US Patent 7934433 Inverse venturi meter with insert capability

An insert meter can be run into an inverse venturi on wireline and make use of the existing pressure taps to allow accurate measurement of reduced flow rates that could not be accurately measured with the inverse venturi meter. The insert meter has seals and can lock into position with peripheral sealing to direct the new and lower flow rate into the throat of the insert meter that is preferably a standard venturi. The venturi devices can be in meter or eductor service and located downhole, subsea or on the surface.