Agglomeration of gas hydrate in a water-in-oil emulsion: Experimental and modeling studies

International audienceThe formation of gas hydrates in water-in-oil emulsion is investigated at the laboratory pilot scale on a flow loop. The Archimede flow loop (30 m long, and 1 cm diameter) has been built to reproduce the thermodynamic conditions encountered in deep-sea pipelines with a maximum flow rate equal to 3x10-5 m3.s-1. Recently, a Moineau pump has been added in order to maintain the flow at a constant rate, especially after the beginning of crystallization and independently of the rheological characteristics (the flow rate can be varied in the range 2x10-5 m3.s-1 to 14x10-5 m3.s-1). This work presents some preliminary experiments to characterize the flow properties. Also some crystallization experiments were realized in order to understand the coupling between crystallization and rheology by following the size of the agglomerates and the water conversion. When water droplets crystallize to form hydrate particles, an agglomeration phenomenon is evidenced by pressure drop measurements. The agglomeration phenomenon is also detected by a Focused Beam Reflectance Measurements (FBRM) probe and is highlighted by a sharp change in the mean chord length and a spread of the Chord Length Distribution (CLD) to larger chord length