Chris Sladek, Mark Coolbaugh, Rick Zehner, Chris Kratt, Robin Penfield - PowerPoint PPT Presentation

1 / 23
About This Presentation
Title:

Chris Sladek, Mark Coolbaugh, Rick Zehner, Chris Kratt, Robin Penfield

Description:

Chris Sladek, Mark Coolbaugh, Rick Zehner, Chris Kratt, Robin Penfield – PowerPoint PPT presentation

Number of Views:208
Avg rating:3.0/5.0
Slides: 24
Provided by: chriss79
Category:

less

Transcript and Presenter's Notes

Title: Chris Sladek, Mark Coolbaugh, Rick Zehner, Chris Kratt, Robin Penfield


1
Title
Development of 2-Meter Soil Temperature Probes
and Results from Desert Queen and Tungsten
Mountain
Chris Sladek, Mark Coolbaugh, Rick Zehner, Chris
Kratt, Robin Penfield
Great Basin Center for Geothermal
Energy University of Nevada, Reno
Funding U.S. Department of Energy, Assistant
Secretary Energy Efficiency and Renewable Energy
under DOE Golden Field Office Financial
Assistance Award DE-FG36-02ID14311
Desert Queen area, near Desert Peak, NV
2
Temperature maps are key tools in geothermal
exploration and development.
Temperature gradient map of Desert Peak area
ASTER thermal infra red image of Bradys
3
Is 2 meters the right depth?
2 meter depth is relatively easy to reach,
effectively masks daily temperature changes.
4
Temp graph
Daily temperature variations at the surface damp
out quickly with depth.
surface
1 meter depth
5
Successful Application of Shallow Temperature
Measurements
Stillwater, NV
  • Soda Lake, NV. (1 meter) Olmsted, 1977
  • Upsal Hogback, NV. (1 meter) Olmstead, 1977
  • Fly Ranch, NV. (1 meter) Crewdson, 1978
  • Stillwater, NV. (1 meter)
  • Coso, CA. (2 meters) LeShack and Lewis, 1983
  • Humboldt House/Rye Patch, NV. (2 meters)
  • Hawthorne, NV. (2 meters) Trexler et al., 1981
  • Pumpernickel Valley, NV. (2 meters) Trexler et
    al., 1982
  • Astor Pass and Smoke Creek Desert, NV. (2 meters)
  • Coolbaugh et al., 2006

6
There must be an easier way to do this!
2M temp measurements using hand soil auger in the
Smoke Creek Desert, NV
7
2-meter Temperature Probe Design goals
  • 1) Minimal thermal disturbance to ground
  • 2) Small thermal mass (thermal intertia) for
    rapid equilibration
  • 3) Ability to penetrate moderately rocky soil
    (minor coarse gravel and small cobbles)

8
Solution A Hollow probe that can be drilled or
driven into the ground and a temperature sensor
inserted afterwards.
First try ¼ schedule 40 pipe with tungsten
carbide hammer drill insert, Driven with hammer
drill.
Problems Medium duty hammer drill did not have
high enough impact energy, and metal fatigue
caused probe to break after 6 uses.
9
Current probe design ¼ schedule 80 seamless
pipe with hard faced tip containing tungsten
carbide particles, and threaded cap to prevent
mushrooming. Probe is driven with 19.9lb
impact hammer (no rotation) Low cost at
approximately 50 each   Limitations difficult
or impossible to penetrate extremely rocky
ground, thick carbonate cemented or silicified
ground.
10
Instruments
Temperature measurement instruments
Instrumentation consists of, Pt RTD (resistance
temperature device), RTD meter and data logger.
Thermistor devices should work equally
well, while thermocouple meters may drift as a
result of the ambient temperature.
11
2M Survey Locations
Detailed 2 meter temperature surveys have been
conducted at two blind geothermal target areas
Desert Queen a thermal anomaly Northeast of
Desert peak (initial test area) Tungsten
Mountain where hot water was encountered during
mineral exploration drilling (on going study)
Desert Queen
Dixie Valley
Reno
Tungsten Mountain
12
Test area
Test Area NE of Desert Peak, NV
Bradys Hot Springs
Three main thermal anomalies have been defined by
temperature gradient drilling at Bradys/Desert
Peak, NV
Northeast anomaly (Desert Queen test area)
Desert Peak power plant
Desert Peak anomaly
13
  • Equipment
  • 40 2M probes
  • Demolition hammer
  • Generator
  • RTDs and Meters
  • Hand held GPS
  • Utility ATV

Up to 20 probes can be placed in one day, and
temperatures recorded the next day.
Driving 2M probe with demolition Hammer
14
Rod puller
Although some probes can be pulled with a pair of
10 locking pliers, a puller is often required,
and it is much easier on the back.
15
Base stations
Two base stations were established to
characterize thermal response of the probes
  • Probe reaches equilibrium
  • in 45min
  • Temperature reaches equilibrium
  • in 15 min
  • Seasonal drift is corrected for
  • using base stations

16
Temp map
Map of 133 temperature measurements collected in
9 days of wield work
Desert Peak
Bradys
Desert Queen anomaly
Desert Peak power plant
N
2kM
17
When 2-m temperatures are measured near the
earlier temperature gradient wells, the shallow
temperature anomaly defined by the wells (30 m
depth) is reproduced
20.7
23.1
24.4
21.8
30.5
21.6
22.6
24.7
25.6
White circles temperature gradient wells
18
1C contours on 2 meter temperatures 100 (30
meter) temperature gradient shape
19
Surface features related to geothermal
activity, Desert Queen area, NV
Artesian wells
Carbonate tufa columns (these pictured are about
1 m tall)
20
Tungsten Mountain Blind target with no
associated hot springs or steam vents. Mineral
exploration drilling encountered hot water. 2M
temperature probe survey indicates zone of
anomalous temperatures (5oC greater than
background) 5kM or greater in length that may
continue to the NE.
21
Real time data
Real Time Data
drive probe
Allows the ability to modify survey in real time
quick measurement
22
Conclusions
2 M temperature surveys can be useful as infill
to conventional gradient drilling, but likely
more valuable for siting conventional gradient
drill holes. It has the potential to be a
valuable tool for exploration in the great basin
and other arid regions where heat signatures are
less likely to be masked by ground water. The
Great Basin is dotted with fossil and
geologically recent geothermal features, and
there are likely many more blind systems yet to
be discovered. 2M temperature probes add to the
tools that can be used to locate these blind
systems.
23
Improvements
Because the probes were made of ¼ mild steel
pipe, their use is limited to areas that are not
excessively rocky. The use of a light duty rock
drill and portable compressor to pre-drill a
hole, in which the 2M probe could be inserted,
would allow the probes to be used in areas where
large rocks or sinters are encountered.
Write a Comment
User Comments (0)
About PowerShow.com