Ongoing research into the performance of Venturi tubes has found that installation effects can cause significant errors and that current standards for the measurement of gas flows using such devices need to be reviewed and updated. Further research is underway to inform this process and to improve the accuracy of this type of technology.
“We have found errors in the region of 10%,” says the leader of the research team, Flow Measurement Engineer, Dr. Emmelyn Graham. “These findings pose challenges to end-users in terms of the management and optimisation of reservoirs and allocation, as the errors we’ve highlighted may be introducing significant discrepancies in flow measurement and financial accounting.”
The project began in March utilising NEL’s wet gas flow facility. The installation effects being investigated include the orientation of meters and up-stream conditions in the flow that is being measured. Although the research has highlighted potential problems for end-users and meter suppliers, it could also bring benefits.
“Venturi meters are a cheaper option than many commercial wet-gas meters,” explains Emmelyn. “If we can produce the data necessary to reduce and correct errors, then we’ll help industry to capitalize on the cost savings that such meters can deliver.”
“Current standards for the measurement of wet-gas flows by Venturi meters cover horizontal installations and two-phase flow,” Emmelyn adds. “However, three-phase conditions exist in the field, as do non-standard installations. Our initial findings indicate that the standards need to be reviewed. The next steps in our research will be instrumental in this process.”
The standards that the NEL team has highlighted for review are ISO/TR 12748:2015 and ISO/TR 11583:2012.
For more details, contact Dr. Emmelyn Graham.
NEL is a world class provider of technical consulting, research, measurement, testing and programme management services to clients across many industries including oil & gas, renewable and sustainable energy, process and government.
NEL also holds the UK National Standards for flow measurement and has an international reputation in key engineering areas such as flow measurement, computational fluid dynamics, environmental and thermal engineering.