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Borewell Troubleshooting - Retrieving Pump: Retaining Bore - Vidarbha

I drilled a bore , 6.5 " dia. with casing pipe for 20 ft in hard black rock in the Vidarbha region. Struck water at 80 ft (approx 1/2"). With yellow soil for aproximately 5-6 ft at 250 ft deep. hard rock till 350 ft. water at 350 ft , 380 ft, 450 ft. as per driller he has neverseen such water source before at 500 ft. There was some mud at 510 ft. drilling stopped at 510 ft.

After drilling , we procured a 25 stage, 5 HP pump, 2.5" HDPE pipe and best quality power cable.

Before installing the pump, when we checked the bore we observed siltation upto 450 ft. So we lowered the  pump upto 400 ft. Pump ran continuously with out drying, we operated pump for 6-8 hrs a day. No problem.

One day , we observed that electric cable was stretched. we pulled it and tied it properly. Next day again we observed same phenomenon, but observed that cable is broken. We doubted the improper joining of the cable with HDPE pipe. because of self weight cable might have broken. We tried to pull out pump with the help of HDPE pipe. it came up to 270 ft but then stuck. We tried pulling with bullock cart (to pull pump out), it did not move. The pump is jammed so badly that it could not be removed even with chain pulley block arrangement which pump mechanic set up.

My expectation.

Ready to lose the pump but not the bore. I have gone through almost all related  Q & A on this portal about casing pipes. pebbles filling, but I am confused. I would like to request for suggestions / responses that will help me retain the bore.Also contact information of suitable experts to do a hands on evaluation in the Vidarbha area will be appreciated.

 

 

 

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1. Dear Vijay Dhote

Dear Vijay Dhote,

 

You may have to push it down the pump and try it again. I do not see any otherwise chance of recovery. 

 

With regards,

 

S. C. Jain

Programme Coordinator

AFPRO (Action for Food Production)

New Delhi - 110058

2. Dear Vijay Dhote,   This is

Dear Vijay Dhote,

 

 

This is a classic case of poor designing of the tubewells, emphasizing the requirement of a proper design for the tubewells.

 

You said that casing pipe was installed upto 20 feet only, and then 6.5" boring was continued till 500 feet, while there was a 6 feet thick patch of yellow soil at 250 feet. This soil at 250 feet has now collapsed in to the bore, and has filled up the bore up to 270 feet. Soon it will rise up to 250 feet level.

 

Most people in our country (the clients as well as the drilling contractors) consider tubewell drilling work as something which does not require any planning. They just bring the drilling machine, and start the drilling, without ever thinking what might be in store for them.

 

In fact when the drilling was started at your site, the driller should have known before hand, that there might be a clay layer at 250 feet, 5 to 6 feet thick, which might need to be protected by a casing. But he just went ahead, starting the drilling and continuing up to 500 feet without providing the casing at 250 feet.

 

If the strata would have been known to the driller, he would have planned the bore; he would have started with a bigger diameter at the beginning, to install casing of suitable size at a deper level.and then only drilling further.

 

Any way, if he did not know about collapsible zone at 250 feet, he should have immediately stopped further drilling and you should have been happy with whatever water was available to you up to 250 feet. That way you would have saved the cost of your pump, pipes, cables, and the drilling cost beyond 250 feet.

 

Well, the remedy now depends entirely on the water availability before 250 feet level. Please measure the static level (the depth at which the water now stands in the tube-well) by means of a rope, and communicate to me. Please also tell me your daily water requirement.

 

I shall be able to provide you some solution after you provide this information to me. But the solution will definitely require that you lose your pump now, and the cable, and the pipe. You will have to install a fresh set up of pump, pipes and cable.

And yes, the drilling which was done in excess of 250 feet has gone waste, and the effective depth of the bore would always be 250 feet now.

 

With best regards,

 

Sudhindra Mohan Sharma

Hydro-Geologist

S.S. Exploration Enterprises

Indore

Madhya Pradesh

3. Borewell Troubleshooting - Retrieving Pump: Retaining Bore - Vi

 

Dear Mr. Vijay,

 

 

Since the hose and pump have come upto 270 feet level from the 400 feet level.   The jamming of the pump may be due to the cable get coiling round the hose pipe and get tightly brushed and squeezed between the bore wall and pump/hose.

 

When we use HDP hose for lifting water from the bore during erection it is easier, but during lifting it becomes problem or the effect of the process cause damage to the bore well itself if we have put PVC casing pipe or if the terrain is soft.  This is because you have to negotiate lot of load in a curvilinear way and naturally the body of the pump will damage the bore wall or pipes.  

 

Since the pump have come up  270 feet and crossed the main yielding zone the jamming of pump may not be due to siltation, though some clay zone occur close to 220 feet. 

 

You can make still and attempt to lift the assembly by employing a high capacity JCB.    If the assembly is not coming out then drill a new bore well very close the same bore well may be within about 3 feet radius, along the same strike direction of the underground stream.  If you can get experienced Geophysicist, then with appropriate spread length of current cable, they can conduct micro distance resistivity profile for about 10 feet along the four direction and locate the stream strike and help you to get near to same yield bearing underground stream.  Under our state of art of development, it is difficult to do with other methods, and getting consultants is also difficult.

 

Alternatively you better drill bore well as close as possible and install pump at appropriate level.   When you get water at 80 feet and again huge yield below 350.400 and 450 feet level, because of hydrostatic pressure, the static water level should have come to a depth of 50 or 60 or 70 feet.

 

You have nearly left with a minimum of 380 feet water column.  Your 5 h.p pump that has continuously yielded for 2.5 inches hose.  The discharge might be a maximum of 650 lpm.  Hence the pumping water level should not have gone down below 200 feet from 60 feet,  unless otherwise your area is situated in a elevated part of your basin.   Putting the pump at 400 feet is unwarranted under your high yielding condition.  This has created the problem for you.

 

Hence for your new bore well please try to put your pump at a level of about 250 feet first if you are not getting good yield then you can put it down.  Your pump company has given you a wrong advise and you have incurred excess cost on hose and cable also.  We cannot blame them, it is their business. As you are getting swelling clay below 510 feet do not try to limit your drilling upto 500 feet.

 

Nothing to worry,  by drilling as close by as possible,  a new Borewell you can get back your water.  If you could not succeed in getting the assembly back by even JCB, please fill your bore with fine sand and proceed with drilling, otherwise problem with drilling will occur due to compressed air escape.   Please take care of erecting the pump at 250 feet range.

 

With best wishes,

A.      Raja Mohamed Ambalam

Geophysicist

Coastal Energy Pvt Ltd

 Chennai- bismi124786@gmail.com

 09443619352

 

 

A. RAJAMOHAMED AMBALAM GEOPHYSICIST COASTAL ENERGY Pvt Ltd, CHENNAI +919443619352

4. Borewell Getting Silted Even With Filter Pipe

Sir, We have a small community site of 1300 sq ft with a 4 floor choultry . Since there is no space we dug a 7 inch dia borewell to a depth of 302 feet in the Portico Area which has the Water Sump. A 10 inch protective sleeve to a depth of 30 feet was installed. Then a 7 inch MS Casing to depth of 74 ft was installed. The Driller reported rock at a depth of about 80 feet. The 7 inch MS Casing could not be pushed to the full 80 ft with the 12 ft Mast Triangular Base Drill Rig.

The Driller reported 2 inch water at a depth of about 90 feet. He also said the soil is loose with lots of small black stone particles 2 to 3 mm dia after about 105 feet. He suggested a 4 inch dia PVC Filter Pipe for the full borewell depth of 300 feet (bottom 220 ft filter + top 80 ft std pipe). The Geologist had suggested a depth of 300 ft as in the HAL III Stage Bangalore area water is found normalyy at 300 to 400 feet.

We found a clear depth of 230 feet inside the Filter Pipe (70 ft lost to mud or silt). Water was visible at a depth of 20 feet from the floor. So the 1.5 HP 3 inch dia 20 stage Texmo pump was installed at 200 feet. It pumped muddy water for about 15 mins then stopped. Next day there was no water. The pump could not be pulled out. Presumed to be burried in silt.

Low pressure air was discharged through the pump and then pulled out. The bore was flushed to a depth of 250 feet with a semi rigid HDPE Pipe.

After 3 days the depth was checked. It was only 85 feet. The Pump was not installed as there would not be enough water at this head. Heavy silting.

Request please advise a solution to get the borewell operative.

Madhuri G.

 

 

 

5. borewell casing pressed

Dear Sir,

My builder was digged bore well of 4 and half inch size in loose and bolck soil area. Generally in that area water will found in 40ft only. but in my case we went up to 260 feet. 70 feet casing was inserted and motor was went upto 230feet. After that in my bore well many water layers was opened suddenly, now the water level is in my bore is 15feet. My house is consturcted and we are staying since last two months. Because of frequent pumping problems, The mechanic was trying to pullout the pump for repaire. unfortunately motor was struck at 60feet level and recovered by using chain block machine expert. He told me that around 15feet of casing pipe has been pressed it is not difficult to push the motor again into the well until casing pipe is expnded by using bore well machine. Around 15ft casing was pressed from 46 ft to 60ft from top level as per the measurement made by the man who recovered my motor from borewell. What is recasing Sir ? Whether it is useful in my case? I had contacted few people regarding this matter, they are preferring digging new borewell rather than operating current one. There is hardly no space to digg new well in side compound wall of my house as slab area is almost equal to compund wall area of the house. I am very confused. Please advise. What could be the problem ? quality of casing pipe ? or problem in the bore well design ? Please give your valuable suggestions to save my bore well.

with regards,

 

d. partha sarathi

hyd

6. What action I took ?

Condition of the bore when I started work on it.

Pump stuck at 270 ft.

We tried to remove water and silt with specially developed venturi pump (air pump), in which compressed air lifts up water and silt. When we started removing mud, we started it from 150-180 ft, it means there was mud up to the level.

Mud and water was removed up to 225 ft or so. We could not go below, as there was cable above the motor.

We tried but could not remove cable nor we could go below.

Then the mechanic developed special tools which he inserted from the pump delivery HDPE pipe, with 1/2 dia c class GI pipe, tool was such that when it goes inside the motor delivery chamber, it will lock with motor.

Thus we tried to pull the motor with the tool attached to GI pipe with chain pulley block. Failed again, pipe joint removed, mechanic made special arrangement to hold the GI pipe at the depth of @ 100 ft , inside the 2 '' HDPE pipe.

I my self is Mechanical Maintenance engineer with 20 years of industry experience. For me it looks like impossible task. But the mechanic not only held the thread slept 1/2 pipe but also have re-threaded it in situ at 100 ft below, and connected new pipe and removed his rod line (GI pipes)

When the mechanic could do this, I was pretty sure that this mechanic will take off my motor and make the bore functioning.

The mechanic has tried his level best to remove the motor; he worked for more than 15 days with his men on the job, but could not remove the motor

Finally he pushed the motor down along with @ 100 ft long cable. We inserted new casing pipe of 5.5-inch dia, slotted and plain depending upon location and water.

Today, the motor is at @ 500 ft below with cable on it, casing pipe inserted up to 350 Ft, new motor installed at @ 300 ft. Motor is working and we are getting sufficient water, whole day till power is available.

Considering this year’s draught condition, availability of water is more than sufficient for us hence we decided not to put casing pipe further neither remove the old pump.

In the whole episode, the following are my learnings:

1. Drilling a bore is not as simple as it is thought and dealt with. Proper planning & knowledge is required. One must keep record of drilling depth, water, soil condition etc

2. Casing pipe or slotted casing pipe is not a BAD option, if need is felt it is wise decision to go for casing pipe up to the depth.

3. Installation of pump is not simple, any mistake like we did in tying the cable can create big problem.

4. If you are struck, only mechanic like we could get, only help you out. I really salute him, for his technical makeshift arrangements (JUGADs), his patience and finally COMMITMENT towards his job.

Hope my experience is useful in solving your problem.

 

7. Black water coming through bore, motor at 70 ft- pls help

Sir,

We have bore of 300 ft and motor is hanging at 180 feet, suddenly after one week black water is coming through the bore. Presently the motor is 70 feet in water, I do not know from where the black water is coming, please help me.

8. Guidance in taking out submersible motor from a tubewell

Hello,

We have a 6 inch diameter PVC casing pipe top to bottom and 200 ft deep tubewell. Our 10 HP submersible motor has slipped into the tubewell and is stuck at a depth of 50-60 ft. How can I take out the motor without damaging the tubewell. Please guide me.  Also please suggest any service provider company who can help me do this. Please contact at 09922769484 09421887685

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