Posted: 7/20/2017 11:03:01 PM EDT
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Mrs. ALG and I are involved with an orphanage in Kenya. They are drilling a well so that the staff and kids can grow their own food. So they have a nice plot of land and they hire a company to drill.
They get 200 meters down and find good water, however when they pull the drill back up at about 110 meters there is a layer of gravel and it collapses and falls into the hole so the casing can't be inserted. This is a 6" hole. They don't really have another site to drill. The drill guys say it will be the same thing if they try anywhere else on the property.. The drilling company (pretty much the only one in Kenya) says that they can try to dill a 10" hole 100 meters deep then line the hole with casing. Then they drill some more and put an 8" casing down. Then again with a 6" casing to try and get through the gravel. I know nothing about all this drilling stuff. I thought the casing followed the drill bit down so one the well was drilled they just pulled the head of the drill back up through the pipe and all is good. Will this 10" to 6" pipe thing work or is it a shot in the dark? |
| Yes it should work. You drill down to the depth you want to put casing down to and pull the drill pipe/bit. Then put casing pipe in the hole. The cement goes down the pipe and out the bottom and then it comes back up the sides cementing the pipe in and you are done when the cement comes to the surface. |
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If you drilled another hole down though this gravel zone stop just below the base of it. Next cement the hole above this zone and let the cement cure. Finally drill the hole through the cement and finish your hole.
You could also case the hole as you go through this interval. Not a well expert but have done lots of exploration. |
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Mud and bran mixture to seal the hole.
Are they wet drilling or dry ? In my old days of seismic drilling on a conventional rig I can painfully remember mixing mud and bran in the pit to seal a fast hole to get circulation back flowing in the pit. We went through pumps regularly on leases with bad drilling. It aint all cheese drillin' |
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If I recall correctly There is a guy that had a old blue ford bronco as an avatar from one of the Carolinas that drills wells all over the world. I can't remember his account name on here hopefully someone else will. |
| When I pulled pipe for a wet drilling company installing geothermal heating and cooling loops we would mix Portland cement with the water. As the water leached through the porous material, usually sand and fine gravel, the cement would hold it together long enough to pull the drill pipe and feed the loop down. I don't know if it would help in your situation though. |
| A whole lot of it depends on the drilling you're using. It can be done with either type, just the time and difficulty vary. Cable tool or rotary? If rotary are they drilling with water or air? I have the same problem you described on my farm. Using a cable tool we drill to the gravel, then drop casing to that point. From that point on we drill inside the casing and hammer the casing down as we go. No need to cement anything until the casing is at the bottom of the hole. |