Measurement of Two-Phase (Steam Water) Flows in Geothermal Pipelines Using Load-Cells: Field Trial Results

Abstract

A method with the ability to provide continual monitoring of two-phase flow in geothermal or other pipelines has been tested. The sensor uses strain gage measurement on pipe supports to measure flow characteristics in a large volume of piping from one pipe support to another. Horizontal discharge well output tests were performed on wells at Wairakei geothermal field, New Zealand, with the sensor included during the tests for performance comparison and calibration to the standard output test. Early results show the sensor successfully measures changes in the flow; with the advantage of simple construction, no direct contact required with internal pipe content, no restriction to the flow, and easy setup. The sensor is able to determine changes in dryness fraction for the calculation of enthalpy in the pipes and wells in real time. The method has the potential to complement (improve) the accuracy of existing two-phase orifice plates, or with the application of two sensors could be used to measure total mass flow rate along with dryness fraction. Accurate tracking of changes to dryness fraction were observed, as well as detection of other phenomenon. Results of field trials and calibration methods are presented.