CN-117106129-B - Clean environment-friendly self-degradation inverse emulsion polymer and preparation method thereof

CN117106129BCN 117106129 BCN117106129 BCN 117106129BCN-117106129-B

Abstract

The invention relates to the field of oil-gas field development, in particular to a clean environment-friendly self-degradation inverse emulsion polymer and a preparation method thereof. The technical scheme is that a water-soluble monomer is dissolved into water to prepare a water phase, the pH value of the water phase is regulated to be neutral, an emulsifier is added into an environment-friendly dispersing agent to be used as a continuous phase, the mixed water phase and the continuous phase are stirred at a high speed to form reverse microemulsion, and after nitrogen is introduced for deoxidization, an initiator is slowly added to initiate polymerization, so that the clean environment-friendly self-degradation emulsion polymer is obtained. The clean environment-friendly self-degradation type inverse emulsion polymer prepared by adopting the inverse emulsion polymerization method realizes the spontaneous gel breaking of polyacrylamide, reduces the application of solvent oil and is cleaner and more environment-friendly. The continuous phase is applied with a degradable ester compound, the ester can be automatically degraded into alcohol and acid, and the application of the ester compound as fracturing fluid can be used for helping polymer gel breaking and reducing the water locking damage of external fluid to a reservoir.

Inventors

LAI XIAOJUAN
WEN XIN
MA QINQIN
WANG LEI
LIU GUIRU
GAO JINHAO
LU LIJUAN
LIU YAMENG

Assignees

陕西科技大学

Dates

Publication Date: 20260505
Application Date: 20230818

Claims (5)

1. The preparation method of the clean environment-friendly self-degrading inverse emulsion polymer is characterized by comprising the following steps of: (1) Preparing an oil phase and a water phase: adding 200-300 parts of oil phase disperse phase and 20-30 parts of emulsifier into a beaker, and stirring to completely and uniformly mix the oil phase disperse phase and the 20-30 parts of emulsifier to obtain an oil phase for standby; Dissolving 200-300 parts of water phase reaction monomers into 200-400 parts of water under the action of magnetic stirring, adding 1-3 parts of 1% ammonium persulfate after uniformly mixing, adjusting the pH to 8 by using NaOH solution, adding 1-3 parts of initiator, uniformly stirring, and cooling to room temperature to obtain a water phase for later use; (2) Mixing the water phase and the oil phase, and stirring at a high speed to obtain water-in-oil pre-emulsion; (3) Pouring the pre-emulsion into a flask, introducing nitrogen to remove oxygen, and controlling the temperature of the system to be 10-18 ℃; (4) Slowly dripping initiator accounting for 0.5-1.5% of the mass of the water phase reaction monomer for polymerization reaction, reacting for 4-6 hours at the temperature of 10-40 ℃, adding phase inversion agent accounting for 3.5% of the total mass of the emulsion, and uniformly stirring to obtain the self-degradation reverse phase emulsion thickener; The oil phase disperse phase in the first step is isoamyl butyrate; the aqueous phase reaction monomers in the step (1) are Acrylamide (AM), acrylic Acid (AA) and 2-acrylamide-2-methylpropanesulfonic Acid (AMPS) with the mass ratio of 13-17:5-8:2-5.
2. The method for preparing the clean and environment-friendly self-degrading inverse emulsion polymer according to claim 1, wherein the emulsifier in the step (1) is one or a mixture of two or more of sorbitan oleate Span80, sorbitan stearate Span60, polyoxyethylene sorbitan monooleate Tween80, sorbitan monostearate polyoxyethylene ether Tween60 and polyoxyethylene octyl phenol ether OP-10 in any proportion.
3. The method for preparing the clean and environment-friendly self-degrading inverse emulsion polymer according to claim 1, wherein the initiator in the step (1) is one or a mixture of two or more of ammonium persulfate, ascorbic acid and white suspended solids in any proportion.
4. The method for preparing the clean and environment-friendly self-degrading inverse emulsion polymer according to claim 1, wherein the phase inversion agent in the step (4) is one or a mixture of two or more of nonionic surfactants OP-10, TX-10, tween80, tween60 and FC-4430 in any proportion.
5. A clean and environment-friendly self-degrading inverse emulsion polymer prepared by the preparation method of claim 1.

Description

Clean environment-friendly self-degradation inverse emulsion polymer and preparation method thereof Technical Field The invention relates to the field of oil-gas field development, in particular to a clean environment-friendly self-degradation inverse emulsion polymer and a preparation method thereof. Background Inverse emulsion polymerization is one of the ideal methods for obtaining high molecular weight polymers, playing an irreplaceable role in the preparation and application of polymeric materials. The liquid drop nucleation is a main mechanism of acrylamide inverse emulsion polymerization, and forms free radicals by utilizing monomers on an oil-water interface, diffuses and transfers the free radicals into a reaction core, and wraps hydrogel formed by polymerization in oily liquid drops to form inverse emulsion. The quality of the emulsifier and the oil phase in the inverse emulsion polymerization process directly affects the size of the polymer particles and the polymerization efficiency, and thus the product quality. The preparation process of nanometer polyacrylamide microsphere system includes the first step of mixing oil soluble solvent and emulsifier, adding water phase containing acrylamide monomer, cross-linking agent and oxidant, stirring thoroughly, deoxidizing with N2, adding reductant to the mixed system to initiate reaction, continuing to react for 0.5-2 hr after the peak of heat release, the second step of adding water phase containing acrylamide monomer, cross-linking agent and oxidant to the system, stirring thoroughly, deoxidizing with N2, and adding reductant to initiate reaction to obtain transparent or semitransparent nanometer polyacrylamide microsphere system. The oil-soluble solvent used in the invention is gasoline, kerosene, diesel oil, white oil, paraffin, vegetable oil, toluene, cyclohexane or isooctane. The oil-soluble solvent such as white oil is produced by fossil raw materials, the consumption of the raw materials is unavoidable, the cost is high, the product is not environment-friendly because a large amount of oil-soluble solvent damages the environment in use, and the water-locking damage to a reservoir can be caused by external fluid because the gel breaking effect of the inverse emulsion polymer is not ideal. In summary, the continuous optimization of inverse emulsion polymerization and its preparation method is an important research direction for the scientific researchers in the field. Disclosure of Invention The invention provides a clean environment-friendly self-degradable inverse emulsion polymer and a preparation method thereof, which are used for solving the problems of environmental protection, difficult self-degradation and water lock injury in the prior art. In order to achieve the aim of the invention, the invention provides the following technical scheme that the clean environment-friendly self-degradation inverse emulsion polymer comprises the following steps: (1) Preparing an oil phase and a water phase: adding 200-300 parts of oil phase disperse phase and 20-30 parts of emulsifier into a beaker, and stirring to completely and uniformly mix the oil phase disperse phase and the 20-30 parts of emulsifier to obtain an oil phase for standby; Dissolving 200-300 parts of water phase reaction monomers into 200-400 parts of water under the action of magnetic stirring, adding 1-3 parts of 1% ammonium persulfate after uniformly mixing, adjusting the pH to 8 by using NaOH solution, adding 1-3 parts of initiator, uniformly stirring, and cooling to room temperature to obtain a water phase for later use; (2) Mixing the water phase and the oil phase, and stirring at a high speed to obtain water-in-oil pre-emulsion; (3) Pouring the pre-emulsion into a flask, introducing nitrogen to remove oxygen, and controlling the temperature of the system to be 10-18 ℃; (4) Slowly dripping initiator accounting for 0.5-1.5% of the mass of the water phase reaction monomer for polymerization reaction, reacting for 4-6 hours at the temperature of 10-40 ℃, adding phase inversion agent accounting for 3.5% of the total mass of the emulsion, and uniformly stirring to obtain the self-degradation reverse phase emulsion thickener. Further, the oil phase disperse phase is one or a mixture of two or more of methyl methacrylate, isoamyl butyrate, phenethyl acetate and methyl benzoate in any proportion. Further, the emulsifier is one or a mixture of two or more of sorbitan oleate Span80, sorbitan stearate Span60, polyoxyethylene sorbitan monooleate Tween80, sorbitan monostearate polyoxyethylene ether Tween60 and polyoxyethylene octyl phenol ether OP-10 in any proportion. Further, the aqueous phase reaction monomers are Acrylamide (AM), acrylic Acid (AA) and 2-acrylamide-2-methylpropanesulfonic Acid (AMPS) with the mass ratio of 13-17:5-8:2-5. Further, the initiator is one or a mixture of two or more of ammonium persulfate, ascorbic acid and sodium silicate in any proportion. Further, the phase i