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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.
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Map
1. Devine Test Site located in south-central Texas. |
Map
2. Local map of the Devine Test Site. |
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.
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Map
3. Test area and key wells. |
Map
4. Detail of key wells. |
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.
Stratigraphic
Section. Formations and rock types penetrated by the test wells.
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