DEVELOPMENT OF FLUIDIC FLOWMETERS FOR MONITORING CRUDE-OIL PRODUCTION

Details are given of the development of no-moving-part fluidic devices for the measurement of oil flow deep in the production string where t he flow is single-phase. Two devices have been investigated which gene rate pressure pulses at a frequency proportional to the flowrate. The pulses are transmitted via the flowing two-phase mixture for detection downstream. A balance has been struck between pulse amplitude and pre ssure loss in the device so as to minimise any reduction of flow. One of the devices, the Blown Venturi flowmeter, is constructed from an os cillating Coanda Switch attached to a Variable Recovery Venturi. The o ther one is a Coanda Switched Vortex flowmeter, which is a hybrid devi ce consisting of a Vortex Amplifier and an oscillating Coanda Switch. Optimisation of both flowmetering devices has been conducted and they show good performance over a wide operating range in the laboratory. ( C) 1997 Elsevier Science Ltd.