Compared to sand wells, artesian wells have a much longer service life. In addition, the water in such mines in most cases is very high quality and environmentally absolutely clean. The only disadvantage of limestone wells is their high cost and difficulty in drilling.
Pros and cons of using
The owners of several suburban areas usually equip such a source of water supply at once. An artesian well is expensive, but the flow rate is very large. Water from such a mine can easily be enough for several households.
Some owners of country plots are interested in which well is better - on sand or on limestone. Of course, if there is such an opportunity, it is best to equip an artesian mine outside the city. The only drawback of this type of springs is that the water supplied from them is very hard. Therefore, before using it in the house, it has to be driven through special softeners. However, according to sanitary standards, the degree of purity andthe taste characteristics of such water are significantly superior to those supplied from wells to sand.
Main Features
The high debit and excellent water quality in limestone wells are explained primarily by the fact that they are drilled very deep. The arrangement of such a mine can take from 1 to 5 days. Water lies in limestone rocks in different areas at a depth of 50-400 m. Before getting into a well of this type, it passes through different rocks and is cleared almost to a crystalline state. In addition, it acquires excellent taste.
The answer to the question of how much it costs to drill a well for water on limestone is usually large sums. The high cost of such mines is explained not only by their considerable length, but also by the need to use a large number of casing pipes. Sometimes water from artesian mines flows upward due to the pressure difference by gravity. In this case, not too expensive shut-off equipment is installed in the upper part of the well. If water does not flow by gravity from an artesian well, owners of suburban areas who decide to equip such a source have to additionally buy expensive pumping units.
Preparations
Water can lie in the lime layer in areas, as already mentioned, at different depths. Therefore, before drilling such a well, preliminary geological surveys are mandatory. Experienced specialists perform this work.
In the process of research, experts not only determine the approximatewater level, but also assess the structure of the soil. Depending on these data, methods for drilling a well for limestone and the type of equipment used for this purpose are subsequently selected.
What are the types of artesian wells
A total of four types of such mines can be equipped in suburban areas:
- double-cased;
- with conductor;
- with transition;
- classic.
The choice of a specific type of well is carried out taking into account the geological features of the area. Depending on which mine will be drilled, the parameters of the necessary equipment are also selected.
Classic artesian well casings reach the top of a calcareous aquifer. Such mines are equipped in those areas where there is sufficient pressure in the horizon, and there are no sand and clay layers.
Drilling in a double-cased well section is performed using pipes of different diameters. Those that are larger are brought only to the border of the lime layer. Perforated pipes of smaller diameter are introduced into its thickness to the very horizon. Mines of this type are equipped on aquifers with insufficient pressure.
Wells with surface conductors are drilled in much the same way as wells with double casing. However, the second pipe (in this case it has a larger diameter) is placed at theirarrangement in the upper layers of the rock, cutting off Quaternary deposits. The use of such a conductor avoids getting into the artesian surface water. Such a construction of wells for limestone is usually used where there are no sand and clay layers, there is sufficient pressure in the horizon, but at the same time, the upper layers do not allow conventional drilling.
Shafts with a transition are structurally a telescopic structure assembled from several casing pipes at once. Such wells are equipped with:
- presence of problematic top layers;
- presence of sand and clay lenses in the lime layer;
- with sufficient pressure in the aquifer.
Drilling equipment
When arranging a well for limestone, all the required technologies must be observed exactly. Otherwise, the equipment used to perform such work may simply fail. In addition, the water in an incorrectly drilled well will subsequently be of poor quality.
The construction of wells for limestone does not apply to the types of licensed works. However, it is, of course, impossible to drill such a mine on your own. In any case, you will have to invite specialists to equip it.
The depth of a well in limestone is usually significant. Therefore, very powerful equipment is used for its arrangement. For example, URB 2A-2 drilling rigs can be used by professionals for artesian wells.based on KAMAZ, ZIL or URAL vehicles. Such equipment is complemented by special rock cutting tools called cone bits. This device rotates due to the torque transmitted through the rods from the engine of the installation, sustainer or deck.
Drilling technology
Methods of arranging artesian wells for limestone can be used differently. Very often, such mines are drilled, for example, using the flushing method. A feature of this method is, among other things, the fact that specialists in the process of performing work see what rocks the working tool of the installation is currently passing through, since they are carried out with the flow of water supplied to the mine.
As soon as the bit reaches the limestone, the well is cased with pipes and flushed out. For further drilling, specialists use a smaller working tool. They break through the actual limestone before reaching the aquifer. Rinsing water at this stage is used exclusively pure.
Sometimes, as already mentioned, lenses of sand or clay can be found in the limestone layer. Information about the presence of such formations during drilling is mandatory recorded in a special log. Subsequently, such sections are covered with casing pipes of a smaller diameter than the main one.
Drilling a well in limestone sooner or later ends up reaching the desired strata. From this moment, the absorption of the supplied flushing begins.liquids. Its stock is replenished by water brought by tankers. As soon as the absorption of the drilling fluid reaches certain values, drilling of the well is stopped. The master at the same time beats the water level in the mine.
Leveling
At the final stage of drilling a well for limestone, it is flushed. To do this, lower the pump into the mine and turn it on. Pumping is carried out until visually clean water comes out of the well. In practice, this procedure can take from one to several days.
During pumping, specialists, among other things, measure the dynamic water level. This indicator is subsequently used for the final calculation of the mine flow rate.
Installation of equipment
As with the arrangement of a conventional mine on sand, when drilling in an artesian well section, at the final stage, a caisson is poured around the casing pipe that comes to the surface. Mount it in this case according to standard technology. That is, they dig a pit around the pipe up to two meters deep. Next, a trench is brought to it for the cable of pumping equipment and the supply pipe.
The walls and bottom of the caisson are poured with concrete. Sometimes a finished container of this type with a hatch is also installed in the pit. At the final stage, the pump is lowered into the well, pipes are connected and additional equipment is installed. The shaft pipe itself is cut off and a head is put on it.
If water is ejected from the mine under pressure, a special fitting cuts into the casing pipe below ground level. A pipe is subsequently attached to it,the opposite end of which is brought to relief.
Self-draining well can also be closed hermetically. But when using this method, there is a risk of pipe rupture when water freezes in winter in the upper part of the mine. To prevent this from happening, a meter hose, hermetically sealed on both sides, is installed in the column. This element will subsequently take on the pressure of expanding water when freezing.
How much does it cost to drill an artesian water well
The construction of such mines, as already mentioned, is usually quite expensive. Buryat artesian wells owners of suburban areas most often pooling. The price of a meter of sinking of such mines can vary greatly and depends on many factors. But in most cases, for 1 m of such a well, the owners of suburban areas have to pay about 1500 - 2000 rubles. That is, if the depth of the mine on the sand reaches 100 m, you will have to pay at least 150 thousand rubles for drilling it.
