MARTINEZ, ALEX, Kansas Geological Survey, Lawrence, KS; JOSEPH M. KRUGER, Department of Geology, Idaho State University; and EVAN K. FRANSEEN, Kansas Geological Survey, Lawrence, KS
High-resolution ground-penetrating radar (GPR) is a subsurface imaging tool that can extend results gained from reservoir analog outcrop studies into three dimensions and add detailed information about reservoir analogs that is unavailable from either seismic data or well control alone in order to provide quantitative data for modeling. Integration of GPR reflection information and outcrop photomosaics can allow detailed study of subtle changes in lithology and bedding surfaces by observing lateral and vertical changes in GPR reflection character. Outcrops of three Lansing-Kansas City group limestone units which produce in the subsurface elsewhere - the Captain Creek Limestone, the Plattsburg Limestone, and the Drum Limestone were used as test sites for determining the vertical imaging resolution, penetration depth, and reflection character of high-frequency (500 MHz) GPR in limestones. Features as small as 0.1-0.2 m, including major architectural elements such as bounding surfaces, and internal features such as fractures and crossbedding, were successfully imaged. Shale can sometimes be helpful in GPR studies. For example, variations in GPR reflection character from thin shale seams at bedding contacts of arillaceous limestone units in the subsurface increased imaging resolution. Successful results from this study indicate that GPR is a powerful tool for high-resolution imaging and quantification of stratigraphic architectural elements in 3D, especially in locations where outcrop data is sparse.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah