Method for recycling of oil based drilling fluid contaminated with water and water contaminated with oil based drilling fluid

A method of cleaning slop water, wherein the slop water comprises a water component emulsified with an oleaginous component, the method comprising:

• feeding the slop water and an emulsion breaker into an emulsion breaking tank of an apparatus for recycling drilling fluid, wherein the apparatus for recycling drilling fluid comprises:
• the emulsion breaking tank, which comprises an agitator, a means for the addition of the emulsion breaker, a means for the addition of the drilling fluid, and a means for removing at least a portion of a demulsified water;
• a water treatment tank, which comprises an agitator, a means for adding the at least portion of demulsified water, a means for adding flocculation materials for producing a treatment water and a treatment sludge, a means for removing the treatment water, wherein the emulsion breaking tank is in fluid connection with the water treatment tank;
• and
• hydrocarbon filters for filtering the treatment water, wherein the water treatment tank is in fluid connection with the hydrocarbon filters;
• mixing the slop water with the emulsion breaker in the emulsion breaking tank, wherein the emulsion breaker is selected from the group consisting of a non-ionic surfactant, an anionic surfactant, and an alkyl polyglycoside;
• separating the water component of the slop water from the oleaginous component of the slop water;
• mixing the water component in the water treatment tank with the flocculation materials to produce a treatment sludge and a treatment water;
• skimming the treatment water from the water treatment tank;
• passing the treatment water through the hydrocarbon filters;
• and
• discharging the treatment water.