Effect of nanoparticles on clay swelling and migration

Clay migration/swelling has been widely documented as the main reason leading to oil recovery impairment. Interactions of clay particles with the medium surface in the presence of permeating fluid have been recognized as a critical parameter controlling the fate of clay particles. These interactions are strongly functions of the ionic strength of the permeating fluid. It is widely reported that reducing the salinity of the reservoir environment facilitates the challenges induced by clay particles. On the other hand, low salinity reservoir environment has been recognized as a very favorable condition for oil recovery. Accordingly, one should consider the positive effect of reducing salinity on oil recovery and its deteriorative effect on clay particles at the same time to improve oil recovery in a controlled formation damage mode. This experimental work aims to investigate the potential remedial effect of different metal oxide nanoparticles to treat clay swelling. Several core flood experiments and micro-model tests have been conducted to achieve the mentioned goal. Furthermore, swelling tests were quantified in terms of swelling indices to explain the effect of nanoparticles on clay swelling. We concluded that although nanoparticles can be used as a permanent stabilizer to prevent clay migration, they are not able to prevent clay swelling and may also increase the pressure drop due to fitting between clay crystals and blocking pores.