Abstract

Meeting global energy demand in a sustainable way requires cost-effective, environmentally friendly, and biodegradable water-based drilling fluid (WBDF) that can be used for sustainable drilling. Nevertheless, the fluid loss into the formation during the drilling is a major issue of WBDF. Various chemical-based fluid loss additives in the industry have been used to control WBDF loss into formation. However, using chemical additives poses a risk to the environment, pollutes water reserves, and threatens the ecosystem. In this study, based on pumpkin peel waste (PPW), a biopolymer additive was introduced to enhance WBDF filtration and rheological properties. The sample of the PPW was dried, crushed and grounded using a ball mill into two very fine (10μm) and fine (75μm) particle sizes. Then, the samples were added to the conventional WBDF at optimum weight concentrations of 3wt%, and the rheological and filtration properties of the proposed WBDF were investigated using industry API filtration and rheological tests. Furthermore, major elemental analyses of the samples were carried out using an energy-dispersive x-ray spectrometer (EDX), fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The results of filtration test indicate adding 3wt% of very fine (10μm) and fine (75μm) PPW biopolymer reduced fluid loss by 38.8% (from 18cc to 11cc) and 33.3% (from 18cc to 11cc) for the duration of 25 minutes. This also resulted in formation of thin filter cakes of 3mm and 2.5mm when very fine and fine particles of PPW were added to the mud, respectively.
The rheological property tests indicated that using PPW biopolymer in WBDF increases mud density slightly by 1.12%. Moreover, the apparent viscosity of the reference WBDF was increased by 50% (from 4cp to 8cp) and 35% (from 10cp to 13.5cp) adding 3wt% PPW of 10μm and 75μm, respectively. In addition, adding same concentration of very fine and fine particles of PPW would increase the yield point of the WBDF by 33% (from 12 to 18 Ib/100ft2) and 7.7% (from 12 to 13 Ib/100ft2).
The proposed biopolymer not only has environmental benefits but also offers technical enhancements to drilling fluid performance, particularly in filter cake formation where they contribute to improved sealing capabilities and fluid loss control.