Grafted graphene oxide nanoparticles as a yield point enhancer in water-based drilling fluids

Drilling fluids are used in exploration and production (E&P) for oil/gas. More recently, nanomaterial additives such as nano clay, nano-silica, nanocellulose, etc., have been of interest in improving drilling fluids' performance. Graphene and oxide (GO) nanomaterials have been attractive for oil-field applications. Furthermore, water-based drilling fluids are more environmentally desirable than oil-based fluids. This study demonstrated the successful synthesis and use of bi-facial grafted graphene oxide with two random copolymers and one block copolymer for water-based drilling mud application. The successful polymerization was verified by FTIR spectroscopy, EGA, DLS, and Raman spectroscopy. The dispersity and stability of GO-AMPS-r-DMA were tested in different water-based and oil-based solvents, indicating better dispersity and stability in water and DMF than GO. The thermal behavior of the three GO-polymer composites was studied by TGA, DSC, and EGA, showing higher stability with block copolymers than random ones. The performance of such grafted graphene materials was tested in water-based drilling fluids at simulated downhole temperatures and pressures. Results demonstrate the positive effect of these produced grafted graphene materials on mud rheological behavior at temperatures up to 350F and 10,100psi.