The Importance of Dielectric Properties for the Optimization of Microwave Drying Systems in the Treatment of Drill Cuttings

Abstract

With the increasing severity of environmental legislation, the disposal of drill cuttings has become a critical issue. Once the solids control system reaches contaminant contents close to the established limit value, alternative treatment technologies have been studied, such as microwave drying. In this scope, dielectric properties of two distinct cuttings, one obtained from clay formations and the other from reservoir, were measured in different conditions. It could be inferred from the results that the cuttings are absorbent materials and the loss tangent is directly proportional to their contaminant content. Additionally, a predictive kinetic model previously designed for clay cuttings was tested for reservoir cuttings, showing that the model is also aplicable in the analysis of the drying behavior of reservoir cuttings for low values of applied power. It was concluded that the insertion of dielectric parameters into the kinetic models enabled not only yield prediction, but also provided a better understanding of how the selected materials behave under different microwave process conditions, both qualitatively and quantitatively. It is important to highlight that this knowledge on microwave drying is fundamental not only to the optimization and control of the process, but also to the development of new technologies that make use of specific characteristics of the phenomena.