Abstract : Over the last years, Differential Scanning Calorimetry has proven to be a powerful and versatile tool for the study of hydrates, particularly in complex media such as slurries, water-in-oil emulsions and drilling fluids. The paper presents various uses of this technique in the fields of thermodynamics, kinetics, and hydrate formation characterization in water-in-oil emulsions. Results of ambient pressure DSC, performed on model hydrates, and high pressure DSC, performed on gas hydrates in the range 4 to 12 MPa, are completed by results of coupled X-Ray diffraction-DSC.