After dinner:

Michael Byrne, Principal Consultant, Senergy and SPE Distinguished Lecturer

This presentation attempts to demystify many of the legends of formation damage and their evaluation. Fines migration and wettability alteration have long been the mechanisms employed by engineers (or geologists) to explain and justify almost every well or reservoir behavior. These mechanisms share the characteristics of being difficult to prove and identify and having serious positive or negative effect on fluid flow. Their complexity should not be a barrier to understanding these mechanisms. With appropriate study, these processes can be identified, understood, and at least semi-quantified for most reservoirs. With understanding, it is then possible to evaluate damage mitigation or remediation. Fresh examples of the process of understanding and avoiding damage will be presented.

The cost of formation damage to our industry is difficult to quantify precisely, but it is undoubtedly true that less damage is better than more damage and significant productivity or injectivity can be added through damage awareness and mitigation. An attempt is made to quantify the cost of damage by country and region to put the technology presented in perspective. In 2007, the global annual cost of formation damage is estimated at one hundred thousand million dollars! Members should take away some insight in to formation damage mechanisms as well as an appreciation of the cost of damage to our industry.

A graduate of University College Dublin, Michael Byrne has worked in the oil industry for 19 years, and has spent 18 years evaluating formation damage and sand control problems. He has written and presented various training courses, and acted as a consultant to major oil companies worldwide. Numerous technical publications include key SPE papers on drilling and completion related formation damage mechanisms. He has been a principal author of papers on recommended laboratory practice and on description of formation damage mechanisms. He has served SPE as technical editor, short course instructor, and steering committee member and session chair at several SPE conferences, workshops and forums. Michael joined Senergy in Aberdeen in August 2007 as principal formation damage consultant.

Before dinner:

Kes Heffer, Reservoir Dynamics

A recently developed technique analyses the statistical correlations between fluctuating injection and production rates at pairs of wells in a reservoir - data that are readily available at practically zero cost.  From the results of applying this analysis to several fields further support has been obtained for the concept that geomechanics is playing a strong role in waterflood mechanisms, a physics that is commonly missing from field reservoir models.   Many of the well pairs whose rate fluctuations are correlated are very long-range, which cannot be explained by Darcy flow alone.  They also appear to be stress-related and fault-related.  
 
The postulated mechanism behind these characteristics has a basis in the concept that a significant proportion of the earth’s crust is close to a critical mechanical state with a high susceptibility to perturbation.  It is envisaged that faults and fractures are reactivated during field development due to the stress changes brought about by fluid pressure and temperature perturbations.  Generic and field-specific coupled modelling of geomechanics and fluid flow has supported this interpretation.  Reactivated structural features are likely to be major influences on the hydraulic flow paths in the reservoir and therefore their identification is of substantial advantage to efficiency in reservoir management.  Recognition of the involvement of additional physics in reservoir behaviour can lead to benefit for practical issues of well placements, injectivities, productivities, sweep efficiencies, short-term and longer-term forecasting.  The technology is well-suited to mature fields, but lessons can be learnt for green fields.
 
Results of the application of this novel technology to several fields in the North Sea will be presented.  In one field, comparison with independent data provides very encouraging calibration.  The means of integrating the technology with other reservoir management processes will be outlined.  

Reservoir Dynamics Ltd is a small company providing research and consultancy in geomechanics and fluid flow.  The above technology has been developed in partnership with the University of Edinburgh and Schlumberger Reservoir Geomechanics Centre of Excellence, Bracknell.

Kes Heffer received an MA in Natural Sciences from the University of Cambridge in 1970 and an MSc in Petroleum Reservoir Engineering from Imperial College, London in 1971.  He worked for BP for 29 years, initially in worldwide operations as a petroleum/reservoir engineer, and latterly in research into issues of reservoir description, particularly faults, fractures and geomechanics.  Since 1999 he has been an Honorary Fellow of the Institute of Petroleum Engineering at Heriot Watt University, Edinburgh.