posted on Jun, 13 2010 @ 09:54 AM
SECONDARY WELL CASING LINER
I have several generations of plumbers in my family... let me lend some insight:
A traditional US domestic water well is cased using 1/4 thick 6" steel pipe. The original 6" steel casing typically extends about 100' deep and
into the bedrock; from that level and further down, a water well is usually uncased and has 6" round bedrock walls.
If you improperly weld together the 20' sections of well casing, or if you should accidentally nudge the well head with farm equipment or bump it
with your F350 4x4, or if you experience an earthquake, you might crack the casing. When this happens... you can dump bleach into your well once a
week, but you'll never get the microbes (e coli, coliform, et al.) out because "surface" ground water will be able to leach into your well through
the cracked steel casing. You'll also be getting sand/clay infiltration which will ultimately fill in your well.
This is what you do when you have a cracked steel casing:
You first remove your submersible water pump, then lower into the 6" casing an inner liner of 4" pipe (typically PVC; though if budget allows,
schedule 40 steel) that extends deeper than the crack in the original casing, or simply further than the original 6" casing. The bottom of the 4"
pipe has a flange that partially seals between the 4" pipe and the 6" pipe. (If it is difficult to get the liner down into the original casing
because of deformities to the pipe a "electro-mechanical swage" can internally straighten the original casing) Then, in the doughnut shaped area
between the 4" liner and the 6" casing, from top to bottom, "grout" is pumped in to form a permanent seal. Your well is now lined with 4" pipe
to a depth of, say, 120' and then from that point down it has 6" diameter walls of bedrock. Your pump can then be lowered back into the hole, you
can bleach the well, and now your water is kosher again! A competent well company can usually accomplish this task for under $1200; much cheaper than
boring a new well ($6000+).
So I ask...
If we have a ruptured casing, why can we not shove a new liner down the hole, grout in between, and effectively re-line an oil well casing?
[edit on 13-6-2010 by Sri Oracle]