Ensemble-based data assimilation has become established as a school of viable and popular methods for data assimilation in very large models including those describing atmospheric, oceanic, and petroleum reservoirs systems. Although the basic concept is straightforward, successful practical implementation has often required modifications that are problem specific. For isntance, methods that are highly successful in meteorology have not always been appropriate for porous media flow. By bringing together experts from diverse fields, we aim to explore the basis and connections between methods that work, so that the resulting applications are more robust and efficient. In the petroleum reservoir engineering field, the ensemble Kalman filter, ensemble smooher and their iterative forms have become increasingly popular over the last years as methods for updating of reservoir simulation models to be conditioned both on prior geostatistical information and on production data. They have proven to be exceptionally powerful on the Brugge benchmark case for closed-loop optimization and on real field studies. Still there are many challenging problems both for data assimilation and for optimization. The EnKF workshop provides a platform for presenting the status of the research that has been performed and for giving inputs to the researchers and practitioners for their further work.
By bringing together leading technical experts, practitioners, researchers and students for presentations and informal interchange of information we hope to accelerate the development of this area, by giving practitioners ideas of the possibilities of the methodology and the researchers feedback on the most important challenges that have to be addressed. This workshop will follow the lines of the previous workshops.
The first EnKF workshop took place in Voss (Norway) and had 37 participants. It was initiated by Geir Nævdal (NORCE), Sigurd Aanonsen (CIPR, now NORCE), and Dean Oliver (University of Oklahoma, now NORCE) who felt the need to gather experts and practitioners of EnKF for reservoir engineering applications. Since the workshop has always welcomed participants coming from other fields of research (meteorology, oceanography...) sharing an interest in exchanging their experience about the use of EnKF and even sometimes about related data assimilation techniques. This has led to even more fruitful discussions and raised the scientific level of the workshop to a very high standard.
We, as organizers, are proud and humbled to see that so many (approximately 50) experts, students and practitioners take each year some of their time to come to Norway to participate and make the EnKF workshop such a success.
We sincerely hope that the annual International EnKF Worshop will meet the expectations.
The organizing committee.