The microscopic scale...

Core description gives us data on the microscopic scale and assists the team in depth shifting logs to match the core properties. Qualitative logs can be developed to display lithology, rock textures, and pore types (connected vs. unconnected). Thin sections, core analysis data, X-ray diffraction, and SEM analysis can provide additional data to develop transforms between porosity and permeability and to understand the ability of the reservoir to produce economically.

The macroscopic scale...

Log curves provide data on a macroscopic scale and assist the project team in understanding the reservoir rock as measured near the wellbore. Well log measurements collected by different well service companies, under different wellbore conditions, and with different vintages of tools need to be normalized. Normalization can be accomplished using a number of methods, including: a type well approach, using modern log tools, and by applying log curve corrections. Cross plots are often used to invoke the power of statistics to benefit the normalization procedure.

After normalization, petrophysical analysis includes tying the core to the log curves for agreement in depth. If necessary, Vshale corrections can be made to correct logs for the influence of shale. Effective porosity, water saturation, and permeability determinations can be calculated. Again, cross plots play an important role in determining relationships and developing transforms where linear relationships exist. Complex relationships may require more eloquent methods of developing a transform, such as, the use of neural networks.

The megascopic scale...

Geophysics gives us data on an inter-well or megascopic scale. Important steps in the utilization of geophysical data include: the proper acquisition and processing of 3-D seismic data, interpretation, phase analysis (for rotation to zero phase), and the generation of seismic attributes. Geostatistics are then used to determine relationships, if they exist, between the seismic attributes and the petrophysically derived reservoir properties. Statistically significant relationships can be used to generate seismicly guided maps of reservoir properties, such as, porosity and water saturation.

Finally, the results of the geological, petrophysical, and geophysical studies are used to develop a 3-D geologic model with discretely defined flow units or layers. Interpolation of the reservoir properties in three dimensions are output as a grid for use in reservoir simulation.

In conclusion, GeoSpectrum’s presentation displays the results of integrated reservoir projects utilizing the above methodology and leading-edge software technology.