Abstract
Many EOR processes fail because of the existence of unaccounted high permeability channels or fractures. Given a field under waterflood, where downhole pressures in producers can be continuously measured via permanent downhole gauges (PDG), we present a workflow process for pinpointing of high permeability channels without much disturbance of the field operations. The methodology requires a systematic scheduling of variations in the injection levels at selected injectors. The purpose of this study was to investigate the accuracy of estimated heterogeneity trends from processing of downhole response data.
The field setting is first divided into a series of clusters. Ranking of estimated high permeabilities among the clusters is the basis for mapping and pinpointing the location of the high perm channels. We demonstrate how the proposed algorithm can be used to detect sub seismic high permeability channels that negatively affect sweep efficiency. It can further allow an estimation of regional values of effective total compressibilities related to fluid types and areas with limited pressure support. This offers an enabling tool in designing and forecasting of field pilots for processes requiring expensive injected fluid.
