Reduction of Synthetic Based Fluid Discharges Offshore by the Use of Vertical Basket Centrifuges

摘要

Currently many operators are making a concentrated effort toreduce the amount of synthetic based drilling fluids or muds(SBM) discharged offshore. In order to achieve these goalsmany new devices are being developed such as the verticalbasket centrifuge. Vertical basket centrifuges have been usedin the mining industries for years to dry water-wet coal andother processed minerals. These centrifuges have provensuccessful in the reduction of synthetic- based drilling fluid oncuttings (SOC) for drilling operations worldwide (Fig. 1).This paper will describe the typical cuttings dryingequipment suite, layout, and performance of the verticalbasket centrifuge. The SBM recovery package involves a twopart process: a vertical basket centrifuge for drying of theSBM drill cuttings and the use of a high speed decantingcentrifuge for reconditioning and re-use of the recovered SBMdrilling fluid.In most instances the rig’s shale shakers are unable toconsistently produce dry drill cuttings in relation to theamount of synthetic on cuttings (SOC). Field data has shownas much as 50 to 70 percent reductions in the percent byweight SOC between shale shakers and vertical basketcentrifuges samples, thereby effectively reducing the amountof synthetic-based drilling fluid that would have otherwisebeen discharged overboard.