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07/06/2011 Professor Tor Austad (University of Stavanger) and the Corec research centre at IRIS have been awarded the NPD’s 2010 IOR prize. Austad and Corec have been honoured for the very important research that has been carried out to improve oil recovery from chalk fields.
The IOR prize (IOR, improved oil recovery) was presented at the Norwegian Petroleum Society’s (NPF) conference on reservoir management in Stavanger today, 7 June.
Professor Tor Austad at the University of Stavanger (UiS) and Corec will both receive the IOR prize for 2010. Their research results are crucial to understanding the reservoir recovery mechanisms for the chalk fields in the southern part of the North Sea. Their research thus forms an important basis for the decisions the oil companies must make to improve the oil recovery.
”Based on Austad’s long-term research within reservoir chemistry and wettability properties in chalk rock, and the connection between this and further recovery from the chalk fields in the southern part of the North Sea, he is a particularly deserving winner of the Norwegian Petroleum Directorate’s 2010 IOR prize,” Director General Bente Nyland says.
Through a systematic cooperation with a large number of doctoral students, Austad has, over the course of 15 years, identified the special properties of seawater as an EOR and compaction fluid in chalk reservoirs with a high temperature. This has given an important contribution to understanding how injection of seawater displaces oil so efficiently on the Ekofisk field.
He has also contributed significantly to clarify the chemical mechanism for weakening the chalk rock with seawater. This will also have considerable economic significance in the work to improve the efficiency and lifetime of wells in the area.
The Corec research centre, with which Austad shares the award, has been working with improved recovery since its establishment in 2002. The NPD emphasises the significance of Corec’s thorough work to find different methods to improve oil recovery from the chalk fields in the Ekofisk area, which also includes investigating the effect of injecting CO2 following water injection in the chalk fields.
”The potential for improved recovery with use of CO2 is undoubtedly large. At the same time, the integrity and stability of the chalk rock is a challenging question if CO2 is injected,” Nyland comments.
”The research on these topics is very significant regarding important decisions in the future. We don’t have all the answers yet, but so much good work has been completed that the NPD also wants to honour this with the 2010 IOR prize.”
Most likely there will be production from chalk fields on the Norwegian shelf until 2050 and beyond. There is no doubt that the research efforts have contributed to the positive results, and have thus helped create significant values both for licensees and the Norwegian society.
Water injection does not function in the same manner in a fractured chalk field as in a sandstone field. Understanding how injection of seawater works both at a microscopic level and on a larger scale has posed a challenge to researchers for several decades. One of the questions regards whether it would be possible to inject produced water from the reservoir together with the oil. We also know that the chalk rock is compressed during production. This has led to the seabed at Ekofisk sinking as much as 9.5 metres in the middle of the field. This effect also leads to more oil being recovered from the field. How this dramatic and important effect is influenced by long-term water injection in the field, is another important research topic.
For many important decisions that have already been made, or will be made in the future, and which concern billions of Norwegian crowns in investments, it is essential to have good enough answers to the challenging questions of what happens in the reservoir.
The Ekofisk, Tor, Valhall and Hod chalk fields in the southern part of the North Sea still have a lot of oil and gas which could be profitable to recover. Ekofisk, Eldfisk and Valhall are three of the six fields on the Norwegian shelf that will have the most subsurface oil remaining when the current reserves are produced.
In addition, the Tommeliten Alpha gas condensate discovery can be developed, and it might become relevant to re-develop one or more of the chalk fields that have already been shut down. It takes longer to produce the oil and gas from chalk fields than sandstone fields.
Is it possible to increase the oil recovery further from the chalk fields with the use of more advanced recovery methods in the future, when it is difficult to recover more with water injection? Here lie new challenges for the researchers and oil companies to delve into.
Many different bodies have contributed research to improve recovery from chalk fields. These include the companies’ own research centres, the Norwegian-Danish research cooperation Joint Chalk Research and the University of Bergen, for example.
ConocoPhillips (then Phillips Petroleum Company) received the IOR prize in 2000 for its efforts to improve the recovery from Ekofisk – during times with low oil prices. This effort was continued in 2010 and 2011 with the submission of the plans for Ekofisk Sør and Eldisk II.
Furthermore, BP and Valhall Unit received the IOR prize in 2003 for the project Life of field seismic on Valhall, which was the first project of this type on the Norwegian shelf, and which contributes to improved recovery on Valhall.