Comparison of Reservoir Characterization Approaches Used in Models for CO₂ Sequestration Within the Illinois Basin

James R. Damico, Rex Knepp, John P. Grube, and Scott Frailey
Illinois State Geological Survey, Champaign, Illinois

The Illinois State Geological Survey, as part of the Midwest Geological Sequestration Consortium, has designed a number of field pilots to test CO₂ injection as a means for enhanced oil recovery. The first pilot involved a huff-n-puff well stimulation technique in the Louden field in Illinois in 2007. In order to make useful predictions, a detailed model of the reservoir architecture was required to produce injection and transport simulations.

Due to the plethora of work on reservoir modeling, there are a variety of different approaches available. One of the main challenges in selecting a model is finding a balanced approach that honors the data as well as the input from the theoretical depositional model. In this case, a pure stochastic approach was utilized in order to best honor all the data available. This approach allows the data to control the model interpretation. In order to perform a post-operation review, we will revisit this model using a deterministic facies modeling approach. This approach incorporates a conceptual model of the facies into the model, making more use of the geologist’s interpretation skills.

The focus of this research will be to objectively evaluate the two methods and compare the results of modeling in a heterogeneous environment. The analysis will look at the variation produced among the realizations as well as the subsequent predictions from the injection simulations. Successful analysis will lead to better refined models for future tests as well as provide insight on model selection.

Presented AAPG Eastern Section Meeting, Pittsburgh, Pennsylvania 2008 © AAPG Eastern Section