Study on Reverse Demulsifier GBED-08 for Deoiling of SAGD Produced Water of High Extra-Heavy Oil Content

A quarternary ammonium salt of polyether,containing about 60% active substances,was prepared as an inverse demulsifier GBED-08 by reacting a polyhydric alcohol with epichlorohydrin to form a chlorinated polyether and by ammonization of the later by dimethylamine;the synthesis was depicted concisely.The deoiling capability of GBED-08 was investigated for a high oil content produced water from Liaohe's utra-heavy oil reservoirs exploitated by SAGD.The produced water sample(PWS) was characterized by oil content 55163 mg/L,which was lowered down to 44903 mg/L after 90 minute sedimentation at 90℃.The oil content of GBED-08 treated PWS after 90 minutes sedimentation at 90℃ dropped to 1005 mg/L at GBED-08 dosage 200 mg/L and to a minimum of 110 mg/L at GBED-08 dosage 350 mg/L and slowly rose at further increased dosages,which was explained in physicochemical terms.At GBED-08 dosage of 300 mg/L the oil content kept unchanged after sedimentation at 70℃ in 60 minutes and longer and rose with decreasing temperature of 90 minutes sedimentation,being of 276 mg/L at 90℃ and about 700 mg/L at 50℃.The oil content was higher than 25000 mg/L for all PWSs treated by one of commercial chemicals presented below and sedimentated at 90℃ in 90 minutes:5 water soluble and 3 oil soluble crude oil demulsifiers and coagulant PAC.