ROBUST LITRE METER PD FLOWMETERS IDEAL FOR HIGH PRESSURE HIGH VOLUME SUBSEA APPLICATIONS
UK flowmeter specialist Litre Meter (www.litremeter.com) has supplied a bespoke flow meter/totaliser for use in a high pressure/high volume application for monitoring and control of a high pressure/high temperature subsea tree.
Subsea trees are used on offshore oil and gas fields to monitor and control production. Fixed to the wellhead, subsea trees can also manage fluids or gas injected into the well – for example, in ‘bull heading’ procedures where methanol is used to control the build-up of crystals that might otherwise restrict flow.
The Litre Meter HF40 VFF flowmeter is installed on the high pressure system of an intervention workover control system (IWOCS) unit. The high pressure feed goes to a stab plate on the IWOCS, which is connected to the tree workover and landing string reeler umbilical jumpers.
The HF40 VFF is used for monitoring the high pressure flow through the umbilicals and also to monitor for any leaks. It is constructed from F55 super duplex and is capable of measuring flows of between 0-40 l/min. The meter was custom-calibrated across the customer’s specified minimum/maximum flow conditions and working viscosity within the meter’s range of 0.5 to 100,000 centistokes.
Two reed switches in a single compact sensor housing were set for reverse flow detection or redundancy. They are tested for over one billion pulses. The HF40, as with all other Litre Meter PD flowmeters, delivers an accuracy of one per cent of reading
The robust VFF flowmeter is suitable for measuring liquids with flow rates from 0.0004 l/m (0.5 litres per day) to over 270 l/min, at pressure ratings up to 4,000 bar (60,000 psi). It is of intrinsically safe design and manufactured to operate reliably at temperatures ranging from -40 to 100°C.
Standard meters are available with 316 stainless steel, titanium, duplex and super duplex steel bodies, with a variety of connections. Flowmeters are also available with the state-of-the-art direct space-saving FlowPod instruments. These provide local display indication in an enclosure that is only 85 mm in diameter and back lit with large rate and totalizer digits providing local display of flow rate and total flow. They have HART 7 protocols on a two-wire system mounted in an ATEX Exd stainless steel housing.
As a flowmeter specialist working with suppliers to major companies such as BP, Chevron, Anadarko, Shell UK and Tyco, Litre Meter has supplied meters for chemical injection in the oil and gas industry for projects around the world for over 20 years. This experience in subsea chemical injection applications has confirmed the instrument’s capability to reliably measure fluids to help maintain flow assurance under extreme conditions of both temperature and pressure.
