3D Seismic Characterization of UER Karst, Offshore Qatar

Produced water from the Al Shaheen Field is currently re-injected into the Umm Er Radhuma (UER) Formation. To model the impact of future increase of water disposal into this unit a detailed and multidisciplinary characterization of the karst system was done. In this work the spatial distribution, connectivity and geometry of the karst network in the Umm Er Radhuma Formation present in the Al Shaheen Field has been mapped in detail using horizon extractions and time slices on full-stack, spectral whitened, discontinuity, curvature and spectral decomposition seismic volumes fully integrated with drilling and regional geological data. The presence of faults and fractures associated with the interpreted karst features was also investigated and provided alternative scenarios for the distribution of subtle (sub-seismic) areas of karstification. This 3D seismic characterization of the Umm Er Radhuma karst network helped to generate a static model. The model serves as basis for the hydrodynamic modeling that will generate different scenarios for the expected increase of injection of produced water into this karstified unit. This integrated workflow has proven to be successful for the characterization of geobodies related to karstification of carbonate rocks; providing key insights for porosity and permeability distribution in similar karst reservoirs in the region.