Iintegrated study of the Veslebjørnprospect, South Norwegian North Sea

Abstract

In the study of a sedimentary basin, a good geological background of the area is fundamental, and then, seismic data and well logs are essential tools for its characterization.

The main objective of this project is to generate a description of the Veslebjørn prospect, a Jurassic play located in the high pressure - high temperature (HPHT)compartment of the Eastern Central Graben, that still has not been drilled.

The Upper Jurassic itself hosts about 20% of the most important remaining exploration targets. Indeed, it may contain the majority of yet-to-be-found reserves in subtle stratigraphic, structural and combination traps (Johnson and Fisher, 1998;Boldy and Fraser, 1999).

The first part of this project is focus in generate a geological description of the area,based on available publications.

After that, characteristic wells of the Ula and Gyda fields and possible analogues were selected, petrophysical logs were checked and fluid substitution modeling was carried out in the reservoir intervals. Then, with the purpose of identifying the prospect, seismic interpretation was performed.

The next step is the evaluation of quantitative techniques for seismic interpretation such as seismic modeling (1D) and offset dependent amplitude modeling (AVO).

To quantify the petroleum potential, a description of the prospect is included; base on the data and publications available. Finally volumetric calculations of the hypothetical prospect were made. The uncertainty in the estimation of resources is directly related to the density of available data.

This work was done in cooperation with Det Norske Oiljeselskap ASA, with Kjell Berg(Det Norske) Kjersti Hagland Hansen (Det Norske) and Professor Martin Landrø(NTNU), as main supervisors.