Faults as Barriers or Channels to Production-Related Flow: Insights from Case Studies
C. Wibberley, J. Gonzalez-Dunia and O. Billon
Event name: 80th EAGE Conference and Exhibition 2018
Session: The Best of Petroleum Geoscience (Dedicated Session)
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 574.47Kb )
Price: € 20
Faults at many scales are amongst the most common structural heterogeneities which can impact reservoir flow both in positive and/or negative ways for development projects. This contribution presents examples of how transient behaviour of fault zones can differ to long-term “static” behavior, leading to pitfalls in interpreting exploration / appraisal well data when preparing the development stage. Case studies are presented from W. African post-salt turbidite reservoirs where seismic and well evidence allow us to advance concepts on the behavior of faults in terms of time scales for fault-related flow - both across-fault compartmentalization and up-fault leakage. Lessons learned in hindsight from the modelling and evaluation in the appraisal and development planning stages are highlighted, particularly in cases where initial contact and pressure data were incorrectly used to make suppositions about the future behavior of the faults during reservoir depletion which were demonstrated as invalid by later development well data and 4D seismic. Analytical calculations based on realistic fault property constraints are used to illustrate the timescales of across-fault flow for multi-panel trap charging and reservoir compartmentalization. The case studies presented along with the supporting calculations shed light on how past errors can be avoided in future.