In the oil and gas industry, retrieving accurate information regarding subsurface characteristics in a reservoir is especially critical for the role engineers and geoscientists play on an asset team. The ability to associate information obtained from various petrophysical logs to reservoir characteristics is essential in identifying the production and economic potential of the project. However, the geological complexity of the subsurface can significantly hinder the accuracy and reliability of the petrophysical analysis, especially when applied beyond the areas immediately adjacent to the wellbores.
This uncertainty can be reduced with the integration and visualization of geological and geophysical data and models into a single 3D geospatial volume. This provides the advantage of optimized project design and development for cost-efficient hydrocarbon extraction opportunities.
Ensuring Accuracy in Petrophysical Data Analysis
Petrophysical data analysis is generally associated with reservoir characterization and oil-in-place calculation. This is facilitated with the use of various data collection techniques including seismic surveys, and well logging to derive the information which includes subsurface lithology, porosity, permeability, hydrocarbon and water saturation, rock volume, and fluid characteristics. However, the mathematical approximation of this information away from wells can be flawed due to the geological complexities within the reservoir, creating uncertainty in the analysis.
- Most data are collected with inspection of a small sample volume. Due to the geological complexities, the analysis derived from the small point data must be extrapolated in a model for areas between the wellbores. This creates uncertainty in the model and characteristics of the oil field derived from it.
- Most geological and geophysical data are collected individually, but they may have interdependency with each other. For example, each well log could be skewed to anomalously high or low values compared with others due to different logging companies or different BHA’s. The whole group of wells would need to be normalized to each other.
Uncertainty of data can severely hinder the asset development process causing huge economic loss. Accuracy in the analysis can be ensured by integrating the relevant petrophysical data into a geospatial environment for effective visualization.
Uncertainty Mitigation With Data Integration
Uncertainty can be reduced with the integration and 3D visualization of geological and geophysical data, models, and interpretations into a larger 3D geospatial volume to facilitate close cross-correlation of near-wellbore petrophysical analysis. Advanced visualization software packages can help in data correlation in a single platform to help depict complex relationships between these data. The ability to view the information together allows drilling and reservoir engineers to:
- Compare different types of well logs and seismic attributes via cross-correlation to analyze the accuracy of the interpretation.
- Identify a dominant fracture orientation and flow pattern between the nearby wellbores to assist in recovery decisions.
- Study well paths and designs to examine pressure loss in the nearby wells during the recovery process.
- Minimize uncertainty over time with time-phased analysis.
Software like CoViz 4D and EarthVision are ideal for data integration and visualization for correlation analysis between different geoscientific data to facilitate uncertainty mitigation in petrophysical data analysis.
CoViz 4D and EarthVision: 3D Integration for Refined Analysis
CoViz 4D and EarthVision are uniquely suited for efficient integration and comprehensive visualization of diverse geoscientific data in a 3D geospatial environment for refined petrophysical data analysis. EarthVision is adept in integrating geological and geophysical data for creating a 3D model of the subsurface that alleviates the complex correlation analysis between various rock properties within the reservoir. This analysis can aid planners by identifying optimal locations for well planning. CoViz 4D allows asset teams to integrate the various models so that the relevant parameters can be analyzed side-by-side. Features such as “data-filtering” and “scaling” allow the comparison of different well logs with each other to highlight different rock properties. The extensive integration and visualization technology allows for the most accurate identification of a pay zone possible, facilitating the optimal production as well as cost-saving initiative throughout the lifetime of the project.
