Fault Seal Risk Maps and Volumes - A Tool for Better Understanding Uncertainty and Focusing Interpretation Effort for Prospect and Field Development

Bradbury, Will ¹; Freeman, Steve ¹; Harris, Simon D.¹; Jones, Philip ¹; Knipe, Rob ^1
1 RDR Ltd, School of Earth Sciences, University of Leeds, Leeds, United Kingdom.

Often the likelihood of fault compartmentalization is a critical component in the successful development of a prospect or a field. At early stages of development it can be more useful to know what the generic impact of a fault with a given throw range can be rather than knowing the detail on any specific fault. In many cases the seismic data is insufficient, the interpretation is not fully developed and the well data is too sparse to develop a high resolution fault seal prediction. In these cases a generic understanding of the likely impact of faults is far more useful and can drive appropriate data collection, interpretation or uncertainty modelling and quantification.

In this contribution we present workflows and results that allow the general seal risk of a stratigraphic stacking sequence volume to be defined. These maps highlight the probable seal risk for a range of fault throw values. The maps also rapidly define zones across prospects or fields that are of low, moderate or high risk of sealing if a fault were present in that volume. The technique utilizes standard populated stratigraphic geocellular volumes to model the seal risk variability across the area as a function of both lateral and vertical stratigraphic variation. The examples shown will highlight seal risks generated via capillary and juxtaposition seals in prospect cases on geological timescales and via transmissibility retardation in production cases.

AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009