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 friendly. The only drawback of limestone wells is their high cost and difficulty in drilling.
Pros and Cons of Using
Equip such a source of water supply is usually immediately the owners of several suburban areas. The artesian well is expensive, but the flow rate is very large. Water from such a mine can easily be enough for several farms.
Some owners of suburban estates are interested in which well is better - on sand or limestone. Of course, if there is such an opportunity, it is best to equip an artesian mine in the country. The only drawback of sources of this type is that the water from them is supplied very hard. Therefore, before using it in the house, you have to drive it through special softeners. However, according to sanitary standards, the degree of purity and taste characteristics, such water significantly exceeds that which is supplied from the wells to the sand.
Key Features
The high debit and excellent water quality in the limestone wells are explained primarily by the fact that they are drilled very deeply. The arrangement of such a mine can take from 1 to 5 days. Water lies in limestone rocks in different places at a depth of 50-400 m. Before entering a well of this type, it passes through different rocks and is purified almost to a crystalline state. In addition, it acquires excellent taste.
Large amounts are usually the answer to the question of how much it costs to drill a water well for limestone. 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 up due to the pressure difference by gravity. In this case, not too expensive locking equipment is installed in the upper part of the well. If the water does not flow by gravity from the artesian well, the owners of suburban areas who have decided to equip such a source have to additionally buy expensive pumping units.
Preparatory Activities
Water in the calcareous layer in areas may occur, as already mentioned, at different depths. Therefore, before starting drilling such a well, preliminary geological surveys are mandatory. This work is performed by experienced professionals.
In the process of research, specialists not only determine the approximate water level, but also evaluate the structure of the soil. Depending on these data, subsequently, methods of drilling a well for limestone and the type of equipment used for this purpose are selected.
What types of artesian wells exist
On suburban areas, a total of four types of such mines can be equipped:
with double casing;
with a conductor;
with the 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.
Casing pipes of classic artesian wells reach the upper part of the calcareous aquifer. Such mines are equipped in areas where there is sufficient pressure in the horizon, and sand and clay layers are absent.
Drilling on a section of a double-casing well is carried out using pipes of different diameters. Those that have a larger size, while bringing only to the border of the calcareous layer. Perforated pipes of a smaller diameter are embedded in its thickness to the horizon. Mines of this type are equipped on aquifers with insufficient pressure.
Conducted wells are drilled in much the same way as double casing. However, the second pipe (it has a larger diameter in this case) is located during their arrangement in the upper layers of the rock, cutting off the Quaternary deposits. The use of such a conductor avoids getting into artesian surface water. This construction of limestone wells is usually where there are no sand and clay layers, there is sufficient pressure in the horizon, but the upper layers do not allow normal drilling.
Shafts with a transition are structurally a telescopic structure assembled from several casing pipes at once. Such wells are equipped with:
the presence of problematic upper layers;
the presence in the lime layer of sand and clay lenses;
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 carry out such work may simply fail. In addition, water in an incorrectly drilled well will subsequently be of poor quality.
The arrangement of wells for limestone is not a type of licensed work. However, it is, of course, impossible to drill such a mine on its own. In any case, it will be necessary to invite specialists for its arrangement.
The depth of the well on limestone is usually significant. And therefore, very powerful equipment is used for its arrangement. Used by professionals for artesian wells, for example, URB 2A-2 drilling rigs based on KAMAZ, ZIL or URAL vehicles can be used. Such equipment is complemented by special rock cutting tools called a cone bit. This device rotates due to the torque transmitted through the rods from the installation engine, marching or deck.
Drilling technology
Different methods for arranging artesian wells on limestone can be used. Very often such mines are drilled, for example, using the flushing method. The peculiarity of this method is, among other things, and that specialists in the process of performing the work see which rocks the installation tool currently passes, 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 lined with pipes and washed. For further drilling, specialists use a smaller working tool. Limestone itself breaks through them until it reaches the aquifer. Wash water at this stage use exclusively pure.
Sometimes, as already mentioned, sand or clay lenses may occur in the limestone layer. Information on the presence of such formations during drilling is mandatory recorded in a special journal. Subsequently, such sections are overlapped by casing pipes of a smaller diameter than the main one.
Drilling a well for limestone sooner or later ends with reaching the desired formations. From this point, absorption of the supplied flushing fluid begins. Its supply is replenished by the water brought in by tankers. As soon as the absorption of flushing fluid reaches a certain value, the drilling of the well stops. 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 shaft and turn it on. Pumping is carried out until visually clear water flows from the well. In practice, this procedure can take from one to several days.
During pumping, experts, 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 the artesian well section at the final stage, a caisson is poured around the casing that comes to the surface. Mount it in this case according to standard technology. That is, they dig a pit around a pipe with a depth of up to two meters. Next, a trench for the cable of the pumping equipment and the supply pipe is brought to it.
The walls and bottom of the caisson are poured with concrete. Sometimes a pit of this type with a hatch is also installed in the pit. At the final stage, lower the pump into the well, connect the pipes and install additional equipment. The shaft pipe itself is cut off and a head is put on it.
If water is ejected from the shaft under pressure, a special fitting cuts into the casing below the ground. A pipe is attached to it in the future, the opposite end of which is displayed on the relief.
A self-flowing well can also be shut off 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 that is tightly closed on both sides is installed in the column. This element will subsequently assume the pressure of water expanding upon freezing.
How much does it cost to drill a well for artesian water
The arrangement of such mines costs, as already mentioned, usually quite expensive. Artesian wells are drilled by the owners of suburban areas most often with a crevice. The price per meter of penetration of such mines can vary greatly and depends on many factors. But in most cases, for 1 m of such a well, owners of suburban areas have to give about 1,500 - 2,000 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.