(531c) Reducing Drilling Fluid Losses Using a Lab Scale Shale Shaker

The recovery of drilling fluid is essential in the oil and gas drilling under the environmental and economic point of view. These fluids are basically colloidal suspensions classified according to their base components in aqueous and non-aqueous fluids. The equipment typically utilized in solid-liquid separation units are divided into three groups sequentially arranged: shale shakers, hidrociclones (desander and desilter) and centrifugal decanter. Understanding the dynamic behavior of the shale shaker is very important to reduce the process load applied to the subsequent equipment. This paper presented a contribution on the experimental research on employment of g-force control loop dimensionless number applied to a vibrating screen prototype. The study was conducted based on the method traditionally employed in solids control units. The manipulated process variable is the rotation imposed on motor vibrators installed in the vibrating screen. The results obtained in the experiments indicate an appropriate and consistent operation of the proposed control loop. The dimensionless number g-force was maintained close to the set-point value, ensuring repeatability for the experiments.
The use of higher dimensionless values of g-force does not necessarily assured greater removing of residual liquid entrained with the solid material retained by the sieve screen. One possible reason for this behavior is the fact that the greater intensity of vibration provided by motor vibrators helped to increase the solid transport speed on the display screen, reducing the effect of elimination of retained fluid.