Cellular grids are created so gridlines align to the major structural components of the model such as the faults and horizons.
Greater accuracy in reservoir modeling supports better field development and operational decisions. With the wealth of geologic, stratigraphic, geophysical, and petrophysical data, geoscientists have never been in a better position to build models that characterize reservoirs at the macro and micro level.
Save Time With 3D Geocellular Modeling
The Workflow Approach
Given the types and volumes of data, parametric variations used to develop individual models, and iterative aspects of the geocellular modeling, a workflow approach brings efficiency and consistency to the modeling process. A workflow that creates a 3D geocellular model with attributes true to their depositional arrangement might follow these steps:
- Input data—interpreted, depth converted seismic and well tops.
- Build the earth model based on seismic picks, with fault picks quality controlled and limited by tip-line polygons.
- Compute a fault tree that describes the fault framework and fault dependencies.
- Grid stratigraphic picks from the seismic interpretation, optionally using well-top picks as constraints on the resulting horizon‘s shape and depth.
- Superpose depositional, erosional, or unconformable stratigraphic horizons to form the stratigraphic sequence.
- Evaluate input horizon picks in the context of modeled faults and other horizons to produce an earth model geometrically consistent with input data.
- Populate model with attribute data using 3D grids within stratigraphic layers and reconstructive techniques to compensate for fault displacements. Grid cell size would be determined by the user.
- Conform attribute grids with layer boundaries for better representation of the attribute distribution.
3D Geocellular Modeling With EarthVision
To address the need for efficient 3D geocellular modeling, Dynamic Graphics, Inc., a leader in 3D visualization and analytic software offers an optional geocellular module as part of its EarthVision product. Using configurable workflows, the module efficiently converts structure or attribute models into a cellular-grid format for input to reservoir simulators. EarthVision improves the efficiency and accuracy of geocellular modeling by:
- Using fault-optimized algorithms to calculate cellular reservoir grids, accurately depicting the structure/attribute in the original 3D model.
- Aligning grid lines with major structural model components (faults and horizons).
- Calculating attributes within each non-orthogonal 3D cellular grid so that they are ”cell-centered” (averaged over rock volume of a cell).
- Supporting multiple attributes per cell, with either floating-point or discrete values.
- Providing upscaling options—arithmetic, geometric, harmonic, and power mean; hybrid schema for heterogeneous attributes like permeability.
The resulting 3D geocellular grid provides a framework for calculating and predicting fluid flows within a reservoir. This 3D geocellular modeling method minimizes the loss of information between the structural modeling and reservoir simulation processes and more accurately reflects the modeled geologic features.
Visualize and Verify Geocellular Models
A rich 3D environment for visualization and analysis facilitates model building and anomaly calculation where users can collaboratively evaluate the goodness of fit and quickly modify parameters and rerun the workflow if needed. Once the geocellular grid is finalized it can be exported to a wide range of reservoir simulation software products.
With EarthVision, the 3D geocellular model can be interactively visualized against a 3D geologic model.
Computationally Efficient, Visually Detailed 3D Geocellular Models
EarthVision, from Dynamic Graphics, Inc., enables geoscientists to quickly build, visualize, analyze, and update precise 3D models. It enables model examination and interrogation in the context of datasets provided by all members of an asset development team, allowing you to confidently make development and operational decisions that positively impact profit and reduce operational risk. To learn more about EarthVision contact our team.
