Cleaning a water well casing

[Ouachita]

I've been studying on different methods of cleaning my well casing. I did use a "bore brush" (it was a 4" chimney brush) and attached it to the PVC pipe, pulled and and pushed it up and down the well several times, reinstalled submersible pump and it was better for a a couple years. That was 7 or 8 years ago. Well is 20 years old this year.
I watched them drill it. It was cased with 4" PVC all the way to bottom, which is 187 feet. Instead of using perforated PVC, like what is used for septic leach lines, they used regular 4" PVC and made their own perforations with a chainsaw, cutting about 1/4" wide grooves every few feet. I think these grooves get plugged up over time, and reduce the flow of water back into the casing. I'm looking to do a better job of cleaning this next time. I've read that using the "bore brush" is the best first step, but there are also additional processes to pressure "wash" by having a setup similar to a pressure washer, and then also pull a vacuum on the casing. Back and forth..........pressure/vacuum. Has anybody here done this personally (not hired out to a "professional" company? If so, any tips, or alternative suggestions?

I could drill another well, but this one has such great quality water that I am reluctant to gamble 5k for a new well if I can just get this one back to its original production.

 

[Ouachita]

I've got the pressurization figured out. I'm curious about what other might consider a good method to draw a vacuum on the well casing. It would need to a large volume. I was thinking of a attaching a duct from the well casing to the carburetor on my old 82' Chevy truck and spool up the RPM. Yes I risk ingesting water into the engine, but I have easy free access to 30 or 40 feet of flexible spiral wired reinforced ducting. I figure I could situate in such a way that when the water reached the ducting, I could shut the engine off. Stupid idea???

 

[SmokinM]

Wouldn't think a carb would pull enough vacuum. How about a big leaf blower/leaf vacuum or if you know an old dairy farmer a silage blower. Could use your brush and put the pressure washer with it down the pvc pipe. Good luck nothing like good well water.

 

[Ouachita]

Wouldn't think a carb would pull enough vacuum. How about a big leaf blower/leaf vacuum or if you know an old dairy farmer a silage blower. Could use your brush and put the pressure washer with it down the pvc pipe. Good luck nothing like good well water.

Engine will pull a lot of vacuum. I've used it to do pipe over pond dam to draw water up the side and fill up the downhill side to syphon a pond dry. I just don't know at what lift level it'll quit "sucking"

Edit to add..........even if I don't get water up to the desired level, if I can pull 18" vacuum on the casing????? That is a very powerful force that should still help clear the perforations in the casing clear out a bit. I'm all for trying. I may be wrong, but I'll YouTube it and y'all can laugh at me.

 

[hurleyjd]

I've been studying on different methods of cleaning my well casing. I did use a "bore brush" (it was a 4" chimney brush) and attached it to the PVC pipe, pulled and and pushed it up and down the well several times, reinstalled submersible pump and it was better for a a couple years. That was 7 or 8 years ago. Well is 20 years old this year.
I watched them drill it. It was cased with 4" PVC all the way to bottom, which is 187 feet. Instead of using perforated PVC, like what is used for septic leach lines, they used regular 4" PVC and made their own perforations with a chainsaw, cutting about 1/4" wide grooves every few feet. I think these grooves get plugged up over time, and reduce the flow of water back into the casing. I'm looking to do a better job of cleaning this next time. I've read that using the "bore brush" is the best first step, but there are also additional processes to pressure "wash" by having a setup similar to a pressure washer, and then also pull a vacuum on the casing. Back and forth..........pressure/vacuum. Has anybody here done this personally (not hired out to a "professional" company? If so, any tips, or alternative suggestions?

I could drill another well, but this one has such great quality water that I am reluctant to gamble 5k for a new well if I can just get this one back to its original production.

Really doubt that you can do this yourself. I think that a well specialist would inflate a packer just above the perforations and pressure to clean the perforations. After that they would air jet the well for several hours. What Happens when you release the vacuum the water level will either stay in the well to the level that you pulled it to or fall back. Plus the column of water is pretty heavy and doubt the vacuum would every lift it.

 

[Ouachita]

Hurley, I'm not sure what my static water level is. It varies I'm sure at different times of year. The idea of drawing a vacuum on the casing is NOT to change the static water level. My plan was to draw a vacuum to decrease the normal atmospheric pressure inside the casing. This would cause water to "rush" through the casing perforations much faster than regular gravity fill up, thus washing out these perforations. I've already got the case bore cleaning and pressure washing figured out, and I know how to make an airlift to suck out the silt and residual junk after I clean it. Im going to do this when weather cools, probably late September, and after I have my water tanks full.

 

[greybeard]

I've been studying on different methods of cleaning my well casing. I did use a "bore brush" (it was a 4" chimney brush) and attached it to the PVC pipe, pulled and and pushed it up and down the well several times, reinstalled submersible pump and it was better for a a couple years. That was 7 or 8 years ago. Well is 20 years old this year.
I watched them drill it. It was cased with 4" PVC all the way to bottom, which is 187 feet. Instead of using perforated PVC, like what is used for septic leach lines, they used regular 4" PVC and made their own perforations with a chainsaw, cutting about 1/4" wide grooves every few feet. I think these grooves get plugged up over time, and reduce the flow of water back into the casing. I'm looking to do a better job of cleaning this next time. I've read that using the "bore brush" is the best first step, but there are also additional processes to pressure "wash" by having a setup similar to a pressure washer, and then also pull a vacuum on the casing. Back and forth..........pressure/vacuum. Has anybody here done this personally (not hired out to a "professional" company? If so, any tips, or alternative suggestions?

I could drill another well, but this one has such great quality water that I am reluctant to gamble 5k for a new well if I can just get this one back to its original production.

Really doubt that you can do this yourself. I think that a well specialist would inflate a packer just above the perforations and pressure to clean the perforations. After that they would air jet the well for several hours. What Happens when you release the vacuum the water level will either stay in the well to the level that you pulled it to or fall back. Plus the column of water is pretty heavy and doubt the vacuum would every lift it.

/\ This. I don't know how far down the casing the perforations start, but just going by your 187' TD, it would take a heck of a lot of vacuum to overcome both atmospheric pressure on top of any water column and the weight of any column of water inside the casing. And, I don't think you will 'see' much "rushing in" of water once vac has been achieved. Ever tried to suck 1/2 a strawberry thru the straw of a strawberry malt? The strawberry just gets lodged tighter and tighter, and I think that's what is going to happen to the crap plugging the perfs and the gravel pack.
Keep in mind, that absolute vacuum (IF it were possible to achieve that--it is not) will only lift a column of water from 33.7'.

And, if both your perforations and the gravel pack are plugged, you will have a heck of a chore doing this with brush and vac.

Did they install a screen over the outside of the perforated liner/casing segment?

 

[bbirder]

Wouldn't you be better off pressurizing your casing and blow the sediment back in the formation. :?: :?: It seems the trash blocking it must have come from outside the casing. Dunno, just asking.

 

[Ouachita]

I've been studying on different methods of cleaning my well casing. I did use a "bore brush" (it was a 4" chimney brush) and attached it to the PVC pipe, pulled and and pushed it up and down the well several times, reinstalled submersible pump and it was better for a a couple years. That was 7 or 8 years ago. Well is 20 years old this year.
I watched them drill it. It was cased with 4" PVC all the way to bottom, which is 187 feet. Instead of using perforated PVC, like what is used for septic leach lines, they used regular 4" PVC and made their own perforations with a chainsaw, cutting about 1/4" wide grooves every few feet. I think these grooves get plugged up over time, and reduce the flow of water back into the casing. I'm looking to do a better job of cleaning this next time. I've read that using the "bore brush" is the best first step, but there are also additional processes to pressure "wash" by having a setup similar to a pressure washer, and then also pull a vacuum on the casing. Back and forth..........pressure/vacuum. Has anybody here done this personally (not hired out to a "professional" company? If so, any tips, or alternative suggestions?

I could drill another well, but this one has such great quality water that I am reluctant to gamble 5k for a new well if I can just get this one back to its original production.

Really doubt that you can do this yourself. I think that a well specialist would inflate a packer just above the perforations and pressure to clean the perforations. After that they would air jet the well for several hours. What Happens when you release the vacuum the water level will either stay in the well to the level that you pulled it to or fall back. Plus the column of water is pretty heavy and doubt the vacuum would every lift it.

/\ This. I don't know how far down the casing the perforations start, but just going by your 187' TD, it would take a heck of a lot of vacuum to overcome both atmospheric pressure on top of any water column and the weight of any column of water inside the casing. And, I don't think you will 'see' much "rushing in" of water once vac has been achieved. Ever tried to suck 1/2 a strawberry thru the straw of a strawberry malt? The strawberry just gets lodged tighter and tighter, and I think that's what is going to happen to the crap plugging the perfs and the gravel pack.
Keep in mind, that absolute vacuum (IF it were possible to achieve that--it is not) will only lift a column of water from 33.7'.

And, if both your perforations and the gravel pack are plugged, you will have a heck of a chore doing this with brush and vac.

Did they install a screen over the outside of the perforated liner/casing segment?

I may well be wrong. Regardless of whether there is water in the well or not, a vacuum would still result in water flowing in to the casing at a greater rate than normal infiltration. This is fact. It's just an idea for possibly unclogging some perforations. I do not see it as a waste of time. I'll video the process and report back.
Since my first post here, I have received replies from another website that suggest this as a viable option. Maybe they and I are wrong. Vacuum is a very powerful force. The problem is getting a large enough vacuum pump to accomplish this. An internal combustion engine makes a pretty good "pump". Ideally I would pump the casing dry, then immediately apply the vacuum.
I'm holding out for cooler weather, and to temporarily tap another well for the house during my experiment.

 

[Ouachita]

Wouldn't you be better off pressurizing your casing and blow the sediment back in the formation. :?: :?: It seems the trash blocking it must have come from outside the casing. Dunno, just asking.

Yes, and this will be one of the processes........pressure then vacuum.......rinse and repeat

 

[Red Bull Breeder]

Seems to me about a 1/4 stick would clean it right up.

 

[Ouachita]

Seems to me about a 1/4 stick would clean it right up.

With an old hand dug well, yes Sir, I've watched it happen and it worked.

 

[greybeard]

I personally believe, that any vacuum capable of 'sucking' any debris or biological buildup thru the gravel pack and perforations would also risk collapse of the casing itself.

 

[highgrit]

I would think a pressure washer with a orbital tip mounted at a 90 degree angle would be the ticket. And the put a 10 lb canon bull on a swivel below the tip for stabilization.

 

[greybeard]

He is determined to pull it all into the ID of the wellbore casing--not pressure wash it back out into the gravelpack or water bearing formation.

 

[Ouachita]

He is determined to pull it all into the ID of the wellbore casing--not pressure wash it back out into the gravelpack or water bearing formation.

No. My first operation will be to mechanically clean the bore with a brush, and then pressure wash. These processes will no doubt loosen debris in the perforations and near the perforations on the outside of the casing. GB, I'm not trying to pull 29"; I agree that would cause the casing to collapse. It will take very little pressure differential to make a big difference in how fast the water flows back thru the perfs into the casing. The objective here is to evacuate as much of the loose material (which was disturbed and loosened during the previous ops). It will work better than no action.
Then I will use an airlift to suck the sediment out of the bottom of my well. Then use my old submersible pump to pump the well dry several times before I place it back in use. I will check fill rate before and after.

 

[greybeard]

Well, (pun intended) good luck with it.
(BTW--Your river namesake looked awful inviting when I crossed it a couple times last week at Malvern.)