Insights into application of acorn shell powder in drilling fluid as environmentally friendly additive: filtration and rheology

Abstract

Conventional additives used in drilling fluid may have detrimental short- and long-term impacts on the surrounding environment. The employment of biodegradable green material in drilling fluid as alternative additives will eliminate these harmful impacts. In this study, acorn shell powder is proposed as a novel biodegradable additive for application in drilling fluid. First, the acorn shell powder was prepared and then characterized in terms of chemical structure, particle size, and morphology. The acorn shell powder, with four different concentrations, was then introduced into a water-based fluid; its functionality in the fluid system was evaluated with respect to rheological and filtration characteristics at high-pressure, high-temperature and low-pressure, low-temperature conditions. The observed results indicated that the incorporation of acorn shell powder into the fluid significantly improves filtration behavior; the introduction of 9 lb per barrel of the powder into the fluid system led to a dramatic reduction in volume filtrates by 80.1 and 63.3%, respectively, at high-pressure, high-temperature and low-pressure, low-temperature conditions. The rheological test outcomes displayed a considerable enhancement in the fluid system’s rheology in the presence of the powder. Furthermore, the efficiency of the proposed powder in reducing the filtration was compared with those of four traditional additives, in which the powdered acorn shell demonstrated a comparable efficiency in filtration controlling with those of the traditional additives. The promising efficiency with which the proposed powder controls filtration and enhances rheology justifies its applicability and employment in drilling fluid as a low-cost and eco-friendly additive.