Due to supply chain issues and time-sensitive deadlines, Mike Piechowski, LHG, is modifying the way he does his job.
The principal hydrogeologist at Robinson Noble Inc. in Tacoma, Washington, Piechowski, pictured here, has thus far predesigned four wells for municipal clients based on the logs of nearby existing wells. At the same time, he has advised clients to preorder screens and materials to circumvent the unusually long lead times.
Before Piechowski’s job was flipped upside down, he typically worked alongside a driller on the jobsite to log samples and then analyze them in the lab. They would conduct a sieve analysis of the samples to calculate the water well’s screen size and filter pack design. The information would be used to figure out how to construct the well, designing the best well possible for the formations encountered.
“When you’ve got a lead time of two to three weeks that blows up into two to three months, and you’ve got wells that need to be built in that timeframe, you can’t do that anymore,” says Piechowski, president of the Washington State Ground Water Association and chair of the National Ground Water Association’s Northwest Regional Policy Committee.
“It comes down to asking the well driller what screens do you have? What can we work with? What can we get? What’s your vendor able to provide us? We struggled with that for a little bit and then I just realized, ‘Alright, if we have to prebuild these wells, let’s prebuild the wells and let’s do the best we can with the information we have.’”
For the city of Gig Harbor, a small town on the Puget Sound, an emergency well replacement was underway with the well needing to be done by May 15, 2021. Piechowski’s team began working on it in October 2020 and didn’t have a drill rig on site until late November/early December, leaving them five months.
“If I’m going to eat up two-plus months of that as lead time on my filter pack and my screen material, that’s a project killer,” says Piechowski, who has 27 years of professional experience. “So, we elected to take everything we knew at the time and make as educated of a guess as we could make, which meant we chose to go with a gravel pack because I’ve got control.”
The predesign process amounted to learning from the previous well’s design as well as the design of a recent well that was less than two miles away in the same aquifer that turned out well for the client. The process consisted of “keeping the project moving as fast as possible without cutting too many corners,” Piechowski says.
With fluid rotary as the drilling method, the predesign led to the selection of a conservative filter pack (a glass bead pack equivalent to 8-12 silica commonly used in the region) and conservative screen set (40-slot) based on the geology they expected to see based on the existing well.
“You don’t know exactly where the sands came from, you don’t know exactly where the gravels came from,” Piechowski explains. “You’ve got some ideas and you kind of piece it together, so you’re almost always obligated to go a little more conservative on the big fluid rotary wells anyway because the formations get blended during the drilling process.
“You don’t have as clear-cut stratigraphy, but the thought on that one was we would just select sections of screen and then place that screen based on our geophysical logging of the borehole.”
A similar approach was used on a large supply well for the Silverdale Water District in Silverdale, Washington.
After completing the geophysical logging with his company’s geologist, Piechowski met with the district’s geologist and went through their formation picks for the screen placements on the tailgate of a truck. Like the Gig Harbor well, Silverdale had another well in the same aquifer on the property as well as information from other nearby wells to draw from. A similar design was chosen, using 40-slot screen and an 8-12 silica sand pack.
Gig Harbor’s 930-foot well produced 1200 gallons per minute and exceeded the capacity of the previous well that pumped 700 gpm. Silverdale’s 1000-foot well produced 880 gpm, considerably more than the 290 gpm from its existing well.
Piechowski is looking ahead to a major project that calls for a pair of 500-horsepower submersible pumps and says the lead time is between 18 months to never.
“If we can’t get a submersible in a timely manner, what’s our option?” Piechowski says. “Well, we’ve got to go with a topdrive turbine. Topdrive turbines are great, but they have lead times too.”
It’s again forcing Piechowski to be flexible with how he approaches designing a well.
“We’re adjusting to the realities of the new normal,” he says. “I’m not sure how much of the new normal is going to switch back to the old normal. I have a hunch it won’t ever get back that way — at least not in a timeframe of a couple of years. So, we just have to plan a little differently as a result.”
— by Mike Price