StatoilHydro, FMC Improve Subsea Oil Recovery at Asgard

New drilling and well technology developed by StatoilHydro and FMC Technologies will improve the oil recovery from subsea fields. The technology has now been successfully tested on the Asgard field in the Norwegian Sea.

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

Entering Existing Wells

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.

"Now we see the result of 4-5 years of technology development in the company," said Oystein Arvid Haland, 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 Asgard 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," said Haland.

Bid in the Autumn

A conventional rig, Stena Don, was used at Asgard 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," Haland said.

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

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 utilizing subsea concepts is growing, and both StatoilHydro and other companies have a strong focus on improved oil recovery (IOR).

In Deep Waters

This new technology may be used in waters down to 500 meters. 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," Haland concluded.

What is TTRD:

StatoilHydro applied new technology this summer. This technology enables the reuse of old subsea wells in a simpler and more inexpensive way than before, by drilling a new well directly through the production tubing in an existing well. This technology is called Through Tubing Rotary Drilling (TTRD).


  • More oil from mature fields
  • May enable recovery from marginal fields
  • Less expensive than conventional drilling operations
  • Increases the well’s lifetime and raises the income per well
  • More efficient operations
  • Less handling of heavy equipment


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