Hamed, Néjib (2006) Study of the kinetics of methane hydrate formation in drilling fluids using high pressure differential scanning calorimetry. PhD thesis Génie des Procédés, ENSTA / UCP - Laboratoire des Procédés, ENSMP.

Full text available as: - these_NHamed.pdf ( 2404 Kb )

Licence: Copyright

Abstract

Oil based drilling fluids are used in offshore drilling operations to cool and lubricate the drilling bit, to transport the cuttings to the surface and to maintain the hydrostatic pressure in the well. With the increasing depth of offshore drilling, the thermodynamic conditions (high pressure and low temperature) are favourable to the formation of gas hydrates in the water-in-oil emulsions contained in the fluids.
High pressure Differential Scanning Calorimetry (DSC) is a proven technique for the study of thermodynamic equilibrium of the system gas - water - hydrate. DSC was chosen to study the kinetics of hydrate formation because it is particularly well adapted to complex dispersed media. A study was curried out at variable pressure from 11 to 40 MPa and at variable sub-cooling degree from 14 to 30 K. Hydrate formation kinetics was studied in four fluids of different compositions. Performed experiences highlight the effect of different kinetic parameters.
The use of classic models allowed representing the experimental results for low and high driving forces. Furthermore, we developed a kinetic model which combines the theory of the crystallization, the statistical aspect of nucleation and the mass balance on different components of the drilling fluid.

Statistiques de consultation

Repository Staff Only: edit this item