Water well drilling with a skid steer

[JDWY]

That's for sure, a lot of know-how and engineering involved.

 

[Georgia Iron]

Hey Guys, I see this is an old thread. A basic well put in by a pro costs about $5000 for a 1 hp / 1" pipe well, $6500 for 1.5 hp 1"1/4 pipe to $8500 for a 2 hp 2" pipe at about 120' depth were I need it.

I have an assortment of heavy equipment to include a bobcat and a hydraulic drive unit. I have a 9" post hole type auger head and I have 300' of used ditch witch 6' long drill stem that is about 1.5"s in size.

I was looking at attempting to drill a water well myself. I thought this might be a good skill set to have if I needed to do it again. Planning on using a 4" casing with a 1.5 to 2 HP motor to go for maybe 30 to 40 gallons a minute.

I was thinking of trying to drill the hole without water. I spoke to a local well driller and he did not think I could get down deep enough and that I needed water and a large piston mud pump to get the cuttings out of the bore hole. He made it seem like a would fail without the large mud pump setup.

He told me that I could not attempt to drill the hole dry because when I get to the wet sandy soil the soil will not stay on the auger.

I am planning on drilling through coastal type soil that is a dark red color and will more than likely turn to sand.

The drill stem I have is hollow and I believe I could fab or buy a water swivel to use water if I must. There is a well 1000' from where I am and I could use a long roll of pex to get water to a holding pond near the new well site. I am not sure if I need quick gel or not. I saw where you can use a semi trash pump from harbor freight to get a fair amount of water flow...

I was thinking I could put two 30' tall trees / posts in the ground to each side of the bore hole and put a pulley and a cable up in the air to pull the auger head up and get the dirt out if I tried to do the job dry.

Do you guys think it can be done to a depth of say 120' with the items I have?

Any thoughts or suggestions on how to accomplish this task.

 

[Welder Dave]

I found drilling deeper holes with a skid steer required lifting the auger up and down while drilling so it wouldn't get stuck in clay type soils. Not fun when the bit is stuck down in the hole. Not sure a skid steer would have enough lift capacity with 120' of extensions and would take a lot of time removing and recoupling all the extensions every time the auger had to pull out to remove the soil. Would probably want the extension boom attachment most contractors use for drilling deeper holes. Below is a contractor in the area who spent mega bucks converting his 975 Bobcats into specialized drilling units.

Home - Lund Enterprises

 

[skyking1]

you have to pay yourself something, and the odds of completely wasting your time getting down 120 are pretty good with what are really the wrong tools.
That link above Lund was drilling for footing piles and things like that, 20~30' and as Dave said it was mega-bucks to develop.

 

[Welder Dave]

I think it was over $100K to convert a 975 into a specialized drilling rig. About the only thing original on the machine is the frame. Note that the Lundrill has 4 times the torque of a standard Bobcat auger so must be using pretty high pressure pumps.

 

[skyking1]

Any thoughts or suggestions on how to accomplish this task?
Yes get out the checkbook and pay the man $5,000.

 

[Welder Dave]

Yup, some jobs you just need the right machine. 30 feet maybe you could attempt but 120 feet is a long way down. I live in an 80ft. mobile home so have a good prospective of how far down 120ft. is. I don't think you'd need a real huge drilling rig if it's a small diameter. When they drilled test holes to check percolation rates when I sub-divided they had a neat drill rig on a 1 ton truck. Actually lost a bit in the hole but I later dug it out with the backhoe. It was only about 5' down. You might need something a little bigger but not much.

 

[Georgia Iron]

Maybe you guys are right. Today i drilled in 25 3.5' deep fence post holes the auger never missed a beat I did it on low idle. Pushing down with the 12,000 skid steer seems to be plenty of down force to send a bit down. I understand if I hit rock but I donot believe there is anything more than hard packed clay. seems like each time you add a drill stem it would just add a little more weight to help it bore down. Not sure what I am missing or not understanding about this. Seems like if you keep the machine running on low power you could avoid breaking the drill stem.

My skid steer is a vertical lift type so it moves the boom up in more of a straight line

But I do not mind loosing a few pieces of pipe and an auger head giving it a go. I spoke to a man in TX today that does boring work. He stated that as long as I make sure the slurry coming back out of the hole contains the cuttings and I keep the pump going that he thought I could get it done with just using regular bentonite clay to cake the walls. Once I get down to the wet sandy area the question is if the bore hole will fall in on the drill stem and auger head and stick it. He told me they make specialty drilling compounds that can be bought to hold the walls in place if it starts falling in. But he thought it would not be needed.

He told me regular gel-rite would complete the task. And he calculated how much based on a 10" bore with a 120' depth and told me to run 6 to 8 bags pre mixed in the bore . He said give it go and just make sure that I do not bore faster than the pump and water flow can handle removing the cuttings. He stressed that the mud pump bringing the cutting back up and out of the bore is the key to success. And told me to slow way down and give it extra time to work

We spoke about me using a 2" harbor freight semi-trash pump attached to a water swivel on my drill stem. He stated it would provide enough flow to get this bore in..

Now I need to figure out how to put a homemade water swivel together without a using a mill or lathe, I would like to make it out of common junk laying around the yard.

 

[Legdoc]

I started getting set-up to drill several wells years ago but never finished due to a back issue. I went with the following design:
Hydraulic motor that will drill 24" in soft soil
2 3/8" tubing cut and threaded at 7' tapered thread with collar bucked and tack welded no tool joint ( not ideal without tool joint but for a few jobs it would work)
swivel with 1 1/4" water course coupled to hydraulic motor
old forklift mast for derrick (could use track loader with vertical lift)
3" trash pump for circulation (probably not enough pressure or volume)
break-out table with slot for pipe in place of slips
While this is certainly no "professional " rig I have less than $1,000.00 in it as I had everything but the pipe and swivel. Son in law just had a 300' well drilled and cased for 7K in soft strata so if time permits I think it is very doable.
There are many YouTube videos on this where people drill on the cheap. Sure there are problems but I consider is another adventure for cool weather. I think most problems occur due to not having enough pump to flush the cuttings and don't get their drilling fluid right.

 

[Georgia Iron]

I have decided a mud pump is not the way to go. I ran into a fellow that learned how to drills his own wells for his farm. He learned the hard way and in the process had 4 different bores collapse every time he attempted to use a mud pump each time spending more money to get more pressure. He used 2 different water swivels , one pro-made and a custom home made one and 3 different types of pumps including a top of the line 3" pump. No rock mostly sand and hard clays. According to him, it was too hard to get the cuttings out of the bore once you went below 35 to 40' deep. The sand would just want to sit back down on the auger and the boring would slow down to a snails pace.

He found out that an air pump is the way to go. Using a wheel barrow air compressor and a 1.5" pvc pipe along with an airline he was able to create a pump that would reach close to 90 gpm suction from 100' down. It will clean the sand and clay out just as fast as you cut the bore. Using a basic home made platform with a hydraulic motor from a lull he spins a short auger bit using the rigid metal pipe. Using a short 9' auger type bit and 3" ridged metal electrical pipe from home depot sold in 10' pieces. He uses this type pipe because the fittings are well machined and the pipe is very straight right from the big box store. After doing several small wells, he was able to increase to a large well with the goal being to run a pivot. Using a 24" top casing to a lower 18" screen getting 700 gallons a minute with a 30 horse electric motor. That is a $35,000.00 well.

Keeping the bore full of water from a gravity top feed is the key to keeping the bore open. The air pump will preform similar to an super expensive professional mud pump on a drill rig. The holding pond for the water to keep the bore full is quite large at 20' x 20" x 2' deep with an earth dam in the middle similar to a gold rush holding pond to allow the silt to settle out.

No special mud or pumps required. No pump is even used. The PVC pipe is duct taped together and increases in length as the auger goes down. It takes 3 people to do the job. One to hold the pvc just above the drill stem, one to keep up with the water and one to run the drill. Water from the holding pond is gravity feed to the bore hole with a 6" pipe.

Of course I figured this out after I bought my benonite, and water swivel bearings about $200.00 down the hole....