High adhesion-promotion salt resistant water-soluble copolymer, preparation method and application thereof

Abstract

The invention discloses a water soluble copolymer with high viscosity and salt resistance, and a preparation method and an application thereof. The preparation method comprises the steps of: adding acrylamide 20 weight parts, an anionic monomer or / and a cationic monomer 0.1-15 weight parts,, a vinyl polycyclic aromatic hydrocarbon 0.05-4 weight parts,, a surfactant 0.5-90 weight parts,, and deionized water 70-900 weight parts, into a three-neck reaction bottle, adjusting the solution pH to 2.5-9, introducing N2 for 30min, adding an initiator persulfate 0.001-0.2 weight parts, at 20-70DEG C, and reacting for 6-36 hours to obtain a low-molecular weight water soluble copolymer with molecular association ability, high viscosity and salt resistance, which can be used in intermediate-permeability oil reservoir and low-permeability oil reservoir development. An associated water soluble polymer oil displacement agent is obtained by preparing the copolymer into an aqueous solution with copolymer concentration of 0.3-3 g / L and surfactant concentration of 0.01-4 mmol / L, adding into a mixer with a stirring device, and stirring uniformly at room temperature; and the obtained oil displacement agent has high viscosity, salt resistance, temperature resistance and shear resistance, and can be used in intermediate-permeability oil reservoir and the low-permeability oil reservoir development.

Description

1. Technical field [0001] The invention relates to a high viscosity-increasing and anti-salt water soluble copolymer and its preparation method and application, belonging to the fields of polymer materials and enhanced oil recovery. 2. Technical background [0002] At present, the contradiction between oil supply and demand in my country is becoming more and more prominent, and there are still a large amount of crude oil in complex oil reservoirs, especially in medium and low permeability reservoirs, which seriously restricts the development effect of oilfields and the improvement of reserves production. Among all oil displacement technologies, polymer flooding can significantly increase oil recovery, and the implementation process is simple, but it is difficult to develop polymer flooding technology for medium and low permeability reservoirs. Industrial polymers suitable for the development of medium and low permeability reservoirs. Today, my country still uses water injecti...

Images