Investigation of the use of nanomaterial surfactants for oil emulsion drilling muds for deep-hole conditions

(MSc (50/50) Research Report in Oil and Gas Engineering) School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa September 2018The challenges faced by recovery methods for the extraction of oil and gas from reservoirs are related to existing drilling operations. Consequently, the muds become susceptible to poor heat transfer, disintegration, gelation, pipe sticking, poor cleaning ability, and poor lubrication. The challenges in drilling operations at high temperature and high pressure (HTHP) conditions can be mitigated when rheological properties are controlled and monitored. This research focusses on the investigation of the use of nanomaterial surfactants for oil emulsion (OBM) drilling muds in order to address the challenges in HTHP conditions. Emulsion drilling fluids with and without nanoparticle were prepared. ZnO nanoparticle was selected for this research based on its unique thermal stability properties. The drilling fluid package comprised 100 g of distilled water, 1 wt% of NaCl, 1 wt.% of CaCl2, various amount of surfactant (Triton® X-100 or DTAB) and + 6 wt.% of bentonite. The surfactant concentration varied from 0.25 to 1.25 % with 0.25 intervals. To evaluate and compare the contributions of surfactants and nanomaterial, the prepared drilling fluids were subject to rheological and filtration test. The results showed that DTAB surfactants-based drilling mud with ZnO nanoparticle showed a more stability compared to Triton. The decrease in viscosity with DTAB did not have a significant impact of the filtration loss in the presence of ZnO nanoparticles. The drilling fluids showed a dilatant and shear thickening behavior. The filtration test showed that 1 % of surfactant loss minimal amount of fluid and ZnO nanoparticle reduced the fluid lost capacity. The emulsion contained DTAB as surfactant and ZnO nanoparticle performs better in terms of retaining water and/or liquid in the mud; therefore, making it suitable for drilling at HTHP conditions.E.R. 201