Drilling a well
March 30th, 2007 by
cowgirljules
Since I suspect that this will be my last time this up close and personal with the process of installing a well, I’ve been taking lots of photos. And what the hell; I’ll share them with you all, because I love drilling so and therefore you must too.
Drilling’s in a roundabout way what got me interested in photography. When I first got my job, one of the biggest projects going on involved puncturing the base with lots and lots of holes, and my job was to observe and document it. It was shortly thereafter that I discovered my life-long appreciation for working mens’ asses, but that is another post.

This particular well is going in to one of three houses that were put on base water when their water supplies were found to be contaminated, about fifteen years ago. We’ve cleaned up the contamination, and transferred the base to the new owners, who don’t want to be water suppliers and requested that we put these houses back to wells. The wells are going hundreds of feet below the original contamination zones, which was clean water all along. This is the last of the three; it was held up for reasons beyond our control.
Nobody lives here anyway.

Which is fortunate, as drilling is loud, and it’s messy, and it takes up a lot of space. This is why people usually put the wells in before the houses are built. This is not all of the equipment yet.

I’m definitely not supposed to play favorites, but I’ve worked with this company for a long time; they’ve taught me a lot, and I have a ton of confidence in their competence. A lot of really good people work for them.

Setting up the 20-inch conductor casing that keeps the top of the hole from wallowing out and making a giant mess. This will be pulled out when the well is finished.

To set the 20-foot long conductor casing, they use a technique called Air-Rotary Casing Hammer. The casing is hammered straight down into the ground with a hydraulic hammer, with a smaller drill bit rotating and advancing inside it to make room. Compressed air is blown down in through the central drill string, and comes up out between it and the conductor casing, bringing the drill cuttings up with it. The cuttings, or the soil that’s removed by the drilling, blow through that eight-inch hose and through the cyclone, which slow them down enough to make the soil drop into the hopper for removal.

The shoe at the top of the conductor casing bounces a little with the rebound of the hammer, which is the squarish assembly, and cuttings are blown out a little now and then. See the driller ducking? It’s messy. It’s even messier if they use this technology to install an entire well, pounding it down below the top of the water table. Then what’s blown out isn’t dirt; it’s mud.
It’s a dirty job.

The conductor casing’s almost in. It needs to be down to a foot or so above the ground, so the drilling mud they use later for the main event can flow out and over it, and back into a tub for collection.

The shaker table is finally here, and as clean as we’ll see it until they finish.
They’re using mud-rotary drilling here, which uses a heavy bit on a long hollow drill stem. Drilling mud, which is composed of water and a specific amount of bentonite clay, depending on the soil conditions, is pumped at pressure down through the center of the the drill string, where it shoots out through holes in the drill bit. The mud cools and lubricates the rotating bit while also providing a thick enough medium to carry the bits of soil that are removed, or the cuttings, back up to the ground surface between the wall of the boring and the outside of the drill string.
The mud is collected in a tub right at the top of the well, and pumped up to this shaker table, where the cuttings are removed and shaken down to a hopper. The mud falls through a series of screens and is pumped back to the rig for reuse.

The driller and his helpers are adding a piece of drill rod, or “tripping in.” I’ll ask them next week how much one of those things weighs. Sorry, I missed a photo of the bit; they zipped that thing into the ground while I was back in the office. I’ll get a picture when they take it back out.

They use the winches and pulleys on the mast to do the heavy lifting; Jose’s guiding the bottom end of the drill rod in so it doesn’t drag or hit someone.

Jose is handing off the dangerous end of the drill rod to Matt the driller, who will guide it over the end of the previous section.

Matt and Victor are tightening the connection between the new piece of drill rod and the one they were already using. The tub on the ground is the mud collection tub.

I love to watch the cuttings pile up in the hopper, especially if they’re drilling through a sand formation like this. It’s not so fascinating when it’s gravel and pieces are flying everywhere. And it’s a little tricky to get a picture of it before Jose or Victor knock it down with their shovels to keep the hopper filling evenly.

Victor’s a little bit of a ham. I love a man who will pose for me. He’s working on making sure the shaker’s running right, as it’s a particular piece of equipment, and also mixing more mud in it. They have to keep making more, as some is lost downhole, especially if they’re drilling through a gravel zone, and some just doesn’t get separated from the cuttings and ends up in the bin.

James the geologist inspecting the cuttings to see what kind of soil they’re drilling through at the moment. We’re not down to the level we want yet, but we have to look for a water-producing type of soil when we get near there. Gravels and sands are porous and let the groundwater flow through them freely; clay, not so much.

The spouts on the shaker, separating the mud from the cuttings. I can easily find myself a little hypnotized by the patterns in the drilling mud, which has the consistency and almost the color of a chocolate milkshake. Doesn’t taste too much like one though.

And that, my dear friends, concludes this week’s thrilling episode of Holes in the Ground: Why We Like Them. Tune in next week for the shocking conclusion. Will we drop a three-ton drill string three hundred feet below ground? Will we find water where we expect it? How long will it take to ream out a borehole? And what if we strike oil?
All of these burning questions answered and more!
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