Swelling and rheological behavior of preformed particle gel nanocomposite: simultaneous effect of pressure, temperature, and salinity

Preformed particle gel treatment is a proper method for increasing oil recovery factor in heterogeneous reservoirs. The swelling ratio and elasticity properties of particle gels determine the efficiency of a treatment project. They can be altered with any change in environmental properties, specially, salinity, temperature, and pressure. In this work, a new kind of preformed particle gel synthesis procedure using nanogel particles is introduced and the synthesized product is characterized using swelling and rheological tests. For the first time, the simultaneous effect of environmental conditions on the properties of preformed particle gel is investigated for an ordinary gel and the synthesized nanocomposite gel. Also, a novel and precise equation is proposed to model the swelling kinetics versus salinity, pressure, and temperature. For both gels, the temperature had an increasing effect and the pressure had a decreasing effect on the swelling ratio. However, the effect of salinity on the swelling ratio was dependent on the temperature and was a little different for two types of gels. At all experimented conditions, the results showed that the nanocomposite particle gel had higher swelling ratio compared to the ordinary one. The storage modulus of both gels was increased with the increase in salinity from 10,000 to 180,000 ppm. However, the increase in salinity from 0 to 10,000 ppm led to lower strength of ordinary gel and higher strength of nanocomposite gel.