The objective of this study is to acquire a better understanding of the demulsification of water-in-oil emulsions using electric fields. An experimental study is conducted on the deformation behaviors of single water drops and water drop pairs in hydrocarbon media (model oils as well as diluted bitumen) under applied electric fields. For visualization, sequences of high speed video images which capture the coalescence of water drop pairs under applied fields are also shown.; For a single water drop under an electric field, the deformation in the limit of very low electric field was found to be in accordance with Taylor's leaky dielectric theory. At higher electric fields, however, the deformation of a single drop was found to be larger than that predicted by Taylor. Similar conclusions were drawn for both model oil systems and diluted bitumen systems. For a water drop pair, the drops' deformations are largest when the two drops are in close proximity. The drop deformation behavior will deviate noticeably from the single drop's behavior when the edge-to-edge separation distance is less than one radius of the undeformed drop. Weber number appears to be a reasonable parameter for predicting drop deformations.
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