Geocellular
Model Construction for Enhanced Recovery of the Southern
Duan, Taizhong1 (1) Marathon
Oil Company,
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.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California