Water-soluble micro-crosslinked copolymer, preparation and use thereof

Abstract

The invention discloses water-solubility micro-crosslinking copolymer, a method for making the same and an application of the same. The method is characterized in that: 20 portions of acrylamide, 0.5 to 15 portions of anion monomer, 0.1 to 6 portions of divinyl benzene, 0.5 to 50 portions of sodium laurylsulfate and 50 to 800 portions of deionized water are added in a three-necked reaction bottle, and the pH value of the solution is adjusted to between 4 and 9; after N2 is injected for 30 minutes, 0.001 to 0.2 portions of initiator persulphate is added in at a temperature of between 30 and 70DEG C so as to carry out reaction for 6 to 36 hours, thereby obtaining PADM; then, the PADM is diluted by water to obtain a PADM solution, thereby obtaining the water-solubility micro-crosslinking copolymer which has ideal water solubility, copolymerization micro-crosslinking structure, difficult intramolecular crimp and molecular association capacity and can be used in oil expulsion. The copolymer is made into an aqueous solution with the mass concentration of between 0.3 and 3 g / L and the surfactant concentration of between 0.01 and 4 mmol / L, and then is added in a mixing vessel provided with a stirring device so as to be stirred evenly at room temperature, thereby obtaining a polymer oil displacement agent which is tackifying, salt resistant, thermotolerant and shear resistant and has excellent age resistance under the conditions of high salt and 110 DEG C. Moreover, the raw materials of PADM are easy to obtain; therefore, the water-solubility micro-crosslinking copolymer and the method have enormous application prospect in increasing crude oil recovery ratio.

Description

1. Technical field The invention relates to a water-soluble slightly cross-linked copolymer and its preparation method and application, belonging to the fields of polymer materials and enhanced oil recovery. 2. Technical background At present, many large oil fields in my country have entered the middle and late stages of exploitation, and the water content of the produced fluid is increasing day by day, and the water content of the produced fluid of many oil wells is as high as 90%. Therefore, chemical flooding by adding chemical agents to water injection has become an important technical measure in my country's petroleum industry, and polymer flooding is an effective technology in chemical flooding. The primary goal of polymer flooding is to develop cost-effective oil displacement polymers. The polymer used for oil displacement should have excellent water solubility, and the polymer can still maintain a strong viscosity increase under the environmental conditions of the oil...

AI Technical Summary

Problems solved by technology

The present inventors have found that various reaction conditions in the polymerization reaction, such as cross-linking comonomer concentration, anionic monomer concentration, surfactant concentration, reaction temperature, etc., have a great influence on the structure of the obtained polymer and the properties of the solution.

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