| 摘要 |
Method for determining pressure profiles in wellbores, flowlines and pipelines flowing singlephase and multiphase fluids and use of such a method. The flow is temporarily stopped or restricted with a quick acting valve and the pressure is continuously recorded at a point a short distance upstream, using the Joukowsky equation: DELTA p_a= rho u a, where rho (kg/m3) represents the fluid density, u(m/s) the fluid flowing velocity and a (m/s) the speed of sound in the fluid, to estimate the magnitude of the water hammer and using the Darcy-Weisbach equation: DELTA _f=(f/2)( DELTA L/d)) rho u &cir& 2, where f (dimensionless) is the friction factor, L (m) the pipe length, d (m) pipe diameter, (kg/m3), rho (kg/m3) fluid density and u (m/s) fluid velocity, to determine the frictional pressure drop, thereby obtaining a time-log of the pressure change in the wellbore, flowline or pipeline measured. A distance-log of pressure change may be obtained from the time-log and an estimate of the speed of sound in the actual multiphase flow media, using the formula: DELTA L = 0.5 a DELTA t, to obtain the relation between time ( DELTA t) and distance ( DELTA L). The method is useful for detecting and locating leakages, inflow, deposits, collapses etc.
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