Remediation of oil-contaminated drill cuttings using continuous microwave heating

Abstract

This paper outlines a novel, continuous pilot-scale microwave treatment process for the remediation of oil-contaminated drill cuttings from North Sea drilling activities. The underlying scientific methodology is highlighted, and the development of the continuous processing concept is discussed. Continuous tests were carried out at throughputs up to 250 kg/h using microwave hardware capable of delivering up to 15 kW of microwave power at 2.45 GHz. It is shown that the cuttings can be remediated to below the offshore discharge threshold of 1% oil on cuttings, and that clean-up can occur to below 0.1% oil, which is the classification for non-hazardous waste. The trade-off between applied power, throughput and residual oil content is shown for tests carried out continuously over several hours. The energy consumption of the process is also shown in relation to the remediation levels achieved. The results obtained with the continuous pilot-scale system are compared with previous batch laboratory studies.