Data calibrated migration modelling in the assessment of Brent Group prospectivity: a case study from the Veslefrikk area of the Norwegian North Viking Graben

A study of the prospectivity around the Veslefrikk oil field in Block 30/3 of the Norwegian North Sea included an evaluation of petroleum migration an d trapped gas to oil ratios. The study followed a procedure which involved the assessment of source rock distribution and quality, source rock maturit y, petroleum generation and expulsion, and secondary migration. Inside a semi-regional framework two prospects are discussed: (1) B-prospec t, a down faulted hanging-wall trap to the west of the Veslefrikk Horst whe re the existing discoveries of Veslefrikk, Oseberg East, and Zeta exist; an d (2) C-prospect, a tilted fault block foot wall trap to the south of the H uldra discovery, 1D thermal modelling coupled to map based petroleum migrat ion analysis and 2D multi-layer migration modelling were used in this multi -source, multi-carrier setting to evaluate the petroleum system. With the integration of available well and seismic data basin modelling tec hniques can deliver more confident assessments, especially where multiple g eological models may exist. In this study area, data, such as temperatures and source rock properties, were used to constrain the model input options, thereby reducing parameter uncertainty. Other data, such as geochemical fl uid to source correlation and observed petroleum distribution and compositi on, served as a validity check for the simulated results from different geo logical models, The use of these data in this case history are discussed an d illustrated. (C) 2000 Elsevier Science Ltd. All rights reserved.