RockScale
Make your 3D seismic data available to the engineers
in a form they can use
RockScale transfers 3D models from orthogonal (seismic) grids to corner point grids. Its unique Zonal Adjustment technique ensures proper mapping of the seismic property samples into the correct stratigraphic layers in the Corner Point Grid.
Flow geometry is preserved for NTG, Porosity, and other volumes. Seismic derived property models are rescaled directly into the CPG models. The rescaled CPG models can be used directly or as 3D trend models for co-simulation in FastTracker® or other geomodeling programs.
Rescaling Orthogonal to Corner Point Grids
RockScale enables regridding and scaling in three dimensions of seismic derived properties from (orthogonal) gridding systems into mesh (CPG) gridding systems used in geologic modeling. It works in time and in depth and has the ability to regrid properties using its unique Zonal Adjustment algorithms.
These properties can then be used in a true 3D sense to assist in building more accurate reservoir models.
Full use of 3D Seismic Improves Accuracy
Engineers and geologic modelers have long realized that incorporation of seismic data can improve the predictive capability of their reservoir models. The limitations have been in using the full 3D seismic or seismic-derived petrophysical properties to build the model, rather than simply reducing the 3D data to 2D maps of the average attribute in the reservoir layer.
FastTracker and RockScale use the new Stratigraphic Model Grid (SMG) along with Corner Point Grids (CPG’s) to manage the transform of the properties (from one grid to the other) and ensure that they are structurally and stratigraphically correct. This includes the management of detailed structural models with many faults and sub para-sequences.
Additionally, Corner Point Grids can be rescaled into orthogonal grids to produce seismic synthetics for model QC purposes. This workflow can be used for evaluating 4D seismic studies and their relationship to fluid movement and detection using seismic data.
Critical Rescaling Issues for Seismic Models
RockScale handles critical issues in preparing multi-million cell models from seismic and properly preserves geometry (including flow geometries) and volumetrics for any volumes prepared in a seismic gridding system, including:
- Net to Gross
- Effective Porosity
- Impedance (Shear and Acoustic)
Zonal Adjustment
Zonal Adjustment is RockScale’s method for properly incorporating 3D properties derived from the seismic data into flow simulation models. It solves the traditional problems of resampling, regridding, and upscaling.
This example shows the initial seismic-derived porosity and two versions of resampling, where the corner-point grid has very nearly the same resolution as the seismic grid, but the grids are not aligned.
Note how the simple resampling in the middle picture shows obvious grid artifacts and also how the coherent regions of high and low values are broken up by “noise”. In addition, the green permeability layer above the red reservoir layer is gone in this resampling. This stems from the small (sub-cell) lateral shifts and consequent small vertical shifts which make the property values incorrect.
Flow units and associated net to gross are properly preserved using zonal adjustment, as shown in the bottom picture. Note also that the permeability barrier above the pay zone is preserved, and the overall size and character of the pay zones much more closely resembles the original seismic-derived values.
Shown here is a seismic-derived porosity model that was imported to a FastTracker corner point grid using RockScale.
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