Method for on-site treatment of oil and gas well waste fluids

A mobile water treatment process for use in treating waste fluids from oil and gas well drilling operations in a waste collection area at the site of such operations, said processing comprising:

• a. pumping said waste fluids from said collection area, through a mobile treatment apparatus and back into said collection area;
• b. adding an alkaline agent to said waste fluid as said waste fluids are pumped through the mobile treatment apparatus in an amount necessary to bring the pH of said waste fluids to a range of about 10.3 to 10.5 before return to said collection area and also sufficient to cause soluble contaminants in the waste fluid to form a precipitate;
• c. allowing said waste fluids to clarify as the precipitate and soluble contaminants, through flocculation, settle and form a sludge at the bottom of said collection area;
• and
• d. filtering said waste fluids in said mobile water treatment apparatus after said clarification step;
• and
• so that the said waste fluid, after said filtration step, has less than about 30 mg/l of iron, a pH of between about 9 and 12 and suspended solids having diameters no greater than about 5 microns.

A mobile water treatment process for use in treating waste fluids from well drilling operations in a fluid waste collection area at the site of such operations, said processing comprising:

• a. pumping said waste fluids from said collection area, through a mobile treatment apparatus and back into said collection area;
• b. adding an alkaline agent to said waste fluids as said waste fluids are pumped through the mobile treatment apparatus, before return to said collection area, in an amount necessary to bring the pH of said waste fluids to a range sufficient to cause soluble contaminants in the waste fluid to form a precipitate;
• c. allowing said waste fluids to clarify as said precipitate of soluble contaminants, through flocculation, settle and form a sludge at the bottom of said collection area;
• d. filtering said waste fluids in said mobile treatment apparatus after said clarification step;
• and
• e. pumping said waste fluids, after said filtration step, into storage tanks for reuse at future drilling operations.