Evaluation of Rice Husk as Fluid Loss Control Additive in Water-Based Drilling Mud

Abstract

Abstract Organic polymers are commonly used to control filtrate loss in water-based drilling fluids both in circulating and non-circulating periods during drilling operations. In Nigeria, the over dependence on these polymers to achieve this function of drilling fluid is worrisome on the overall well drilling cost. Therefore, a substitute for these polymers with locally available materials is indispensable. In lieu of this fact, an agro by-product, rice husk was evaluated as a possible filtration loss control additive in water-based drilling mud and the results compared with sodium carboxymethyl cellulose (CMC) and polyanionic cellulose (PAC) using static fluid loss measurement approach. The results obtained depict that with a concentration of 20g content of rice husk to 350mL mud (about 20lb/bbl) there was a decrease of 64.89% in fluid loss compared to 62.77% and 59.57% for CMC and PAC respectively at a content of 10g per 350mL mud. Additionally, filter cake thickness measurement from the husk showed a decrease of 3.03% and 8.57% respectively when compared to CMC and PAC. Thus, exploitation of rice husk as fluid loss control additive in water-based mud would be a welcome development in the oil and gas industry since its characteristics of high resistance to water penetration and thermal stability would be applicable to deep wells where high temperature is anticipated since CMC and PAC temperatures degrade at this condition.