Using 3D Geological Modelling and Connectivity Analysis to Locate Remaining Oil Targets in the Brent Reservoir of the Mature Brent Field

Abstract As part of the drive to locate remaining oil targets in the Brent Field prior to depressurisation1, full-field 3D static reservoir models for the main Brent Field (excluding the fault-scarp degradation area called the ‘slumps’2) were constructed last year. Both the Brent Group and the Statfjord Formation reservoirs were modelled using the Shell proprietry 3D geological reservoir and property modelling program known as GEOCAP'J. This paper briefly outlines the approach taken in the GEOCAP modelling of the Jurassic Brent Group Ness reservoir, which formed the basis for the first test-case application of a new well-clustering technique, CRF (Cumulative Resistance to Flow) which is the focus of this paper. The CRF module is one of the latest technological enhancements of GEOCAP, developed by RTS (Shell International Research and Technical Services, Netherlands). It is a permeability-distance based well-clustering module, that calculates connected reservoir volume to perforations, using the GEOCAP 3D permeability models. Subsequent removal of these connected rock-volume clusters from the model, results in a 3D model of unconnected reservoir volume. The model can then be used to identify unconnected areas that are large enough to be considered as potential remaining oil targets. These areas then warrant further investigation as potential target locations, most importantly in terms of dynamic reservoir modelling aspects, and calibration with latest surveillance data. The results indicate that there are still several sizeable ‘targets’ (in excess of 1 MMbbls STOIP) left in the Ness reservoir after the currently planned wells have been drilled and these are currently undergoing independent review.