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fax 01-972-952-9435. AbstractHeavy oil always poses a great challenge to production and transportation systems due to its high viscosity. This paper evaluates fourteen dead, eight saturated and nine under saturated live oil viscosity correlations against a databank consisting of heavy oil data from various parts of the world with wide ranges of temperature, pressure and fluid compositions. The existing empirical viscosity correlations were mostly developed for significantly lighter oils. Most of them cannot reasonably predict the heavy oil viscosity at low temperatures. Three new empirical correlations for dead, saturated and under saturated oils are developed that are applicable for the heavy oils with API gravity ranging from 10 to 22.3. When compared with the databanks, the new dead oil, saturated and under saturated oil viscosity correlations showed 3 to 50%, 3 to 13% and 22 to 27% improvement over the existing best correlations, respectively. Saturated, Aromatics, Resin and Asphaltenes (SARA) data of some heavy oils were also analyzed to understand the role of the asphaltene and resins in heavy oil viscosity.

Water-in-oil emulsions are of particular interest concerning methane hydrate formation during crude oil production. The objective of this work is to understand the morphology of the hydrate/water drops in waterin-oil emulsions. Hydrogen nuclear magnetic resonance (NMR) is used to directly measure the formation of methane hydrates in water-in-oil emulsions. A 2 MHz NMR spectrometer is used to investigate the relationship between the drop size distributions of water-in-oil emulsions and methane hydrate formation. The drop size distributions of two crude oil and two model oil emulsions are measured by the pulsed-field gradient with diffusion editing technique. This technique is particularly useful because it does not assume a priori the functional form of the drop size distribution. The amount of liquid water converted to hydrate is directly measured by transverse relaxation measurements. These NMR techniques investigate the entire emulsion sample, and they provide useful information regarding the relationship between drop size distributions and methane hydrate formation in emulsified systems.