Subsurface geologic models can be significantly improved by integrating interpreted seismic, borehole data, reservoir simulation models, and virtually any source of xyz data with reservoir attributes such as temperature, pressure, and well logs to foster a better understanding of the geologic structure and faster, better decision-making.
Precise geological modeling depicting intricate relationships among lithology, rock properties, and faults in structurally complex reservoirs are essential to successful hydrocarbon production. With access to detailed models geologists, geophysicists, and reservoir and production engineers are better informed to make critical decisions affecting reservoir development and operations.
Data, Algorithms, and Visualization Enhance the Value of Geological Modeling
This level of detail provides a better understanding of geological models and facilitates collaborative decision making among reservoir team members.
Combine Relevant Subsurface Data to Create Detailed Geological Models
EarthVision integrates all relevant data such as interpreted 2D and 3D seismic surveys, interpreted well logs, processed gravity and magnetic surveys, and borehole data (core samples, temperature, and pressure, etc.). Essentially any data with x/y/z location and associated attributes can be incorporated into the subsurface model. EarthVision uses a variety of algorithms to build the models, including capabilities to:
- Define faults and lithology surfaces using three-dimensional surfaces.
- Automatically calculate fault block 3D intersections and truncations.
- Grid horizon and property information in geometrically restored, unfaulted space to ensure consistency.
- Spatially sort horizon information by fault block with horizon surfaces generated for each block.
- Calculate intermediate surfaces based on a reference surface and limited intermediate horizon picks where horizon data are scarce.
- Integrate seismic interpretations in time with depth models using geo-model-driven velocity and time-to-depth conversion.
- Apply 2D and 3D minimum tension gridding algorithms to calculate a smooth surface that closely fits input data values.
- Employ kriging techniques to create 2D or 3D grids.
Workflow Facilitates Model Development
Each data component (fault data, geologic horizons, rock properties, etc.) is reviewed, analyzed, cleaned up, and edited to improve data quality. Data are then used to calculate specific parts of the model.
- Fault data generate a model of each fault surface. Fault surfaces are then compared to all the other faults for consistency. A fault hierarchy or fault tree is generated to define how fault blocks in an area fit together.
- Geologic horizons data are examined together and compared to check for consistency and “geologic sense.”
- Fault and horizon data are combined to create a “zoneblock” model with all of the fault blocks and all the geologic zones inside them. These zoneblocks are rock containers—bounded by faults and geologic horizons.
- With zoneblocks created, the property modeling process begins. Rock properties such as porosity, permeability, shale content, gamma ray values, resistivity, etc., are modeled inside the 3D rock containers.
With property modeling completed, a wide range of calculations and analyses are now available. Volumetric calculations answer questions such as, “How much volume of oil could potentially be inside ‘Sand A’ of ‘Faultblock B’ where porosity is >35%, resistivity >200 ohms, permeability >90 millidarcies, and everything is above the oil-water contact at –7,500?”
Visualization for Data and Model Verification & Analysis of Complex Relationships
EarthVision from Dynamic Graphics, Inc., is an integrated software package for the analysis, synthesis, modeling, and visualization of any spatially referenced data. Powerful analytic and visualization capabilities enable you to explore data relationships inherent in complex geological models, allowing your team to confidently make asset development decisions that positively impact profit and reduce operational risk. To learn more about EarthVision contact our team.
