It often happens that a natural source of sand or limestone loses its flow rate after prolonged use. Many craftsmen decide to drill an old well, rather than make a new one. How appropriate is this option is determined by several parameters - the complexity of the upcoming work, the root cause of lowering the water level in the source.
The reasons for the disappearance of water in the well
To make sure that the water level in the well is constantly decreasing, you need to watch it. Perhaps this is a temporary problem, provoked by the characteristics of the aquifer or weather conditions in the region. It is useful to talk with neighbors and find out how things are with their sources. If the problem arose only with a specific well, it means that we are talking about the exhaustion of the resource.
The main reasons for the drop in water level in the well:
- clogging of the bottom filter if the source is drilled into a true floater;
- deviation of the shaft from a vertical position, subject to technical errors at the time of construction of the well;
- casing depressurization;
- a large number of sources in the village, fed from one aquifer (especially the problem of the disappearance of water in the hydraulic structure is noted immediately after drilling a well at a neighbor);
- long period of summer drought (the problem is typical for sources on the sand);
- well construction during a period of high standing groundwater.
It is advisable to drill a well or deepen it in summer or winter.
It is possible to deepen an existing well if its life is not more than 5-10 years. It is important to weigh the pros and cons of such work. The financial possibilities of the master are taken into account (more often, deepening the source is more expensive than building a new one), the possibility of building up the casing string, and the results of geological surveys. There is no point in doing work without them, since the next aquifer can be extremely deep.
Preparation for work
The preparatory phase is important when deepening a well under water. The result of secondary drilling depends on how correctly everything is done. Preparation looks like this:
- fluid resets are pumped out of the well;
- if at this moment a skew of the barrel rings is detected, eliminate the defect if possible. If the bias is strong, work will have to be stopped at this source;
- all joints of the column are carefully fixed with special plates - this will protect the mine from rupture during drilling; plates are placed at an equal distance from each other;
- prepare a shovel, sand containers, electric or manual winch, drill, flashlight.
All do-it-yourself deepening actions can only be carried out with an Abyssinian source (depth not more than 5-6 meters). In other cases, it will not work to deepen the well without drilling.
Deepening Methods
One of the most common methods for resuming a source is by using a bailer. This is a metal pipe with a valve at the bottom. So that the bellow can freely cut under its weight into the ground during manual drilling, you can sharpen its lower edges or cut the teeth. The principle of well deepening is as follows:
- The source shaft is completely freed of liquid residues.
- The casing string is cleaned of sludge.
- The bailer is attached to the winch and lowered down to the source.
- From a height of 1-1.5 meters, a metal pipe is thrown so that it cuts into the ground a few centimeters. At the time of its sharp lowering, the flap opens to take soil from the shaft of the mine.
- When lifting the choke valve closes, preventing the soil from crumbling down.
- On the surface, the pipe is freed from sand and the steps are repeated with a recess until a result is obtained.
It is advisable to perform the work together. As soon as the master reaches a new aquifer, you need to grind the casing from below. To do this, a segment of the mine, with a diameter smaller than the already existing one, is collected on the surface and lowered down. Then produce the merging of two sections of the column.
Using the same method, specialists with drilling rigs work. The difference lies in the fact that the special equipment functions faster and can deepen the well for a larger length.
Deepening with rings
An old well can be drilled using rings. They also have a bailer. To lengthen the barrel of the casing string, segments of rings or pipes are used that are similar in diameter to those already existing. The work looks like this:
- Using a metal pipe, deepen the source.
- As the depth of the shaft increases, new pipe sections are installed on top of the casing. Under their weight, they lower the existing barrel down. The main thing is to carefully seal the joints of the elements.
- With each new meter, recesses touch the well shaft.
After achieving the result, water from a new horizon should be submitted for analysis.
Quicksand Deepening
This is a special type of soil characterized by its constant movement. To properly drill the source, you need to act quickly. To do this, prepare a longer bailer so that it absorbs a larger amount of soil. Also, when working on quicksand you need to use more powerful equipment, since wet soil has an impressive weight.
Ready deep hole in the lower part is equipped with a filter. To do this, take a plastic pipe of slightly smaller cross-section than the casing. Holes of 3-4 mm are made along its entire surface in increments of 3-5 cm. The outer part of the tube is wrapped with a fine mesh. It remains to lower the makeshift filter to the bottom of the well and close up the joints with the main shaft.
An in-depth source needs to be pumped well.
Common mistakes
When performing work, it is important to avoid common mistakes. These are:
- Inaccurate reason for draining the source. If this phenomenon is temporary, at the time of a new drilling, the previous aquifer may resume its work.
- Work during the season of high standing groundwater (spring / autumn). Here, the appearance of water during drilling will be false. When groundwater flows down in summer or winter, fluid from the well will disappear.
- Technological errors, incorrect calculations. This threatens a further displacement of the sections of the casing.
- Lack of specialist advice before performing work. It may happen that it is more advisable to drill a new source than to try to resume the old one.
Without accurate geological surveys, deepening a well into limestone (artesian) is not recommended.
