新型低界面张力纳米微球调驱剂的合成与性能研究OACSTPCD

As a new type of nano oil displacement material,polyacrylamide nanospheres are widely used to improve oil recovery in oil fields.However,currently polyacrylamide nanospheres are mainly used for plugging,and there are problems such as low monomer solid content,fast expansion speed of its aqueous solution,poor oil displacement performance and poor reduction ability of surface and inter-face tension.In this paper,a new nano microsphere profile-control oil-displacement agent with plugging function,ultra-low surface and interface tension and high oil-washing efficiency was obtained by inverse emulsion polymerization at 35℃.White oil is used as the oil phase,the mixture of 2-acrylamide-2-methylpropane sulfonic acid(AMPS)and acrylamide(AM)as the water phase,the mixture of o-leic acid,gemini polyether and OP-10 as the emulsifier,and methylene bisacrylamide(MBA)as the crosslinking agent.The optimal ra-tio(mass fraction)ofoil phase/emulsifier/water phase is 33.93%∶24.87%∶41.2%according to the ternary phase diagram.The opti-mal synthesis conditions are:monomer ratio m(AM)∶m(AMPS)is 8∶1,the mass fraction of crosslinking agent is 0.1%,the mass frac-tion of oxidation-reduction agent is 0.3%,and stirring speed is 450 r/min.The characterization and performance evaluation of the poly-acrylamide nanospheres showed that its solid content is 20.1%,particle size is 54 nm,and plugging rate can reach 95.1%.The interfa-cial tension of its 0.2%aqueous solution is 0.332 mN/m,and the oil washing efficiency is as high as 89.13%.It can be used as a pro-file-control oil-displacement material.