Experimental Study on Methane Hydrate Formation from Water-based Drilling Fluid

The three phase equilibrium conditions of methane hydrate from water-based drilling fluid were measured ranging from 3oC to 13 oC by isochoric pressure-search method. The methane hydrate formation from water-based drilling fluid was carried out under isochoric conditions with an initial pressure of 8 MPa, 10 MPa and 12 MPa respectively. Results showed that the inhibition effect of water-based drilling fluid on methane hydrate was not obvious thermodynamically. Meanwhile, increasing the initial pressure could greatly reduce the hydrate formation time, increase the production and initial hydrate growth rate and spoil the homogenous hydrate growth in liquid bulk. Strengthening the heat and mass transfer in water-based drilling fluid and lowering the pressure in drilling site would be useful to inhibit the hydrate growth.