PGS shows off electrical marine vibrator to capture ‘alternative’ seismic source market

One of the prize exhibits at the recent SEG annual meeting in Houston was the large, bright yellow, elliptical-shaped object standing on the Petroleum Geo-Services (PGS) booth. ‘The reaction was overwhelming,’ says Rune Tenghamn vice president, marine technology. The oversize exhibit was in fact the first public showing of a prototype electro-mechanical marine vibrator for seismic surveys that can produce energy penetration and frequency bandwidth comparable to a small airgun or dynamite charge. Tenghamn says that PGS is responding to a perceived demand from industry for an alternative source of energy for meeting very specific marine survey circumstances. Probably the most pressing of these involves environmentally sensitive areas where the disturbance of marine mammals is an issue with use of airguns deemed inappropriate. The other area of potential interest in the marine vibrator may be as a seabed source in permanent monitoring of reservoirs using seismic methods. ‘To date our main concern has been to demonstrate that the concept works and let everyone know,’ Tenghamn says. He began taking an interest in alternative seismic sources before he joined PGS, and in 1994 presented a paper at the EAGE Annual Conference in Paris on an electrical-type source. At PGS ideas formulated in the mid 1990s were realized in 1999 with a series of field trials of a marine vibrator and testing with a major oil company which ended in 2002. ‘Since then we haven’t really done very much with the technology, but believe that the time is now ripe to go public. We know there’s a lot of discussion about alternative sources and we hope that this will translate into a collaboration to turn our prototype into a commercial product. There are clear cost and operational advantages over any other option.’