The most recent Statements of the Month have covered turbine and positive displacement (PD) meters, and in this issue we’ll wrap up our mini-series on meter types with an introduction to Coriolis meters. These devices are based on technology that’s often considered new to the energy industry, but, in fact, Coriolis meters have been part of the API measurement standards since 2002. Chapter 5.6 of the API Manual of Petroleum Measurement Standards (MPMS) specifically addresses the use of Coriolis meters, while other chapters also reference their use in custody transfer applications.
Unlike turbine and PD meters, the operation of Coriolis meters is not dependent upon rotating mechanical parts to indicate flow. By measuring the Coriolis effect on the internal vibrating flow tube(s), they directly determine mass flow. This ability to directly measure mass flow is perhaps the most unique feature of Coriolis meters versus other metering technologies. In addition, they can simultaneously measure the density of fluid flowing through the vibrating tubes which allows them to determine (or infer) volumetric flow.
As with any metering technology, there are both advantages and disadvantages to the use of Coriolis meters. Among the benefits are:
- Measurement of mass flow and fluid density at flowing conditions;
- Infers a volumetric flow;
- No rotating mechanical parts to wear out;
- Broad range of fluid compatibility;
- Wide flow range; and
- Seamless integration with SCADA and other CPU-based measurement systems.
Some qualifying considerations for Coriolis meters are:
- Higher initial costs;
- Greater power requirements;
- More complex operation and support; and
- Pulse delays from flow computations can make meter proving difficult.
Coriolis meters are deployed in applications throughout the oil & gas industry, having initially gained widespread adoption in processing plants with their ability to accurately handle even the most challenging product streams. Today they’re often used in NGL mass measurement and many other custody transfer applications because they are capable of measuring mass and determining volumetric flow in addition to flowing density indications. Overall, the accuracy of Coriolis meters for both mass and density measurements make these a good choice for many applications. If Coriolis meters seem to fit your operational requirements, be sure to consult with your measurement experts for a thorough assessment.
"The heart of science is measurement."
~ Erik Brynjolfsson, American academic