A sonar-based flow measurement technology, capable of clamp-on flow measurement of single and multiphase flow applications within the chemical and petrochemical industries, is described. Developed and field proven in oil and gas production industry over the last five years, sonar- based flow measurement technology provides robust accurate volumetric flow rate measurement for a broad range of process fluids, slurries, pipes sizes and flow conditions.

The sonar-based flow metering technology utilizes an array of sensors to listen to, and interpret, unsteady pressure fields within standard process flow lines. The methodology is implemented using strain-based sensors which clamp-on to existing process piping. This paper presents data for sonar-based flow meters utilizing two independent, yet complimentary, techniques to determine volumetric flow rate. The first technique measures the speed at which turbulent eddies, inherent to turbulent pipe flow, convect past the sensor array and is well-suited for liquid- continuous single and multiphase flows. The second technique, well-suited for gas-continuous single and multiphase applications, measures the flow rate by comparing the speed at which ambient acoustic waves propagate with the flow to that speed which acoustic waves propagate against the flow. Both the convective and acoustic techniques are based on listening to, and interpreting, naturally occurring pressure fields within process flows lines using sonar-based algorithms and each can be implemented with common sensor arrays.