Treatment of Drilling Fluid Wastes in an Environmentally Acceptable Manner

Abstract

Abstract Drilling fluid wastes derived from the drilling process presents a unique disposal challenge to the drilling industry. New technology allows the environmental treatment and subsequent disposal of these wastes lessening the liability and costs to the operator. Through chemical and mechanical treatment the disposal material is separated into the basic components water and solids. 2.0 PROCESS DESCRIPTION Environmental treatment includes chemical and mechanical processing of the drilling fluid and cuttings. The mechanical process equipment includes: process equipment includes:Thickener UnitCentrifugeElectro Flotation Unit The waste drilling fluid is initially pumped into the thickener unit and pumped into the thickener unit and treated to lower the pH in order to achieve maximum flocculation. After flocculation the solids rapidly settle within the fluid. The sides of the bays within the thickener unit are sloped to accelerate the settling rate. The liquid flows over a weir to the second bay, where additional settling takes place. The liquids then flow over the final weir into the last tank of the thickener. From this tank the liquid phase goes on to the Electro Flotation Unit. The processed liquid at this point contain processed liquid at this point contain 2% solids, or less, by volume. The solids are removed from the bottom of the thickener and are sent to the centrifuge unit which further separates solids from the liquids. This phase dewaters the solids by high "G" centrifuging. The centrifuge is specifically designed for mud solids dewatering. This increased "g" environment enhances the settling rate of the solids. The processing includes the addition of proprietary encapsulating polymer to proprietary encapsulating polymer to coat the solids and impart non-leaching characteristics. This allows for safe disposal of the solids into the environment. The liquid phase derived from the centrifuging is flowed again to the Thickener Unit for further solids separation. The solids removed by the centrifuge are dropped onto a conveyor belt and eliminated from the system. p. 295