Migri 2.4.2 with Lithofacies modelling

Migris is very pleased to announce the release of the 2.4.2 version of Migri and MigriX tools for modelling the generation and migration of hydrocarbons in sedimentary basins. With the completion of this release, we have streamlined the modelling of migration within different sedimentary facies using e.g. the Norwegian Offshore Directorate (SODIR) lithofacies scheme.

This approach makes it easy to efficiently create alternative carrier facies distributions based on existing paleogeographic maps and rapidly test these as migration scenarios. The lithofacies method can be applied on single or multiple layers, complementing the existing lithology-based definition.

Using the LithoFacies editor, each facies can be assigned lithological parameters such as Vsh (fraction of shale – see table in Figure 1) and/or Vca (fraction of carbonate). The areal extent of each facies can then easily be assigned to different areas using digitized polygons (see map in Figure 1). Once the Vsh fractions are defined, the model is ready to be simulated with the resulting shale fraction map (Figure 2) and the consequences for the migration and trapping of oil and gas can be studied through time.

Figure 1. Lithofacies map (left) with assigned lithology fractions and colors in table (right). SODIR facies names and colors are used.
(Table 6.2.3 in the 2022 Geostandard)
Figure 2. Shale fraction maps for 3 layers of the model. The lithofacies map is used for the 141Ma layer. A permeable sheet sand is modelled for the 159Ma layer. The Source layer at 210Ma is modelled as a type B using the Baur 4 component kinetics.

Figures 3 and 4 show the oil and gas migration after two of the time steps, 40 and 0 Ma, respectively. Notice how migration from the deeper Brent carrier has leaked up into the Lithofacies layer above in the areas with lower shale fractions. Also note how trap A is first charged with oil at 40Ma and thereafter spills all the oil into trap B between 40 and 0Ma. This results in trap B receiving large volumes of oil and growing in size between 40 and 12 Ma, as shown in Figure 5. During the last modelled timesteps trap B also changes from an undersaturated oil trap to an oil and gas trap with significant volumes of condensates due to deeper burial.

Figure 3: Hydrocarbon migration modelled until 40Ma for the 3 layers shown in Figure 2. Oil is green while gas migration is in yellow and gas traps are red. Trap A is modelled to contain oil (green).
Figure 4: Hydrocarbon migration modelled until 0Ma for the 3 layers shown in Figures 2 and 3. Trap B is modelled to contain oil (green) and gas (red).
Figure 5: Trapped hydrocarbons in trap B though time. The trap changes from an oil trap until 3 Ma to an oil and gas trap at 0 Ma.