Geomodel Update while Geosteering ERD wells based on Deep Electromagnetic Reservoir Mapping Technology, Russia Far East

The paper describes case study and methodology of updating geological model with elements of paleo reconstruction based on data accrued from deep electromagnetic reservoir mapping while drilling technology utilized in ERD horizontal wells drilled in Russian Far East region, Sakhalin Island. Odoptu-more field is known as very challenging for its geology. Major challenges are structural, stratigraphic uncertainties and lithological heterogeneity of the reservoir. Additional problem for well planning and well placement is lack of good-quality seismic and gas effect on top of the zone of interest. Even many wells already been drilled on the field, still reservoir continuity, sands distribution, pressure regime are not clear, actual and forecasted production rates correlation not sufficient. Thanks to mapping technology few geological features were observed, as an example a big sand distribution channel with thickness up to ∼45 mTVD. Shape and property of the geological bodies detected has been utilized while updating geological model and helped to trace some features in other parts of the target bed. In addition, a new knowledge allows to confirm seismic interpretation for some zones of the field and sufficiently change vision of reservoir production for few wells.