Palynological review of the Brent Group, UK sector, north sea

Abstract

Abstract A biostratigraphical zonation of the Brent Group, applicable within local oil field areas, has been established. It comprises 11 palynozones and subzones, eight of which are confined to the Ness Formation. Palynomorph associations and palynofacies types are shown to broadly correspond to specific palaeoenvironments. A regional ‘event’ scheme is outlined which establishes chronostratigraphical correlations and suggests temporal relationships between deltaic and delta front sediments. Integrated palynofacies data have allowed the development of deltaic sub-palaeoenvironments and lithofacies to be examined with respect to time and, in this way, to chart the possible progress of the delta as it prograded. Similarly, this approach enables possible areas of concentrated fluvial channel activity to be identified and the likely migration of these fluvial fairways with time. The implications of this depositional model for reservoir development and performance is discussed, showing the varying orientation of the delta front and barrier sands as it changed from a predominantly N-S trend during its early stages to WNW-ESE in its final stages.