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Wisting Central prospect "probably rejected" without CSEM

Oct 17 | 2013
In an interview last month with the Norwegian trade journal GEO, former Chief Geophysicist Tor Veggeland at Spring Energy said the Wisting prospect probably would have been a no-go had CSEM data from EMGS not shown a clear anomaly there.
wisting well EM by EMGS_seismic shown with kind permission of TGS3
3D EM resistivity surface and 2D seismic (courtesy TGS) at the Wisting Central well location

In the September issue of GEO, Veggeland recalled why Spring Energy (now Tullow) decided five years ago to apply for a concession for production license 537.

Bet his career on Wisting

Veggeland is also known as the man who promised his geoscience colleagues that he would devote the remainder of his professional career to writing poetry if the Wisting Central well proved to be dry.

As is public knowledge since news of Wisting was announced 6 September this year, the well was drilled, proven to be a commercial discovery, and Veggeland's typewriter is for sale.

Exploration manager in Tullow Oil plc, Per-Gustav Granholm, was also interviewed, together with Veggeland, about the discovery made approximately 170 kilometres northeast of 7220/8-1 Johan Castberg and roughly 310 kilometres north of Hammerfest. OMV (Norge) AS is the operator of production license 537 with a 25% interest. Tullow, has a 20% interest.

Steering clear of shallow gas

Granholm recalled how it felt to be one of the team of believers who had faith in the shallow prospect, just a few hundred metres below the seabed:

"We almost felt as if other companies were musing at this shallow prospect. In the industry, I think many people believed the seismic anomalies were caused by shallow gas, and that consequently, it was best to steer clear."

Fluid contact with good, AVO response

But for Veggeland and his colleagues in the geoscience team for the Barents Sea, it was the seismic data analysis, conducted on the basis of an amplitude anomaly over the prospect, that marked a turning point.

"We found a fluid contact with a good AVO response," Veggeland said. However, he also admitted that that it was difficult to place too much emphasis on it seeing that the fault ran from the presumed reservoir up to the bottom of the quaternary layers.

CSEM data from EMGS lit up the prospect

To gather more facts to better describe this interesting prospect, Spring Energy acquired CSEM data from EMGS. Veggeland remembered what the CSEM data showed:

"It really lit up across the structure, and it was then that we began to think that this could be an interesting prospect. But without the CSEM data, the prospect would probably have been rejected."

Source of article: "Oljefunn som bestilt" by Halfdan Carstens, GEO, September 2013. References to the GEO article have been made with the kind permission of GEO's editor.

GEO is a Norwegian trade journal dedicated to the geosciences, and published by GeoPublishing AS.