A HP micro DSC-VII from SETARAM was used to study the efficiency and mechanism of
action of commercial kinetic inhibitors for gas-hydrate formation in drilling fluids (OBM). The
main objective was to find a suitable and reliable method of screening for these chemicals. The
DSC technique consists in monitoring the heat exchanges, due to phase changes (here hydrate
formation or dissociation), either versus time at constant temperature or versus temperature
during a heating or cooling program. All products showed a gas hydrate dissociation temperature
(at a given pressure) that matched with theoretical and previously published data. Nevertheless,
for some additives two thermal signals were observed on the thermograms, one that corresponds
to the theoretical value and another at a higher temperature (about +4°C). This second peak is
insensitive to the heating rate applied for the dissociation, but the areas ratio (1stpeak/2nd peak)
changes with the additive concentration and with the driving force applied during the hydrate
formation. Additionally, additive/water and additive/water/THF systems were tested. In each
case, two dissociation peaks were also measured. The results allow us to disregard any kinetic
effects bonded to this thermal phenomenon, and lead us to infer that some additives may induce
non-classical crystalline structures of gas hydrates. To verify these results, crystallographic and
spectroscopic experiments must be performed. The stabilities of these new compounds are under
study.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1163 |
| Date | 07 1900 |
| Creators | Malaret, Francisco, Dalmazzone, Christine, Sinquin, Anne |
| 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 | Malaret, Francisco; Dalmazzone, Christine; Sinquin, Anne. |
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