Building a geological reservoir model in the North Sea

Abstract

This thesis is submitted as the partly requirement to fulfill the Masters of Science (M.Sc.) in Petroleum Geosciences at the Department of Petroleum Geosciences (IPT), Norwegian Universi-ty of Science and Technology (NTNU).The study utilizes 3D seismic surveys from Northern North Sea to study the deformation and structure development in the Skade and Utsira Formations. The deformation took place in the study area during the deposition of sediments derived from Shetland platform deposited as Utsira Formation.Series of sand inejctites identified in the study area mostly occurred as high amplitude anomalies within low amplitude reflections in the study area Utsira High northern North Sea. Detailed mapping of these injectites displays peculiar V, U, and W shape in vertical seismic section circu-lar to oval in plan view and conical in 3d geometry with dimension ranges from 70-80ms in two-way-travel time (TWT).In the study area two phases of mobilization are observed, Oligocene deep injectites and mobilization of Skade Formation during deposition of lower Utsira Formation. The mobilization of Skade Formation and lower Utsira deposition took place at the same time compaction of the lower mid Miocene shales plays a role in formation of thick sand basin in lower Utsira Formation and anticline structures. Miocene sand 2 of the Skade Formation is highly deformed and mobilized in the area creating more accommodation space for Utsira sand infill. Most of the elevation created in the area due to mobilization of the Skade Formation.