The Flaming
Fountain is an important component of the South Dakota veteran’s memorial site
at Capitol Lake next to the state capitol building in Pierre. The Flaming
Fountain is a water well that was drilled back in 1910 and completed in the
Dakota aquifer at a depth of 1280 feet. The well is uncapped and free-flowing,
driven by artesian pressure in the aquifer. Until recently, enough natural
methane gas was produced with the water to sustain a flame, giving the fountain
its name. This flame no longer burns
continuously, snuffing out within hours to days after being re-lit.
Stacy Langdeau, PE,
the State Engineer and an SD Mines graduate inquired if the Geology and
Geological Engineering (GGE) Department at SD Mines had any interest in
investigating the now non-Flaming Fountain. Coincidentally, a methane sensor
had recently been transferred to SD Mines from the U.S. Department of Energy to
investigate the occurrence of stray gas in drinking water aquifers in the
vicinity of fracked shale gas wells. The engineers at DOE had not gotten the
unit operational, so several SD Mines graduate students in the Electrical and
Computer Engineering Department (ECE) took on the task. They included Md
Raqibull Hasan, Saeed Shahmiri, and Sandesh Acharya. Each contributed to solving a significant
piece of the puzzle, and Sandesh was eventually able to resolve issues with the
datalogger and controller, bringing the unit up to operational status. No place
had been identified to field test it.
After Dr. Foster
Sawyer and ERI Director Dan Soeder visited with the State Engineer, she cleared
the way with the Governor for SD Mines to monitor the methane output of the
Flaming Fountain well. This was the
perfect site to field test the sensor, because at least some methane was known
to be in the well. Two GGE
undergraduates, Daniel Lucas and Logan Kocab then took on the Flaming Fountain
as a senior research project. Daniel focused on the instrumentation aspects,
and Logan focused on the geo-hydrological aspects. Geology graduate student Disha Gupta led the overall project effort. With the
assistance of Dr. Dan Dolan at the Center of Excellence for Advanced
Manufacturing and Production (CAMP), the students were able to re-design and
construct the unit within a few short weeks for deployment at the Flaming
Fountain.
The electronics of
the methane sensor consist of an Axetris solid state device that uses a laser
tuned to the adsorption wavelength of methane, and measures concentrations by the
attenuation of the beam. A Campbell
Scientific electronic data logger and programmable controller operates the
laser unit. The Axetris sensor was designed for use in a laboratory environment
under controlled climate conditions with clean line power and an adjacent laptop
computer to collect data. Adapting it for use on a wellhead in the field was a
significant technical challenge. Power
management was a major concern, especially after the DOE engineers found out
the hard way that turning off the sensor between readings to save the battery
ended up burning out the laser. As such,
the device had to remain powered-on when taking readings. Both Saeed and Sandesh did an admirable job
of addressing the power supply and power management issues.
Daniel Lucas led
the re-design of the external unit, including the weather-tight cabinets and
supporting structures. He tried to re-use as much of the original DOE materials
as possible. Logan Kocab investigated
the history of the Flaming Fountain well, discovering the original drilling
records and well logs at the South Dakota Geological Survey.
The methane sensor
was deployed on the Flaming Fountain well on Sunday, March 24, 2019. All four students: Sandesh, Disha, Logan and
Daniel gave up their Sunday to get the instrument into the field. Tellingly,
the students had asked to go to Pierre on a Sunday to install the unit instead
of a weekday so they wouldn’t have to miss class. The unit was set up in a
grassy area alongside the Flaming Fountain walkways and steps. A length of ¼ inch nylon tubing was run from
a clamp on the fountain casing to the detector. A sign is displayed on the
upper cabinet explaining what is being done and why. The plan is to leave the unit on the fountain
until autumn and collect data over the summer.
Long-term
measurements of the amount of methane produced by the well may help GGE
researchers advise the State Engineer on some ways to bring the flame back to
the Flaming Fountain. Ideas include
re-completing the well in the Dakota aquifer with a horizontal borehole to
intercept more methane or adding a lateral borehole in another formation known
to be gassy, such as the Niobrara above the Dakota aquifer. Defining the trends of methane production in
the current well over time may provide a clearer picture of why the Flaming
Fountain no longer flames.
By:
Daniel J. Soeder, Energy Resources Initiative, South Dakota School of Mines
& Technology, (dan.soeder@sdsmt.edu)