Introduction, Purpose, and Scope, continued Assessing reservoir heterogeneity

The goal of reservoir heterogeneity studies is to understand the extent, continuity, and volume of the reservoir and fluid migration paths. Several technologies are available to address these issues, including diagnosis of the external shape of the reservoir, internal geometry and architecture of the reservoir, pore shape and geometry, and finally, inter-grain and intra-grain contacts, cements and diagenetic paragenesis. These are also scalar differences.

External geometry of the reservoir includes the spatial location of the reservoir and surface analogs in terms of regional setting and sequence stratigraphy; and the external geometry of the reservoir in terms of structural attitude and orientation, size and shape, and continuity.

Internal geometry of the reservoir and surface analogs focuses on characterization, distribution and genetic controls on pay and non-paying horizons, and documentation of continuity of fluid flow barriers and distribution of rock properties (e.g., porosity, permeability, saturation [capillary] properties). The goal is to develop an understanding of the three-dimensional distribution and continuity of the rock-pore-fluid system of the reservoir.

Pore analysis and inter-grain analysis is used to diagnose specific reservoir problems, such as swelling clays, pore throat constrictions, and passage of water versus petroleum. Maps of clays, fine clastic particles, and cements are important to reservoirs with restricted permeability and limited susceptibility to secondary recovery by water injection. Such technologies are applicable to specific reservoirs and will be applied as appropriate during the course of study.

One of the new and most important technologies now available to analysis of reservoirs is high-resolution correlation, which requires exceedingly detailed studies of cores and logs. This relatively new field of reservoir heterogeneity analysis has been very effective in major oil company research programs, and has been advanced by the Colorado School of Mines research group. A fuller discussion of these techniques and their applications to reservoir heterogeneity analysis is Appendix A. This technology will be widely applied to the documentation of typical fields within plays.

Kansas Geological Survey, Digital Petroleum Atlas
Updated June 1996
Comments to webadmin@kgs.ku.edu
URL=http://www.kgs.ku.edu/DPA/frontEnd/Intro/intro04.html