PerGeos Process Based Modelling
Process Based Modelling modules for PerGeos
validated over the years with Oil & Gas companies, simulates the natural
processes of sedimentary rock formation (sedimentation, compaction, and
diagenesis). The calculation of petro-physical parameters (for example, absolute
permeability, formation factor, and NMR) and the calculation of multiphase flow
properties are based entirely on the 3D numerical rock models, or
imported Micro CT volumes, combined with information on the fluid characteristics.
The 3D numerical rock models are generated through sedimentation, compaction, and diagenesis simulation.
The Process Based Modelling comes as four fully documented new PerGeos modules, accessible from the Analysis workspace.
component in the process-based modelling routine provides a set of model types to choose
between; each model mimics the grain skeleton of known sedimentary rock
types. Each grain bed is characterized by a set of parameters: for example, grain size distribution, grain shapes, and information on mineralogy. These parameters are based on expert knowledge about the actual rock or information derived from thin section analyses (point counting or SEM analyses). PerGeos also supports a set of sedimentation processes for the various rocks, such as low or high energy depositional environment.
The size of the grid and associated voxel size is defined under the Grain Bed Properties options.
The Sedimentation module outputs an implicitly defined data set of type GrainBed. To visualize the GrainBed data, it is necessary to apply the Grain Bed Gridder, which transforms the implicit data into Label data.
Compaction of the sediment due to vertical stress from the overburden, is an important agent for porosity reduction during burial. PerGeos emulates both vertical and horizontal compaction through bulk volume reduction.
The last step in
the rock formation process is Diagenesis. PerGeos supports
a set of relevant diagenetic processes, such as quartz cementation, clay coating,
clay filling, clay bridging, carbonate cementation, pyrite growth, and feldspar
dissolution. In addition, the sheet silicate Muscovite mica also may be added
during the diagenesis process.
The diagenetic modelling must be based on a selection of reliable rock parameters derived from Scanning Electron Microscope (SEM) images, point counting of thin sections, X-ray diffraction (XRD), or X-ray microtomography (Micro CT).