An understanding of the mechanism for hydrate formation from water-in-oil emulsions is integral
for progressing from preventing hydrate formation through expensive thermodynamic means to
hydrate blockage prevention. This work presents hydrate formation and agglomeration in a
stirred system studied using two complementary particle size analysis techniques, a Particle Video
Microscope (PVM) and a Focused Beam Reflectance Measurement (FBRM).
The PVM provides qualitative visual information through digital images in the black oil
illuminated by a series of lasers. The FBRM provides a quantitative chord length distribution of
the particles/droplets in the system. Three sets of experiments were performed using two different
Crude oils, Conroe with a very small asphaltene content and poor emulsion stability, and
Caratinga with a much higher asphaltene content and emulsion stability. The first experiments
looked at ice as an analogy to hydrates, studying the morphology with both the PVM and FBRM.
The second experiments looked at the effect of droplet size on hydrate formation and
agglomeration, and the third set of experiments studied the dissociation process using a
combination of the PVM and in situ conductivity measurements to determine the continuous
phase.
For hydrate formation, droplet size was found to have a major effect on whether or not
agglomeration will occur. During dissociation agglomeration is extremely dramatic due to the
creation of surface water on the particles. The dissociation of these agglomerates results in a
significant destabilization of the suspension into a water/hydrate phase at the bottom of the cell
until dissociation is complete. The dissociation conceptual picture presented illustrates an
important implication when operating a flow line with hydrates present; dissociation within the
pipeline should be prevented until the hydrates are out of the flow line.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1131 |
| Date | 07 1900 |
| Creators | Boxall, John A., Greaves, David P., Mulligan, James, Koh, Carolyn A., Sloan, E. Dendy |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Rights | Sloan, E. Dendy; Koh, Carolyn A.;, Sum, Amadeu |
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