Apparatus for separation of water from oil-based drilling fluid and advanced water treatment

An apparatus for separating and treating water from an oil-based drilling mud comprising:

• a separation tank receiving slop, wherein the separation tank comprises:
• a surfactant inlet through which a surfactant is selectively introduced into the separation tank to separate oily water from the oil-based drilling mud;
• a distribution apparatus for distributing the surfactant in the slop mud;
• a rake apparatus to facilitate and maintain separation of oily water and the oil-based drilling mud;
• a water outlet arrangement for selectively removing separated oily water from the separation tank, wherein the water outlet arrangement includes a plurality of valves;
• a sensor apparatus for detecting a location of separation between the oily water and drilling mud and transmitting a signal indicative of the location of separation;
• a control apparatus for receiving the signal from the sensor apparatus and selectively opening at least one water outlet to remove water from the separation tank;
• a water treatment line in fluid communication with the water outlet apparatus;
• a chemical treatment apparatus in fluid communication with the water treatment line for providing de-oiling polymers to the oily water in the water treatment line, wherein the de-oiling polymers adhere to oil in the water to form solid particulates;
• an aging tank receiving the chemically treated water and preventing damage to flocs formed in the treated water;
• a dissolved air flotation unit in fluid communication with the water treatment line for receiving chemically treated water and for removing the solid particulates from the water, wherein the dissolved air flotation unit comprises:
• a separator unit receiving the flocs and water from the aging tank;
• a solids discharge for removing settled solids from the separator unit;
• a dissolved air introduction apparatus for introducing dissolved air to the water and flocs in the separator unit;
• a skimmer for removing flocs from a top surface of the chemically treated water;
• a froth tank receiving and collecting skimmed flocs from the skimmer;
• a treated water outlet for selectively removing treated water from the separator unit.

An method for separating and treating water in an oil-based drilling mud comprising:

• directing slop to a separation tank;
• adding surfactant to the separation tank;
• distributing the surfactant through the slop mud to separate oily water and drilling mud by selectively rotating a set of distributing blades located within the separation tank;
• maintaining the separation of oily water and drilling mud by selectively rotating a rake apparatus within the separation tank;
• sensing a separation layer between the oily water and the drilling mud with a sensor apparatus;
• removing the oily water from the separation tank through a water outlet arrangement on the separation tank;
• adding de-oiling polymers to the oily water in a water treatment line;
• mixing the de-oiling polymers with the oily water so that the de-oiling polymers react with oil in the oily water to form solids particulates;
• releasing dissolved air into the water and solid particulate mixture to cause the solid particulates to form a froth on a top surface of the water;
• skimming the froth from the top surface of the water;
• discharging the water.