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CN-121991310-A - Nano-silicon-loaded para-position phenolic pre-polymerization crosslinking agent and preparation method and application thereof

CN121991310ACN 121991310 ACN121991310 ACN 121991310ACN-121991310-A

Abstract

The invention relates to the technical field of oilfield plugging, and discloses a nano-silicon loaded para-position phenolic pre-polymerization crosslinking agent, a preparation method and application thereof. The method comprises the following steps of (1) reacting hydroquinone, ethylenediamine, silane coupling agent modified nano silicon oxide and a dispersion stabilizer under alkaline conditions to obtain a first reaction solution, (2) reacting the first reaction solution with part of hexamethylenetetramine to obtain a second reaction solution, and (3) reacting the second reaction solution with the rest of hexamethylenetetramine. The nano-silicon-loaded para-position phenolic pre-polymerization crosslinking agent has high gel forming strength and aging stability under the condition of super high temperature and high salt, and is used for preparing phenolic gel with good structural stability, rheological property and reservoir large pore canal plugging property under the condition of super high temperature and high salt.

Inventors

  • LIU YIFEI
  • Si Shuanghu
  • DAI CAILI
  • LIU JINMING
  • ZHAO GUANG
  • WU YINING
  • ZHAO MINGWEI

Assignees

  • 中国石油大学(华东)

Dates

Publication Date
20260508
Application Date
20260225

Claims (10)

  1. 1. The method for loading para-phenolic pre-polymerization cross-linking agent by nano silicon is characterized by comprising the following steps: (1) Under alkaline conditions, hydroquinone, ethylenediamine, silane coupling agent modified nano silicon oxide and a dispersion stabilizer are reacted to obtain a first reaction solution; (2) Reacting the first reaction solution with part of hexamethylenetetramine to obtain a second reaction solution; (3) Reacting the second reaction solution with the rest of hexamethylenetetramine; wherein the amount of hexamethylenetetramine used in the step (2) is 50 to 70% by weight, and the amount of hexamethylenetetramine used in the step (3) is 30 to 50% by weight, based on the total weight of hexamethylenetetramine used in the step (2) and the step (3); the reaction temperature of the step (3) is 5-20 ℃ higher than that of the step (2); in the step (1), the silane coupling agent is KH560.
  2. 2. The process according to claim 1, wherein in the step (1), the dispersion stabilizer is one or more selected from the group consisting of silicate, sodium hexametaphosphate, and sodium dodecylbenzenesulfonate, and/or The particle size of the silane coupling agent modified nano silicon oxide is 10-100nm.
  3. 3. The process according to claim 1 or 2, wherein in step (1), the molar ratio of hydroquinone to ethylenediamine is 1:0.03-0.07, and/or The weight ratio of the dosage of the hydroquinone to the dosage of the silane coupling agent modified nano silicon oxide is 20:0.1-0.2, and/or The weight ratio of the hydroquinone to the dosage of the dispersion stabilizer is 20:0.1-0.2.
  4. 4. A process according to claim 1 to 3, wherein in step (1), the reaction conditions comprise a temperature of 120 to 160℃and a time of 14 to 20 hours.
  5. 5. The process according to any one of claims 1 to 4, wherein the molar ratio of the amount of hydroquinone to the total amount of hexamethylenetetramine used in step (2) and step (3) is from 1:0.5 to 1.5.
  6. 6. The process according to any one of claims 1 to 5, wherein in step (2), the reaction conditions comprise a temperature of 70 to 85℃for a period of 3 to 4 hours, and/or In the step (3), the reaction conditions comprise a temperature of 80-90 ℃ and a time of 4-6h.
  7. 7. A nano-silicon supported para-phenolic pre-polymerization cross-linker prepared by the method of any one of claims 1-6.
  8. 8. A nano-silicon-loaded para-phenolic jelly, characterized in that the nano-silicon-loaded para-phenolic jelly comprises a functional polymer and the nano-silicon-loaded para-phenolic pre-polymerization cross-linking agent of claim 7; preferably, the weight ratio of the functional polymer to the nano-silicon loaded para-phenolic pre-polymerization crosslinking agent is 1:3-8.
  9. 9. The nano-silica supported para-phenolic jelly of claim 8, wherein the functional polymer is a copolymer of an acrylamide-based monomer and a sulfonic acid-based monomer; Preferably, the weight average molecular weight of the functional polymer is 1000 to 2000 tens of thousands.
  10. 10. The use of the nano-silicon loaded para-phenolic jelly of claim 8 or 9 in the crude oil recovery process of a high temperature high salt reservoir; Preferably, the application process comprises the steps of injecting the functional polymer into the stratum, then injecting the nano-silicon loaded para-phenolic pre-polymerization cross-linking agent, and then aging.

Description

Nano-silicon-loaded para-position phenolic pre-polymerization crosslinking agent and preparation method and application thereof Technical Field The invention relates to the technical field of oilfield plugging, in particular to a nano-silicon loaded para-position phenolic pre-polymerization crosslinking agent, a preparation method and application thereof. Background Phenolic aldehyde cross-linking agents are synthetic high polymer materials, and are widely focused on the advantages of low price, easy preparation, excellent thermal stability, rigidity, solubility and flame retardance. The modified polyurethane foam is widely applied to various fields such as oilfield water shutoff agents, adhesives, flame retardants and the like. Phenolic glue is usually prepared by polymerizing phenols and formaldehyde to obtain a phenolic prepolymer, and then crosslinking the phenolic prepolymer and the polymer at a certain temperature to obtain a viscoelastic body with a three-dimensional network structure, wherein the network structure and physical properties of the glue are greatly influenced by the crosslinking density and the crosslinking strength. In addition, the performance of the phenolic gel is directly related to the water plugging effective period of an oil field, the long-term effective phenolic gel is beneficial to effectively preventing water channeling of the oil field, the development benefit of the oil field is improved, the viscosity of the phenolic gel into a gel solution is low, the phenolic gel solution is easy to inject, the phenolic gel solution can enter a stratum dominant seepage channel preferentially, and the phenolic gel solution is gradually solidified into gel at the stratum temperature after being injected into the stratum, so that the water channeling channel is plugged, the water driving wave and efficiency are improved, and the crude oil recovery ratio is further improved. However, the gel prepared by the phenolic aldehyde cross-linking agent has greatly reduced gel forming strength and stability under the high-temperature and high-salt condition of the stratum, and does not have the capability of blocking the water channeling for a long time. Therefore, the high-temperature high-salt tolerance of the phenolic jelly is enhanced, and the plugging effect of the jelly in a high-temperature high-salt oil reservoir is improved. Disclosure of Invention The invention aims to solve the problems of poor gel forming strength and long-acting blocking stability of phenolic glue and poor high-temperature and high-salt resistance of the prior art, which cause the reduction of the recovery ratio of crude oil in the crude oil exploitation process, and provides a nano-silicon loaded para-phenolic pre-polymerization cross-linking agent. In order to achieve the above object, the present invention provides a method for loading para-phenolic pre-polymerization crosslinking agent with nano silicon, which comprises the following steps: (1) Under alkaline conditions, hydroquinone, ethylenediamine, silane coupling agent modified nano silicon oxide and a dispersion stabilizer are reacted to obtain a first reaction solution; (2) Reacting the first reaction solution with part of hexamethylenetetramine to obtain a second reaction solution; (3) Reacting the second reaction solution with the rest of hexamethylenetetramine; wherein the amount of hexamethylenetetramine used in the step (2) is 50 to 70% by weight, and the amount of hexamethylenetetramine used in the step (3) is 30 to 50% by weight, based on the total weight of hexamethylenetetramine used in the step (2) and the step (3); the reaction temperature of the step (3) is 5-20 ℃ higher than that of the step (2); in the step (1), the silane coupling agent is KH560. Preferably, in the step (1), the dispersion stabilizer is one or more selected from silicate, sodium hexametaphosphate and sodium dodecyl benzene sulfonate. Preferably, in the step (1), the particle size of the silane coupling agent modified nano silicon oxide is 10-100nm. Preferably, in the step (1), the molar ratio of the hydroquinone to the ethylenediamine is 1:0.03-0.07. Preferably, in the step (1), the weight ratio of the hydroquinone to the dosage of the silane coupling agent modified nano silicon oxide is 20:0.1-0.2. Preferably, in the step (1), the weight ratio of the hydroquinone to the dosage of the dispersion stabilizer is 20:0.1-0.2. Preferably, in step (1), the reaction conditions include a temperature of 120-160 ℃ for 14-20 hours. Preferably, the molar ratio of the amount of hydroquinone to the total amount of hexamethylenetetramine used in step (2) and step (3) is from 1:0.5 to 1.5. Preferably, in step (2), the reaction conditions include a temperature of 70-85 ℃ for 3-4 hours. Preferably, in step (3), the reaction conditions include a temperature of 80-90 ℃ for a period of 4-6 hours. The second aspect of the invention provides the nano-silicon loaded para-phenolic pre-polymerization cros