Breakthrough Solutions for Lost Circulation Control in Oilfield Drilling: Unleashing the Power of Biopolymer Modified Graphene and CaCO3 synergy

Abstract

Lost circulation is a common problem encountered during drilling operations, where drilling fluids escape from the wellbore into the surrounding geological formations, resulting in reduced drilling efficiency and increased costs. Conventional lost circulation materials (LCMs) like calcium carbonate (CaCO3), mica, ground walnut shells, fibrous materials, and cross-linking agents are usually added to drilling fluids to plug the lost circulation zone. Further, nanoparticles, such as graphene and carbon nanotubes, offer a new generation of solutions for controlling fluid loss into lost circulation zones. The particle size distribution of LCMs, their stability, and dispersion play a significant role in controlling losses. The combination of LCMs and nanoparticles can provide a synergistic effect for lost circulation control. In this study, a mix of biopolymer-modified graphene and CaCO3 is proposed as a potential solution for lost circulation control that combines the unique properties of biopolymer, graphene, and CaCO3. The potential of the novel solution was investigated by conducting rheology and fluid loss tests. Their synergistic effect was investigated by incorporating them in different concentrations in drilling fluid and the optimum concentration was chosen based on rheology and fluid loss results. Experimental observations revealed that the combination of biopolymer-modified graphene and CaCO3 resulted in the formation of a durable and impermeable mud cake on the wellbore wall, effectively bridging the lost circulation zone. This innovative approach significantly reduces fluid loss in comparison to the conventional use of CaCO3 alone. By filling the nanopores of the CaCO3 bridge, the modified graphene contributes to a robust and reliable lost circulation control solution. Moreover, the inclusion of modified graphene improves the rheological properties of the drilling fluid, facilitating easier pumping and enhancing its capacity to suspend CaCO3 and other weighting materials. The proposed solution is biodegradable, environmentally friendly, and can withstand HPHT conditions, making it a viable option for real drilling conditions.