The Homemade Heat Pump Manifesto

[Geo NR Gee]

When we hit around 15 to 20 feet, the bit seems to hit large rock outcropings. Thats what it feels like in both bores at that depth. We spent an hour going down to 20 feet only to get the bit stuck.

The 2000 lb electric winch makes easy work of pulling it up to 15 feet to get it to release, but it seems like some weight on the machine would help in keeping it from bouncing up and down. Maybe some exercise weights would help with that, now that the electric winch will take a good share of the load.

I will vacuum out the mud and see what is causing the holdup. Sure hoped the rig didn't have to be moved again so soon! Why can't it be easier? I don't need more character.

[Geo NR Gee]

After pulling up the drill bit, you could see that it is being worn down quick. Any ideas on which style bit would work best in bores with small to medium rock and gravel? We have access to a wire feed welder, so almost anything is possible.


After vacuuming out the hole, and viewing with the camera down the hole, I was right that there were large rocks sticking out of the bore. The hole will easily accommodate the geo pipes, but would surely be difficult with a casing.

[AC_Hacker]

Originally Posted by braebyrn

After pulling up the drill bit, you could see that it is being worn down quick. Any ideas on which style bit would work best in bores with small to medium rock and gravel? We have access to a wire feed welder, so almost anything is possible.

Looks like your bit is a pretty good one. I tried lots of configurations. I found that 2-flute bits worked very poorly. Three and more flutes worked better.

You might try making up smaller and medium and bigger size bits and try them all.

Might try drilling with a smaller bit, then enlarging the hole with a bigger bit, see how that goes.

If you have access to a stick rig, there is a larger variety of rod types available than there is welding wire. I think you could build up the edges of your bits with harder steel. I think there is even welding rod that has bits of carbide embedded in the rod. That would be really good for reducing wear.

I made a three-flute bit that had really large flutes, that worked wonderfully for drilling through clay, which was one of my biggest problems.

You might try Google images and search for well drilling bits to get some pictures for ideas.

-AC_Hacker

[herlichka]

As I've read your Manifesto, it has occurred to me that there may be a relatively inexpensive source of drilling hardware available to you. I used to work in the underground utility business, and there are several manufacturers that make earth boring equipment, featuring quick connect bits and rods. There are numerous styles and diameters of bits, as small as 1-3/4", some are designed for rocky conditions, some for sandy soils, most actually push the soil outward and compact it as the bit passes. Where this becomes interesting is that most contractors have switched to "directional boring" technology, and there is a lot of rotary bore stuff sitting idle. You may find some stuff on e-Bay, Kijiji, or at an auction (telephone companies used to use this equipment to place telephone wire under streets and driveways), or even the equipment dealers, such as Ditch Witch, or Vermeer. The two manufacturers that come to mind are Case Power, and McLaughlin (mightymole.com). You may get lucky and find some pieces cheap!

[Geo NR Gee]

I spent some time today speaking to a well driller and reseller of drilling equipment. He is familiar with my unit and suggested that I go to the geology department at the local university. They will know the lay of the land as far as the soil conditions in my area.

He said the problem that I am having is that the drag bit (pictured in a few posts back) will little to no effect on the football size rocks that are in the borehole. He mentioned that I am drilling in unconsolidated formations (A sediment that is loosely arranged or unstratified (not in layers) or whose particles are not cemented together (soft rock); occurring either at the ground surface or at a depth below the surface).

He said that it will bounce the drilling rig and cause early wear and possible breakage. He suggested that I look for a hardened Tri cone bit.

[AC_Hacker]

Originally Posted by braebyrn

I spent some time today speaking to a well driller and reseller of drilling equipment. He is familiar with my unit and suggested that I go to the geology department at the local university. They will know the lay of the land as far as the soil conditions in my area.

He said the problem that I am having is that the drag bit (pictured in a few posts back) will little to no effect on the football size rocks that are in the borehole. He mentioned that I am drilling in unconsolidated formations (A sediment that is loosely arranged or unstratified (not in layers) or whose particles are not cemented together (soft rock); occurring either at the ground surface or at a depth below the surface).

He said that it will bounce the drilling rig and cause early wear and possible breakage. He suggested that I look for a hardened Tri cone bit.

This all sounds like knowledgeable advice.

I searched through ebay and found quote a few tricone bits, here's the smallest one I saw:

Looks like it has a very tapered thread, so you'll need to come up with an adapter of some kind. I bet the drilling equipment guy knows just what you need.

Looks like herlichka's advice could hardly be more timely.

-AC_Hacker

[AC_Hacker]

For those who may be particularly hard-bitten heap pump geeks, I have found an on-line Heat Pump Design Program that was created by the US government.

...if only they had written one that could be downloaded to your own computer...

Regards,

-AC_Hacker

[charlesfl]

I found this site which may be of interest to some.

In go search under ricks geothermal website

Thanks AC for all your great work

Charlesfl

[benpope]

Originally Posted by AC_Hacker

...if only they had written one that could be downloaded to your own computer...

Regards,

-AC_Hacker

This is the reason they don't have a downloadable version:
"executes the FORTRAN application..."

My guess is that the software was written ~20 years ago and never ported to anything else (why fix it if it works?). I'm sure you could find an old FORTRAN box and see if they would send you the software .

[AC_Hacker]

Originally Posted by benpope

I'm sure you could find an old FORTRAN box and see if they would send you the software .

Ben,

Why don't you give it a try?

I did write to them several years ago and requested a downloadable version. At the time they said that something like that was in the works.

Of course that was several trillion dollars in military spending ago, so chances are that's not gonna happen.

Death & destruction must come first.

-AC_Hacker