Semi-Regional Seismic Interpretation of the Triassic in the Hammerfest Basin

Abstract

The Jurassic play is by far the most explored thematic in the Hammerfest Basin, but its remaining potential is very small. However, the Triassic section is under-explored and its potential is not well known. As a first approach the oil companies will explore near or under already existing fields because it is considered relatively cheap exploration due to the infrastructure in place.

The basis for this semi-regional seismic interpretation study was generated from a geological background study of the Hammerfest Basin. The tectonical and paleogeographical history has been described with emphasis on the Triassic period. In addition the petroleum systems were investigated and especially the Tornerose area due to discoveries in the Triassic section.

The main seismic interpretation was carried out on areas neighboring the Snøhvit and Albatross Fields on the survey ST0306. Three key seismic horizons in the Triassic were chosen for the interpretation; Top Snadd, Top Kobbe and Top Klappmyss. After horizon interpretation and gridding several layered attribute maps were generated. With these maps many channels and sand bodies were mapped around the Snøhvit and Albatross Fields. Unfortunately the channels are smaller here than on Tornerose, but most of the sand bodies are very interesting regarding the size and also the location.

For the Triassic section in the Hammerfest Basin a fully functional petroleum system is most likely in place, but some uncertainties regarding for instance the reservoir quality and the lack of structurations in the Kobbe Formation and also the possible paleographical distal placement of the Triassic part of the Snøhvit area. However, the paleogrographical map is a big uncertainty itself and some studies indicate that the coastline should be shifted westwards, placing the Snøhvit area in a better position regarding the reservoir quality and thickness.

The conclusion from this interpretation study is that there has to be done further investigations before the petroleum potential is fully established, and the target area could also be expanded further.