Reza Jamali Toygun - MSc Student, Department of Petroleum Engineering, Petroleum University ofTechnology, Ahwaz, Iran

During production from gas condensate reservoirs, pressure drops below the dew point can lead to the accumulation of condensate around the wellbore. This condensate formation has a significant impact on reducing gas relative permeability and gas recovery factor. Additionally, the build-up of liquid can cause damage to the formation. In recent decades, one permanent solution that has emerged is the alteration of wettability near the wellbore. This approach aims to eliminate the negative consequences associated with condensate accumulation. The main aim of this study is to create a nanofluid by utilizing the interaction between an anionic surfactant (Silnyl ®FSJ(SY)) and silica (SiO۲) nanoparticles. The nanofluids were prepared with modified SiO۲ nanoparticles that were dispersed in an SY solution in deionized water (SSY). The intended outcome is to modify the wettability of the reservoir from a state of being liquid-wet to a gas-wet state. To evaluate the impact of the chemical agent on the surface wetting behavior and fluid flow characteristics of the rock samples, we performed contact angle measurements and core flooding experiments. The contact angle measurement demonstrated that the application of a chemical treatment led to a transition of the liquid phase to a non-wet phase. The surface chemical compound (SSY) exhibited a high capability in reducing the free energy of the sandstone surface. To investigate the influence of wettability on two-phase fluid flow in porous media, gas/liquid core flooding experiments were conducted. Moreover, the injection of brine indicated that surface modifiers in a high-permeability sandstone core plug resulted in a pressure drop reduction of ۲.۵۴. Based on these findings, it can be concluded that the nanofluid employed is well-suited for application in high-permeability scenarios.

Nanotechnology،Gas wetting،Wettability alteration،sandstone reservoir،Condensate Reservoirs