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

A composite point bar sediment body in the Tertiary Loranca Basin of central Spain was the subject of a detailed analysis of the relation between sedimentary facies heterogeneities and permeability contrasts.Comparison of field-measured permeability data with grain size, sorting and diagenetic features shows that a strong decrease in permeability (from 10D to 0.1D) over the contact zone of two stacked point bar units is related to the occurrence of a cemented, rootletted mud layer which formed during a channel abandonment stage. This type of low-permeability horizon is observed to extend from the adjacent floodplain downslope onto the abandonment layer. In the topographically lowest part of the abandonment slope, however, the mud layers usually are eroded during a subsequent channel reactivation stage, and stacking of point bar units is characterized by sand-on-sand contacts with normal, high-permeable transitions.Statistical processing of permeability data from cross-bedded sets within a point bar unit reveals that the average foreset permeability is significantly higher than the average bottomset value (total permeability range from 0.5 to 17 D), and that the foreset values are highly variable. Both observations are directly related to grain size and sorting differences. In reservoir equivalents of the composite point bar sediment body, the effect of the permeability contrasts on fluid flow is two-fold: 1 channel abandonment layers, when preserved after channel reactivation, cause partial compartmentalization of the reservoir unit; 2 in water-flooded oil-reservoirs, permeability contrast between adjacent foreset laminae and bottomsets may cause a capillary pressure-determined water fingering effect.@en

EOR requires detailed knowledge of permeability distribution in a reservoir. In reservoirs with a complex architecture, permeability distribution can be modelled with stochastic models which incorporate geological information such as width/thickness ratios of reservoir units and width/length ratios of shales layers. Reliable geological data can be derived frorn the reservoir itself or from analogue outcrops. This paper presents the preliminary results of an outcrop study of a turbidite channel sediment body, the Lower Ainsa Channel. The deposits are of Eocene age and outcrop near Ainsa, central Spanish Pyrenees. The sediment body is at least 375m wide, has a maximum thickness of 30m and consists mainly of interbedded conglomerate, sandstone and mudstone. Five li thofacies are recognized. Their spatial arrangement is related to rnass­transport processes. Data are presented on spatial distribution and geornetry of the sandstone and mudstone layers. A shale length distribu­tion curve is compiled from the outcrop data. @en

The Upper Cretaceous Cliff House Sandstone in the San Juan Basin, New Mexico is characterized by en-echelon, NW-SE elongated linear sandstone complexes representing successive phases of coastal sedimentation along the western margin of the Cretaceous Seaway. Detailed analysis of the lithofacies, spatial facies relations, and geometry of the stratigraphically highest Cliff House Sandstone complex in the southern part of the basin indicates a storm-dominated, tidal linear barrier island coast as the depositional environment. The complex consists of four stacked sandstone bodies; each body is bounded above and below by a sharp erosion surface. Offsets of the stacked sandstone bodies along the erosion surfaces mark minor transgressive and regressive shifts of the Cliff House coast. The Cliff House Sandstone is generally known as a transgressive sequence; accumulation of barrier sands, however, took place during the regressive intervals. In subsequent transgressive intervals, part of the accumulated sediment was eroded, and only topographically low-lying parts of the barrier, e.g., shoreface, tidal-inlets, and lagoonal sediment were preserved.@en

The Menefee Formation (Mesaverde Group, Late Cretaceous) in the San Juan Basin, northwestern New Mexico, consists largely of deltaic plain and paralic deposits. The deposits were formed along the west coast of the Cretaceous Seaway. The upper part of the Menefee sequence displays isolated sandstone bodies with a Jo bate geometry. The sandstone bodies are embedded in carbonaceous shales of coastal swamp/lagoonal origin. Sedimentary structures include inclined lamination, tabular and wedge-shaped cross-bedding in the lower parts of the sandstone bodies, and trough cross-bedding in the upper parts. The bi po lar distribution of transport directions, as well as the presence of mud drapes on foresets and bottomsets, point to a tidal environment of deposition. The lobate sandstone bodies are thought to have been generated as flood tidal deltas. Based on theoretica! models for the stacking of tidal delta deposits, an indication is given of the relation between relative rise of sea level and behaviour of the flood tidal del tas and connected tidal inlets on the harrier coast of the Cretaceous Seaway. @en

Several harrier island sand bodies are well exposed in the southern Pyrenees, Spain. They belong to the Pano Formation of Lutetian (Upper Eocene) age and were formed in an environment which was strongly influenced by rising sea level. A detailed sedimentological study of a calcarenitic sediment body in this Formation is presented. The larger part of the harrier system described here is made up of tidal inlet deposits and washover sequences. The sediment body has a lense-shaped geometry: The width of the exposed body is 260 m and its maximum thickness is 20 m. It is made up of thin to thick bedded calcarenites. The tidal inlet part consists of massive, and tabular to lense-shaped beds. Laterally, in a landward direction, massive beds alternate with thinner washover beds, which have a primary landward directed dip. The marl/sand ratio increases in this direction. In their proximal parts, washover beds are subdivided by horizontal erosional surfaces. The subdivision shows a regular pattern and is attributed to varying storm intensities during one single storm event. Vertical stacking of tidal inlet and washover deposits is ascribed to a balance between the amount of sediment deposited and the rate of relative rise of sea level. @en