The reservoir characterization of the Sea Lion Field

Abstract

The reservoirs that form the Sea Lion Field comprise a series of canyon-fed fans deposited into a deep, anoxic lake, on the hanging wall of the basin boundary fault. The fans primarily form stratigraphic traps with an element of fault seal on the west flank. These fans are dominated by mass flow and high-density turbidite sands, with subordinate low-density turbidites set within lacustrine shales. The fans mapped on seismic profiles are partitioned into lobes, based on sand bodies penetrated into the wells or the conceptual model where correlation between wells is not possible. Ten facies are identified from core but attempts to discriminate facies met with mixed success. Facies are therefore combined into four associations (‘Rock Types’) for use in dynamic flow modelling. Rock Types are distributed within the fans using a hierarchical reservoir architecture (‘fan-lobe-surge’). This paper describes the reservoir and fluid characteristics, and outlines the challenges associated with converting the detailed geological model into a form suitable for reservoir simulation, while preserving the main reservoir features that will influence fluid movement within the reservoir