Compared with the polymer solution

the polymer microsphere solution is a discontinuous phase

and the particle size distribution of the microspheres is more concentrated. It can "plug large pores and not plug small pores"

to a certain extent

the swept volume of water phase were increased

and the phenomenon of "profile inversion" was slowed down. In recent years

polymer microsphere flooding technology research and field test have received extensive attention. In order to meet the needs of profile control technology in offshore oilfield

a hydrophobically associating polymer microsphere was synthesized by inverse emulsion polymerization. Chemical characterization and core seepage experiments were used to study the particle size distribution

slow swelling

plugging

reservoir adaptabilityand transmission and migration capacity of polymer microspheres. The results show that the water-soluble monomer AMPS and the hydrophobic monomer alpha methylstyrene can be copolymerized with acrylamide and sodium acrylate to form a random distributed hydrophobically associating copolymer

that is microsphere material. On this basis

nine microsphere samples (AMPS) were synthesized by four-factor three-level orthogonal test to study the effects of AMPS content

emulsifier content

initiator content and temperature on microsphere particle size. The initial particle size of AMPS-8 microsphere is about 2

µ

m

and the particle size is stable at about 18

µ

m after the hydration of 240h. The expansion ratio reached 8 to 9 times

and the residual resistance coefficient is the largest when the core permeability is 1600 × 10

-3

µ

m

2

reaching 9. 53

indicating that the permeability limit is 1600 × 10

-3

μ

m

2

and the microsphere has a strong retention and plugging effect in the core.Under the condition of injected water in Bohai oilfield

there is little difference in the median size of AMPS hydrophobic polymer microspheres

indicating that it has good salt resistance. The transport and migration experiments of 60cm long core were carried out by using AMPS-8 microspheres with better expansion effect. The results show that the residual resistance coefficient near the entrance is as high as 19. 417

the residual resistance coefficient of the middle is 6.6

and the residual resistance coefficient near outlet is 2.8

indicating that AMPS-8 microspheres have good deep transport and migration ability.