HOUSTON– StatoilHydro and FMC Technologies have developed new technology aimed at drilling sidetracks through existing tubing on subsea fields.
The technique, called “through tubing rotary drilling” enables reuse of old wells in a simpler and cheaper way than previous technology, the developers say.
The technology was successfully tested on the Åsgard field in the Norwegian Sea after close to five years of development.
According to Øystein Arvid Håland, head of subsurface technology at StatoilHydro, the drilling operation produced extra oil worth some NOK 1.4 billion ($236 million) based on current prices 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,” says Håland.
A conventional rig, Stena Don, was used at Åsgard 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," Håland says.
The rig will only contain the equipment needed for this type of operations and will be a brand new type of rig. 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 utilize this technology in deep waters, for example in the Gulf of Mexico,” Håland says.
This is how it looks when the equipment is being connected to a subsea installation on the seabed. (Illustration: FMC Technologies)