Enhancement of Fracture for Low-Permeability Reservoir while Drilling using Smart Fluid throughout Experimental Work

Abstract

Nano-fluids show potential use in applications related to upstream oil and gas industry to improve the performance of several processes such as exploration, drilling and completion, production and enhanced oil recovery operations. However, their applications for Water-Based Drilling Mud (WBM) needs attention to address efficient drilling in a High Pyllressure and High Temperature (HPHT) environment. In the present work, Nano-Fluid-Enhanced WBM (NWBM) are prepared using the Nano-fluids of CuO and ZnO (size ˂50 nm) in a xanthan gum aqueous solution as a base fluid, and used as an additive in WBM. The Nano-fluids are prepared for Nano-particle concentrations of 0.1, 0.3 and 0.5 % of wt. in base. The prepared Nanofluids are added as an additive of 1.0% (by volume) to WBM. The enhancement in thermal and electrical properties of NWBH is studied. It is observed that NWBM show improved thermal and electrical properties by about 35.0% compared to WBM. An increased concentration of nanoparticles further enhances electrical and thermal properties of drilling fluids. The NWBM based on CuO Nano-fluid are observed to show improved thermal properties, and are more resistant to HPHT condition than ZnObased NWBM. High pressure rheological studies are conducted on NWBM to understand the effect of Nano-fluids on the rheological properties at varying temperatures (25, 70, 90 and 110 0C) and pressures (0.1 MPa and 10 MPa). The effect of pressure on the rheology of NWBM is more significant at higher temperatures, and indicates that the better rheological stability in case of NWBM. The most significant role that the Nano-fluids play is in-stabilizing the viscosity at higher temperatures. The experimental data on flow curves obtained for various NWBM are fitting to the classical drilling fluid rheological models (Power Law model, Bingham Plastic model and Herschel-Bulkley model). The Herschel Bulkley model is observed to be the best fitmodel for rheological behavior of NWBM and can be applied for efficient NWBM design.