Success stories

Flow Measurement on Test Separator Gas Leg

1 min read

Z1G Flow Meter

The test separator is used to separate gas, oil and water to a level that permits accurate measurement of each produced phase. Gas is typically measured using a differential pressure device (orifice), where accuracy and reliability of the measurement can be affected by changes in pressure and flow ranges.


An international oil and gas company operating in South East Asia has three to four production wells connecting to a test separator, and traditionally used an orifice flow meter. Due to changes in process conditions from swapping wells, the customer identified a need to replace the orifice plate for one with a different beta ratio in order to measure the flow. Since a single orifice meter cannot handle the flow conditions from the various wells, the customer wanted a flow meter technology capable of measuring under all its process variations.



  • No need to change the orifice plate to measure the flow rate
  • Minimizes any potential safety hazard during a plate change out
  • Reliable and robust signal
Typical Test Separator

Panametrics PanaFlow Z1G ultrasonic gas flow meter was selected and installed based on its ability to measure relatively wet gas at low pressure. The PanaFlow Z1G does not create any pressure drop since the ultrasonic transducers do not restrict the fluid flow. Additionally, the meter offers a wide turndown ratio which can measure the required flow range regardless of which well is connected to the system.


After eight months using the PanaFlow Z1G, the customer realized lower maintenance costs while maintaining an accurate and reliable flow measurement. The savings experienced using the Panametrics flow meter included:

  • Four man-hours per operation
  • Production down-time reduced by four hours
  • Energy efficiency with no pressure drop

Learn more about Panametrics' Ultrasonic Flow Meters

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