Water wash/oil wash cyclonic column tank separation system

A system for removing oil or oil base drilling mud from drill cuttings using a continuous phase liquid, either aqueous or non-aqueous, and for separating for recirculation and reuse the removed drilling mud and the continuous phase liquid, said system comprising:

• platform shakers for receiving cuttings contaminated with oil or oil base drilling mud and for flushing the cuttings with the continuous phase liquid in a manner delivering the cuttings an continuous phase liquid to a wash drum;
• the wash drum agitating the cuttings and continuous phase liquid together so that the oil or oil base mud is removed from the cuttings and is dispersed in the continuous phase liquid;
• a vibrating, drying screen for receiving the cuttings, continuous phase liquid and dispersed oil or oil mud from the wash drum, for separating the larger cuttings from the continuous phase liquid an dispersed oil or oil mud, for drying the separated out larger cuttings, and for feeding the separated and dried larger cuttings to an inspection and discharge location;
• a catch pan and pump arrangement for collecting and delivering the continuous phase liquid, dispersed oil or oil mud, and small sized cuttings which pass through the drying screen to a first column tank;
• the first column tank facilitating the settling of a dense suspension including oil, oil mud, emulsifiers and fine solids to the bottom of the tank;
• a first column tank pump feeds the dense suspension from the bottom of the first column tank to at least one high "G" centrifuge;
• the at least one centrifuge removing substantially all of the remaining cuttings from the liquid portion of the suspension, the separated out cuttings being transferred to a sampling an discharge location, the centrifugally separated out liquid portion containing continuous phase liquid, oil emulsifiers and very fine solid particles being delivered to a small catch tank and then transferred by a catch tank pump to a second column tank;
• the second column tank allowing for further separation of a high density suspension to the bottom of the second column tank;
• a third column tank receiving continuous phase liquid having fine solids, oil and oil mud suspended therein from the second column tank and allowing for the separation of higher density continuous phase liquid, tied up oil, emulsifiers, mud additives and fine solids to the bottom of the third column tank;
• a continuous phase liquid line provides fluid communication between each of the first, second, and third column tanks at a high level on tank below the upper surface of the liquid in each tank;
• a second column pump and a third column pump periodically draining the high density mixture from the bottom of each of the second and third column tanks into a recovered oil and emulsifier holding tank;
• the liquid level in each of the first, second, and third column tanks being equalized by a high level equalizer line located at the liquid surface of each of the first, second, and third column tanks;
• a holding tank pump feeding the recovered oil and emulsifiers from the recovered oil and emulsifier holding tank to an active system premix tank for reuse in an active mud system;
• and,
• a high level suction pump recycling the continuous phase liquid from the third column tank to the platform shakers, the continuous phase liquid being used to flush the contaminated cuttings from the platform shakers.