The invention discloses a novel anti-shearing
branch polymer oil displacement agent and a synthetic method thereof. According to the technical scheme, the following raw materials and monomers in
mass percent are used: 73.5-84.95% of
acrylamide (AM), 15-25% of
sodium acrylate NaAA and 0.05-1.5% of polyamidoamine modified
branch skeleton GA taking 1,3-
propane diamine as a core. The synthetic method of the novel anti-shearing
branch polymer oil displacement agent comprises the following steps of: adding NaAA into a reactor, adding pure water, regulating pH to be 6.5-7.5 with NaOH, stirring and adding AM and GA, preparing a solution with the concentration of 15-30%, introducing
nitrogen for 20 minutes, then adding an initiating agent, continuously introducing the
nitrogen for 10-20 minutes, and reacting for 3-10 hours at 30-60 DEG C; and finally washing, smashing and
drying, thus an AM / NaAA / GA ternary
polymer is obtained. The novel anti-shearing branch polymer
oil displacement agent shows good shearing dilutability, the problem of injection of medium and low
permeation oil reservoirs can be better solved, under lower shearing action,
viscosity of the polymer can be rapidly restored, good fluidity control ability and aqueous phase permeability
reducing capacity are realized, capacity of a
polymer solution for expanding swept volume is improved, and simulated
crude oil recovery ratio can be effectively increased by about 12.3%.