Sevier Lake is a bit of a misnomer: The lake, located in central Utah’s Sevier Desert, has historically been dry more often than not.
The lake, which right now has up to 2 feet of water in some locations, is currently the site of a major potash mining project. The salt-rich potassium contained in potash soil is valuable for use in many fertilizers.
Salt Lake City-based drilling company Direct Push Services LLC was recently hired by a mineral exploration firm for a two-stage project to collect continuous soil cores and install 1-inch temporary piezometers at 400 locations in the lake bed’s sediment. The piezometers, which measure static liquid pressure, were set to a maximum 70-foot depth and covered a 30-mile area around the lake.
Sean Bromley, co-owner of Direct Push since 2004, said the project was more difficult than some of the company’s others.
“The stability of working off the deck presented a lot of challenges,” Bromley, 38, said.
The company used a Geoprobe 6600 rig, mounted onto a Sno-Cat trailer, to tow a diesel Sno-Cat unit that featured 5-foot-wide tracks. The trailer was used to move the rig between worksites and to provide a home base for the five
Direct Push employees who were working at the site.
“We also simultaneously used our (Geoprobe) 7730DT and the 6600 configuration in these areas to speed up the installation process, which enabled us to enter difficult areas only accessible with tracked equipment,” Bromley said.
The weather was another obstacle Bromley and his crew had to overcome. Windy days made it hard to keep the equipment stable while they tried to collect the soil samples.
And working in the desert from November 2011 through February 2012 meant it was cold.
“Keeping yourself warm (was hard) because you’re out there exposed to all the elements,” Bromley said. Many days, temperatures were well below freezing.
Sevier Lake’s environment was tough on the equipment as well.
“The water that we were working in, it’s really brackish, it’s really salty. That takes its toll on equipment too because it’s corrosive,” Bromley said. “It definitely increases the maintenance. You’re washing it off every day or every other day to try and keep the salt from building up.”
In addition, working for a mining company meant there was a long list of health and safety regulations the company had to follow, and Direct Push employees were constantly under the client’s supervision.
For employees working on site, days were long-up to 10 hours, and with intervals of 10 days on, followed by four days of rest.
The project’s second phase involved collecting soil cores and placing wells in the lake areas that held water. Some were as shallow as 3 inches while others were up to 2 feet deep. Airboats were used to take crews to and from the drilling sites daily. A specially constructed four-engine barge-style airboat was needed to transport the Geoprobe rig to each site. It performed double duty as the deck that Direct Push workers drilled from.
“We used our (Geoprobe) 7730DT and 66DT for sampling and setting wells in the shallow water and soft clays,” said Chad Russell, who owns Direct Push with Bromley.
For the second phase, employees worked shifts of six days on and one day off.
Officials with Direct Push said they were pleased with how the project turned out.
“The work was completed quickly and effectively because of the hard work of all individuals involved, and because of the skill and professionalism of our rig operators - Darren Bromley and Ryan Roodbol,” Sean Bromley said.
“Because of their innovative design, we were able to use three different Geoprobe drill rigs that we have and rely on the features of each rig to get the entire project completed.”
And the efficiency provided by the rigs made the mining company happy, Bromley added.
“By having the two rigs out there, we were able to collect a lot more and install more piezometers than what they anticipated,” he said. “So it helped them by speeding up the process.”
They were able to drill anywhere from six to 10 borings per day, Russell said, adding that Direct Push took over the project from another company that was unable to meet the client’s timetable.
For Bromley, who says his staff of 10 employees stays very busy with work in the region, the Sevier Lake project was a favorite.
“It was one of the more exciting projects,” he said. “It was a little bit of a change. It’s not very often you get to go out and do this in the water. Usually all our stuff is done on land.” ND