By Carl Wordsworth, Head of Water Sector at TÜV SÜD National Engineering Laboratory

TÜV SÜD National Engineering Laboratory (NEL) has recently completed a £650,000 upgrade of its Elevated Pressure and Temperature (EPAT) test facility, funded by the UK Government’s Department for Business, Energy and Industrial Strategy (BEIS) as part of the UK’s National Flow Programme.

NEL originally invested £1 million to create the EPAT test facility, which allows customers to test equipment at close to field conditions and replicate the effect of high pressure and temperature on instrument performance. In 2016 it was awarded ISO/IEC 17025 accreditation, making it the first and only high-pressure, high-temperature facility in the UK to hold this internationally recognised certification.

Previously, the standard practice for calibrating flow meters for the oil and gas industry was to match the fluid viscosity and, if possible, the fluid temperature and pressure. However, matching all parameters was seldom possible due to the limitations set by a calibration facility’s operating range and available test fluids. Industry, therefore, had to rely on testing flow meters at ambient conditions in a laboratory, even though they would be deployed at elevated conditions in the field.

To ensure optimum performance, end users now demand a meter calibration that is closer to service conditions, delivering high accuracy and low uncertainty flow measurements. Furthermore, in Issue 9 of its Guidance Notes for Petroleum Measurement under the Petroleum (Production) Regulations 2014, the Oil and Gas Authority (OGA) stipulated that temperature and pressure compensation applied to any meter between its calibration conditions and its operating conditions must be “agreed in advance with OGA” and must be “traceable and auditable”.

Recreating in-field service conditions

NEL’s EPAT test facility is a traceable flow laboratory that enables operators, meter manufacturers and end users to recreate conditions that are more closely matched to those experienced in the field. By operating across a range of temperature, pressure, flow rate and viscosity conditions, the effects of these factors can be determined more effectively to ensure that flow meters are more closely matched to process conditions and measuring accurately in the field. These more realistic measurements reduce oil and gas operators’ financial exposure as the uncertainty of meters deployed in the field is minimised significantly.

This latest upgrade to the EPAT test facility greatly improves operability and incorporates NEL’s FlowStudio, an interface and calculation engine for effective data capture and live uncertainty determination. A new in-line heater will also enable the automation of process control.

Optimising data

FlowStudio is NEL’s in-house data acquisition and traceability management software, which offers advanced configuration and collection of data for engineers conducting tests on the UK’s national flow facilities. Furthermore, FlowStudio performs real-time engineering and uncertainty calculations, and assists with the management of quality critical instrumentation with associated traceability data, thereby serving to minimise the cost of providing traceability to the UK’s national flow facilities.

FlowStudio can be pre-configured with a matrix of testing conditions that allows the software to automate the execution of tests. The test matrix includes acceptance criteria to allow for automated validation of the data. The outputs and calculations can also be pre-configured allowing the software to produce a full draft certificate of calibration automatically.

Giving industry confidence

The EPAT test facility’s loop is a unique, purpose-built flow meter calibration and evaluation facility, having two separate flow lines that cover a wide range of flow rates in different line sizes. Offering great flexibility, the facility can allow a large selection of flow meter sizes to be calibrated at service conditions. The test sections can be constructed to offer long, straight lengths upstream or specific configurations designed to replicate actual installations. The loop can operate at pressures up to 100 bar(g), flow rates up to 100 l/s, and temperatures up to 80°C. The facility can calibrate flow meters at temperatures between 20°C and 80°C, at flow rates between 0.5 – 100 l/s, and at fluid pressures between 4 - 93 bar(g).

Muir Porter, Head of Facility Operations at TÜV SÜD National Engineering Laboratory, said: “This additional investment in our EPAT test facility is an important step, as it will give both our UK and international customers confidence that their meters have been independently assessed and that all of the measurements it makes are traceable and auditable. Oil and gas production is increasingly taking place in fields where high temperatures and pressures are the norm. The EPAT facility more effectively fills the gap between calibration and real field conditions, allowing manufacturers to prove the performance of their meters, while operators and taxation authorities can be assured of more accurate fiscal reporting.”

NEL is the Designated Institute for Flow and Fluid Density Measurement, under contract from BEIS, and part of the UK’s National Measurement System. The EPAT upgrade is part of a wider programme to refurbish existing flow measurement standards at NEL’s laboratory to address the future needs of flow measurement in the UK.

About TÜV SÜD National Engineering Laboratory www.tuvsud.com/en-gb/nel

The company is a global centre of excellence for flow measurement and fluid flow systems and is the UK’s Designated Institute for Flow and Density Measurement, with responsibility for providing the UK’s physical flow and density measurement standards.

TÜV SÜD National Engineering Laboratory is a trading name of TUV SUD Ltd, a company of the TÜV SÜD Group, an international service organisation. More than 24,000 employees work at over 1,000 locations in about 50 countries to continually improve technology, systems and expertise. They contribute significantly to making technical innovations such as Industry 4.0, autonomous driving and renewable energy safe and reliable.TÜV SÜD National Engineering Laboratory (NEL) has recently completed a £650,000 upgrade of its Elevated Pressure and Temperature (EPAT) test facility.

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