The invention includes a method for dewatering and/or desalting a water-in-oil emulsion comprising introducing a plurality of streams of the emulsion into the electrostatic field under opposed flow whereby the water coalescence is enhanced. The invention also includes an improved electrostatic apparatus for dewatering and/or desalting a water-in-oil emulsion comprising a plurality of horizontally directed nozzles positioned to introduce a plurality of streams of the emulsion into the electrostatic field under opposed flow conditions.
A method for determination for a given oil the relative stability of a water-in-oil emulsion that will be formed by that oil with water comprises measuring for the given oil the weight fraction of the oil that is most strongly adsorbed on a silica gel column successively eluted with n-hexane, toluene and methylene chloride-methanol mixture solvents and determining whether said weight fraction is greater than about 0.05; with a value above 0.05 being determinative of an emulsion more stable than one with a value less than 0.05.
