Patent ID: 6993963

Claim:
Method for determining pressure profiles in wellbores, flowlines and pipelines flowing singlephase or multiphase fluids, wherein the flow is temporarily closed or partly closed with a quick acting valve and the pressure is continuously recorded at a point a short distance upstream, using the Darcy-Weisbach equation: Δ ⁢ ⁢ p f = ( f 2 ) ⁢ ( Δ ⁢ ⁢ L d ) ⁢ ρ ⁢ ⁢ u 2 ⁢ where f (dimensionless) is the friction factor, L (m) is the pipe length, d (m) is the pipe diameter, ρ (kg/m3) is the fluid density and u (m/s) is the fluid velocity, to determine the frictional pressure drop, while a distance-log of pressure change is obtained from a time-log and an estimate of the speed of sound in the actual fluid, while using the formula: ΔL=0.5 a Δt where a is the speed of sound in the fluid, to obtain the relation between time (Δt) and distance (ΔL) and thereby obtaining the pressure profiles.