A Public-Domain Geophysical Field Laboratory Operated by the Exploration Geophysics Laboratory (EGL)
The University of Texas at Austin Bureau of Economic Geology
University Station, Box X, Austin, Texas 78713-8924; 512-471-1534
Test Site Overview
The 100-acre Devine Test Site (DTS) is located less than 50 miles southwest of San Antonio, Texas, in Medina County, Texas (Maps 1 and 2, below). The site is managed by the Exploration Geophysics Laboratory (EGL), an Industrial Associate Program at the Bureau of Economic Geology. It is a state-of-the-art public-domain geophysical research facility for academia and industry donated to UT in 1998 by British Petroleum (BP). The test site is used for surface-based seismic and potential-field experiments performed in conjunction with downhole and crosswell experiments.
Test Site Attributes
The size and shape of the 100-acre field laboratory and the adjacent area for which surface-access rights can be negotiated with property owners is shown on Map 3. BP drilled three test wells (2, 4, 9) during its 12 years of ownership, which are cased to 3,000 ft. Wells 2 and 4 are completed with fiberglass casing to allow for testing of borehole electromagnetic (EM) sources and receivers. These wells are popular with logging companies as resistivity tools can be tested without the complications of steel casing attenuating EM wave propagation. Four shallow (100-200 ft) steel-cased holes are available for borehole-based seismic energy sources and other instrumentation. The wells are in excellent condition. Permanent concrete and gravel pads provide consistent vibrator coupling in a wide range of weather conditions.
Significant upgrades to the site have been made as a result of generous donations by the SEG Foundation. The site now has electricity, flood lights for nighttime use, a water well and water lines, new and refurbished chain fences, new entry gate, tractor mower, and storage sheds.
The stratigraphic section (shown below) breached by the site's 3,000-ft wells is well suited as a field laboratory for geophysical experiments. A key attribute of the site, which appeals greatly to developers of downhole geophysical instruments, is its stable geologic condition. The nearest oil and gas production is several miles away, which ensures that no fluid-exchange processes are occurring in rock facies immediately around the wellbores. Petrophysical properties of the formations, therefore, are well calibrated by numerous historical well logs preserved in the public database. Equipment manufacturers and researchers can also quickly determine if a new tool, a new measurement procedure, or a new petrophysical analysis procedure is providing correct data.