In the first part of this article, Andy Wiesenhofer of Reynolds Drilling Corp., Riverton, Ill., told us about his firm’s entry into the bored water well market, and how the use of fiberglass pipe in those applications has evolved. Here, in part two, we’ll look at a little company history and some of the specifics of Reynolds’ work.
Reynolds Drilling usually has 20 employees, depending on the workload, and the firm’s drilling projects are about evenly split between well drilling and pump repair and test drilling.
Wiesenhofer started out cable-tool drilling in 1976 for his dad, who still has a drilling business in Washburn, Ill. “In the early 1980s, the bottom kind of fell out, and I left to pursue some other interests. I worked for some consulting engineers, and that’s where I got into the test drilling with auger rigs and split-spoons for geotechnical projects. And then the environmental market started to come on a little bit. Then, in 1988, I went back to drilling cable-tool until the mid-1990s, when I went to Springfield to work for AE Exploration doing environmental and geotechnical drilling again. In the late 1990s, we got a bucket rig to do methane wells in landfills, and that’s what got us started on the bored wells.”
As detailed in the previous article, Wiesenhofer went through no small effort to make fiberglass pipe an integral part of his company’s bored well projects. That’s what works best for Reynolds, and that will continue to be its standard procedure.
On Occasion …
There are exceptions, however. “We also use some PVC – 16-inch, large-diameter – in some bored well applications,” Wiesenhofer explains. “Last year, we did three 16-inch jobs out of 140 total projects, so that’s a pretty small percentage.”If he runs into a fine-sand situation, he tells us, “With our fiberglass pipe, we slot it in the field, and we can get about a 50-slot screen. We use buckshot gravel around the outside of it for the gravel pack. Sometimes, if we have a sand-pumping problem, we’ll line that 30-inch pipe with a 6-inch pipe and screen, and use a finer filter pack to make kind of a double filter pack. Last year, we only ended up with about four jobs that we needed to do the 6-inch liner on.
“Of those 140 jobs, we flood-drilled 60 of them. On 24 of them, we did rock drilling where we cut into the shale and sandstone, and made wells in the bedrock. It’s kind of hard to do with the bucket rigs in limestone or cap rock. We will core that with core buckets. Of our three bucket rigs, two of them have hydraulic pulldowns on them, and that’s where you actually can put the weight of the rig on the drill string; the other one is a straight kelly rig. We bought a new bucket rig last year that has 120-foot kellys, and now we can do down to about 115 feet without having to put on any extension bars. Our fiberglass pipe is OK’d to 120 feet of depth.
“In some areas, you can do drilled wells in sand and gravel just fine, but in other places, if you drill down into the bedrock, you’ll get saltwater. A bored well in the shallower part gives you fresh water still. According to state code, we are able to use water after 10 feet; anything above that we’re not supposed to use.”
Typical Installation
For Reynolds’ wells, Wiesenhofer explains, “We typically start off at the top with a 43-inch hole, and then down about 15 feet, we’ll drop down to about a 36-inch hole. And then we take that down to the depth we want and set the pipe. That allows for about 3 inches of gravel pack all the way around. From 10 feet down, there is a transition from that big pipe to a 6-inch pipe that comes up to about a foot above grade. The gravel pack goes to the top of that lid, and then there’s a 1-foot bentonite layer that goes in on top of that – in the 11-foot to 14-foot region. Then that’s backfilled with clay. This makes the transition to the smaller-diameter pipe easier to facilitate the installation of a pitless adapter. That bentonite layer has to be in there to keep out surface water. That was one of the improvements in the code; in the past, there wasn’t any provision to seal that off.“We’ll get calls about old bored wells that experience problems after it rains, and we’ll dig them up around the outside – down to the lid – and put in a bentonite layer, and that usually solves the problem.”
Asked about well decommissioning, Wiesenhofer relates, “Those wells have to be filled with either all bentonite or a bentonite-cement grout. But because of the diameter, a lot of times, we’ll just dig down to the top of the lid and backfill with clay. If the lid is very deep and it can’t be reached with a backhoe, we’ll fill the larger part of it with pea gravel, and then a foot below the lid, to a couple of feet below the surface, that has to be filled with bentonite. It’s better to actually take off the lid and backfill it with clay, but that’s not always possible. Some of the older concrete wells came all the way to the top of the ground, actually above grade, and that still is a provision in the code that they can be done like that, but they have to have concrete poured around the outside from 10 foot down to grade.” He also notes that the casing must be removed to 2 feet below grade for proper abandonment.
Long-term Plans
“We’re going to continue to do what we do,” Wiesenhofer states confidently. “We have a pretty good corner on the market.” An important key to that position, he says, is the utilization of fiberglass pipe. “That has made it easier to travel more efficiently because of the decrease in weight compared to the concrete. Before, if we were working 100 miles away, we’d have to shuttle tiles back and forth; one 3-foot tile weighs about 1,000 pounds. The fiberglass pipe weighs a lot less, so we can head out with up to 200 feet of pipe on one trailer. The fiberglass has been a big improvement to the installation of bored wells; I’d never go back.”ND
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