Geocellular Model Construction for Enhanced Recovery of the Southern Oregon Basin Oilfield in Wyoming, USA

Duan, Taizhong¹ (1) Marathon Oil Company, Houston, TX

In a case study to enhance the recovery of a brown oil field, a geocellular model was constructed that included both matrix and fracture reservoir properties. Dataset consists of over 200 vertical and directional wells, and 3D seismic data. Depositional environments and sequences were determined and fractures were described in detail from five selected wells. Four horizons were mapped from seismic volumes for major stratigraphic tops. Over 40 sub-seismic stratigraphic tops were picked from well logs. 19 faults were mapped interactively from seismic data. The model was built in Gocad. Framework was built from seismic horizons, well picks and selected 5 major faults. Porosity was simulated using SGS and permeability was populated using cloud transform, conditioned both with well log data. The ant-tracking technique in Petrel was used in detecting and characterizing faults and fractures from 3D seismic data. The ant-tracked seismic volume was derived as a fault/fracture attribute from a texture-analyzed seismic volume, and calibrated with faults mapped manually from seismic data and fractures identified from wells. Then individual faults and fractures were auto-extracted, and divided into different sets based on regional stress and strain field evolution. The fracture density, porosity and permeability are calculated based on the attribute and the fracture-sets types, and calibrated with dynamic/production data. The model is used in infilling/farming drills and in CO2 injection planning.