Experimental and numerical study of single-phase pressure drop in downhole shut-in valve

In this work an experimental and numerical analysis of single-phase pressure drop in a downhole shut-in valve is performed. The main goal was to develop a 1D numerical model suitable for both compressible and incompressible flow. For the experimental study a mock-up of the shut-in valve was built and instrumented with pressure sensors and flowmeters. The pressure drop along the different sections of the valve were recorded for various flow rates using water, oil and air as working fluids. For the numerical analysis a two-step approach was used. First a commercial CFD package was used for 3D simulations of the flow, and different turbulence models were compared. Then a 1D model was developed based on a spectral element method, with minor loss factors derived from the CFD simulations. Both the 3D CFD simulations and the 1D model simulations provided a good comparison with the experimental data. The small difference in the simulation results can be attributed to the difference in the frictional coefficient which showed a discrepancy of about 20% compared with the measurements. Minor loss factors derived from CFD simulations of incompressible flow are found to be valid also for 1D simulation of compressible flow of air. The 1D model is developed for future simulation of compressible multiphase flow.