Predicting the Effects of Faults on Fluid Flow

Knipe, R.J., Q.J. Fisher, R.K. Davies, S.D. Harris, S. Freeman, D.T. Needham, G. Jones, A. Li, P. Jones, Rock Deformation Research Limited, University of Leeds, Leeds, United Kingdom

Predicting the fluid flow behaviour of faults is often a critical component in the explo­ration, appraisal and production of petroleum reservoirs. A multi-disciplinary approach to fault seal has proved successful in recent years. The integrated approach involves; amal­gamation of detailed microstructural and petrophysical property analysis of fault rocks, the characterisation of the population and distribution of sub-seismic faults from well, core and outcrop data, and an evaluation of the seismic scale fault array attributes. This paper will review the progress and achievements of fault seal analysis. Examples where successful application has been possible will be presented and the important uncertain­ties that limit application of fault seal prediction will be highlighted and used to identify the challenges for future work.

Reducing the uncertainty associated with fault zone behaviour prediction is achievable if the following are recognised:

Seismic resolution places important limitations on the characterisation the fault zone architectures needed for flow modelling.

Robust databases on fault zone architectures and fault rock properties are required.

Multi-phase flow properties of faults need to be considered in reservoir simulation.

New more flexible reservoir modelling packages are required, which can incorporate the more detailed and more realistic fault property data now available.

The calibration and validation of fault analysis ‘tools’ is needed from well-constrained situations so that misapplication is avoided.