Methods of drilling for water wells: best practices and their full description

The device is associated with water well drilling using various methods. Loose soil and saturated with water is recovered via bailer. For the sinking of clay and rock drilling techniques are used, based on the rotational and vibrational principle.

The work involved mechanisms to make the development of soils of different types and at different depths. We'll show you how to choose the optimum drilling technology, which allows fast and flawless production go to the water intake device.

For a visual representation of our proposed text is supplemented by useful information schemes, photo collections, video tutorials.

Types of drilling methods

Earlier drilling aquifer wells for personal use has mainly manually. This was a laborious and lengthy process, so not every site owner or cottages could boast the presence of its own supply source.

Gradually mechanized drilling supplanted manual methods due to significant simplification and acceleration of the process.

Today, virtually all water-bearing borehole drilled a mechanized method, which is based on the ground breaking, applying it to the surface of one of the two ways: dry when removed from the spent ground well using hydraulic mechanisms and, when it is washed by the water supplied under pressure, or gravity.

There are three basic methods of mechanical drilling:

• rotary (Primer designed rotation).
• Shock (Bursnaryad destroys primer beats).
• vibrational (Primer designed frequency oscillations).

Rotational method is considered the most productive in 3-5 times the efficiency of shock and vibration 5-10. In addition to this rotational method is the most inexpensive and accessible, it is often used as the primary method of manual drilling.

In turn, rotary drilling method, widely used for the construction of water wells, divided into four main types of drilling:

• coring;
• auger;
• shock-rope;
• Rotary.

Each type of rotary drilling has its own peculiarities and is done specifically designed for this equipment. Consider these types of drilling in more detail, define what are their differences and what method should be used in each case.

Specificity of core drilling

Core drilling - mechanical rotational method, which process a dense clay or sandy ground is taken up in a cylindrical shape of the core. The drill core drilling is a thick-walled metal pipe.

Above the core drill tool arranged for joining rods needed for building up the drillstring. Below - the crown, whose form is selected depending on the type of soil to be drilled.

When driving by coring soil collapses annular crown. The inner part of the core is retained in a form not destroyed. To facilitate the drilling process and semi-solid loam, clay, rock face in the washing liquid is fed.

Sludge from the face sometimes removed by washing - injecting into the trunk of generating large quantities of water. In most cases, washing is replaced by blowing compressed air supplied by the compressor into the tube. This type allows drilling drill hole depth of 1000 meters and a diameter of 8 to 20 cm.

Mechanical core drilling rigs manufactured type mill, UGB, UCB, be mounted on vehicles such as KAMAZ, KrAZ, skidders, etc. In the embodiment, for manual drill core barrel is shortened is called bell or cup. With the latter, upside-down related subject, structurally similar core barrel.

Drilling coring method is used in the following cases:

• exploration of mineral resources;
• exploratory drilling;
• device aquifer wells of any depth, including bezfiltrovyh boreholes in rock.

for devices private water wells in some cases, coring method is used before the start auger or rotary drilling, completing both reconnaissance and preparatory role.

The device private boreholes used in combination with shock-rope. The clay layers are core barrel. Adding loose sands, gravel and gravel with sand filling, are not retained in the core barrel, the barrel is removed from zhelonirovaniem.

On the effectiveness of the method of coring is slightly inferior to the screw method for drilling water wells. Auger drilled quickly, but it can not completely release from the trunk of the drilled rock. They are rarely used in pairs. And if you lead, the screw are the first few meters.

Used equipment and tools

For core drilling tools, the following:

• of diamond drill bits or other carbide material (steel, tungsten, win);
• core barrel;
• pipe for withdrawing slurry;
• rods, required for building the drill string;
• coupling compound adapter between pipes, washing gland.

When drilling in rock drill bit wear out quickly and must be replaced. Crown material - an expensive, can withstand enormous loads, the most widely used diamond drilling options.

All materials used in the process of drilling tools must correspond to the alignment, ie, exactly positioned relative to the drilling axis.

Coring Technology

The main feature of coring - passing breed full its preservation in the core barrel. Those. when the drilling equipment on the crown ring destroys the soil, which, as penetration is pushed into the core barrel and held it by its own density.

When removing the tube from the barrel filled with produce, freed from its core by the tapping hammer.

The gradual process of core drilling is as follows:

• drill bit connected to the core barrel;
• core barrel coupled with the rods, which are built up as the recess;
• an upper rod is fixed in the drilling machine;
• drill press rotates the drill string and gradually "screws the" it into the ground;
• core barrel gradually filled cored - jammed in its cavity primer;
• penetration after 50 - 70 cm, the drill string is retrieved to the surface, the rod in turn to disconnected until ejects core barrel;
• tube free from cuttings;
• emptied shell again lowered to the slaughter, increasing the drill rod string.

Actions carried out in the described manner as long as the well is not will open the aquifer and not bury 50 cm into the underlying rock waterproof.

If the fixation of the upper aquifer is not the purpose of penetration, the upper layers may drilling with flushing. In this case it sells pump washing solution through the hose into the pipes. The solution was then makes soil generated on the surface.

Compelling advantages and disadvantages

Compared to cable-and rotary mechanical drilling coring is done fairly quickly, significantly reducing the time of work. His main drawback - the inability to lift the loose soil and gravel saturated with water. Slowly moves through rock, boulders required for sinking a chisel.

The advantages of core drilling include:

• high productivity and the ability to drill deep wells in excess of 100 m;
• reduction of loads on the drilling equipment at the expense of the destruction of shale, comparable to its excision;
• the possibility of using a mobile drilling rig compact dimensions.

Core drilling - one of the fastest methods of development of water intake openings. The hole in the sand with its application can be completed in one working day. developed Manual production of water intake It takes much more time.

Especially auger drilling

This type of drilling today is most often used when the device aquifer wells in private households. A feature of auger drilling is that developed the breed is completely removed from the alignment hole without additional equipment. The method resembles screwed, allows drilling to a depth of soil and remove unwanted simultaneously.

Used for drilling tool called auger. It is a metal rod with blades. Screwing into the ground, the auger breaks the rock that lingers on his blades. Due to the design specifics of the screw can not be completely free from the slaughter of the blade. Therefore, it is mainly used for sinking the upper layers.

Drilling using a screw does not require much effort and cost, so the scope of application of this method is quite wide exploration wells communications gasket device of bored wells and partially boring for water.

It is now being actively used for device Abyssinian wells, so as not to completely clog the well-needle into firm ground and the trunk slightly to facilitate the process of immersion in advance of rock destruction.

The method is suitable for the development of water-bearing wells up to 30 meters on the soft and loose soils and up to 20 m for the medium-dense. After sinking the screw and casing installation, be sure to clean the wellbore from the bailer unrecovered breed.

Auger categorically not suitable for use in the rocks! It is used for partial penetration wells to 120 m, wherein the method is combined with others: rotary, shock-rope, coring.

Cycled equipment and instruments

Auger drilling rig is made, the main element of which is a screw type drilling tool made of a ductile metal. Drillstring as increasing penetration screws of equal size.

Included are sometimes used drag bits required for the passage of loose rocks and chisels with round or conical heads used for the development of hardwood.

Most modern drilling rigs equipped with hollow projectiles equipped with reversible locks that prevent the movement of the tool in the opposite direction.

The cutting portion of the screw during the drilling process due cooled developed soil and rock developed rises along the spirals. This allows the drilling stops without significantly reducing the time and energy consumption for creation aquifer wells.

Auger drilling technology

After performing penetration, which depth is 1.5 - 2.0 m, the screw is removed, and the well established casing. The diameter of the water well drilled by means of a screw is 50 - 200 mm, depending on the size of the tool used.

Collapse of the walls of the well prevent the casing. This is especially important for a loose non-cohesive soils, so drillers there is a rule: use when driving and sandy loam loam worms with the location of the blade at an angle of 30 - 60º, and in drilling the sands solid build tool with a blade angle 90º.

With a smaller slope turns screw spiral blade longer disconnected it brings to the surface the screw.

Pros and cons of applying the screw

A screw drilling method allows to produce wellbore apparatus as quickly as possible, provided that the size of the auger and the angle of inclination of the bit have been chosen correctly.

The advantages of auger drilling include:

• primer lying immediately to the surface in the drilling process;
• High speed depressions in the ground without the technological stops;
• there is no need to do the washing of the borehole;
• compact screw installation or manual screw can be drilled inside the house (in the basement);
• there is no need to raise to the surface of the first link and parse / assemble the drill string as in the coring method.

The main drawback of auger drilling can be regarded as the inability to work on the dry and very hard ground, but at the However, the screw - an ideal tool for drilling in loamy, mixed (clay and loam) and soft clay soils.

Another drawback that limits the application of the screw for a device-bearing wells - necessity to use cable-way for cleaning the barrel rolled away from the rock.

Similarity screw - serpentine widely used in manual drilling. He likewise destroys the rock and grabs her lopostyami to extract up.

Characteristics of rotary drilling

Rotary drilling - Method rotationally vibrating drilling where soil degradation is carried out using the bit driven by the downhole drilling rig from the rotor. The rotor is rotated by a vehicle engine or a motor mounted separately via a drive shaft.

Designed primer is eluted from the shaft hole by direct or reverse flushing. The wash solution may be supplied both by gravity and the pumping station.

Rotary drilling is used to develop rock and semi device soils during deep wells to 150 m. Rotary Drilling Rig with a properly chosen bit and drill collars copes with rock rocks.

Specialists drillers recommend using this method of drilling under the following conditions:

1. Hydrogeological sectional area fairly well studied. It is known that drilling will rock. Known level of occurrence of the aquifer in the bedrock.
2. Underground water has a characteristic pressure boreholes
3. It is possible to smooth delivery service water for washing the well.

In southern rotary drilling can be carried out all year round, and in northern climates the use of this method is limited because of the possibility of freezing wash liquid.

Application equipment and tools

Rotary drilling wells aquifer is performed using a frame or lattice tower, wherein arranged on the lifting equipment and the other elements of the rig. The tower allows raising and lowering into the well drill string.

The structure of the rotary type rig includes:

• frame or a lattice tower;
• motor-driven;
• the rotor and the drill string;
• pumps and the washing liquid purification system;
• lifting equipment, pressure line, swivel, seals, etc.

The self-propelled unit as a motor vehicle internal combustion engine is used, which is placed on the base of drilling complex. In this case, the engine power of the drilling tool are governed speed.

The rotor by means of a gear device transmits rotation of the lead pipe, which in turn reported it to the core drilling tool - chisel. The chisel may have a different shape and made of high-strength materials: composites, steel coated with diamond, and others.

For each type of soil is selected a particular size and shape of the bit, thereby providing high efficiency and ROP.

The originality of rotor technology

Rotary drilling water wells is carried out in three stages:

1. Destruction of rocks by using chisels.
2. Removal of broken rock on the surface of the injection water flow.
3. Strengthening of the well casing wall.

Removal of the destroyed soil is made by the reverse or forward flushing. Selection washing process depends on the specific conditions: well depth, type of soil, the presence of the desired volume of washing water.

As a rule, in private households is used to direct drilling technology washing, which includes the following steps:

• penetration in soil large diameter bit;
• bit rotation of the rotor under the influence;
• drill pipe installation and assembly of weighted pipes between them and chisel;
• removing the spent ground pressure fluid by a pump;
• assembling the casing in order to prevent soil obsypaniya within the borehole;
• drill bit of smaller diameter and repeating the cycle.

When backwashing the soil is removed from the wellbore through the pipes of the drill string, and flushing liquid is filled between the walls of wells and pipes.

Water flows by gravity to the previously prepared tank where it comes from clean soil and sludge, and returns to the drill string for a new portion of waste rock.

Advantages and disadvantages of rotary drilling

The main advantage of rotary method is the possibility to drill deep wells with water intake in fractured limestone.

In addition, this drilling method has the following advantages:

• high quality water-carrier in the opening of the indigenous rocks;
• Device possibility of large-diameter wells to 200 cm;
• high speed drilling, small energy costs.

A significant drawback of the rotary drilling may be mentioned the necessity of organizing washing wells.

What a way to select the drilling?

All of the mechanical drilling methods are widely used for device aquifer wells.

Summarizing, we can say:

1. Core drilling should be used for penetration in plastic clay soils. Coring method is suitable for the majority of the water intake devices workings, is used in tandem with shock-rope if necessary.
2. Auger drilling in scope similar to coring method. It differs from the defective cleaning of the barrel, require the use bailer or long wash well before using.
3. Rotary drilling - the best option for punching bore holes in the rocky soil.

The cost of development wells using a particular method of drilling depends on what kind of equipment is used, as well as the categories passed rock drillability.

For information on how to make the drilling machine with their own hands, you can read in the other popular article our website.

Conclusions and useful videos on the topic

Video # 1. Demonstration of the principle of classic core drilling with the extraction of the core water pressure:

Video # 2. Features drilling screw:

Video # 3. Core drilling wells by washing with slaughtering and installation double casing, wherein the outer part is made of steel pipes, the inner polymer:

Drilling wells aquifer - a time consuming process. The correctness of the chosen method of drilling depends not only on the rate of autonomous water supply device, but also the financial costs.

The first thing you should pay attention when choosing a drilling method, this type of soil and the depth of the aquifer. Based on these parameters, you can choose the best option, which will allow you to drill down quickly and inexpensively.

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