A Case Study in Processing Drill Cuttings

摘要

Friction-based thermal desorption is used to separate liquids from oil-based drilling fluid cuttings prior to disposal, thereby recovering valuable base fluid while protecting the environment. Using temperatures between 500 and 572°F(260 to 300°C), the oil and water phase is evaporated and subsequently condensed and recovered, thus leaving the solids behind for safe disposal. This paper discusses a novel friction-based thermal desorption system currently deployed in the Koshken sector of the Caspian Sea in Kazakhstan. It is estimated that 50,000 tonnes of oil-based mud (OBM) cuttings will be produced every year, which must be treated to below 1% Total Petroleum Hydrocarbon (TPH) before disposal. Any treatment technology utilized in this remote and hostile environment faces a number of operational and logistical challenges, including the severe climate and the need to transport the drill cuttings to an onshore centralized location. Improvements in friction-based thermal desorption technology were developed specifically for the Kashagan Development Project to ensure health, safety and environmental (HSE) compliance and allow a best-in-class system to operate in this harsh environment. The authors describe the friction-based thermal desorption process equipment, including details on the overall mass and energy balance involved. Analytical data collected over a two-year period is analyzed in terms of the discharged treated solids material, recovered base-oil, recovered water, and air emissions. Further, the analysis includes ambient air monitoring conducted during the project.