One of the measures to extract more oil from the fields is to drill more wells, but drilling subsea wells is expensive.

New equipment enables drilling of new sidetracks through existing tubing on subsea fields.

The new technology is called "Through tubing rotary drilling" (TTRD) and enables reuse of old wells in a much simpler and more inexpensive way than earlier.

The rig will only contain the equipment needed for this type of operations and will be a brand new type of rig.

”Now we see the result of 4-5 years of technology development in the company,” says Oeystein Arvid Haaland, head of subsurface technology in StatoilHydro.

He estimates the drilling operation to produce extra oil worth around NOK 1,4 billion, based on the current price, from the Åsgard field alone.

The new equipment is better adjusted to the task to be performed than the equipment currently used on ordinary drilling rigs.

“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,” says Haaland.

A conventional rig, Stena Don, was used at Aasgard this time, but the result of this technology will be even better on a purpose-built rig.

"In the autumn we plan to invite bids for a rig to be tailored to such operations, and the aim is to get the new rig into place in 2012/2013," Haaland says.

Today more than 40 percent of StatoilHydro's oil and gas production is produced in some 500 wells on subsea fields.

The number of fields utilising 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,” Haaland says.

(Press release)

Rolleiv Solholm