Hit a geyser - 35GPM over the casing

My friend just drilled 700' and hit the mother lode. Its a 6" well and its got 35 GPM spilling out the casing. It has only 20 foot of 6" casing [PVC] grouted into granite, and the well driller advised the owner NOT to cap it and use the pressure instead of a pump, he worries that the pressure might blow out the casing. I have a feeling that the driller was planning for the typical dry hole or a 2GPM slogger.

It seems to me that wasting 35 GPM down the hollow might endanger someones water up the mountain, and be a general waste in a relatively dry area.

The well driller is pretty new, I do not think he has much experience with such a well. [or/and maybe he did not grout the casing correctly?]

My advice to the owner was to install a valve and a gauge and to slowly close it and monitor the pressurebefore deciding how to use this gift... I really do not see the casing squirting up into the sky, and it seems to me that the pressure might be quite low at surface to push out 35 GPM from 700 feet.

How would you big guys tackle this deal assuming the owner wants to NOT use a pump, preserve the ground water for the neighbors, and not have the water bypass his [short] casing? Check the pressure then set more casing if a high value?

This sounds more like an oil well issue than a water well problem!

I have only read about wells like that.

Shades of Beverley Hillbilly's, to bad it's not oil !!!!!!

Raucina said:

This sounds more like an oil well issue than a water well problem!

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Well, if ya want the oilfield solution:

MIRU rotary rig and tools. NU and test BOPs to 80% of PVC's pressure rating.

TIH to +/- 625' open ended.

Mix and pump 100' balanced cement plug (5 3/4" nominal hole diameter)

TOH to 475' and circulate clean. WOC 24 hours. Pressure test to 80% of PVC rating.

Report test results. If good, we'll set and cement 400' o 3 1/2" casing then drill out the cement plug. If bad, we'll probably try again with a retainer.

Report all costs daily.

I'm not sure what CHH just said, but the gauge and valve test is what I would try. The flow might be great, but the pressure might be very low. The most pressure I have ever seen on a flowing well was 12 lbs or 27 feet. If you only have a couple lbs, you could raise the casing where the water just gets near the top and stays there. Then put in a submersible pump. I think this owner is having dillusions of grandure if he thinks there is enough pressure to run his house.

I do know there are a lot of Rotary operators who don't know how to properly grout casing and some don't pump anything up around the casing but cuttings. This is not cool with a flowing well.

bob...

The oilfield solution sounds good but would need it in english too. If more casing becomes needed maybe it could be 4" inside the existing, deeper and with a "packer" at the bottom and grout then placed around [?]

Its not the homeowner that came up with the idea of the high pressure and casing shooting out of the ground, that was the well driller - it sounded a bit off to him and thats why he called me. I think you are correct about the pressure - 35 gpm out a 6" hole could be just a few PSI.

If he gets it capped and has a few psi he will run into a 3000g tank and use the existing booster set up. At least save on the submersible until the day the well gets tired. Right now he is having fun with the new stream on the property.

I have had three flowing wells on three different properties I have owned, two in Michigan and one here in Florida. They are pretty cool, especially when your in the business. I also know that if you cap one off that does have pretty good pressure and the casing isn't very tight, you can have some major problems once it leaches up around the casing. I wouldn't want it to happen to one of my jobs.

bob...

Looks like the casing and well is ALL in granite - that should help [?] and what would you call a high pressure where you would not trust this drillers grouting?

It really wouldn't matter as long as there was enough force to push it to the surface and a little more. But in granite there wouldn't be any erosion like there would be in sandy soil like I'm used to. Imagine a hole in the ground that used to be 4" and is now 12' plus justa flowing away. Scary.

bob...

Raucina said:

The oilfield solution sounds good but would need it in english too. If more casing becomes needed maybe it could be 4" inside the existing, deeper and with a "packer" at the bottom and grout then placed around [?]

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I posted the response as a joke in typically oilpatch shorthand. Oilfield and waterwells really don't mix.

Just for grins:

MIRU = move in, rig up
BOP (or BOPE) = blow-out preventer or blow-out prevention equipment
NU = nipple up which is to connect flanges and hoses e.g. the plumbing
TIH = trip-in-hole
TOH = do I really need to 'splain this one?
WOC = wait on cement

Note that only civil engineers use grout, they use cement in the 'patch

A little more seriously: from a shear load point of view five feet of good cement/casing bond will hold the world. From an industry practice point of view 10 feet of good cement/casing bond is considered a hydraulic seal.

If the original well driller reciprocated or rotated the 6" pipe while placing the grout then there may be a good seal. If the grout was just placed around static pipe, well from my perspective all bets are off and a seal shouldn't be expected.

Qualifier/non-qualifier: I've been around many oil wells. I've never drilled a single water well. I did have a home with a water well for about 4 years and had lots of fun with a leaky bladder (tank, not me) and frozen pipes.

in the middle of north dakota is a fairly young lake. in the center of that lake are two things: a drilling rig and an improperly cemented and grouted well. the driller was not prepared for a flowing well and did not grout his casing properly. the well got away from him and has never been stopped. his insurance company has since had to handle the environmental issues as the well driller has been forced out of business by the mistake. also, several hundred acres of land have been destroyed, although some may argue that simply being in north dakota destroyed the land to begin with.

I saw a well that literally "ate" the drilling rig. They hit a shallow saltwater flow at ~220' and it washed out a crater about 100 yards across and 20' deep. For awhile they had a river of saltwater descibed as "two dozer blades wide and eight feet deep" running away from the crater. When I was there they were trying to pull drilling rig parts out of the crater. Six cats (3 5's, a 6 and a 7) couldn't budge the substructure.

At least saltwater doesn't burn and no one was injured. They were drilling surface hole without setting a conductor pipe. It cost'em a rig rebuild and they got to pay for killing a bunch of fish in a nearby river.

Pretty scary stories. This stuff does happen and if your not careful one of these scenarios could be very costly in a lot of ways.

Here we have to deal with sinkholes. I could tell you a few scary stories about them also.

bob...

This guy's hole is in granite so very likely a wash out won't occur.

The best drilling tale is from Louisiana or Texas where oil drillers in a lake punched into an abandoned sulphur or limestone mine and drained the entire several lake in a few minutes. I think it was in the 50's before video cameras, so no one really brings it up much. I recall several people were killed including some boaters that went down the whirlpool like bugs in a toilet.

Imagine watching a lake disappear in a few moments!

Raucina said:

... punched into an abandoned sulphur or limestone mine and drained the entire several lake in a few minutes ...

Imagine watching a lake disappear in a few moments!

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... and imagine watching that from the lake!

I once saw some footage of a similar catastrophe, and I would not have wanted to be that fisherman out there in his small boat. He was pointed toward shore, and his outboard motor running wide open had just enough power to keep him just outside the whirlpool until the flow had decreased enough for him to actually make some headway.