An investigation of polymer-modified activated carbon as a potential shale inhibitor for water-based drilling muds

Abstract

The dendrimers are a class of synthetic macromolecules with unique regularly branched three-dimensional structures, monodispersed, a large number of functional groups at the periphery, and a relatively non-toxic nature. In the current work, for the first time, the application of activated carbon functionalized with polyamine dendrimers (AC-PAD) as the environment-friendly swelling inhibitor is reported. To verify the adsorption of AC-PAD on the clay surface, its inhibition mechanism was investigated by various kinds of techniques such as Fourier transforms infrared spectroscopy (FTIR) analysis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-Ray spectroscopy (EDX). The FTIR confirmed the attachment of AC-PAD with the clay surface, while TGA demonstrated the shale materials' stabilization after the addition of AC-PAD. The SEM established the plugging of nanopores of the shale material which is very crucial in swelling control. The effects of AC-PAD on rheological features, shale inhibition, and linear swelling inhibition mechanism of clay were studied. The outcomes revealed that 0.85 wt% AC-PAD modified water-based muds (AC-PAD-WBM) displayed the highest shale recovery in dispersion analysis and inhibition stability tests and low swelling rate as related to KCl(aq) and traditional WBM. The high efficiency of the AC-PAD could be accredited to the synergetic effect of the composite. The AC block the pores, however, the cationic PAD attaches to the clay particles and hinders the interaction of water by making the clay surface hydrophobic. The AC-PAD carries functional groups that can disturb the hydrogen bonding between water and clay. The AC-PAD proved to be an impressive alternate as compared to less efficient shale inhibitor and swelling control agents utilized in the drilling industry.