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CN-121991286-A - Nanometer microgel material and preparation method and application thereof

CN121991286ACN 121991286 ACN121991286 ACN 121991286ACN-121991286-A

Abstract

The invention belongs to the technical field of petroleum, and particularly relates to a nano microgel material and a preparation method and application thereof. In highly mineralized formation water, volume expansion is limited and the process of volume expansion is not uniform and controllable. According to the nano microgel material provided by the invention, the sulfonate anion group with excellent salt tolerance is introduced into the microgel, and the cationic functional monomer is added, so that the initial expansion of the microgel in high-salt stratum water is slowed down, and the microgel material can smoothly enter into the deep part of an oil reservoir with relatively more residual oil content through narrow pore throats in a near wellbore zone. The ester group in the cation functional monomer can be gradually hydrolyzed to break bonds, so that the cation group is separated, the sulfonate anion group is released, the microgel is hydrated and expanded, and the addition amount of the cation functional monomer is controlled, so that the microgel is basically expanded at a uniform speed in high-salt stratum water, the deep stratum is blocked and accumulated, the subsequent water injection is caused to turn, the residual stratum oil in the deep stratum of an oil reservoir is displaced, and the crude oil recovery ratio is improved.

Inventors

  • CHENG CHEN
  • WU BAOQIANG
  • ZHU JIAJIE
  • WANG YAN
  • ZHANG RONG
  • YAN CHANGHAO
  • YI PING
  • ZHENG LIJUN
  • WU TIANJIANG
  • LIU YUNLONG
  • CHEN JIAJUN
  • WANG JUN
  • REN JIANKE

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (18)

  1. 1. The preparation method of the nano microgel material is characterized by comprising the following steps: s1, adding acrylamide, an anionic functional monomer, a cationic functional monomer and a crosslinking agent into water to obtain a monomer solution; s2, adding an oil-soluble surfactant and a water-soluble surfactant into the oil phase to obtain a mixed oil phase; S3, adding the monomer solution of S1 into the mixed oil phase of S2 to obtain a uniform and transparent system; S4, dissolving the photoinitiator by using a cosolvent, and adding the cosolvent into the uniform transparent system in the S3 to obtain a mixed system; s5, conveying the mixed system in the S4 into a photo-reactor, and continuously carrying out illumination reaction to obtain a photopolymerization system; And S6, adding the pre-phase inversion agent into the photopolymerization system in S5 to obtain the nano microgel material.
  2. 2. The nanogel material of claim 1 wherein the anionic functional monomer is selected from one of sodium 2-acrylamido-2-methylpropanesulfonate, sodium allylsulfonate, sodium styrenesulfonate.
  3. 3. The nanogel material of claim 1 wherein the cationic functional monomer is selected from one of methacryloxyethyl trimethyl ammonium chloride, acryloxyethyl trimethyl ammonium chloride.
  4. 4. The nanogel material of claim 1 wherein the cross-linking agent is selected from one of N, N-methylenebisacrylamide, polyethylene glycol diacrylate, pentaerythritol triacrylate.
  5. 5. The nano microgel material according to claim 1, wherein the following reaction raw materials are used in percentage by mass: 20-30% of oil phase, 9-15% of oil-soluble surfactant, 6-10% of water-soluble surfactant, 15-25% of acrylamide, 1-5% of anion functional monomer, 0.01-0.5% of cation functional monomer, 0.0001-0.001% of cross-linking agent, 0.005-0.05% of photoinitiator, 0.5-1% of cosolvent, 1-3% of pre-phase inversion agent and the balance of water.
  6. 6. The nano microgel material according to claim 1, wherein the following reaction raw materials are used in percentage by mass: 25-28% of oil phase, 12-14% of oil-soluble surfactant, 7-9% of water-soluble surfactant, 20-24% of acrylamide, 2-4% of anion functional monomer, 0.1-0.4% of cation functional monomer, 0.0004-0.0007% of cross-linking agent, 0.01-0.03% of photoinitiator, 0.6-0.8% of cosolvent, 1.5-2.5% of pre-phase inversion agent and the balance of water.
  7. 7. The nanogel material of claim 1 wherein the oil phase is selected from one of white oil, naphtha, liquid paraffin.
  8. 8. The nanogel material of claim 1 wherein the oil-soluble surfactant is selected from one of sorbitan monostearate, sorbitan monooleate, and sorbitan monopalmitate.
  9. 9. The nanogel material of claim 1 wherein the water-soluble surfactant is selected from one of polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.
  10. 10. The nanogel material of claim 1 wherein the photoinitiator is selected from one of 2-hydroxy-2-methyl-1-phenylpropion, 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-propanone, benzoin dimethyl ether, benzoin diethyl ether, 2, 4-dihydroxybenzophenone, isopropylthioxanthone.
  11. 11. The nanogel material of claim 1 wherein the co-solvent is selected from one of benzene, toluene, xylene.
  12. 12. The nano-microgel material according to claim 1, wherein the pre-phase inversion agent is a water-soluble surfactant with an HLB value of not less than 9.
  13. 13. The nano microgel material according to claim 12, wherein the water-soluble surfactant with the HLB value of more than or equal to 9 is selected from one of alkanolamide, sodium fatty alcohol polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether AEO-7, fatty alcohol polyoxyethylene ether AEO-9, nonylphenol polyoxyethylene ether NP-10 and octylphenol polyoxyethylene ether OP-10.
  14. 14. The nanogel material of claim 1 wherein the conductivity of the system during the addition of S3 to the monomer solution is maintained at 0-1 μs/cm 2 .
  15. 15. The nanogel material of claim 1 wherein the S5 hybrid system is delivered at a rate of 1-5mL/min.
  16. 16. The nanogel material of claim 1 wherein the S5 reaction temperature is 15-40 ℃.
  17. 17. A profile control system comprising the nanogel material of any one of claims 1 to 16.
  18. 18. Use of the nanogel material according to any one of claims 1 to 16 or the profile control system according to claim 17 in an oilfield.

Description

Nanometer microgel material and preparation method and application thereof Technical Field The invention belongs to the technical field of petroleum, and particularly relates to a nano microgel material and a preparation method and application thereof. Background In the technical field of three-production of oil fields, in order to improve the recovery ratio of a middle-and-far well oil layer with more residual oil content, researchers design and prepare a microgel deep profile control and flooding material which has small initial particle size, can smoothly enter the deep part of an oil reservoir through a near-wellbore zone, expands the volume under the conditions of the temperature and mineralization degree of stratum water, has certain viscoelasticity, seals and stacks at the narrow pore throat of the stratum of the deep part of the oil reservoir, and generates resistance to subsequent water injection, thereby expanding the water injection wave and volume and achieving the purpose of dewatering and oil increasing. In the prior art, acrylamide is taken as a main monomer, a certain amount of ionic monomer such as sodium acrylate or 2-acrylamide-2-methylpropanesulfonate and a cross-linking agent are added for copolymerization to prepare the polymer. In the polymerization process, the microgel is dispersed into a large amount of stratum water, the volume of the microgel rapidly expands and reaches an extreme value due to the action of ionization repulsion, and then the amide bond of the main polyacrylamide of the microgel is hydrolyzed under the action of the temperature of the stratum water to form carboxylate ions, so that the microgel ions are increased, the ionization repulsion action is enhanced, and the volume of the microgel gradually expands. However, the hydrolytic expansion is limited by the formation condition, the higher the temperature of the formation water is, the faster the hydrolytic expansion is, and the slower the hydrolytic expansion becomes in the formation water with medium and low temperature, and the volume expansion cannot occur for a long time. In highly mineralized formation water, particularly water with a high content of calcium and magnesium ions, carboxylate ions generated by hydrolysis are easily affected by polyvalent metal ions, the volume expansion is limited, and the expansion speed is uncontrollable. The existing microgel material has the defects that the initial expansion speed in stratum water is too high, the subsequent expansion is very slow, the whole volume expansion process is uneven and uncontrollable, gel is easy to accumulate and stay in a near-wellbore zone after being injected, and cannot enter the deep part of an oil reservoir, and even if the gel enters the deep part of the oil reservoir, the gel cannot effectively block the injected water due to poor subsequent volume expansion performance. Meanwhile, in high-mineralization stratum water, volume expansion is limited by high-concentration ions, and expansion plugging effect in the deep part of an oil reservoir cannot be effectively realized. Disclosure of Invention In view of the technical problems mentioned above, the invention provides a nano microgel material and a preparation method thereof, wherein the nano microgel material can be uniformly bulked in high-salt stratum water of an oil field, and is prepared by adopting monomer water-liquid one-step mixing and reverse microemulsion dynamic continuous UV photopolymerization, polymerization heat can be effectively dissipated in the reaction process, the polymerization temperature is low, and premature failure of a decomposition type functional component in a system is effectively avoided. The uniform-speed bulk swelling nano microgel material prepared by the invention can smoothly pass through pore throats of near-wellbore zones of oil fields to enter into the deep part of oil reservoirs under the condition that the total mineralization degree is 30000 mg/L-120000 mg/L and the initial average grain diameter of water phase is 150 nm-300 nm, reaches the maximum swelling grain diameter in 5-10 days under the condition that the stratum temperature is 40-80 ℃, and can realize the basically uniform growth of the average grain diameter of microgel within 5-20 nm/day before swelling to the maximum grain diameter. Therefore, the technical scheme provided by the invention is as follows: the uniform-speed volume-expansion nano microgel material in the high-salinity stratum water of the oil field is prepared from the following substances in percentage by mass: 20-30% of oil phase, 9-15% of oil-soluble surfactant, 6-10% of water-soluble surfactant, 15-25% of acrylamide, 1-5% of anion functional monomer, 0.01-0.5% of cation functional monomer, 0.0001-0.001% of cross-linking agent, 0.005-0.05% of photoinitiator, 0.5-1% of cosolvent, 1-3% of pre-phase inversion agent and the balance of water. Preferably, the oil phase is 25-28%, the oil-soluble surfactant is 12-14%, the