Litre Meter Ships 3,000th Meter for Offshore Flow Assurance Applications

Aug 22, 2013 | Flow & Level

Recent shipments for offshore applications include a series of meters to be used subsea, on a variety of chemicals, over a wide range of flows at high pressure and calibrated at specific viscosities. For example, Litre Meter rotary piston flow meters are part of systems used to control the amount of ‘antifreeze’ injected into pipelines at high pressure (430 bar) in subsea gas exploration on fields in the Caspian Sea and the North Sea.

‘Antifreeze’ fluids like methanol are used as thermodynamic inhibitors, which lower the freezing point of gas hydrate. They are injected into pipelines where there is a risk of hydrates (dew) forming then freezing at low temperature.

The antifreeze prevents gas hydrates solidifying as crystals and blocking pipelines – which can result in a costly shutdown and the risk of explosion or unintended release of hydrocarbons into the environment.

Litre Meter has also recently shipped flowmeters for use in chemical injection skids on a number of fields in the Gulf of Mexico and the Persian Gulf off Dubai. These meters are used in the flow measurement of wax dispersants and pour point depressants (PPD) to control their use to a very high tolerance.

Wax dispersants break apart and prevent the reformation of hydrocarbon sludge deposits and improve flow by reducing the viscosity of the fluid. PPDs are used to reduce the viscosity of oil and to maintain flow rate by preventing the build-up of wax crystals at low temperatures.

Sludge deposits are typically composed of varying concentrations of hydrocarbon, asphaltene, paraffin, water and inorganic materials. They are commonly found in storage tanks and vessels, production and transportation pipelines, process systems and hydrocarbon-producing formations where they have an adverse effect on the flow of crude oil from the well head.  Other recent offshore applications for Litre Meter equipment include a potable water chlorine dosing skid for a North Sea gas platform. Litre Meter instruments are used to measure the flow of water in a range of 1,470 to 5,000 l/hr at a pressure of 8.5 bar. The meters need to be both accurate and robust over long periods of continual use. All the process wetted and pressure retaining parts had to be constructed from 6 Moly austenitic stainless steel.

Litre Meter CEO Charles Wemyss said: “The shipment of the 3,000th meter for an offshore chemical injection application fully demonstrates the variety of demanding applications that VFF flowmeters can be used for, from maintaining flow assurance to ensuring the supply of potable water on offshore platforms.

“Litre Meter’s VFF flowmeter is ideally suited for use in the oil and gas industry and in particular for low flow / high pressure applications.

“Years of experience in chemical injection applications onshore and offshore have confirmed the instrument’s capability to reliably measure fluids under extreme conditions of both temperature and pressure.”