KYYC Series Demulsifiers for Very High Water Cut Produced Fluids from Polymer Flooded Reservoirs

In polymer flooded areas of Dagang oil field the produced liquid mixture contains 90% of water, the oil content of freely separated water is of 10 g/L, and the dehydration of the watery crude oil is difficult. By treating such produced water/oil mixture, for example, from Yangsanmu region with standard crude oil demulsifiers purified crude oil of water content 0.8-1.2% can be obtained but the oil content in the separated water is as high as 10 g/L. By modifying triblock polyether of AE type through introducing hydroxyl group into EO end segment and lengthening EO segements to increase the molar weight of the polyether, a water soluble demulsifier, KYYC 4, for the produced liquid mixture from Yangsanmu is prepared and capable of to deoiling of the separated water as well as dehydration of the crude oil. And in a similar way KYYC 2 for the produced liquid mixture in the 2nd western oil gathering/treating plant is developed. At Yangsanmu central plant KYYC 4 is used to replace demulsifier JN 01H, the chemical of dosage 25 mg/L is introduced into the produced liquid mixture and leads to significant decrease in oil content of the separated water along the treating line and from 400 to 50 mg/L, to 20-35 mg/L in general, for filtrated and sedimentated wastewater; and the crude oil purified by thermochemical dehydration and two stage sedimentation contains 2.0% water. At the 2nd western plant the gathered liguid mixture is degased and sedimentated and the separated water is purified through a cyclone and a filter to give wastewater of high oil content of 200 mg/L; introducing KYYC 2 of dosage 50 mg/L leads to notable decrease in oil content of water along the treating line: slightly higher than 200 mg/L after sidimentation, 20-30 mg/L after cycloning and filtration.