Preparation of Crosslinked Polymer Microspheres and Evaluation of Oil Repellent Performance

A W/O microemulsion of AM/H2O Span80/Tween80 kerosene system was prepared with acrylamide (AM) monomer aqueous solution as dispersion phase, Span80/Tween80 as emulsifier and kerosene as dispersion medium. The crosslinked polyacrylamide microspheres with nanometer size were prepared by inverse microemulsion polymerization at 70°C. The microscopic analysis shows that the internal structure of the microsphere is broken during oil displacement, the water cut decreases and the oil recovery increases. When the amount of crosslinking agent is 1.3%, the microsphere flooding effect is good. After the microsphere is injected, the water content of the high permeability pipe decreases by 29.4%, and the oil recovery of the low permeability pipe increases by 33.8%, indicating that the microsphere has a good effect of precipitation and oil increase. The injection pressure was low at the initial stage and then rose to nearly 100 kPa, indicating good injectivity of the microspheres.