Auger drilling of a well

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Auger drilling of a well
Auger drilling of a well

Auger design for manual well drilling. A typical set of tools for doing the job. Mine drilling technology in various types of soil. Auger drilling of wells is the execution of shallow vertical shafts with a spiral tool from the surface to the aquifer to extract water using a pump. In the process of operation, the blades of the device grind the rock and bring it to the surface. The article provides useful information for everyone who wants to make a well manually using this tool.

Design and types of augers for drilling a well

Auger drills

The auger is used to create shallow wells for water production. Most often, in this way it is possible to get to free-flow aquifers located at a depth of 5-20 m. Usually this liquid is not recommended to drink, but the decision to use it is finally made after the analysis in the sanitary and epidemiological station.

The auger is a screw-shaped product that is screwed into the ground and lifts the crushed soil to the surface. The device consists of an axle with blades and a tip. There are augers for hand and machine drilling.

The types of hand tools and their purpose are shown in the table:

Auger type Features of use
With one row of blades that are tilted at an angle of 30-60 degrees For well drilling in soft and loose soils. The blades crumble the soil and lift it up.
With one row of blades that are tilted at 90 degrees For drilling wells in dense and gravel-pebble formations. The blades cut the soil and lift it up without crushing. When removed from the trunk, the earth does not fall off them.
Double helix The second branch reduces the deviation of the tool to the side during rotation.
With tubular center piece Allows to supply water to the mine while drilling.

The auger is not suitable for working on sandy soils - sand does not stick to the screw surfaces. Also, the device is powerless on rocky or stony layers. Users choose the auger drilling method because of the high ROP and low cost of ownership. Among the shortcomings, one can single out the need to often lift the tool to clean it and the fall of the earth from the device back into the mine during excavation.

It is difficult to rotate the product, so two assistants are required. For drilling in rocky soils, it is recommended to purchase a collapsible compact device powered by an electrical network or a gasoline engine. If the work is one-time, it is better to rent it. The working tool is sold in hardware stores. If you have sufficient experience with metal, the auger can be made independently from pipes and metal sheets.

If the well is deep, a tripod is needed to raise and lower the device - a special structure to which lifting mechanisms are attached. When auger drilling, casing pipes must be installed in the well, performing the following functions:

  • Prevents shedding of the barrel walls;
  • Do not silt the source;
  • Protect the well from overwater and dirty streams;
  • Eliminate source clogging.

When choosing a casing, pay attention to the following points:

  1. To protect the barrel, it is recommended to use stainless steel or plastic products. Their service life exceeds 50 years.
  2. Plastic pipes are fragile and cannot be installed in wells more than 15 m deep. They are not always even and can be damaged by the auger when drilling.
  3. The disadvantage of stainless steel products is their high cost.
  4. Galvanized and asbestos pipes are not installed in the well; they contain elements harmful to humans.
  5. The diameter of the casing pipe is selected so that a gap of at least 7 mm remains between the pump and the walls. For reference: the most common size of a deep well pump is 86 mm.

Preparatory work before drilling a well

Well drilling tripod

Before work, you need to purchase basic and auxiliary devices, as well as consumables. Some of the rigging and component parts for the well are easy to make on your own according to our recommendations.

For drilling, you will need a tripod consisting of three wooden beams with a diameter of 15-20 cm and a length of 3-4 m or metal pipes (if there are extra ones). The height of the structure should be 1.5-2 m higher than what will rise and fall.

Assemble the tripod in the following sequence:

  • Place 2 triangular beams on the ground.
  • Connect the logs at the top with nails or some other method.
  • Drill in the beams, in the lower part, the holes into which the ties will be installed.
  • Pass the pipes through the holes and secure them so that the legs do not part.
  • Raise the triangle one log and secure.
  • Place your third leg on the ground so that the whole structure resembles a tilted pyramid.
  • Fasten the third log at the top to the first two.
  • Connect all the logs together with ties by passing them through the holes made.
  • Place the structure in an upright position.
  • Attach the winch hook to the top.

The lifting mechanism can be fixed at the bottom of the tripod, and at the top, at the junction of the logs, fix the block instead of the hook and pull the chain or rope. A gate can be used as a lifting mechanism, which is attached between the legs of the tripod at the bottom of the structure.

Install the product over the place of the future well and secure it against movement in the horizontal plane. To do this, dig the supports to 0.7-0.8 m into the ground, and place meter-long beams under them. It is not recommended to fix the legs on the ground with vertically driven crowbars.

A filter must be installed in the lower part of the shaft, in the water intake area. It is easy to make from a piece of casing that is first installed in the well.

The work is done in this way:

  1. Drill holes with a diameter of 5-8 mm in a staggered pattern in the elbow at a length of 100-110 cm. Leave a gap of 5 cm between the rows. Do not check the holes more often, they will weaken the product. Instead, you can make slots 2.5 cm long and 1-1.5 mm wide every 2 cm.
  2. Sharpen or make one of the ends of the knee toothed, and spread the points in different directions, like a saw.
  3. On the opposite side of the filter, cut a thread to connect to adjacent elements. Thread the other parts on both sides.
  4. If casing is installed in a finished well, wrap the perforated section with mesh on the sides and bottom. Instead of a mesh, it is allowed to wrap the knee on the outside with stainless wire.

The filter can be installed inside the casing, but for this it must be placed inside the structure. In this case, it is recommended to buy a finished product that fits snugly into the barrel.

A perforated elbow is sometimes installed without a mesh, but in this case there must be a gap between it and the well, filled with rubble, to retain dirt and sand.

Well drilling technology with auger

There are various technologies for auger drilling of wells. The choice of technique depends mainly on the composition of the soil above the aquifer. If the soil is solid throughout the depth of the shaft, the casing is installed after the well is completed. However, in most cases, it settles in parallel with the lowering of the tool or after its deepening to 0.5-1 m.

Drilling a well in solid soil

Drilling a well in solid ground

It is recommended to drill a well with an auger in the winter - all the space nearby is free, and there are no problems with placing a huge amount of dirt that rises out.

This method of drilling a well in solid soil is the easiest to perform:

  • Assemble the tripod as described above.
  • Determine the center of the hole. To do this, attach the drill to the chain and lower it with a winch to the ground with a winch.
  • Dig a 1.5x1.5 hole around the mark and line the walls with wooden planks or shields.
  • Exactly in the center of the hole, dig a hole 2-3 bayonets deep.
  • Lower the auger drill into it and secure the handles.
  • Rotate the device to go deeper to its full length (or as far as strength is enough).
  • Lift the tool with a winch and clear the soil.
  • Lower it back into the shaft and secure the extension. It is better to fix the pieces with a finger, which is threaded through the holes in the pipes. Do not connect the lengths with threads, as the auger often has to be rotated in both directions.
  • Repeat the operations until the tool enters the aquifer. It is better to rotate it together or three - one person must press on the device from above.
  • Continue spinning to reach the lower shale. When the tool becomes harder to rotate again, lift it to the surface.
  • Clean out the mine with a bailer.

After that, a layer of gravel with pebble sizes within 50 mm must be poured onto the bottom. The layer thickness is 20-30 cm. Gravel will retain small particles of soil.

Attach a clamp with handles to the filter, insert it into the hole and lower it all the way. Screw the next elbow to the top of the filter and attach the second clamp with handles to it in the upper part. Remove the stopper from the lower elbow and lower the structures against the stop in the upper clamp. Repeat the operation until the screen and casing are lowered to the bottom. If the structure is heavy, use a tripod and a winch to move it.

Then it is recommended to flush the well by installing pipes in it and supplying water under pressure. The liquid will wash away the dirt, which is removed with the water by a centrifugal pump. Repeat the procedure for 1-1.5 weeks. After the appearance of clear water, the samples should be taken to the laboratory for analysis.

Fill the gap between the casing and the ground with cement mortar so that rainwater does not contaminate the source. Install a submersible pump in the well, after which it can be operated.

To pass various types of soil (loose, viscous, stony), use other tools, such as a spoon-drill, a bailer, a glass-drill, a drill-chisel.

Note! Approach to water can be determined by wet soil raised to the surface. If the tool becomes easier to rotate, then it has entered the aquifer.

Drilling wells in loose or viscous soil

Drilling a well in loose soil

Unlike the previous version, the walls of the mine are reinforced with casing pipes simultaneously with the rotation of the auger.

The work is performed in the following sequence:

  1. Drill a 1m deep hole in the ground in the same way as in the previous section and pull the auger out of the barrel.
  2. Attach a clamp with handles to the filter (lower elbow of the casing), install it in the hole and settle. Turn it if necessary. A segment with a height of at least 100 mm should protrude above the surface.
  3. Place the auger in the casing and lower it all the way. It should stick to the handles of the tool.
  4. Disconnect the winch chain from the drill.
  5. Screw an extension 1-1.5 m long onto it. Attach the winch chain to the new part and take out its slack. Make sure the structure is upright. Otherwise, the casing is hard to move in the well, and the auger will begin to touch the walls of the wellbore. If a slope is found, level the trunk by driving wedges between it and the ground.
  6. Move the clamp with handles to the end of the connected extension.
  7. Rotate the auger to reach the maximum depth.Add water to the well to make turning easier. Raise the tool every 20-30 cm and clean it from the ground.
  8. Remove the drill from the hole, disconnect the hoist.
  9. Attach the next elbow to the filter and lower the casing until it stops. Use a lifting device if necessary.
  10. Repeat the operations until the tool reaches the aquifer. Remove the drill from the hole.

Using a centrifugal pump, you need to pump out several buckets of liquid (do not use vibration devices, they are not designed to pump out dirty thick slurry). After 5-7 buckets, check the water purity. If the desired result is not obtained, use a drill to deepen the shaft another 0.5 m and refill several buckets. If the liquid has not cleared after an additional 2 m deepening, you will have to put up with a small debit of the well. Then swing the well and form a bottom filter, secure the casing from moving.

During auger drilling of water wells, use our recommendations:

  • Mark casing to quickly determine hole depth.
  • If the borehole is more than 7 m, install a guide in it - a piece of pipe, the diameter of which is larger than the diameter of the well. Carefully set the centering device in a vertical position and concrete. It will not allow the shaft to deviate from the vertical.
  • Plastic pipes are easily damaged by the auger, so centralizers are put on the bar every 3-5 m. The cheapest spring, better quality ones are turbolizers, but they are more expensive and are usually used in professional drilling.

How to drill a well with a screw - watch the video:

The article contains proven methods of auger drilling of a well. To get a good result, analyze all the information about the underground layers of the soil and, based on the results, select the tool that is necessary for your case. If you adhere to the rules for working with the auger, then after a short period of time you will solve the problem of water supply to the site.

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