The Geological Modeling Project GM2 under the Joule I research program was initiated in 1990. Two consortia were forrned, which concentrated on separate aspects of geological modeling. The TUD, CSIC, TNO consortium dealt with geological characterization of fluvial sediments as a tool for mathematica! reservoir modeling, whereas the DALUC consortium developed interactive sequentia! forward-modeling software for the investigation and delineation of hanging-wall traps. @en