Custom flowmeter manufacturer Litre Meter has supplied over 100 VFF positive displacement flowmeters for integrated flow solutions (IFS) in a deal worth almost US$350,000.

The meters form part of a chemical injection metering skid system to be installed in Chevron’s Tombua Landana drilling and production platform located offshore Angola, Block 14.

In order to fulfil the order for the injection rate control device (IRCD) skid, Litre Meter had to undergo a rigorous accreditation process to attain Underwriters Laboratories (UL) explosion-proof certification for equipment used in hazardous locations.

This means that Litre Meter flowmeters are safety certified for use anywhere that UL safety standards must be adhered to. IFS specified Litre Meter because it required UL certified equipment and had used similar VFF flow meters on another large project. The meters supplied are low-flow meters designed to measure a range of chemicals, including demulsifier, defoamer, scale inhibitor, water clarifier, corrosion inhibitors and methanol.

Accurately controlling the amounts of chemicals such as corrosion inhibitors that are added to crude oil is essential to minimising production costs. If too much is used they need to be removed when the oil is refined, and this can cost nearly 10% of the price of a barrel of oil.

These chemicals are also expensive. Typically 30% of the running costs of an oil rig are associated with the chemicals used to pre-treat crude oil before it is pumped shore side. The VFF flowmeters measure the flow of the inhibitor chemical to an accuracy of 0.5%, making it possible to control its use to a very high tolerance.

Litre Meter’s VFF flowmeter is ideally suited for use in the petrochemical industry and in particular for low-flow / high-pressure applications. The instrument has been tested and proved capable of operating reliably at 60 times NAS1638, class NAS12. This confirms the instrument’s capability of reliably measuring fluids with very high particle contamination – such as some chemicals that are added to crude oil.

The VFF flowmeter is suitable for measuring liquids at pressure ratings up to 4,000bar (60,000psi) and flow rates from 0.0004l/m (0.5l per day) to over 270l/min. It is of an intrinsically safe design and manufactured to operate reliably at temperatures ranging from -40°C to 150°C.

Flow meters on the Tombua Landana metering skid operate at pressures up to 3,675psig and have been calibrated to monitor a variety of flow rates from 0.0l/hr up to 295l/hr.