Wells are used in miningindustry, in geological exploration, construction, water supply. Therefore, depending on the purpose, well design has its own characteristics in each of the applications.
Well - it is a cylindrical development, the diameter of which is much less than the depth, drilled with the help of special equipment without human access to it from the surface of the earth to the face.
The spatial location and purpose of the wells are
- inclined and vertical,
- water intake,
The design of the well is a diagram of its design withindicating the initial, intermediate and final diameters of the rock-cutting tool, the depth, diameter and length of the casing strings, places and methods of tamponing.
Successful well completion depends on the rightthe choice of its design. This is a very important moment. From the correctly considered working conditions, the wear of the columns (casing pipes, fastening trunks) during the period of operation, the nature of the loading depends the reliability of the entire structure.
The design of the well is based ontechnical and economic and geological factors and depends on the objectives, equipment, drilling techniques, depth and other factors. At the same time, the geological structure of the rock section is always taken into account.
The most complex well drilling device. It consists of the mouth (the beginning) and bottom (bottom), walls, axes and trunk, casing columns for various purposes (production column and intermediate, conductor and direction).
Direction (the first, the widest tube inWell construction) serves to prevent the collapse of rocks around the mouth during installation of the conductor and erosion. Space behind the direction is filled with concrete or grouting mortar.
The conductor covers the upper part of the geological section and all those intervals that complicate the drilling process. It must necessarily block all layers saturated with fresh water.
Intermediate columns are needed to achieve the required depth. The production column (the last column of pipes reaching the bottom of the well) is intended for fossil extraction.
The well design is determined by the depth and diameter of drilling, the number, diameter and length of casing strings, the thickness of their walls, the diameter of the trunk sections, and the angle of deviation from the vertical.
The most demanded is a water well. Its design influences the throughput and service life, it must be easy to use and minimal simple.
For water intake there are two types of wells: filtration (up to 35 m) and deep (up to 100 m and more), they are also called "artesian" wells.
A single-column well design is called,if it consists only of the production column (the lower one, which is in contact with the aquifer), two-column - if there is one intermediate and operating column, etc.
The use of well filters is filtered and with an open barrel.
Well construction depends on its depth. The greater the depth, the more it looks like a telescopic antenna, with ledges of smaller diameter descending downward.
Filter wells are several times cheaper and easier to drill, but lose as much in durability as well.
The requirements for well designs are specific and are in a rather complicated relationship. Therefore, their justification and choice is based on a thorough assessment of all factors.
The chosen design determines the consumption of materials, the amount of work and significantly affects the cost of construction and operation.
Knowledge of the actual well designs allowed the development of rational typical projects that allow introducing progressive drilling methods, applying forced regimes, and reducing accident rate.