As you probably already know, the problem with trying to drill deeper is
friction. If you have tried to drill a well using two hoses, you
know that it goes great at first and then gets harder and harder as you
get deeper. The sides of the hole tend to collapse around the
drillpipe, particularly as you get to the 20 foot depth and beyond.
Many times it feels like you could drill quite a bit deeper but then
when you add a piece of pipe it is suddenly much harder. The sand
in the hole collapsing on the drillpipe causes this.
What if you could hold that sand away from at least the top part of your
drillpipe? What if you could eliminate friction altogether for the
first 10 feet? That is what this technique does. It gives
you a "head start" on drilling your well.
Although this technique is primarily aimed at the two hose drillers, it
applies to mud pump drillers too. Commercial drillers frequently
case the first few hundred feet of very deep wells to keep their well
shafts from collapsing. It simplifies later drilling as well as the
installation of both above ground pumps and submersible pumps.
Assuming you will be drilling with two inch PVC, start out with a 10
foot stick of four inch diameter PVC. Make the bottom of this
piece into a drill bit. Cut teeth in the bottom of
it just like you would for your regular drill pipe. Attach your
two hoses to the top. There is a four inch to two inch adapter
that works well for this. I could not find it at my local Lowes,
Home Depot, or Ace Hardware. I ordered it from Amazon at:
Just use your regular drillhead with the 2" by 4" flexible adapter
instead of the usual 2" by 2" flexible adapter.
2 inch by 4 inch adapter used
to attach drillhead to 4 inch PVC
Also, you will need to adapt your handle so you can attatch it to the four inch pipe.
Usually this just involves buying a couple of larger pipe clamps.
Then drill a hole in the normal manner. It will not go as
fast because you are drilling a four inch hole instead of a two inch
hole. You are removing four times as much material as normal.
When you get the full length of the four inch pipe in, remove the handle
and drill head. Then cut the pipe off at ground level. You
will typically be at about 9.5 feet.
The animation below demonstrates the technique:
If you feel like you can go deeper, feel free to try. Drill as
deep as you can and whenever you
get stuck, just cut the four inch piece off at ground level. You
might even get a 15 or 20 foot head start!
Then start your well drilling in the normal manner with a piece of two inch PVC
and a two inch drillbit.
You will experience no friction in your top ten feet (or however long
your four inch piece is) which will allow
you to drill deeper before friction becomes a factor
This brings up a couple of questions:
1. Why not use a three inch pipe instead of a four inch pipe? The
problem is there is very little space between the standard two inch couplings and
the three inch pipe. I think if you used inside couplings on your
two inch pipe, it might work but I haven't tried it.
2. Why not start with a four inch head start pipe then a three
inch head start pipe and then a two inch drillpipe? The three inch
couplings won't fit in a four inch pipe. If you want to do
something along these lines with a double head start I think you'd have
to start with six inch, then four inch, then the two inch drill pipe.
I haven't tried it. I'm not optimistic. If you do try it,
let me know how it works.