The area west of the Shetland Islands was the U.K.'s hottest play for some years, but a paper presented at the recent Offshore Europe conference in Aberdeen confirmed that things have cooled.
The last big news story from the West of Shetland play was the Suilven oil strike by BP Amoco plc on a block near the Foinaven and Schiehallion fields, which it developed subsequently (OGJ, Mar. 10, 1997, p. 31).
While other operators, including Texaco Ltd. and Amerada Hess Ltd., have struck oil and gas there, and while numerous others have drilled wells, BP Amoco's finds remain the only tangible successes to date.
Any queries about wells drilled by operators other than BP Amoco have been met with the answer that nothing could be revealed because the wells were tight holes.
But the paper by R.S. Parr, D. Cowper, and B.C. Mitchener of BP Amoco's Western Margins-Atlantic Frontiers exploration team supports the growing view that the West of Shetland front is now quieter than operators would prefer.
Parr et al. said that, after the initial strikes in Foinaven and Schiehallion-made in 1992 and 1993, respectively-Suilven was the most notable success. "Several other exploration wells were targeted on surrounding, more poorly defined amplitude anomalies, to ascertain rapidly the potential size of the second field development," said the authors.
"Often the geophysically led exploration emphasis tended to lose sight of geology, and it became apparent that seismic-driven exploration risk reduction was not a panacea, and it required a significant database to discriminate hydrocarbon-related amplitudes from other facies.
"The rapid exploration pace meant there was little time to learn from previous experiences. In 1996, BP-Shell's (Shell U.K. Ltd. is BP Amoco's 50% partner) active exploration effort started a 4-year hiatus as a period of consolidation and understanding began."
The authors confirmed that no other operators have announced significant discoveries and that, over the last 1-2 years, there has been a downturn in West of Shetland exploration, because of the "generally poor success record," high costs of exploration, and low oil price.
The authors said that future exploration will be hampered by the layer of basalt which covers much of the West of Shetland area, obscuring the seismic picture of potential prospectivity below.
"In this environment," said the authors, "seismic-driven exploration is very difficult and direct hydrocarbon detection seemingly impossible.
"Considerable effort has been put into trials that would allow exploration in such environments using non-seismic methods, larger seismic sources (and) longer cables, and cables placed on the seabed.
"A number of wells have been targeted in these areas, but it is too early to know if the oil industry will have any significant success."
However, the authors were hopeful that the resolution of the boundary dispute between the U.K. and the Faroe Islands would renew interest for exploration on both sides through the next U.K. and first Faroes licensing rounds (OGJ, June 7, 1999, p. 32).