Homogenising and metering the flow of a multiphase mixture of fluids.

摘要

It is often desirable to meter multiphase fluid flow in pipes (e.g. bore holes). In order to obtain reliable/accurate flow rate measurements it is known to incorporate obstructions in the flow path to cause homogenisation. A non-obstructive method of homogenising the flow of a multi- phase mixture of fluids in a bore hole comprises providing in the bore hole a pipe section which has an internal surface with a step discontinuity (3), whereby when fluid flows through the pipe section, turbulent stresses are caused by the discontinuity, leading to homogenisation by turbulent mixing. There is disclosed a flow meter which comprises a pipe length with a first section having a step change in cross-section (3) for homogenising fluid flow therethrough, in series with a venturi flow meter (4) in which a differential pressure can be measured in a second pipe section having a smooth change in cross-section. Non-obstructive homogenisers and flow meters do not block the passage of objects such as tools, logging devices, etc along a pipe.