A novel preparation of bio-based graphene from oil palm biomass as a fluid loss additive in water-based drilling fluid

Abstract

The unutilized excess biomass produced by the oil palm sector has become a major source of environmental discussion in Malaysia. Nonetheless, the oil and gas sector has expanded the number of biomass-related projects by implementing zero-carbon net policies. Particularly, graphene has potential applications in the oil and gas industry, including drilling, well logging, desalination, and lubricants. This study introduced a two-step mechanical exfoliation approach to synthesize bio-based graphene (BG) from the lignins of oil palm (Elaeis guineensis) biomass for fluid loss addition in water-based drilling mud (WBM). The BG exfoliation approach is an innovative combination of pyrolysis heat treatment and mechanical exfoliation. This method was developed without chemical exfoliation techniques (Hummers' method) due to its harmful by-products. Several characterization methods were employed, including ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The sample analyses revealed that the synthesized BG acquired a similar structure to reduced graphene oxide (RGO) due to its comparable C/O ratio. Meanwhile, the efficacy of BG biomass as a fluid loss supplement for WBM was determined when BG was combined with bentonite, sodium carbonate, and water. An American Petroleum Institute (API) filter test and a High-Pressure High-Temperature (HPHT) filter test were performed to assess the fluid loss. Although the API filter test revealed that 0.5 wt% BG possessed the least fluid loss at 10 mL for 30 min, the HPHT filter test indicated that 1.0 wt% BG produced the least fluid loss at 18 mL for 30 min. Therefore, the performance of BG as a drilling mud addition was equivalent to commercial graphene in previous studies. This outcome was demonstrated in the 50% fluid loss reduction and noticeably different surface morphology (less permeability) of the mud cake with a less porous structure and smoother surface.