Well-come development

Deep sea processing technology that could cut the cost of oil production is to be tested by energy giant Shell.

UK engineering firm Alpha Thames has developed a system module designed to sit on the seabed and separate oil from water and other impurities at the head of the well.

Built to operate at depths of up to 3,000m, the modules would carry out processes that currently take place on a platform or on land.

Shell is due to test the technology – which its developers claim could save up to $4 per barrel in production costs – in one of its fields by the end of the year.

The Alpha Thames system involves the deployment of at least two control modules containing the pumping, processing and control technology needed for separation.If one module needs to be removed for upgrade or maintenance, another takes itplace to ensure uninterrupted production.

The company, which has been working on the problem of seabed separation for a decade, has engineered a range of custom-developed components for the modules, including high-voltage underwater connectors and electric valve actuators.

Paul Eastaugh, a spokesman for Alpha Thames, claimed sub-sea processing could bring major operational and financial benefits to the oil industry.

Producers are currently faced with the highly inefficient proposition of pumping extraneous products along with the oil before they can be removed.

‘It is a basic rule of production that you separate out your waste products as soon as possible,’ said Eastaugh.

Seabed separation also increases the rate at which oil can be recovered from a field by reducing back-pressure on the wellhead.

However, fixed installations in the hostile deep-sea environment are highly vulnerable to failure and hard to maintain. ‘If one component fails it can effectively shut down the well,’ said Eastaugh.

The flexibility of the Alpha Thames modules aims to overcome this. It also means that they can be re-configured to match the condition of the well – which can alter dramatically during its lifetime – ensuring maximum efficiency.

According to London-based Alpha Prime, studies based on fields in the North Sea and the Gulf of Mexico show a potential saving of between $2 and $4 per barrel, although this will vary according to specific conditions.

The system modules will be lowered from a support vessel and accompanied to the seabed by remotely-operated vehicles.

Eastaugh said that it may eventually be possible for the units to ‘fly’ themselves to and from the seabed using built-in propulsion technology.

The trial, which is being carried out by Shell’s Technology Development subsidiary, is expected to last 15 months.

If the testing process is successful, the technology would be qualified as ‘catalogue ready’ for use at Shell’s offshore facilities around the world.

However, the development agreement with Shell does not exclude other oil companies using the technology in future.

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