| Abstrakt: |
In the early 1970's, oil and gas exploration was started in the west of Shetlands, United Kingdom, which is a part of the Atlantic Margin. One of the main exploration targets in the west of Shetlands is the Paleocene deepwater sandstones, some discoveries of which proceeded to development or production stages. The Laggan field discovered in 1986 is under development together with a neighboring discovery, Tormore field. The Foinaven field has been producing oil since 1997. These Paleocene fields are characterised by seismic attributes including amplitude and AVO anomalies, and understanding of these attributes enables reduced geological risks and estimation of reserves, not only in exploration but also in development and production stages. On the other hand, there are many failures of exploration wells in areas with seismic anomalies. Loizou (2005) examined all the exploration wells in the west of Shetlands drilled until 2005, and concluded that only 9 out of 39 wells, which have targeted Paleocene seismic anomalies, resulted in geological success. To improve the success-to-failure ratio in exploration associated with seismic anomalies,辻 is important to construct a plausible geological model including trapping mechanism, seal, reservoir, source rock and hydrocarbon migration that is consistent with hydrocarbon accumulations implied by seismic anomalies. The Tornado discovery was a prospect, which targeted the Paleocene deepmarine sandstone associated with a seismic amplitude anomaly; The first exploration well confirmed a gas column with oil leg. Prior to the drilling, seismic data analysis was carried out together with a CSEM data acquisition. Those geophysical information was integrated with a geological model built on the information from nearby wells and other geological studies to reduce geological risks (Pickering et al.t 2011). This paper presents successful examples of integrated methods of exploration activities which do not rely only on seismic anomalies. [ABSTRACT FROM AUTHOR] |
