Study on the preparation and mechanism of oil-soluble amphiphilic polymer asphaltene inhibitor

In order to solve the problem that the asphaltene in YM35-6 crude oil is easy to precipitate and accumulate, resulting in wellbore blockage. In this paper, an oil-soluble amphiphilic polymer asphaltene inhibitor (SYRJ) was developed. The wellbore environment was simulated by static experiments and high temperature and high-pressure dynamic experiments. The inhibition effect on asphaltene was evaluated respectively. The inhibition rate reached 84.65% and 82.03% respectively at 400 ppm dosage. Furthermore, the inhibitor showed good inhibition effect on different high asphaltene crude oils. Even at 120 degrees C, the inhibition rate was more than 85%. Finally, the microstructure and particle size of asphaltene after adding SYRJ were studied by scanning electron microscopy and laser scattering system. The results show that SYRJ adsorbs on the surface of asphaltene and penetrates into its crevices by virtue of its ultra-long carbon chain and hyperbranched structure. The interlayer spacing between asphaltenes is increased. Thus, the interaction between asphaltene molecules is hindered, and the growth and aggregation of asphaltene particles are inhibited. The average particle size of asphaltene molecules was reduced from 409.5 nm to 189.3 nm.