Effects of Temperature on the Rheological Properties of Rice Husk Modified Bentonite Drilling Fluids

Abstract

In this study, water base drilling fluids were developed using bentonite clay and rice husk. The pure and blends of bentonite clay and rice husk as specified by samples A with (pure bentonite), B (with pure rice husk), C (1:1 of rice husk to bentonite) and D (2:1 of rice husk to bentonite) were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The XRD result of the samples showed that samples C and D both contains montmorillonite as mineral with the most intense peak at 5.887^o. Samples A and B contain Quartz, and Montmorillonite respectively with the most intense peak at 2Ө value of 26.642^o, 31.578^o, 5.887^o, 26.624^o and 26.627^o respectively. The results show strong interaction between sample A and C. FTIR results of samples A, B, C and D showed number of bands/peaks of 13,9,13 and 14 respectively and showed high level of interaction between pure and blends of the samples were with 14 peaks/bands each. Five water base drilling fluid samples produced using standard laboratory barrel (350 ml) method from bentonite and water with addition of rice husk in different proportion were investigated. The rheological properties (plastic viscosity, yield value, gel strength) of the samples were measured at different temperatures, using FANN 35 viscometer while the pH and density values were measured using pH meter and mud balance respectively. The pH values of all the produced drilling mud samples were alkaline (>7.0), close to the neutral value. Increase in temperatures bentonite drilling mud modified with rice husk does not have negative effect on the rheological properties of the drilling mud. The rice husk could be used as a viscosifier in the drilling mud for being capable of improving the viscosity of the mud at higher temperature.