16. Static Reservoir Modeling

Horizon surface modeling
Horizon surface meshes are watertight with fault surfaces, forming reservoir framework for subsequent workflow. Input data are seismic horizon interpretation and well tops, constrained by fault network models made step 1.
Stratigraphic layering
Stratigraphic layers can be inserted into spaces between two key horizons (zone) on the basis of user-defined contact relationship: proportional, top conformable, bottom conformable, or parallel to external surface. Isochores can be used to add layers. Users specify number of layers (for proportional) or layer thickness ratio distribution (other contact types).
Fluvial Reservoir Model Templates
Build stratigraphic layer and facies models for point bars and all types of stacking patterns in fluvial deposits. User can edit channel geometry and patterns interactively
Upscale Well Logs
Well log curves are “scaled-up” to cell values along well paths in the stratigraphic grid derived in step 3. The well log upscaling method includes “volumetric averaging” for porosity, “volume voting” for facies log, and “harmonic averaging” for permeability. Upscaled well data are called “well conditioning data”.
Geostatistical Data analysis
Well conditioning data can be analyzed through one user interface to estimate the histogram distributions, variogram models, and cross-correlation coefficients of facies, porosity and permeability.
Conditional simulation of facies model
Multiple realizations of facies grids will be generated through the “indicator simulation” algorithm to assign facies code to each cell in the grid. Well conditioning data will be honored.
Conditional simulation of reservoir properties
Multiple realizations of porosity and permeability grids will be generated through “sequential Gaussian simulation” algorithms. Porosity and permeability trends from well data or seismic attributes can be imposed to the simulated realizations. As an option, universal kriging and collocated cokriging algorithms will be used to make the “best estimate” as a comparison to stochastic realizations. Oil and gas saturation grids will be generated either from the relationship between saturation, porosity, and permeability or through direction simulation in the same way as porosity and permeability. Well conditioning data will be honored in each grid derived from geostatistical simulation or estimation method.
Calculation of oil and gas in place and uncertainty quantification
User can select contact surface of oil-water, gas-water for volumetric calculation for conventional reservoirs, together with polygon and target zones. Oil and gas volumes in place are calculated for each realization generated in step 7. Histogram distribution curves of OGIP will be plotted, with indication of P10, P50, and P90 or at any user defined percentile.
Upscaling of geo-model to flow-model
User can define a target grid that has a smaller number of cells. Volumetric averaging method will be used to upscale porosity grid. Arithmetic, harmonic averaging and “flow-based” upscaling method can be selected for upscaling permeability grids.
3-D Seismic Modeling
Generate 3-D synthetic seismic volumes from reservoir models and export them in SEG-Y files.