Non-linear associating water-soluble quadripolymer, and preparation and use thereof

Abstract

The invention discloses a non-linear associated water soluble quadripolymer as well as a preparation method and use thereof, comprising: adding 20 parts of acrylamide, 1-20 parts of nionic monomer or / and cationic monomer, 0.1-15 parts of macromonomer, 0.05-10 parts of hydrophobic monomer, 0.1-50 parts of surfactant and 60-1000 parts of deionized water to a three-necked reaction flask, adjusting the pH to be 3-9, adding 0.002-1 part of initiator (persulphate) at 30-75 DEG C after introducing N2 for 30min, reacting for 8-36h to obtain the quadripolymer PACH, diluting with water, and obtaining concentrated PACH solution. The macromonomer with a long chain and the hydrophobic monomer with a molecular association function are simultaneously introduced in a copolymer PACH, which can obtain the best synergistic viscosifying between rigid conformation of a molecular chain and molecular association and salt resistance. The non-linear associated water soluble quadripolymer is obtained. The copolymer is prepared into aqueous solution with the mass concentration of 0.2-3g / l and the surfactant concentration of 0.01-2mmol / l, added to a mixing vessel with a stirring device and evenly stirred at the room temperature to obtain a viscosified, salt-resistant and shear-resistant polymer oil displacement agent. The PACH has dual functions of a viscosifier and a high molecular surfactant; minute amount of a low molecular surfactant is added to the PACH solution, thus improving the apparent viscosity of the solution, reducing the surface tension of solution and the water-oil interfacial tension, and being beneficial to improving the crude oil recovery ratio. A copolymer PABE is prepared into the aqueous solution with the mass concentration of 0.05-7% to obtain high molecular surfactant with excellent surface activity, and the high molecular surfactant is used as an emulsifier, a demulsifier, a solubilizer and a wetting agent.

Description

1. Technical field [0001] The invention relates to a non-linear associative water-soluble tetrapolymer and its preparation method and application, belonging to the fields of polymer materials and enhanced oil recovery. 2. Technical Background [0002] At present, in my country's tertiary oil recovery, in order to enhance oil recovery, polymer flooding is a widely used oil recovery technology because of its simple implementation process. Polymers can maintain high solution viscosity under various salinities of reservoirs, which has always been the research goal of oil displacement polymers. The currently commercialized industrial products are still 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 . In order to ensure the solubility of HPAM, the degree of hydrolysis of HPAM is generally 10-30%. Although HPA...

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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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