Factors influencing the process of well cultivation

FACTORS INFLUENCING THE PROCESS OF WELL CULTIVATION

Sh.Sh. Alikulov, R.H. Mardonov

Annotation: In the article, the author focuses on the significance of the negative influence of colmatation, which forms an increase in hydraulic resistances during the supply and pumping of technological solutions, on the throughput of injection wells. The work lists geotechnological factors that determine the occurrence of climate control. The article also provides information on ways to reduce the climate, while preserving the throughput functionality of the wells.

Key words: Underground leaching, conditioning, geotechnological well, hydraulic head, filter zone, solution aeration, flow turbulization, hydraulic gradient, siltstone.

During the operation of pumping and injection wells in the process of working the field using the PV method, as a rule, their production rates decrease. The main reason for such a negative technological factor is the process of regulation of the threshold volume of the rock near the filter zone of the wells, as well as the "overgrowth" of the perforation of the filters themselves.

In the process of mechanical conditioning, the water inlet openings of the filters and the cross-sections of the mud-conducting channels are blocked by thin sandy-clay particles, which are contained both in the drilling mud during the construction of wells and during their operation. So, when using in the process of drilling high-clay solutions, with a density of 1.15 - 1.18 g / cm3, to strengthen the walls of geotechnological wells, loaded on hydrogenic deposits, represented by their interlayered loose sandy-loamy, loosely bound tenfold. In the process of clay formation, a clay crust with a thickness of up to 5 - 7 mm is formed on the wall of the wells, the permeability of which is 4 - 5 orders of magnitude lower than the permeability of the permeability.

Along with the mechanical conditioning of the filter perforations and the rate of filtration between the filtration zone and the filtration zone of the productive layer, the processes of chemical conditioning also take place, which is associated with a change in the chemical composition of the fluid and the feed fluid.

So, for example, a decrease in the hydraulic head in the zone of outflow (unloading) wells leads to a violation of the equilibrium of solubility of gases and salts, which causes them to be released from the liquid phase in the form of gel-like salt substances and in the form of gas dispersed bubbling insoluble.

In the band of the filtration front of the supplied acidic solutions, the carbon dioxide equilibrium is violated:

2HCO₃^‾ →CO₃²‾ + CO₂↑+ H₂O.

The cations of calcium and magnesium that have passed earlier into the solution as a result of violation of carbon dioxide equilibrium fall out, filling (colmatizing) the first volume of the productive layer in the form of gelatinous (gelatinous) difficult-to-dissolve Ca3CO3 compounds. When this occurs, at the same time, "overgrowth" with such salt substances of perforations of filters of injection and discharge wells, which causes a decrease in their flow rates.

In the filters of unloading wells, when the water inlet openings are cooled, the values ​​of hydraulic resistances increase. While maintaining flow rates at a constant level, the values ​​of hydraulic heads in the wells and on their outer surface decrease, which also provides an increase in the intensity of salt precipitation and, accordingly, an increase in the filtration resistance of filters.

An increase in carbonate in the productive horizon intensifies the process of conditioning. In the practice of SPW ores, there are also processes of colmatation of the soil with iron-containing precipitates. This process takes place in the presence of ferrous iron in underground waters and mountainous rocks. The presence of dissolved oxygen (oxidizing agent) in the supplied solutions, iron from acidic goes into oxide:

Fe(HCO₃)₃ → Fe(OH)₂ + 2CO₂ ,

_4Fe(OH)₂ + O₂ + 2H₂O = 4Fe(OH)₃. ,

In the practice of SPV, the following types of filtration of the cut-off volume of the filter zone are distinguished, including the perforation of the well filters:

• Mechanical, associated with the presence in the supplied and pumped out solutions of solid sandy-clay particles of various granular composition. Basically, these are thin clay (pelite) particles as a result of the development of suffosion processes.

• Calmatization by air bubbles falling into the reservoir with the supplied working solutions or as a result of their desorption from the water with a decrease in pressure in the depression funnel of the filter zone of the outflow wells [4].

• Chemical combustion can also be caused by changes in hydrodynamic and temperature conditions in the water reservoir during the interaction of stratal water with supplied chemically active working solutions, which leads, as mentioned above, to a difficult form.

Along with the aforementioned chemical composition of the heating substances on the overgrowing of filters of wells, a noticeable effect is exerted by the presence of serum in the productive solutions and underground waters, the appearance of which is especially common in the formation of sulfur fluids is often observed in the pores. The formed hydrosulfite (HS‾), interacting with ions of iron, zinc, copper, leads to the precipitation of difficult-to-dissolve sulfur compounds, which in the form of crusty cover the surface of the filters, stabilizing the perforation.

The presence, although in relatively small quantities, in silicic acid solutions also promotes the formation and precipitation into the porous volumes of the permeate of the productive horizon in the presence of weakly soluble boron silicate gels of iron and the presence

It is practically impossible to eliminate the arising processes of chemical conditioning of near-filter zones of wells, since changes in the parameters of geochemical and hydrodynamic regimes during SPW are an indispensable component of this technology.

Prirodnye geohimichesky and gidrodinamichesky modes podzemnyh vod, priurochennyh to porodam produktivnogo gorizonta for period otrabotki mestorozhdeniya podvergayutsya mnogokratnym changes: kontsentratsy podavaemogo change in the reagent layer, the use of various okisliteley including aerirovanie rastvorov, neravnomerny well production rate, decrease (povyshenie) dinamicheskogo urovnya. All these factors lead to active sedimentation, which improves the production volume of the reservoir.

In the bulk of its mass, the precipitated and colmating substances are represented by a complex multi-component composition: iron hydrates, calcium and magnesium carbonates, silicic acid compounds of various sulfides. As noted above, at the initial stage of formation, the sediments are a gelatinous, gel-like, friable structure, which differ in different strength. Over time, such deposits are dehydrated and compacted.

However, all these structures at the initial stage of their inception are characterized by a relatively low strength, including a relatively quick response, can be removed when exposed to various methods of well processing: electric explosions, pneumatic explosions, hydraulic explosive etc. [1,2].

After the water permeability of the reservoir has been restored, for a short period of operation, the processes of heating are revived outside, and the productivity of technological wells begins to decrease.

The practice of operation of technological wells at SPW indicates that in order to achieve an effective operating mode [3] and maintain productivity at a constant optimal level, it is necessary to know the regularities of the flow rates of the wells and their productivity in reducing the flow rate of

In the practice of SPV, the following types of filtration of the threshold volume of the filter zone are distinguished, including the perforation of the well filters:

• Mechanical, associated with the presence in the supplied and pumped out solutions of solid sandy-clay particles of various granular composition. Basically, these are thin clay (pelite) particles as a result of the development of suffosion processes.

• Calmatization by air bubbles falling into the reservoir with the supplied working solutions or as a result of their desorption from the water with a decrease in pressure in the depression funnel of the filter zone of the outflow wells [4].

• Chemical combustion can also be caused by changes in hydrodynamic and temperature conditions in the water reservoir during the interaction of stratal water with supplied chemically active working solutions, which leads, as mentioned above, to a difficult form.

It is necessary to summarize what has been said in one paragraph. In this way ……

In this way, it is necessary to avoid from the heating, the pumping will slow down from 15-25 atmospheric pressure every 15-20 days. When there are many aluminasicates, HS‾ hydrosulfite can be used. When a well is installed, it is necessary to set well the filter zones. Since the secondary filter zone helps to further avoid calamation

REFERENCES

1. Alikulov Sh.Sh., Markelov S.V., Narziev A.S. "Climate the rock of the productive horizon during the underground leaching of uranium." Mountain information and analytical bulletin. No. 3 2011 p. 239-241.

2. Alikulov Sh.Sh., Markelov S.V., Halimov I.U., et al. "The influence of chemical climate control of the porous-fractured massif on the productivity of underground leaching blocks." Mountain information and analytical bulletin. No. 6 2011 p. 211-215.

3. Altshul A.D. Hydraulic couplings. M - .: Nedra, 1982.

4. Amiyan V.A., Amiyan A.V. Increasing the productivity of wells. -M Nedra, 1986.