(1) The evaluation shows that the demulsifier has a good demulsification performance for Daqin g crude, the dehydration efficiency increases above 5%, oil content in waste water decreases 40%.

(2) The properties of this kind of dendrimer as demulsifier for the simulated O/W crude oil emulsion have been investigated emphatically.

(3) For polymer flooding system, Demulsifier selection is dependent on polymer concentrations in produced liquid.

(4) Polyurethane demulsifier for crude oil were prepared from polypropylene glycol, xylene, toluenediiso - cyanate in xylene solvent.

(5) This method uses water containing a demulsifier an extractant , titration is carried out in aqueous solution.

(6) Demulsifier TKQ comprises of phenol - amine resin block polyethers and quaternized polyamidoamine.

(7) Surfactants used in gathering transportation, include demulsifier, defoamer , deoiler inhibitor, corrosion inhibitor, bactericide etc.

(8) The higher resin and asphalt the crude oil contains , the more demulsifier is needed.