Kinetics of microwave heating and drying of drilling fluids and drill cuttings

ABSTRACT

Drill cutting decontamination by microwave drying has been studied over the past few years and has proved to be a promising technology. This study aimed to investigate fundamental aspects of kinetics of heating and drying of drilling fluids and drill cuttings by microwaves. The microwave heating curve of cuttings free of fluid, drilling fluids, and pure organic compounds usually used in the formulation of these fluids was evaluated to understand the behavior of each component in microwave cutting decontamination. Furthermore, commercial software was used to describe the heating kinetics of the drilling fluids used in this study. The drying kinetics of cuttings contaminated with these drilling fluids was also studied at three temperatures of control. Some classic models of conventional drying of solids were used to describe the removal kinetics of the liquid components present in contaminated cuttings (water and organic compounds). Important aspects related to the interaction of these components in the drying operation and solid heating, water evaporation, and the drag of organic compounds were investigated. Both drilling fluids showed a very similar kinetic heating. Pure organic bases did not show a significant heating. For the same drying time, the removal of paraffin is more intense than the olefin. In respect to organic component removal from cuttings contaminated with both fluids, the kinetic drying curves are similar. The Page model was the one that best describes the drying operation of drill cuttings contaminated with both drilling fluids. The microwave drying model (MDM) model is proposed in this work as a simple modification in the Henderson–Pabis model: the addition of a third parameter. The incorporation of this parameter enabled a better fit of the experimental data. Computational simulations show an electric field with symmetrical patterns for the two BR-MUL fluids analyzed.

KEYWORDS:

• Dielectric properties
• drilling oil
• drying models
• kinetic drying
• microwave drying