Rheological investigation of synthetic-based drilling fluid containing non-ionic surfactant pentaerythritol ester using full factorial design

• Main Authors: Kania, Dina, Yunus, Robiah, Omar, Rozita, Rashid, Suraya Abdul, Jan, Badrul Mohamed
• Format: Article
• Published: Elsevier 2021
• Subjects: QD Chemistry; TP Chemical technology
• Online Access: http://eprints.um.edu.my/28069/

Non-ionic surfactant pentaerythritol ester (PE ester) can be used as a lubricant and chemical thinner in flocculated synthetic-based mud (SBM). However, its adsorption on surfaces and at oil-water interfaces may interfere with anionic secondary emulsifier and organoclay additives in the mud. The interactions between these additives may significantly affect the viscosity of SBM emulsions. Therefore, in this study, we systematically developed SBM formulations containing a non-ionic surfactant PE ester and evaluated the interactions between the surfactant, secondary emulsifier, and organoclay that influence the rheology of SBM using a full factorial design. Three rheological properties were chosen as responses: plastic viscosity (PV) and yield point (YP), and YP/PV ratio. Factorial analysis of the interaction between the secondary emulsifier and PE ester showed that the interactions caused significant effects on PV, YP, and YP/PV ratio. These multiple responses were optimized using the desirability function, and the optimum formulation was at concentrations of 1.0 lb/bbl, 6.2 lb/bbl, and 1.0% for secondary emulsifier, organoclay, and PE ester, respectively. A quantitative relationship between the various factors and responses was established, allowing a prediction of desirable rheological properties for drilling operations.