Abstract
During drilling operations, polymers such as carboxymethyl cellulose (CMC) and polyanionic cellulose (PAC) are frequently employed as additives to reduce filter loss in water-based drilling fluids. These polymers are usually very expensive because they are not produced locally and are generally obtained through importation. The functional group composition of sample were determined using FTIR. In this study, a degradable agricultural waste namely Wild cocoyam starch was used to synthesize a polymer for fluid loss control and rheology in water-based drilling fluid. The FTIR result revealed the presence of several functional groups. In order to obtain a comprehensive result for fluid loss, the study experimented on four concentrations (1 g, 2 g, 3 g and 4 g in 350 ml of distilled water) and 22 g of bentonite clay in each case. The result revealed that the compositions with 4 g and 3 g wild cocoyam starch produce the best data for fluid loss control among the composite samples. In addition; the effect of the composite of wild cocoyam on the density, pH, 10min gel strength, 10sec gel strength, plastic viscosity, viscosity, yield point, temperature, share strength and fluid cake thickness of the water-based fluid showed that the composite samples had an incremental effect on the density, pH, 10min gel strength, 10sec gel strength, plastic viscosity, viscosity, yield point, temperature, share strength of the water-based fluid. A comparison of the result with 1 g of CMC showed that wild cocoyam sample had a better fluid loss of 5 ml in first 5 min and 1.3 ml in the 30 min mark for 4 g of wild cocoyam sample, while the CMC sample had a fluid loss of 6 ml in the first 5 min and 1.6ml in the 30 min mark. Overall wild cocoyam (caladium bicolor) is an excellent viscosifier and fluid loss agent because it is cheaper to process and have better apparent viscosity, gel strength (10secs and 10mins) and a better YP, PV and fluid loss rating than CMC

Key words: wild cocoyam starch, fluid loss, water-based fluid, CMC, PAC, Drilling fluids, Biodegradable polymers, Green polymers