Medal for seismic method

November 18, 1999, 08:00 CET

Three former Statoil employees have been awarded the Virgil Kauffmann gold medal, a major honour in the world of geophysics.

The medal was presented to Eivind Berg, Bjørnar Svenning and James Martin at the recent annual conference of the Society of Exploration Geophysicists in Houston, Texas.

This award is given to people who have made a substantial contribution to developing new geophysical technology over the previous five years.

The trio became pioneers with four-component seabed seismic surveying through the Sumic project, which was run from 1988 to 1994 by Statoil's research centre in Trondheim.

This work aimed to develop technology which could provide major savings on oil exploration and reservoir mapping, and on monitoring fields during production.

Marine seismic surveying traditionally employs a survey ship towing air guns which transmit pressure waves into the sub-surface. Hydrophones (sensitive microphones) on long cables – or streamers – towed behind the ship pick up the same waves echoed back from buried strata.

The Sumic project developed sensors comprising three geophones and one hydrophone which could be planted on the seabed with the aid of a remotely-operated vehicle (ROV).

Contact between sensor and seabed, and the ability to measure seismic vibrations in three directions with the geophones, allowed shear as well as pressure waves to be measured. Shear waves can provide substantial additional data from reservoirs.

Seabed seismic surveying was demonstrated for the first time on Statoil's former Tommeliten field in the Norwegian North Sea, with the results published at an international conference in Vienna in 1994.

Chief geologist Lars Jan Jaarvik in Technology congratulates the medal winners, and reserves particular praise for Eivind Berg's contribution.

"He bears much of the credit for getting work started on the seabed seismic method," says Mr Jaarvik.

Following the completion of the Sumic project, the technology with Statoil's patent rights was licensed to Schlumberger Geco-Prakla. Seismic data are now collected world-wide with the aid of seabed surveying.