Anti-shearing polymer and preparation method thereof

Abstract

The invention relates to an anti-shearing polymer and a preparation method thereof. The polymer is a copolymer composed of acrylic amide, sodium acrylate, hydrophobic monomer dimethyl allyl-N-alkyl ammonium chloride and a functionalized framework monomer. The average molecular weight of the copolymer is 6 million. The preparation method comprises the following steps of: (1) respectively dissolving a polyamide-amide macromolecular framework monomer and maleic anhydride (or acryloyl chloride and acrylic anhydride) into dimethyl sulfoxide; slowly dropwise adding a framework monomer solution intoa maleic anhydride solution; introducing nitrogen and placing the system into an ice salt bath; when the pH (Potential of Hydrogen) value of a reaction solution is 4-5, stopping dropwise adding the framework monomer solution; and utilizing chloroform to repeatedly precipitate to obtain the functionalized framework monomer; and (2) carrying out free radical water solution polymerization on the acrylic amide, acrylic acid, the hydrophobic monomer and the functionalized framework monomer. The anti-shearing polymer and the preparation method thereof have the advantages of reliable principle and convenience for operation; and the synthesized polymer still has good tackifying capability under high-temperature, high-salinity and strong shearing effects.

Description

technical field [0001] The invention relates to a shear-resistant polymer and a preparation method thereof, belonging to the field of polymer materials. Background technique [0002] Polymer flooding technology is the main technical means to enhance oil recovery in my country's oilfield development, and has achieved certain success in technology and economy. Polymer flooding technology has been widely used in tertiary oil recovery at home and abroad, and has broad application prospects. With the development of the national economy and the further exploitation of oil and gas resources, the requirements for enhanced oil recovery are becoming more and more urgent. [0003] In order to improve the effect of polymer flooding and meet the requirements of increasingly harsh reservoir conditions, higher requirements are put forward for the stability of water-soluble polymers, such as higher viscosity-increasing ability and stability. Stability mainly includes shear stability, chemi...

AI Technical Summary

Problems solved by technology

Due to the loss of viscosity, the efficiency of polymer flooding is reduced, which seriously affects the effect of polymer flooding

[0006] The following problems exist during polymer flooding in high-temperature and high-salinity reservoirs: (1) Due to the electrostatic shielding effect between cations, the cations will attract the negative charges on the polymer molecules, so that the polymer molecules become uncharged molecules However, curling deformation occurs, the hydrodynamic radius decreases, and the viscosity-increasing property becomes poor; (2) divalent cations (Ca 2+ , Mg 2+ ) complexes with the -COO- group on the polymer molecular chain to form insoluble or insoluble substances, thereby greatly reducing the viscosity of the polymer solution; Salt conditions have a greater impact on the polymer solution, and the viscosity decreases more; (3) The cation interacts with the polymer molecular chain, resulting in the deterioration of the rigidity of the polymer molecular chain, and the probability of the polymer molecule being sheared and degraded under high-speed shear greatly increased, making the shear resistance of the polymer worse

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