Diagnostics and countermeasures for ensemble collapse - Testing of localization as a measure to prevent ensemble collapse when history matching Reek and Norne

Ensemble collapse is one of the main problems encountered when doing history matching using ensemble based methods. In history matching results where ensemble collapse is a problem it is very hard to distinguish updates due to spurious correlation with noise in the data with actual updates attributed to information in the data. Various localization workflows have been proposed for the synthetic case REEK and the public domain dataset from NORNE. We demonstrate moderate improvements of the localized updates for the REEK case. For the NORNE case, issues around the prior distribution were encountered that prevented further investigation of the proposed localization workflow.