Theoretical Study of the Use of Branched Polymer Gels as Temperature- and Swelling-Resistant Fluids for Water-Based Drilling Fluids

With the continuous exploration and development of oil and gas resources in deep formations, the use of water-based drilling fluids as a key factor faces severe challenges caused by high temperatures and hydration of soil layers. Therefore, the development of heat- and salt-resistant soil swelling reducer systems has always been of interest. In this study, it was attempted to increase the degree of hydration resistance and thermal stability of the soil by using amino-branched polymer-modified nanoparticles. The interaction mechanism between branched polymer and silica nanoparticles in different states was investigated using density functional theory to determine the best polymer attachment state. The amount of polymer absorption energy in the vertical and horizontal states was 280 and 360 kJ/mol, respectively. The horizontal state prevented water from reaching the soil surface by forming strong hydrogen bonds with the nanoparticle. This amount of absorption energy was higher than that of other similar compounds, which showed that. The thermal stability calculation of the polymer-nanoparticle compound showed that the thermal resistance of this compound is maintained up to temperatures above 280 degrees Celsius. In general, it can be found that branched polymers are a good option for preventing the swelling of drilling wells.