example was prepared as follows:

(S01) mixing 15g of bromoalkane source with 10g of dipropylamine, taking 150mL of absolute ethyl alcohol as a reaction solvent, and controlling the reaction time to be 5h and the temperature to be 55 ℃ to obtain a tertiary amine intermediate. Then adding 3.2g of sodium carbonate into the system, controlling the magnetic stirring speed to be 100rpm, stirring for 10min, carrying out suction filtration, taking a liquid part, then dropwise adding 35mL of 10% hydrogen peroxide solution into the system at the speed of 5mL/min, controlling the reaction temperature to be 70 ℃, controlling the magnetic stirring speed to be 100rpm, carrying out rotary evaporation after reacting for 1h, adjusting the vacuum degree to be 250mbar, carrying out water bath temperature to be 65 ℃, controlling the rotation speed to be 150rpm, treating for 1.5h, taking a bottom viscous liquid, and washing with toluene to remove impurities, thereby obtaining the bromoamine oxide.

(S02) mixing bromoamine oxide with 3g urea, adding 50mL of mixed solvent, controlling the temperature to be 55 ℃ for reaction for 5 hours, then distilling to remove the solvent, and washing with alcohol to obtain the modified amine oxide.

The preparation steps of the silica hollow sphere of this example are as follows:

(I) 20mL of ethyl orthosilicate was mixed with 12mL of the mixed template solution, the temperature was raised to 60℃and the magnetic stirring speed was 50rpm, stirring was continued for 5min. Then, 20mL of a 2% strength by mass diluted hydrochloric acid solution was added dropwise to the mixed solution at a rate of 10mL/min, the mixture was stirred at an elevated stirring rate of 150rpm for 3min, and then 10mL of absolute ethanol was added thereto, followed by stirring to obtain a sol solution. Filling the sol into a rubber head dropper, preparing a 250mL beaker, pouring 100mL tetrahydrofuran, dropwise adding the sol into the tetrahydrofuran, maintaining the water bath temperature at 53 ℃, standing for 8 hours, washing with absolute ethyl alcohol, drying and filtering to obtain the silica beads with the diameter of 3 mm.

(II) transferring the silica beads into a muffle furnace, raising the temperature in the muffle furnace to 300 ℃ at a speed of 5 ℃ per minute, preserving heat for 20 minutes, taking out the solid matters from the muffle furnace, naturally cooling to 45 ℃, adding the solid matters into the muffle furnace again, raising the temperature to 600 ℃ at a speed of 10 ℃ per minute, and then keeping the temperature for 2 hours to obtain a sintered product. And transferring the sintered product into 50mL of hydrofluoric acid with the molar concentration of 0.05mol/L, and treating for 10min to obtain the silica hollow spheres.

Wherein the glass fibers (average diameter 9 microns, aspect ratio 300:1). Supplied by tham city spring peak glass fiber limited. Paraffin No. 58 (cat# MF-0005) is supplied by Jiangyin city Mengfan rubber and plastic trade Co. The mixed cross-linking agent is formed by mixing diphenylmethane diisocyanate and tricresyl phosphite according to a mass ratio of 5:1. The bromoalkane source is obtained by mixing 1, 2-dibromododecane, 1, 3-dibromotetradecane and 1, 10-dibromooctadecane according to the mass ratio of 1:1.5:2.5. The mixed solvent is prepared by mixing acetonitrile, potassium carbonate and pyridine according to the mass volume ratio of 50mL:1.5g:1.5 g. The mixed template liquid is prepared by mixing sodium hexametaphosphate, tween 20, soybean lecithin and carboxymethyl cellulose according to the mass-volume ratio of 1g to 0.2mL to 1.03g to 0.5 g.

Example 2

The preparation method of the salt-resistant foam drainage agent for natural gas exploitation in the embodiment comprises the following steps:

(1) 25mL of ethylene glycol was added to 50g of modified amine oxide, the temperature was controlled at 55℃and the mixture was homogenized, then 0.15g of monoammonium phosphate and 1g of dodecyldimethylamine oxide were added and mixed to obtain a solution for injection. 55g of the injection was mixed with 9g of silica hollow spheres, the vessel was then depressurized to 0.02MPa, the magnetic stirring speed was adjusted to 50rpm, the normal pressure was recovered after 1 hour of treatment, and the mixture was allowed to stand for 25 minutes, and the obtained mixture was designated M.

(2) 10G of glass fiber is taken and added into a high-speed pulverizer, the rotating speed is controlled to be 1000r/min, and the glass fiber chopped fiber is obtained after pulverizing for 15 min. The glass chopped fibers were dispersed using 20mL chloroform, mixed with 50g No. 58 paraffin, warmed to 80℃and treated for 25min. Controlling the magnetic stirring speed to 50rpm, continuously stirring for 10min, then adding 4g of mixed crosslinking agent, increasing the stirring speed to 100rpm, continuously stirring for 2.5h, and then reducing the temperature to 65 ℃ and then keeping the temperature constant to obtain the film sealing liquid. And (3) adding the precipitate obtained by filtering M into a film sealing liquid, standing for 1h, filtering again to obtain the precipitate, naturally cooling, and removing the adhesion paraffin after the paraffin on the surface of the silicon dioxide is solidified to obtain the salt-resistant foam drainage agent for natural gas exploitation.

The modified amine oxide of this example was prepared as follows:

(S01) mixing 15g of bromoalkane source with 12g of dipropylamine, taking 150mL of absolute ethyl alcohol as a reaction solvent, and controlling the reaction time to be 5h and the temperature to be 55 ℃ to obtain a tertiary amine intermediate. Then adding 3.8g of sodium carbonate into the system, controlling the magnetic stirring speed to be 100rpm, stirring for 10min, carrying out suction filtration, taking a liquid part, then dropwise adding 35-mL of 10% hydrogen peroxide solution into the system at the speed of 5mL/min, controlling the reaction temperature to be 75 ℃, controlling the magnetic stirring speed to be 100rpm, carrying out rotary evaporation after reacting for 1-2h, adjusting the vacuum degree to be 250mbar, the water bath temperature to be 70 ℃, controlling the rotation speed to be 150rpm, and carrying out treatment for 1.5h, taking a bottom viscous liquid, and washing with toluene to remove impurities to obtain the bromoamine oxide.

(S02) mixing bromoamine oxide with 3.2g urea, adding 60mL of mixed solvent, controlling the temperature to be 55 ℃ for reaction for 6 hours, then distilling to remove the solvent, and washing with alcohol to obtain the modified amine oxide.

The preparation steps of the silica hollow sphere of this example are as follows:

(I) 20-25mL of ethyl orthosilicate is mixed with 12mL of the mixed template liquid, the temperature is raised to 60 ℃, the magnetic stirring speed is 75rpm, and the stirring is carried out for 8min. Then, 24mL of a 3% strength by mass diluted hydrochloric acid solution was added dropwise to the mixed solution at a rate of 10mL/min, the mixture was stirred at an elevated stirring rate of 200rpm for 5 minutes, and then 20mL of absolute ethanol was added thereto, followed by stirring to obtain a sol solution. Filling the sol into a rubber head dropper, preparing a 250mL beaker, pouring 150mL tetrahydrofuran, dropwise adding the sol into the tetrahydrofuran, maintaining the water bath temperature at 55 ℃, standing for 10h, washing with absolute ethyl alcohol, drying and filtering to obtain the silica beads with the diameter of 4 mm.

(II) transferring the silica beads into a muffle furnace, raising the temperature in the muffle furnace to 350 ℃ at the speed of 7 ℃ per minute, preserving heat for 25 minutes, taking out the solid matters from the muffle furnace, naturally cooling to 45 ℃, adding the solid matters into the muffle furnace again, raising the temperature to 650 ℃ at the speed of 12 ℃ per minute, and then keeping the temperature for 2 hours to obtain a sintered product. And transferring the sintered product into 75mL of hydrofluoric acid with the molar concentration of 0.05mol/L, and treating for 15min to obtain the silica hollow spheres.

Wherein the glass fibers (average diameter 9 microns, aspect ratio 300:1). Paraffin No. 58 (cat# MF-0005) is supplied by Jiangyin city Mengfan rubber and plastic trade Co. The mixed cross-linking agent is formed by mixing diphenylmethane diisocyanate and tricresyl phosphite according to a mass ratio of 5:1. The bromoalkane source is obtained by mixing 1, 2-dibromododecane, 1, 3-dibromotetradecane and 1, 10-dibromooctadecane according to the mass ratio of 1:1.5:3. The mixed solvent is prepared by mixing acetonitrile, potassium carbonate and pyridine according to the mass volume ratio of 75mL to 2g to 2.5 g. The mixed template liquid is prepared by mixing sodium hexametaphosphate, tween 20, soybean lecithin and carboxymethyl cellulose according to the mass-volume ratio of 1.5g to 0.3mL to 1.25g to 0.73 g.

Example 3

The preparation method of the salt-resistant foam drainage agent for natural gas exploitation in the embodiment comprises the following steps:

(1) 25mL of ethylene glycol was added to 50g of modified amine oxide, the temperature was controlled at 55℃and the mixture was homogenized, then 0.2g of monoammonium phosphate and 1g of dodecyldimethylamine oxide were added and mixed to obtain a solution for injection. 50g of the injection was mixed with 10g of silica hollow spheres, the vessel was then depressurized to 0.03MPa, the magnetic stirring speed was adjusted to 50rpm, the normal pressure was recovered after 1 hour of treatment, and the mixture was allowed to stand for 30 minutes, and the obtained mixture was designated M.

(2) 10G of glass fiber is taken and added into a high-speed pulverizer, the rotating speed is controlled to be 1000r/min, and the glass fiber chopped fiber is obtained after pulverizing for 15 min. The glass chopped fibers were dispersed using 20mL of chloroform, mixed with 50g of No. 58 paraffin, warmed to 80℃and treated for 30min. Controlling the magnetic stirring speed to 50rpm, continuously stirring for 20min, then adding 4.5g of mixed cross-linking agent, increasing the stirring speed to 100rpm, continuously stirring for 2.5h, and then reducing the temperature to 60 ℃ and then keeping the temperature constant to obtain the film sealing liquid. And (3) adding the precipitate obtained by filtering M into a film sealing liquid, standing for 1h, filtering again to obtain the precipitate, naturally cooling, and removing the adhesion paraffin after the paraffin on the surface of the silicon dioxide is solidified to obtain the salt-resistant foam drainage agent for natural gas exploitation.

The modified amine oxide of this example was prepared as follows:

(S01) mixing 15g of bromoalkane source with 12g of dipropylamine, taking 200mL of absolute ethyl alcohol as a reaction solvent, and controlling the reaction time to 8h and the temperature to 65 ℃ to obtain a tertiary amine intermediate. Then adding 4.2g of sodium carbonate into the system, controlling the magnetic stirring speed to be 100rpm, stirring for 15min, carrying out suction filtration, taking a liquid part, then dripping 45mL of 10% hydrogen peroxide solution into the system at the speed of 5mL/min, controlling the reaction temperature to be 85 ℃, controlling the magnetic stirring speed to be 150rpm, carrying out rotary evaporation after reacting for 2h, adjusting the vacuum degree to be 300mbar, the water bath temperature to be 70 ℃, controlling the rotation speed to be 150rpm, treating for 2h, taking a bottom viscous liquid, and washing with toluene to remove impurities to obtain the bromoamine oxide.

(S02) mixing bromoamine oxide with 3.6g urea, adding 75mL of mixed solvent, controlling the temperature to be 70 ℃ for reaction for 7h, then distilling to remove the solvent, and washing with alcohol to obtain the modified amine oxide.

The preparation steps of the silica hollow sphere of this example are as follows:

(I) 25mL of ethyl orthosilicate was mixed with 13mL of the mixed template solution, the temperature was raised to 65℃and the magnetic stirring speed was 75rpm, stirring was carried out for 10min. Then, 25mL of a diluted hydrochloric acid solution with a mass concentration of 3.5% was added dropwise to the mixed solution at a rate of 10mL/min, the mixture was treated at an elevated stirring rate of 250rpm for 5min, and then 20mL of absolute ethanol was added thereto, followed by stirring to obtain a sol solution. Filling the sol into a rubber head dropper, preparing a 250mL beaker, pouring 150mL tetrahydrofuran, dropwise adding the sol into the tetrahydrofuran, maintaining the water bath temperature at 55 ℃, standing for 15h, washing with absolute ethyl alcohol, drying and filtering to obtain the silica beads with the diameter of 4 mm.

(II) transferring the silica beads into a muffle furnace, raising the temperature in the muffle furnace to 350 ℃ at the speed of 8 ℃ per minute, preserving heat for 30 minutes, taking out the solid matters from the muffle furnace, naturally cooling to 50 ℃, adding the solid matters into the muffle furnace again, raising the temperature to 750 ℃ at the speed of 15 ℃ per minute, and then keeping the temperature for 3 hours to obtain a sintered product. And transferring the sintered product into 100mL of hydrofluoric acid with the molar concentration of 0.05mol/L, and treating for 30min to obtain the silica hollow spheres.

Wherein the glass fibers (average diameter 9 microns, aspect ratio 300:1). Paraffin No. 58 (cat# MF-0005) is supplied by Jiangyin city Mengfan rubber and plastic trade Co. The mixed cross-linking agent is formed by mixing diphenylmethane diisocyanate and tricresyl phosphite according to a mass ratio of 5:1. The bromoalkane source is obtained by mixing 1, 2-dibromododecane, 1, 3-dibromotetradecane and 1, 10-dibromooctadecane according to the mass ratio of 1:1.5:3. The mixed solvent is prepared by mixing acetonitrile, potassium carbonate and pyridine according to the mass volume ratio of 100mL:2g:2.5 g. The mixed template liquid is prepared by mixing sodium hexametaphosphate, tween 20, soybean lecithin and carboxymethyl cellulose according to the mass-volume ratio of 2g to 0.3mL to 1.25g to 0.73 g.

Comparative example 1

The preparation steps of the modified amine oxide of the comparative example are as follows:

(S01) mixing 15g of bromoalkane source with 10g of dipropylamine, taking 150mL of absolute ethyl alcohol as a reaction solvent, and controlling the reaction time to be 5h and the temperature to be 55 ℃ to obtain a tertiary amine intermediate. Then adding 3.2g of sodium carbonate into the system, controlling the magnetic stirring speed to be 100rpm, stirring for 10min, carrying out suction filtration, taking a liquid part, then dropwise adding 35mL of 10% hydrogen peroxide solution into the system at the speed of 5mL/min, controlling the reaction temperature to be 70 ℃, controlling the magnetic stirring speed to be 100rpm, carrying out rotary evaporation after reacting for 1h, adjusting the vacuum degree to be 250mbar, carrying out water bath temperature to be 65 ℃, controlling the rotation speed to be 150rpm, treating for 1.5h, taking a bottom viscous liquid, and washing with toluene to remove impurities, thereby obtaining the bromoamine oxide.

(S02) mixing bromoamine oxide with 3g urea to obtain modified amine oxide.

The rest of the procedure is the same as in example 1.

Comparative example 2

The preparation method of the salt-resistant foam drainage agent for natural gas exploitation of the comparative example comprises the following steps:

(1) 25mL of ethylene glycol was added to 45g of modified amine oxide, the temperature was controlled at 45℃and the mixture was homogenized, then 0.1g of monoammonium phosphate and 0.5g of dodecyldimethylamine oxide were added and mixed to obtain a solution for injection. 60g of the injection was mixed with 8g of silica hollow spheres, the vessel was then depressurized to 0.01Mpa, the magnetic stirring speed was adjusted to 50rpm, the normal pressure was recovered after 0.5 hour of treatment, and the mixture was allowed to stand for 10 minutes, and the obtained mixture was designated as M.

(2) 20G of cellulose acetate (acetyl degree 35.7%, hydroxyl mass fraction content 4.2%) is taken, dried at 45 ℃ for 10-15h, then added into a high-speed pulverizer, and pulverized for 15min at a rotating speed of 1000r/min to obtain chopped fibers. The chopped fibers were dispersed using 20mL of chloroform, mixed with 50g of No. 58 paraffin, warmed to 80℃and treated for 30min. Controlling the magnetic stirring speed to 50rpm, continuously stirring for 20min, then adding 4.5g of mixed cross-linking agent, increasing the stirring speed to 100rpm, continuously stirring for 4.5h, and then reducing the temperature to 60 ℃ and then keeping the temperature constant to obtain the film sealing liquid. And (3) adding the precipitate obtained by filtering M into a film sealing liquid, standing for 1h, filtering again to obtain the precipitate, naturally cooling, and removing the adhesion paraffin after the paraffin on the surface of the silicon dioxide is solidified to obtain the salt-resistant foam drainage agent for natural gas exploitation.

The rest of the procedure is the same as in example 1.

Performance test

Preparation of 100g/L simulated formation water:

weighing 12.87g of calcium chloride, 4.38g of magnesium chloride and 80.00g of sodium chloride to 0.01g accurately, dissolving in distilled water in a beaker, stirring evenly and transferring into a 1000mL volumetric flask, weighing 2.75g of sodium sulfate to 0.01g accurately, dissolving in distilled water in the beaker, stirring evenly and mixing into the volumetric flask, fixing volume to 1000mL, and shaking evenly for later use.

Preparing a class II foaming agent solution:

weighing 2.5g of solid foaming agent in a 250mL beaker, accurately obtaining 0.01g, dissolving the solid foaming agent in 100g/L simulated formation water, and then fixing the volume to a 1000mL volumetric flask, and shaking the flask uniformly for later use.

In the foaming force test, 212.5mL of foaming agent solution is taken, 37.5mL of petroleum ether is added, and the mixture is stirred uniformly for use.

In the liquid carrying amount experiment, 170mL of foaming agent solution is taken, preheated in a water bath with the temperature of (65+/-1) DEG C for 15min, then 30mL of petroleum ether is added, and the mixture is uniformly stirred for use.

Table 1 Performance test items and criteria for examples 1-3 and comparative examples 1-2

Foaming force and liquid carrying amount testing method

The test is carried out by referring to GB/T13171.2-2022 and Q/SYCQ17019-2020 related test methods.

TABLE 2 results of Performance test for examples 1-3 and comparative examples 1-2

As can be seen from analysis of examples 1-3 and comparative examples 1-2 in combination with table 2, the foaming force and liquid carrying capacity data of the salt-resistant foam drainage agent for natural gas exploitation prepared by using the embodiment scheme are higher than those of the comparative example, and the average foaming initiation height and liquid carrying capacity after the embodiment ageing are reduced by about 3.7% -3.8% compared with those before the ageing, and the average foaming height for 5min is reduced by less than 4.5%. Of these, example 3 had the best combination of foaming power and liquid carrying amount. Compared with the examples, the reduction of the foaming force of the comparative example 2 is more than 5.8% and the foaming effect is not stable.

By analyzing examples 1-3 and comparative examples 1-2 and combining tables 1 and 2, it can be seen that the salt-resistant foam drainage agent for natural gas exploitation prepared by the method of examples meets the specification of enterprise standards, and is suitable for industrial production and application.

The present embodiment is only for explanation of the present application and is not to be construed as limiting the present application, and modifications to the present embodiment, which may not creatively contribute to the present application as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present application.

Claims (9)

1. The preparation method of the salt-resistant foam drainage agent for natural gas exploitation is characterized by comprising the following steps of:

(1) Dissolving modified amine oxide, mixing with the hollow silica spheres, decompressing and treating for 0.5-1h, and standing at normal pressure to obtain a mixture, namely M;

(2) Pulverizing glass fiber, dispersing with chloroform, mixing with No. 58 paraffin, treating at 75-80deg.C for 10-30min, adding mixed crosslinking agent, stirring for 2-2.5 hr, maintaining at 60-65deg.C to obtain sealing membrane liquid, filtering M to obtain precipitate, mixing with sealing membrane liquid, standing for 0.5-1 hr, filtering again to obtain precipitate, and cooling to obtain natural gas anti-salt foam drainage agent;

The preparation method of the modified amine oxide comprises the following steps:

(S01) mixing a bromoalkane source with dipropylamine, dissolving, reacting for 5-8 hours at 55-65 ℃, adding sodium carbonate, stirring, suction filtering to obtain a liquid part, dripping hydrogen peroxide solution, reacting for 1-2 hours at 70-85 ℃, then performing rotary evaporation, collecting a bottom viscous liquid, and washing to obtain bromoamine oxide;

(S02) mixing bromoamine oxide with urea, dissolving the mixture in a mixed solvent, reacting for 5-7 hours at 55-70 ℃, distilling and washing with alcohol to obtain modified amine oxide;

the mixed solvent is prepared by mixing (1.5-2) g (1.5-2.5) g (50-100) of acetonitrile, potassium carbonate and pyridine according to the mass volume ratio.

2. The preparation method of the salt-resistant foam drainage agent for natural gas exploitation, which is disclosed in claim 1, is characterized in that in the step (1), the mixed solution obtained by dissolving modified amine oxide is injection liquid, and the mass ratio of the silica hollow sphere to the injection liquid is 1 (5-7.5).

3. The preparation method of the salt-resistant foam drainage agent for natural gas exploitation, which is characterized in that in the step (2), the mixed cross-linking agent is prepared by mixing diphenylmethane diisocyanate and tricresyl phosphite according to a mass ratio of 5:1.

4. An anti-salt foam drainage agent for natural gas exploitation, which is prepared by the preparation method of the anti-salt foam drainage agent for natural gas exploitation according to any one of claims 1-3, and is characterized in that

The preparation method of the silica hollow sphere comprises the following steps:

(I) Mixing tetraethoxysilane with the mixed template liquid at 60-65 ℃, stirring, dropwise adding a dilute acid solution, reacting, adding absolute ethyl alcohol, stirring to obtain a sol liquid, dropwise adding the sol liquid into tetrahydrofuran, standing for 8-15 hours at the water bath temperature of 53-60 ℃, filtering, and drying to obtain a silica bead body;

(II) calcining the silica beads and acid etching to obtain the silica hollow spheres.

5. The salt-resistant foam drainage agent for natural gas exploitation according to claim 4, wherein in the step (S01), a bromoalkane source is obtained by mixing 1, 2-dibromododecane, 1, 3-dibromotetradecane and 1, 10-dibromooctadecane according to a mass ratio of 1:1.5 (2.5-3), and the mass ratio of the bromoalkane source to dipropylamine is 1 (0.67-0.8).

6. The salt resistant foam drainage agent for natural gas exploitation according to claim 4, wherein in the step (S01), the mass concentration of the hydrogen peroxide solution is 10% -15%.

7. The salt-resistant foam drainage agent for natural gas exploitation according to claim 4, wherein in the step (I), the mixed template liquid is prepared by mixing (1-2) g (0.2-0.3) mL (1.03-1.25) g (0.5-0.73) g (weight-volume ratio) of sodium hexametaphosphate, tween 20, soybean lecithin and carboxymethyl cellulose.

8. The salt resistant foam water removal agent for natural gas development according to claim 4, wherein in the step (II), the calcination comprises primary calcination, cooling, and secondary calcination, and the operation is as follows:

Primary calcination, namely raising the temperature in a muffle furnace to 300-350 ℃ at the speed of 5-8 ℃ per minute, and preserving heat for 20-30 minutes;

cooling, namely taking out the solid matters from the muffle furnace, and naturally cooling to 45-50 ℃;

And (3) secondary calcination, namely, adding the solid matters into a muffle furnace again at the speed of 10-15 ℃ per minute, heating to 600-750 ℃, and then keeping the temperature for 2-3 hours.

9. The salt resistant foam drainage agent for natural gas exploitation according to claim 4, wherein in the step (II), the acid etching is performed by using hydrofluoric acid with a molar concentration of 0.05mol/L for 10-30min.