Enhancement of water based mud performance using iron oxide and polyanionic cellulose nanoparticles

Abstract

Iron oxide and polyanionic cellulose nanoparticles (nano-PAC) have been previously used, but individually, to enhance the properties of the drilling mud. The use of iron oxide nanoparticles (IONP) showed significant enhancement in the rheology of the drilling mud while the use of nano-PAC has decreased the fluid loss. However, the use of combination of both has yet to be reported. Therefore, in this study, a mixture of both components was used to investigate its effect on the drilling mud rheological properties, fluid loss and mud cake thickness. Nano-PAC were produced using the ball milling process of PAC, while the IONP was purchased. A total of 6 types of muds were formulated: 1) base-mud, 2) mud with 3.5 wt% IONP, 3) mud with 2.5 wt% IONP and 0.2g nano-PAC, 4) mud with 1.5 wt% IONP and 0.25g nano-PAC, 5) mud with 0.5 wt% IONP and 0.3g nano-PAC and lastly, 6) mud with 0.35g nano-PAC. Generic API & HPHT fluid loss tests were carried out to measure the filtration behaviour and the mud cake thickness of the mud at ambient conditions and after hot rolling respectively. A combination of 1.5 wt% IONP and 0.25g nano-PAC in the drilling mud was found to be the most promising from the formulated mud samples as it showed consistent readings throughout the research and had an even distribution of the nanoparticles in it. By adding 1.5 wt% IONP and 0.25g nano-PAC; the density, 10-s gel strength, 10-min gel strength and the yield point increased by 2%, 23%, 6% and 11% respectively, as compared with the base mud. Whereas, the plastic viscosity and the filtrate volume decreased by 27% and 32% respectively at ambient conditions. The mud cake thickness and the pH remained the same at ambient conditions for both, the base mud and the mud with 1.5 wt% IONP and 0.25g nano-PAC. After hot rolling, the density, 10-s gel strength, 10-min gel strength and the yield point increased by 3%, 56%, 52% and 33% respectively, whereas, the filtrate volume decreased by 21%. There was no change in the mud cake thickness, pH and the plastic viscosity of both, the base mud and the mud with 1.5 wt% IONP and 0.25g nano-PAC. From the findings, it was proven that the combination of nano-PAC and IONP can enhance the drilling mud rheological properties, reduce fluid loss while maintaining the mud cake thickness, therefore has a great potential as drilling fluid additive.