Vuggy porosity is a major control on the quality and engineering properties of many carbonate petroleum reservoirs throughout the world. Most studies of vuggy porosity have concentrated on core data, drilling information, and various borehole imaging tools; these methods can only provide a limited view of the reservoir. This study will provide a larger-scale case study of vuggy porosity development which is more applicable to reservoir characterization, and ultimately can be integrated at the seismic scale.
The study is being performed in Carlsbad Cavern and Lechuguilla Cave within the Permian Capitan Reef Complex of New Mexico and Texas. Over 120 miles of three-dimensional cave mapping data will be used to statistically classify the cave passages into morphologic groups. These groups will be compared to maps of stratigraphic units and to a detailed database of geologic and paleontological information to reveal relationships between geologic facies and the development of vuggy porosity.
Maps of Carlsbad and Lechuguilla show different morphologic patterns on multiple levels. This study is an important step in determining whether this is due to variability in fracture-dominated vs. facies-dominated control of dissolution, or due to superimposed dissolution events. Cave development exposed in these caverns is controlled by the same processes that control the creation of vuggy porosity in many carbonate fields worldwide, and is especially applicable to equivalent units of the nearby Permian Basin. This study will provide quantitative and qualitative data on vuggy porosity development, and will provide a method to relate reservoirs to surface analogs.
AAPG Search and Discovery Article #90925©1999 AAPG Foundation Grants-in-Aid