Fluid loss mitigation via multi-wall carbon nanotubes-enriched water-based drilling fluid

Abstract

Fluid loss is a common drilling problem that should be addressed immediately to prevent formation damage. The most efficient and easiest way to overcome fluid loss is by adding fluid loss control additives in drilling mud as fluid loss control additives can temporarily plug pores in the formations. In this study, combination of durian rind (DR) and multi-wall carbon nanotubes (MWCNT) was studied to increase the effectiveness of fluid loss control due to fibrous nature of DR and complex structure of MWCNT. This can reduce the durian waste and also the cost of fluid loss additives (FLAs). The objective of this study was to study the effect of MWCNT in Hydro-Pac R, a commercial fluid loss control additive and DR to control fluid loss in water-based mud by comparing the rheological and fluid loss properties at different concentrations of durian rind and carbon nanotubes at room condition and after aging. The performance of the fluid loss control additives was also tested in high temperature and high pressure conditions. Fine DR and Hydro-Pac R were tested using five concentrations varied from 0.6 to 1.0 ppb in water-based mud. The mud weight of those mud samples were maintained at 10 ppg. Rheological tests were carried out to determine the plastic viscosity, gel strength, and yield point while fluid loss test was to determine the volume of fluid loss under 100 psi of differential pressure and the mud cake thickness. Then the best concentration for each FLA from the fluid loss test was mixed with MWCNT of concentrations from 0.02 to 0.1 lb/bbl and repeated the rheological test and further investigated the fluid loss performance of the mixture in high pressure, high temperature condition. Overall, the fluid loss results indicated that the performance of drilling fluids with the presence of commercial additive, Hydro-Pac R was better than durian rind. The mixture of Hydro-Pac R with MWCNT produced better fluid loss control in low pressure low temperature (LPLT) filter press and high pressure and high pressure (HPHT) before and after aging process than DR with MWCNT.