Scientific Investigations Report 2010–5258
Along the Great Sand Dunes National Park and Preserve boundary (fig. 1), 10 monitoring wells were drilled by the National Park Service in order to monitor water flow in an unconfined aquifer spanning the park boundary. Adjacent to the National Park Service monitoring well named Boundary Piezometer Well No. 3, or BP-3, the U.S. Geological Survey (USGS) drilled the BP-3-USGS well. This well was drilled from September 14 through 17, 2009, to a total depth of 99.4 meters (m) in order to acquire additional subsurface information. The BP-3-USGS well is located at lat 37°43'18.06" and long –105°43'39.30" at a surface elevation of 2,301 m. Approximately 23 m of core was recovered beginning at a depth of 18 m. Drill cuttings were also recovered. The wireline geophysical logs acquired in the well include natural gamma ray, borehole caliper, temperature, full waveform sonic, density, neutron, resistivity, and induction logs. The BP-3-USGS well is now plugged and abandoned. This report details the full waveform digital signal processing methodology and the formation compressional-wave velocities determined for the BP-3-USGS well. These velocity results are compared to several velocities that are commonly encountered in the subsurface. The density log is also discussed in context of these formation velocities. |
First posted February 7, 2011 For additional information contact: This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge. |
Burke, Lauri, 2011, Digital signal processing and interpretation of full waveform sonic log for well BP-3-USGS, Great Sand Dunes National Park and Preserve, Alamosa County, Colorado: U.S. Geological Survey Scientific Investigations Report 2010–5258, 4 p.
Introduction
Sonic Tool Description
Signal Processing Methodology
Density Log
Results
Acknowledgments
References Cited