StatoilHydro and FMC Develop New Technology to Improve Oil Recovery from Subsea Fields

13 September 2009

StatoilHydro and FMC Technologies have developed new technology to improve the oil recovery from subsea fields. The technology has now been successfully tested on the Åsgard field in the Norwegian Sea.

Through tubing rotary drilling. Source: FMC, DNV. Click to enlarge.

One of the measures to extract more oil from the fields is to drill more wells, but drilling subsea wells is expensive. The new technology—“Through tubing rotary drilling” (TTRD)—enables drilling of new sidetracks through existing tubing on subsea fields. TTRD enables reuse of old wells in a much simpler and more inexpensive way than the earlier alternative, which is to drill a conventional sidetrack after pulling production tubing and the x-mas tree.

Øystein Arvid Håland, head of subsurface technology in StatoilHydro, estimates that TTRD will produce extra oil worth around NOK 1.4 billion (US$236 million), based on the current price, from the Åsgard field alone.

The new concept will highly improve the efficiency of this type of operations in connection with subsea well operations, and enables us to produce oil that we would normally not have recovered.

—Øystein Arvid Håland

A conventional rig, Stena Don, was used at Åsgard for the pilot TTRD project. StatoilHydro will issue a tender this autumn for such a purpose-built rig, with the aim to have in it place in 2012/2013, Håland says. The new rig will only contain the equipment needed for this type of operation, and offer better performance.

More than 40% of StatoilHydro’s oil and gas production is produced in some 500 wells on subsea fields. The number of fields utilizing subsea concepts is growing, and both StatoilHydro and other companies have a strong focus on improved oil recovery (IOR).

This new technology may be used in waters down to 500 metres. The goal is to reach even deeper.

In the future we wish to utilise this technology in deep waters, for example in the Gulf of Mexico.

—Øystein Arvid Håland