The turbulence flow typically found in the oil and gas pipelines can often result in the formation of a water-in-oil (W/O) emulsion. Depending on the size of the dispersed water droplets, the formation of this emulsion may or may not be desirable for the operators. For example, the W/O characteristics, including droplet size distribution, can influence the gas hydrate formation/agglomeration processes, which depend on the available surface area for hydrate formation and the extent of hydrate conversion. Determining the DSD of W/O emulsions before and after gas hydrate formation can also provide insight into the extent of hydrate particle agglomeration, since the latter should result in significant coalescence of water droplets in oil after hydrate dissociation. Therefore, there is a need to determine the water droplet size distribution (DSD) in a W/O emulsion. One method for determining the accurate DSD of an emulsion is the use of Low Field (2 MHz) Nuclear Magnetic Resonance (NMR) spectroscopy. An advantage of using this NMR method is that the entire sample is analyzed, while at the same time maintaining the characteristics and properties of the emulsion. In this work, the DSDs of water-in-oil (W/O) emulsions with water volume fractions in oil ranging from 10 – 70 vol. % were measured before and after gas hydrate formation using a low field NMR spectrometer. Different oils that result in different droplet sizes were used in this work. The use of different oils allows the determination of the limit of the DSD that could be measured using the proposed method. In addition, the DSDs of the W/O emulsions obtained from NMR were found to compare well with microscopy analysis.

Droplet size distributions of water-in-oil emulsions using low field NMR before and after gas hydrate formation

249th National Meeting (2015)

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