Abstract: The Variation in Resource Assessment of Exploration Prospects. Data from Norwegian Licensing Rounds

KALHEIM, JAN-ERIK

Quality Control, systematic risk analysis and post- and pre-drill evaluations are important when the oil industry is focusing on improvements in the exploration phase.

When applying for new licenses offshore Norway, all oil companies have to present their own prospect evaluation of each license they are applying for. This includes both volume estimates, probabilities of discovery and prospect economic evaluation. During the licensing process, the Norwegian Petroleum Directorate has also to carry out their own prospect assessment of the areas in question.

These assessments form a unique database, which can be used to compare the pre-award evaluations with the post-drill results on the Norwegian Continental Shelf. The Norwegian Petroleum Directorate has carried out a study for seven licensing rounds awarded in the period 1984 to 1994. These licensing rounds comprised areas from the entire Norwegian shelf and resulted in 114 awarded licenses.

The study shows that the prospect volumes in average were overestimated with a factor of about 2.5 in the license applications. Even though we take the range of uncertainty into consideration, only 1 of 5 estimates hit the actual discovery size. This study forms a basis for discussing the potential of improving the prospect estimates in the pre-drill phase.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria