Acrylic amide modified graft copolymer, preparation method and application thereof

Abstract

The invention discloses an acrylamide modified graft copolymer and a preparation method and usage thereof. The invention is characterized in that 20 parts of acrylamide, 1-20 anionic monomer and/or cationic monomer, 0.1-15 macromonomer, 0.05-10 ionic lyophobic monomer and 50-1000 deionized water are added into a three-necked reaction bottle, the pH value is adjusted to be 3-9, N2 is introduced for 30min, then 0.002-0.5 part of initiator persulfate is added at 30-75 DEG C, the reaction lasts 8-36h, then copolymer PAB is obtained, and finally water is used for dilution to obtain strong PAB solution. During polymerization, no surfactant is used, and the macromonomer with a long chain and the ionic lyophobic monomer with intermolecular association function are introduced into the copolymer PAB, so the capabilities of cooperative tackification and salt-resistance between the rigid conformation of a molecular chain and the intermolecular association can be played optimally, the PAB exhibits unique solution property and has higher colloidal viscosity in high saline solution than in fresh water, and the PAB obtains the capabilities of tackification, salt resistance, low surface tension and strong molecular association and can be used for the oil-displacing acrylamide modified graft copolymer. The copolymer is prepared into water solution with mass concentration of 0.2-3.0g/L and surfactant concentration of 0.01-2 mmol/L, then the water solution is added into a mixing vessel by a stirring device, and then a polymer oil-displacing agent with tackification, salt resistance and cutting resistance is obtained. The PAB has the functions of both a tackifier and a macromolecule surfactant. The copolymer PAB is prepared into water solution which has mass concentration of 0.05-7%, so the macromolecule surfactant with excellent surface activeness can be obtained and then applicable to an emulsifier, an emulsion splitter, a solubilizer and a wetting agent.

Description

1. Technical field [0001] The invention relates to an acrylamide-modified graft copolymer and its preparation method and application, belonging to the fields of polymer materials and enhanced oil recovery. 2. Technical Background [0002] In order to enhance oil recovery, the polymer currently used in polymer flooding technology is mainly partially hydrolyzed polyacrylamide (HPAM). HPAM has a linear molecular structure, and its viscosity increase mainly depends on ultra-high molecular weight, with a molecular weight as high as 1.6×10 7 ~3.0×10 7 , The degree of hydrolysis is generally 10-30%. The linear molecular structure and high degree of hydrolysis of HPAM make it poor in salt resistance, temperature resistance, shear resistance and aging resistance in high salinity reservoirs. Therefore, HPAM can only be used for low temperature and low mineralization. in chemical reservoirs. In order to improve the salt resistance of HPAM solution and the performance of other solut...

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Problems solved by technology

Luo Jianhui et al., Acta Petroleum Sinica, 2004, 25(2): 67-73, synthesized AM / AHPE comb copolymer (KYPAM), the molecular weight of this type of polymer is as high as 2.514×10 7 , the thickening ability in salt water is more than 50% higher than the thickening ability of domestic ultra-high molecular weight polyacrylamide in salt water, but its apparent viscosity in salt water is also lower than that in fresh water, and the comb polymer The hydrodynamic radius is large, it is only suitable for high permeability reservoirs, and it is easy to block the pore throats of medium and low permeability reservoirs

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