Gelatin-grafted carbon nanocomposite as an efficient biodegradable shale inhibitor for water-based drilling mud

The borehole susceptibility in the drilling process, prompted by the swelling of the shale formations, might cause substantial non-productive time and high expenses. A novel gelatin-grafted carbon nanocomposite (GGCC) was synthesized in-house in the current work. The features of the GGCC were assessed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The shale inhibition features of GGCC were evaluated using a linear swelling test, while its impact on drilling mud performance was assessed through rheological investigation and filtration control testing. The reduction in linear swelling rate was positively affected by an increase in GGCC concentration; 0.2 g and 0.5 g GGCC lowered linear swelling by 10 % and 33 %, respectively, compared to water. The GGCC addition to the drilling mud also disclosed a notable reduction in fluid loss. With the introduction of 0.005 %, 0.3 %, and 0.5 % GGCC, the fluid loss increased up to 3.0 mL. The reduction in fluid loss of GGCC modified base mud was attributed to the development of a dense coating that obstructs the clay nanopores and deters the invasion of water. Subsequently, based on the comprehensive analysis, GGCC can be considered a tough contender that could serve as an eco-friendly shale swelling inhibitor for water-based drilling muds (WBM).