Liquidation of wells

Activities aimed at liquidation of water intake are called cementation or tamponage of the well. Such works are carried out in order to protect the aquifer from possible chemical or bacteriological contamination from the surface. Tampon wells are translated from the French "cork".

This term indicates that during the operation a solution is injected into the interior, which strengthens the rocks, forming an anti-filtration and waterproofing curtain. Liquidation is carried out when the well is out of order, it can happen for various reasons. The main ones are the following:

• The source fulfilled the purpose;
• Not in demand or abandoned;
• Geological reasons;
• Technical reasons;
• Environmental or technological reasons.

Description of varieties of plugging

If we consider geological reasons in more detail, we can say that in this case water abstraction can simply cease to fulfill its role, which quite often becomes a consequence of geological processes. Technical reasons - this is the case when water intake for a long time was not maintained in working order.

As an alternative, there may be a violation of technical standards during drilling. Works could be conducted using inappropriate materials, for a long time no repairs were carried out, and maintenance was not performed. Wells are also drilled in the case when the water intake was lined up for temporary use.

Grounds for liquidation of water intake

If the well is suitable for one of the categories listed above, then it should be eliminated, because there is a possibility that the aquifers will be polluted, and they can be used by other water intakes. Having become acquainted with the Law on Subsoil, you can find out that the user must ensure the liquidation of the source and the safety of the water intake.

Rules of work

In the implementation of oil wells, specialists should use the rules for liquidation of wells, they require the implementation of design work. At this stage, you need to find a passport, which indicates information about the variety of the protective structure, it can be a building, caisson or pavilion. In the documents you can find the parameters and characteristics of the water intake unit, as well as the absence or presence of underground tracks.

Next, we need to carry out a study called logging. As a result, it will be possible to determine the depth of the well, assess the condition of the casing string, or rather, the walls. All this can be called a revision of the source. Tamponage artesian wells must necessarily be accompanied by a definition of the cause, then the category of liquidation is assigned.

On the perimeter of the source, a two-meter pit is excavated, the width of which should be 1 m. The casing should be cut 30 cm above the bottom of the excavation . Drilling equipment will clean the source of foreign objects and junk.

Technology of work

The rules for the liquidation of oil wells in drilling wells require disinfection and washing of water intake with special solutions. The filter column should be filled with gravel or crushed stone all the way down. Next, the grout is prepared and poured. If the water intake has an impressive depth, the filling and cementing can alternate.

With the use of cement, the mouth is poured, then the plug is welded. Liquidation plugging of wells provides backfilling of a crushed stone pillow. It should be 50 cm below the ground. The top layer can be formed with fertile soil or poured with concrete, everything will depend on the purpose of further use. The final stage will be shooting water intakes from the register.

When well shutdown is required

They shut off the well when the aquifer begins to flow. For this, the bottomhole pressure must be increased so that the indices of the in-situ pressure are exceeded. If a 5-meter fountain is hammered from the source, high-density technical fluid should be pumped into it. The total mass in this case should create a higher pressure compared to that noted in the aquifer.

Muffling will eliminate the accident and eliminate its consequences, eliminating the risk of relapse. After completion of repair, the technical fluid is pumped out, flushing is carried out, only after the source can be used again. Sometimes the jamming is done tightly, in this case the well can not be used anymore.

Such a backfilling of wells may involve the use of a chemical or biological agent, in which case the source will not be suitable for operation. Alternatively, cement mortar can also be used. Sometimes seasonal stunning is required, in this case water is drained from the system, and the caisson is insulated. An event of this kind is held in the suburban areas.

Elimination of wells for different purposes

The rules for the liquidation of oil wells for various purposes involve the use of different methods. For example, if the well turned out to be dry, then it can be filled with clay mortar or pelted with clay to the full depth. Engineering geological, hydrogeological, mapping and geological prospecting wells, which have already fulfilled their purpose, and also did not give positive results, can be eliminated by the method of extraction of casing pipes.

If after completion of the work such manipulation is not possible, then the wellbore should be filled with clean sand, and the overlying part should be thrown with clay, and poured with clay or cement mortar. Liquidation tamponage wells for various purposes in this case requires compliance with the requirements of the sanitary and epidemiological service.

According to them, wells and workings are subject to plugging, which exist quite long. They may remain inactive, become silted or clogged. In this case, rinsing can be carried out with a clay solution or water using a drilling tool. Then the well is flooded with chlorinated water, the volume of which should be equal to the triple volume of the wellbore.

If the water intake is within the aquifer, it should be filled with clean sand, the volume of which should be equal to the volume of the wellbore within the aquifer. The upper part is filled with a clay solution, thrown by clay and trampled, as an alternative solution, cement mortar can be used.

Elimination of artesian well

Tamponage artesian wells may involve the use of clay and tampons. To do this, use a thick clay, in which there is no foreign impurities. For what it is mixed with a stirrer, and from the resulting rock roll balls, the size of each of which must be equal to the fist.

The balls are dried, for this they should be left in the sun. Then they are put into workings up to 15 pieces at a time. Sometimes the balls fall inside with the help of a bailer, at the end of which there must be an outward opening valve. If this method is used, the pellets are not previously dried. Each portion is well condensed, while the tube is raised. The height of the cork should be 1.5 m.

The second way to eliminate the artesian well

Wells of artesian wells can be tamped with a concrete solution prepared using a special technology. Some believe that the first way is not so relevant. However, this statement is erroneous. Sometimes it sometimes requires temporary tamponing. But if the well is no longer used, then its elimination should be carried out with concrete. When the water intake for some time should be divided into segments, you should use tampons, which are called packers. They are used in the process of studying rocks, which differ in the presence or absence of pores and cracks. Thanks to them, you can check the quality of cementing rock.

Conclusion

To carry out the plugging, you need some equipment, such as a metal ram, a pump and drill pipes. The pump will be required to inject cement slurry with drill pipes, which will be lowered to the bottom.