Multiphase flow in complex valve geometry

摘要

Downhole shut-in valves are used for testing of oil and gas reservoirs. The internal flow geometry is complex, and contains annulus flow, annular contractions, sharp angles, valve ports and sudden expansions. A new procedure for calculating two-phase pressure loss in a downhole shut-in valve is proposed. Flow-pattern independent two-phase flow correlations are here used with a one-dimensional model of the valve in order to simulate two-phase flow. The one-dimensional model is solved using a Least Squares Spectral Element method. Two-phase flow experiments with air/water and air/oil mixtures are performed on a full-scale shut-in valve mock-up. Experimental two-phase flow pressure drop values are then compared to simulations with different correlations. The Muller Steinhagen and Heck correlation is found to be the best choice, giving an average deviation of 12% with the assumption of homogeneous flow.