Application of acrylamide polymers in oil displacement

Petroleum is one of the most important energy materials in contemporary times. However, since the reservoirs of most oilfields in my country belong to continental deposits, the complex water content of oil layers rises rapidly, and about two-thirds of the crude oil reserves remain underground and cannot be recovered. Therefore, increasing crude oil Oil recovery has become an urgent strategic task for the sustainable development of my country's onshore oil industry, and polymer flooding tertiary oil recovery technology is an important method to enhance oil recovery.

The earliest developed and most commonly used polymer is partially hydrolyzed polyacrylamide. Although polyacrylamide can be effectively used in polymer flooding under most oilfield conditions, it is limited to low hardness because of the formation of polyacrylamide after hydrolysis of the amide group. Carboxylate, and carboxylate can react with Ca2+ and Mg2+ present in the oil field to precipitate polyacrylamide.

In order to improve the thermal stability of polymers, antioxidant stabilizers are often added, such as thiourea, sodium dithionite, etc., in order to reduce the hydrolysis of amide groups, improve the thermal stability of polyacrylamide and the solubility in brine, researchers Some exploratory work has been carried out on acrylamide copolymers for oil displacement, and some polymer oil displacement agents with resistance to temperature and salt have been synthesized, such as 2-acrylamide-methylpropanesulfonic acid/acrylamide/maleic anhydride copolymer acrylamide/N,N-dimethylacrylamide/2-acrylamide-methylpropanesulfonic acid copolymer, acrylamide/2-2-acrylamide-methylpropanesulfonic acid/2-acrylamide Hexadecylsulfonic acid copolymer, acrylamide/2-2-acrylamido-methylpropanesulfonic acid copolymer, acrylamide/2-acrylamido-methylpropanesulfonic acid/vinylpyrrolidone copolymer, acrylamide /2-acrylamido-2-methylpropanesulfonic acid/N,N diethylacrylamide-based copolymer, acrylamide/2-acrylamido-2-acrylamido-methylpropanesulfonic acid/2- Methacrylamide-oxyethyl dimethyl dodecyl copolymer, acrylamide/2-acrylamido-2-methylpropanesulfonic acid/2-acrylamide hexadecylsulfonic acid/diethyl Novel hydrophobic association polymer synthesized from diallyl ammonium chloride copolymer, propylene-based monomer and cationic hydrophobic monomer.