Deoiling of SAGD produce water

摘要

Methods of deoiling oily water such as SAGD and frac produce water. The oily water is treated with a natural coagulant selected from tannins and chitosan. A cationic and/or anionic flocculant may also be added to the treated oily water. The thus treated oily water may be subjected to conventional mechanical oil separation techniques such as hydrocyclonic separation, dissolved air flotation, entrapped air flotation, induced gas flotation, gravity filters, reverse osmosis filters, API, or Voraxial® bulk separators and the like.

主权项

1. A method for treating produce water from a steam assisted gravity drainage (SAGD) operation, said method comprising the steps of:
a) adjusting said produce water to a pH of about 2 to 8; b) after said step a), adding a tannin coagulant to said produce water; c) after said step b), adjusting pH of said produce water to between about 6.5 to 10; and d) adding to said produce water from step c) a cationic flocculant and an anionic flocculant, said cationic flocculant comprising a member selected from the group consisting of an acrylamide/quaternary ammonium salt copolymer, a copolymer of epichlorohydrin and amine, an acrylamide allyl trialkyl ammonium copolymer, and acrylamide/diallyl dialkyl ammonium copolymer, said anionic flocculant comprising a member selected from the group consisting of acrylamide/acrylic acid copolymers and salts thereof, acrylamide alkylacrylate copolymers, acrylamide/maleic acid copolymers, acrylamide maleic anhydride copolymers, acrylamide/(AMPS) copolymers, acrylic acid homopolymers and salts thereof, and acrylic acid (AMPS) copolymers.