Well Drilling
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I have a customer that had the same thing happen. They were down 30 ft and broke through to a cavern. It was a rotary rig and without a narrow hole the grindings from the drill head will pile up behind the head and not be blown out the hole. They drill bit will get stuck in the hole if this happens. What they did was drill a 8" hole to the cavern and then dropped a 8" casing to the bottom of the cavern then change to a 6" bit to drill to bedrock. They set a 6" casing to bedrock and pulled the 8" casing and kept drilling. The funny thing was they drilled 400 ft and all the water and gravel that came up the 6" casing fell down the 8" hole back to the cavern and no water left the site. Kinda made them think that the cavern was big and only 20 ft from the house made me think what was the house sitting on.
Kevin
Kevin
What they did was blank off the loss of circulation zone so that it would not plague them the entire time they were drilling.
Not recycling the mud produced during drilling is a very poor idea. Costs a lot.
There are much better ways to alleviate the situation..
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No luck
Still no luck with the new driller. He was not having a problem drilling, but he could not get the casing in the well because it kept collapsing.
He wants to try another spot, but I have to get a bulldozer to build a pad so he can get his rig backed in there. It shouldn't be a big deal, my neighbor has his dozer within 200 yards of the spot.
If this does not work, we will be digging a ditch to run city water out to the house. I can tie on to an existing line and only have 1/4 mile of pipe to bury. It is about 1/2 mile out to the meter.
It's not as easy as renting a trencher. It's very rocky and steep in places. I talked to the guy who installed my septic tank, he said he can dig the ditch for me.
Anyway, that's where we are. No water.
JR
Still no luck with the new driller. He was not having a problem drilling, but he could not get the casing in the well because it kept collapsing.
He wants to try another spot, but I have to get a bulldozer to build a pad so he can get his rig backed in there. It shouldn't be a big deal, my neighbor has his dozer within 200 yards of the spot.
If this does not work, we will be digging a ditch to run city water out to the house. I can tie on to an existing line and only have 1/4 mile of pipe to bury. It is about 1/2 mile out to the meter.
It's not as easy as renting a trencher. It's very rocky and steep in places. I talked to the guy who installed my septic tank, he said he can dig the ditch for me.
Anyway, that's where we are. No water.
JR
For what it's worth, dual rotary rigs (aka Barber rigs around here) work really well in nasty drilling conditions like your site, if you could find someone in your neck of the woods that has one. They use air/foam for drilling fluid and the casing advances with the bit. I've spec'd alot of wells using this method. I've also seen the mud rotary guys use floculant to try and seal off a zone where they're losing circulation, but that wouldn't work for a huge void.
Only 300? We run anywhere up to 1500psi - its pretty nasty when an airhose blows...
Any turkey can sink a hole in good ground, its in s***ty ground than you need a good driller who knows his muds.
Another strategy to try would be pumping cement into that fractured formation, and then attempting to drill through once its hardened
Drilling can get expenisve... even just for water bores - one bore I worked on took 3 months and a few million dollars to sink! When it was finished, cased and everything, some dropkick dropped a rod down the hole and I did a video inspection to check for damage - discovered little shrimp living down there, that are apparantly endangered! This was to be a dewatering borehole for a mine (which has since had its approval cancelled)
Sean
fantasy... A cave at depth would not have shrimp...
and, shrimp cannot fit in a .100" slot...
I'll see what I can find about these things on the net - they are microscopic little things - think seamonkeys
They live in certain salinity aquifers in the Pilbara region of Western Australia, which can make drilling difficult! Many exploration projects are required to cement their holes off when they transend more than one aquifer in order to prevent a change of salinity hurting the little shrimp/seamonkey things.
The mining company / government werent aware that these shrimp were living in this area - and last I heard they may possibly have been a new species/subspecies.
Its not uncommon for things to live in aquifers - I stayed in one camp where they water comeing out the bore was teaming with bacteria (treated before consumption)
Sean
They live in certain salinity aquifers in the Pilbara region of Western Australia, which can make drilling difficult! Many exploration projects are required to cement their holes off when they transend more than one aquifer in order to prevent a change of salinity hurting the little shrimp/seamonkey things.
The mining company / government werent aware that these shrimp were living in this area - and last I heard they may possibly have been a new species/subspecies.
Its not uncommon for things to live in aquifers - I stayed in one camp where they water comeing out the bore was teaming with bacteria (treated before consumption)
Sean
Ok, spent some time on google, and the correct name for these shrimp appears to be "Troglobitic Fauna"
http://www.epa.wa.gov.au/docs/mesa/Vegetation_FloraFauna/Biota_2006e.pdf
Section 1.3 of this document (page 4) gives a basic description of the critters and where they live. The document is an environmental management plan for dealing with the shrimp, lodged with the EPA (Australian).
Also, on the topic of things living in boreholes, on another project drilling a large bore near to a creek we had small fish comeing out the mud return back into the sump! I guess there must have been a crevice or small cave joining our drillhole to the nearby creek. I have photos of the fish somewhere... From memory they were native perch
Sean
http://www.epa.wa.gov.au/docs/mesa/Vegetation_FloraFauna/Biota_2006e.pdf
Section 1.3 of this document (page 4) gives a basic description of the critters and where they live. The document is an environmental management plan for dealing with the shrimp, lodged with the EPA (Australian).
Also, on the topic of things living in boreholes, on another project drilling a large bore near to a creek we had small fish comeing out the mud return back into the sump! I guess there must have been a crevice or small cave joining our drillhole to the nearby creek. I have photos of the fish somewhere... From memory they were native perch
Sean
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In Karst terrains it is not unheard of to have critters living in the cave systems (obviously). That is a bit different than critters living in the aquifer. I can't understand how filling the hole with concrete would help them tho..
Pretty standard practice to grout up a hole that might lead to cross contamination between aquifers, no? Particularly if salinity is different, as you would might density-driven flow. Only practical way I could see would be to use a packer just above the void.
You think the shrimp like their houses filled with concrete?
Wouldn't be easy. Simplest way I can see to do it is to set a high pressure packer just above the casa de [SIZE=-1]camarones (the rock would have to be competent) then tremie bentonite/neat cement grout some distance above the packer and let the grout set. In theory when the grout sets it swells and binds tightly to the borehole. That column of grout would then hold up the rest of the grout column in the borehole until it sets. Obviously the deeper the packer is the heavier the grout column above it and the more problematic it becomes. Sounds like somebody could make some money on this project...;p
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You know, I have never understood the use of grout to seal a rock formation. All you have to do is go look at Glenn Canyon Dam to see how futile it is. I guess if it is sealing a breach in an impermeable clay or something alright, but that is rarely the case. It will do squat to prevent horizontal seaps.
What do I know, I'm a hydro/well drilling amateur.
What do I know, I'm a hydro/well drilling amateur.
All it really has to do is slow it down.
I have capped artesian flows of 3000gpm with concrete. It actually works quite well.
Some artesian plugs have held for 50+ years (That I know of)
I have capped artesian flows of 3000gpm with concrete. It actually works quite well.
Some artesian plugs have held for 50+ years (That I know of)