Drilling wells - types of wells, general concepts about drilling. What is an oil well? History of Mgri - RGGR

DRILLING WELLS FOR WATER - EVERYTHING YOU WANTED TO ASK ABOUT...

Earth is a planet of water. If you want independence, you need your own water. If you need water, you cannot do without drilling a well on your site.

  • What types of wells are there?

For water intake in the Moscow region there are: filter wells (up to 35 m - “for sand”) and deep (up to 100 m or more - “for limestone”), they are sometimes called “artesian” wells, although Professor A. Gadzhi-Kasumov believes that artesian wells are wells with “self-flowing” (after the name of the French province of Artois, where such wells were first drilled). In the memory of our workers, there was only one such well.

A filter (sand) well is drilled into the nearest aquifer located in sandy soils, and its depth is usually 20-30 m; the well consists of a casing of pipes with a diameter of 127-133 mm and a braided mesh filter. Its flow rate is up to 1 m 3 /hour. Well drilling is done quite quickly - within one to two working days.

However, these wells tend to silt up, and their service life directly depends on both the thickness of the aquifer and the intensity of its operation: the more often a well is used, the longer it lasts (in practice, up to 15 years, more often - 5-8 years).

Deep (“artesian”) wells (for limestone) are drilled to the aquifer lying within Moscow and the region in limestone at depths of 20-200 m, and are distinguished not only by their depth and productivity (up to 100 m 3 /hour), but also the complexity of drilling. Such wells are usually drilled with a larger diameter and greater depth than “sand wells”. This is due to the large number of casing strings in the well, and the higher the price per linear meter of drilling a well directly depends on the diameter of the casing pipes and, consequently, their cost. increases to 5 or more days depending on the rock and depth. The cost of drilling a well with limestone is higher, but the service life is much longer - 50 years or more, since the filter in such wells is the aquifer itself (limestone) and silting does not occur.

  • What is the depth of an artesian well?

Across the Moscow region, aquiferous limestones occur unevenly from 20 m in the south to 200 m in the north. An approximate display of depths can be seen in the diagram; more accurate ones can be found only using cadastres. The most accurate thing is that you will find out after drilling the well itself.

Approximate occurrences
aquifers

  • What is the diameter of the well?

For sand wells: 127-133 mm. For a limestone well for personal water supply, the diameter of the column at the top can vary from 127 to 324 mm depending on the pump performance, depth and design of the well. The volume of water consumption when drilling an industrial well dictates much larger diameters.

  • What kind of pipes are in the well?

Steel ("black"). Steel St20, seamless drawn. Wall 5 mm. Connections are threaded or welded. Galvanized pipes are not suitable for the casing string of the mine - over time, harmful zinc compounds appear in the water. Do not drink water from a galvanized well!

  • Do you need plastic?

The question, of course, is interesting... On the one hand, of course, there are progressive technologies, but on the other, there are no statistics on plastic pipes; they appeared only 1.5 years ago ( The article was written in 2003. - V.S.), how plastic pipes will behave in 40 years is unknown, but a black pipe is predictable: its service life with a wall thickness of 5 mm is 50 years (at a corrosion rate of 0.1 mm per year).

However, for discerning customers, plastic pipes are installed inside the casing (they will not save you from corrosion, but will make the pump more comfortable to operate by cutting off particles of rust from the walls of the steel column from the expensive mechanism), the price of a meter of drilling such a well is 400-700 rubles. expensive. Sometimes, in difficult geological conditions, a plastic column inside a steel one can be useful, i.e. no plastic is used instead of steel pipes, and together with them.

Plastic instead of steel is sometimes used in small wells, but it must be approached with caution: a steel column is stronger than a plastic one and better resists soil movements.

  • But the “black pipe” is iron, and there is already a lot of iron in the water...

In the water of the Moscow region, the presence of iron is due to the content of chemically dissolved divalent iron (in rust - trivalent) in the aquifer. In Moscow, water comes to the tap after passing through kilometers of “black” pipes, but there is no iron in it!

Iron or fluorine present in the chemical composition of water from an artesian well is determined using chemical analysis and removed using special iron-removing filters (by oxidizing and converting it into sediment). Filters are a necessary attribute of autonomous water supply.

  • Which well is better?

A shallow well for sand is cheaper. With a drilling cost of 1,100 rubles per linear meter, a 20-meter well will cost (without equipment) 22 thousand rubles. An artesian well 100 m deep (1,300 rubles per meter of drilling) costs 130 thousand rubles. Their average service life is 5 and 50 years, respectively. The price/lifetime ratio (4400 and 2600 respectively) is clearly not in favor of the sand well. And we did not take into account the costs of arrangement, the price of which, practically, will depend only on the pump, and the caisson will be the same.

At the same time, we must not forget about the incomparable water abundance of aquiferous limestones and perched water. And if you take into account the ecology and the proximity of aquifers to the surface of the earth with its stormwater, cesspools and microorganisms, then everything will become clear. However, any problem is solved based on the goal: for irrigation - a shallow well, for year-round life support for the cottage - an artesian one.

  • What is included in the cost of drilling a well?

Travel to the work site, drilling itself, casing the well with a string of pipes, pumping to visually clean water. Express analysis is possible.

  • Some firms include chem. analysis of the cost of drilling a meter of well...

Chem. analysis can be included in the work of drilling a well, but it will not give a reliable and complete picture, since immediately after drilling the well still contains imported water used in drilling. Water samples for analysis should be taken after three weeks of operation, when the composition of the water is completely stabilized, i.e. It is better if the analyzes are carried out during the installation, because based on their results, water treatment equipment will be selected.

  • At what distance from the house is it possible to install a well?

No closer than 3 meters.

  • What is "arrangement"?

For year-round water consumption, the well must be completed with a buried (sealed steel box) for all-season maintenance of pumping equipment. A pipeline is laid from the caisson at a depth of 1.8 m into the house. Automation is installed for uninterrupted control of the pump and filters for purifying water from the well from mechanical impurities.

  • Why is drilling an artillery well more expensive?

The cost of drilling a well directly depends on the price of the casing metal (recently there has been a sharp jump in prices on the stock exchange). The diameter of the casing depends on the depth of the well and the planned water consumption (a more powerful pump has larger dimensions). Drilling a meter of artesian well is also more expensive because more powerful equipment is used.

  • Why do some companies drill cheaper...

1. There is an old stock of pipes left (this won't last long).
2. Light galvanized pipes are used (they are also beautifully called “anodized”). Due to the anti-corrosion coating, the thickness of the pipe can be reduced, and drilling due to metal savings will be much cheaper. In this case, the health of the customer is not taken into account, who after some time will begin to consume harmful zinc compounds with water. In addition, in acidic groundwater the column will deteriorate more quickly.
3. Some companies make it a prerequisite for the installation of their equipment or arrangement. They will take their share in this part of the estimate.
4. Short warranty period.

  • Do I need a license for the right to use subsoil?

It is not needed for drilling a shallow well in sand, just like for a well. To drill an artillery well, it is necessary. But some companies act as follows: they issue two passports, one for the owner, the other for the inspection authorities. This, of course, is not good. For industrial wells, a license for environmental management is absolutely necessary. takes up to six months.

  • What if there is no water?

In exceptional cases, when drilling into sand in the indicated place, there is no water, or there is not enough water - the well is regarded as an exploration well, and only 50% negotiated price.

  • Which pumps are better?

A recognized leader in its field, the German company Grundfos has been manufacturing its excellent pumps from corrosion-resistant stainless steel for thirty years. Although there are options, pumps from Italy are also quite good, and the cheapest is our “Malysh” (we recommend those produced by the Moscow Dynamo plant). Personally, I have “Aquarius” in my well. Submersible well pumps of various modifications are produced in Italy.

  • Is it possible to clear a silted shallow well?

Yes, it is possible, it requires a special tool, there is a restoration method by flushing the filter in the lower part of the well with water under pressure, the well is pumped, fine particles are washed out of the filter, and the flow of water is resumed. - a complex, high-tech process, it is carried out by specialized companies.

  • Is it possible to install a well right in the house?

Yes, it is possible, but not deep. There are small-sized drilling rigs; you can drill a well in the basement of a house - if the ceilings are at least 2 m. An interesting alternative is. However, a serious well cannot be located in the basement, even if the house itself has not yet been built, because... maintenance and repairs (pump replacement, maintenance, etc.) require the use of large-sized ones, access to which is impossible in the basement of the house.

  • Instead of a conclusion

It is best to start drilling a well before building a house, immediately after marking the area with pegs. This will save a lot of effort and money on restoring the fence and lawn after the drillers arrive, provide the builders with drinking and technical water, and give the opportunity to feel like the owner of the property even before the fence is erected.

If things don’t work out right away with the well, don’t despair - you can do it later, in any case, your own well will give completeness to your property and give you a sense of independence.

  • Post Scriptum

And one last thing. If you find this article in whole or in part on the website of any drilling company without reference to the source, i.e. presented as your own, think about whether it is worth dealing with people who do not care about their reputation.

Victor Svirin

When citing an article, please be sure to provide a link to the source. Thank you.

Enough broad term "well drilling" involves not only drilling for the extraction of resources from the subsoil, mainly hydrocarbons, but also work on drilling wells for water extraction, horizontal directional drilling, drilling for piles, drilling for geothermal heating.

- the process of destruction of various rocks with subsequent removal of destruction products.

Drilling of the wells- this is the drilling of a directed cylindrical mine working with securing the walls (barrel) of the well to prevent rock collapse.

Wellhead is the beginning of a well on the surface of the earth.

The bottom of the well is the bottom of the well.

Wellbore – well walls.

Drilling water wells - drilling a well to an aquifer(sand, limestone) and construction of a well, taking into account the equipment of the water intake zone for the possibility of drawing water from the bowels of the earth.

Basic methods of drilling wells

Rotary with direct flushing

The most common way. It is used when drilling wells in rocks of different hardness and to different depths.

Direct circulation well drilling diagram

  1. Collecting settled drilling mud from the sump
  2. Suction-pressure line
  3. Mud pump
  4. Discharge line
  5. Swivel
  6. Casing
  7. Bit

Rotary with backwash

Mainly used for drilling large diameter industrial wells.

Scheme of drilling a well with reverse circulation

  1. Bit
  2. Mixer
  3. Air supply pipes
  4. Drill pipes (drill rods)
  5. Compressor
  6. Rotor
  7. Swivel
  8. Sleeve
  9. Sump (sump for drilling mud)
  10. Drill cuttings
  11. Delimiter
  12. Gutter

Rotary with air purge

Used when drilling in stable rocks. When using a pneumatic hammer, a high speed of well creation is achieved. Relevant when performing work in areas composed of rocky or hard rocks, as well as when working with fractured rocks.

Shock-rope

It is used when drilling wells in difficult hydrogeological conditions to a depth of 100-150 meters. This method is characterized by low drilling speed and the difficulty of drilling in unstable rocks (quicksand, aquifer sands).

The main advantages of this method include:

  • obtaining a reliable geological section;
  • the near-filter zone and the filter are not clogged with clay solution (as during drilling with flushing) or destroyed rock - a reliable characteristic of the aquifer.

Rotary screw

It is used when drilling in soft and loose rocks to a depth of 30-40 m. Auger drilling is the main drilling method for creating shallow wells for sand (filter wells, see below), for drilling holes and holes (pit drill).

Pit drills are basically hydraulic attachments based on an excavator, manipulator crane and other construction equipment. It is used to speed up the work process, replacing manual physical labor - digging holes, planting seedlings, installing poles, piles, supports and other structures fixed in the ground.

How is well drilling carried out?

A vertical excavation is created by a rotating “drill string”. This is the name for a structure made of series-connected pipes, in the lower part of which a chisel, turbo or electric drill - tools for destroying rocks - is fixed.

To remove cuttings and drilled soil, a clay solution is pumped into the resulting shaft. With this method, drilling is carried out with flushing.

When drilling with an auger, the drilled rock rises to the surface in a spiral (like a drill).

When drilling wells with blowing, the drilled soil is blown out with a powerful air stream.

Casing pipes are used to strengthen the walls of the mine.

This is the most general idea of ​​rotary well drilling. With its help, the largest number of these structures are built, intended for industrial, research or private use.

Main types of wells

In relation to drilling not for industrial purposes, but for private use, engineering structures can be divided into several types of wells.

Filter wells

They are used to extract water from shallow (10-60 m) sand deposits.

Typical sand well design

A filter well (sand well) is a well built on unstable water-bearing rocks, represented by heterogeneous sands, sometimes with inclusions of gravel, boulders, and sandstones. An integral part of a sand well is the filter water intake part, in other words, a filter. Most often it is made from a perforated pipe with a stainless or polymer mesh wound around it.

Artesian wells (limestone wells)

They are used to extract formation fluid from carbonate deposits and limestone, which, in particular, in the Moscow region are located at elevations exceeding 200 m.

Wells for geothermal heating

The stock of “private” wells today is not limited only to the production facility. When arranging a heating system, the use of heat pumps is becoming popular. This technology allows you to use the heat of the earth to heat real estate remote from central communications. For the needs of these units, vertical or inclined workings are drilled, which are filled with a working medium and thereby create a thermal circuit.

  1. Horizontal collector (located below the freezing depth)
  2. Vertical probe (installed in the well)
  3. Heat pump (transfer of heat from the earth to a coolant circulating in the house).

Horizontally directed wells

Drilling such wells is used to lay communications without trenching. Modern technologies make it possible to control the drilling trajectory and set the required direction of movement of the drill. Horizontal directional drilling is in demand when conducting communications in densely populated areas, under overpasses, bridges, roads, oil pipelines and other capital structures.

Directional drilling is ideal for connecting to utility networks in densely built areas.

Wells for studying the geological structure and mining

  • reference, structural-search - to obtain global information about the geological structure of the region;
  • exploration, appraisal - drilling is carried out in order to identify the location of saturated deposits and determine their productivity;
  • production and injection - extract reserves and carry out operations to increase production volumes - injection of water, steam, gas.

How are wells drilled in the Moscow region?

The depth of the deposits and the properties of the rocks to be penetrated determine what equipment to use for drilling wells. For the private sector, the most widely used installation is on the URB 2-A2 wheeled chassis, which is used for work in the entire “range of elevations,” even if the deposit is more than 200 m away from the surface.

Drilling rigs on wheeled chassis (KAMAZ, Ural) are also used when drilling at shallower depths, when the section consists of hard rocks.

At depths of up to 100 m, small-sized and self-propelled units are used, which can be placed on a trailer - Drill unit Strong, Partner of the TS, TM series, on a tracked base - Partner series SBU, Lutz Kurth, Drill unit SBU.

When drilling wells for industrial purposes, URB-3A3, 1BA-15V installations are mainly used.

The Vodnaya Pomoshch company has a wide fleet of drilling equipment and is capable of solving problems of autonomous water supply in difficult hydrogeological conditions, in areas with limited access, throughout the Moscow region and neighboring areas. Provides a full range of installation and maintenance services for engineering and technical support networks.

Borehole

(a. well, drilling hole; n. Bohrloch; f. trou de forage; And. agujero, pozo de sondeo) - bugle. production of premium round section (diameter 59-1000 mm), formed as a result of drilling. B. s. divided into small ones - deep. up to 2000 m (of which the vast majority are up to several hundred m), medium - up to 4500 m, deep - up to 6000 m, ultra-deep - St. 6000 m. In B. s. the mouth, trunk and bottom are distinguished (). According to the position of the trunk axis and the configuration of the B. s. divided into vertical, horizontal, inclined; unbranched, branched; single and bush. According to their purpose, they distinguish between research, intended for studying the earth, operational (development, see Fig.) - for the development of deposits, construction - for the construction of various types. structures (bridges, piers, pile foundations and foundations, underground storage facilities for liquids and gases, water pipelines), mining engineering. B. s. - for the construction and operation of the forge. structures.
drilling fluid; 4 - cement stone; 5 - production string; 6 - productive; 7 - perforated holes; 8 - column head; 9 - valves; 10 - . ">
Development well design: 1 - guide column; 2 - conductor column; 3 - drilling fluid; 4 - cement stone; 5 - production string; 6 - productive formation; 7 - perforated holes; 8 - column head; 9 - valves; 10 - cross.
Research B. s. are divided into mapping, structural-exploration, support-geological, support-technological, engineering-geological, parametric, prospecting and exploration. Operation B. s. According to the type of deposit being developed, they are divided into wells of oil, gas and water deposits ( cm. Oil well, Gas well, Hydrogeological well), according to the function performed - production, injection, evaluation, control (piezometric, observation), according to operation. state - operating, repaired, inactive, mothballed and liquidated. Mining Engineering B. s. They are divided into explosive (they account for the largest volumes of drilling - about 50 million m per year), freezing, plugging, ventilation, drainage, etc.
Depending on the depth and purpose of the borehole and the drilling conditions, the walls of the wells are secured or left unsecured.
The barrel is not secured for mining purposes. (for example, blasting) and other shallow wells (up to 50 m), drilled in stable rock masses. Bases intended for operation and research are secured during construction. They have the most complex design, the edges are determined by the dimensions of the parts of the trunk, casing columns and the cement ring in the space behind the casing columns; type and number of casing columns; equipment of casing columns, wellhead and bottom of the B. s. Casing columns (guide, conductor, intermediate and production) are intended for fastening the wall of parts of the borehole. and isolation of decomposition zones. complications, as well as productive strata from the rest of the geol. cut. Usually they are screwed (welded) from steel pipes; in small wells, casing pipes made of plastic and asbestos cement are used. The guide column (direction) is the first (up to 30 m long), which is lowered into the upper (guide) part of the shaft in order to isolate the upper alluvial soil and divert the upward flow of drilling agent from the wellbore into the treatment system, and is cemented along the entire length. Conductor string () - the second casing string lowered into the borehole of the reservoir, designed to cover the upper unstable deposits, aquifers and absorption strata, permafrost zones, etc. They install on it; the annulus behind the column is usually cemented along its entire length. The intermediate casing is lowered, if necessary, after the casing to secure unstable rocks, isolate zones of complications and aquifers. The depth of descent of intermediate and conductor columns is calculated taking into account the prevention of hydraulic fracturing, the stability of the borehole wall, and the separation of application zones. drilling agents. The number of intermediate columns depends on the depth of the B. s. and complexity of geol. cut. The last casing is designed for production and isolates the productive formations. To extract fluids from productive formations into production. the column is lowered by pumping columns into the decomposition. combinations depending on the number of layers being developed and the extraction method used. In intermediate and operational part of the trunk of B. s. Instead of a full-length casing string, casing liner strings can be lowered on drill pipes, the top of which is secured using special equipment. pendants After completion of the well construction, the liner column is sometimes extended to the mouth of the well. column-extension.
To facilitate lowering and cementing of casing strings and improve the quality of these works, casing strings are equipped with guide shoes, decomp. valves, connect. and disconnects. devices, cement turbulators, packers, centralizers and scrapers. During multi-stage cementing, cementing sleeves are introduced into the casing string.
According to the number of casing strings lowered into the borehole. after the conductor, there are one-, two-, three- and multi-column well designs; by type of bottomhole zone equipment - B. s. with cased and uncased bottomhole zone. Design of B. s. with a cased bottomhole zone can be obtained either by lowering a continuous production into it. column, followed by cementing it and perforating the column, cement stone and productive formation, or lowering production into it. columns with a tail section having round or slot-like holes placed against the productive formation.
The design of gas wells is characterized by greater tightness of the casing columns, which is achieved by using casing pipes with special. connections and lubricants for them, lifting the cement mortar behind all columns to the mouth of the B. s. etc. The mouths of development oil and gas wells are equipped with special equipment. fittings. The design of a mine, intended for searching and exploring deposits of solid mineral deposits, is much simpler. The guiding part of such B. s. has a length of several. m and is secured with a guide pipe, the conductor part has a length of. 30-150 m. Next, the trunk is drilled with full core selection, and fastening of unstable rocks is carried out with quick-setting mixtures. Literature : cm. lit. at Art. Drilling. Y. A. Gelfgat, D. E. Stolyarov.


Mountain encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .

See what a “Borehole” is in other dictionaries:

    A borehole is a cylindrical mine working, driven by a drilling tool into the rock of the earth's crust, characterized by a large ratio of its length to diameter. The beginning of a well is called its mouth, the bottom is called its bottom,... ... Wikipedia

    See Drilling well... Big Encyclopedic Dictionary

Drilling General diagram of the drilling rig: 1 - drill bit; 2 - UBT; 3 - drill pipes; 4 - conductor; 5 - wellhead shaft; 6 - blowout preventer devices; 7 - drilling rig floor; 8 - drilling rotor; 9 - leading drill pipe; 10 - drilling riser; 11 - swivel; 12 - hook; 13 - traveling block; 14 - horse worker's balcony; 15 - crown block; 16 - traveling rope; 17 - kelly hose; 18 - load on bit indicator; 19 - drilling drawworks; 20 - mud pump; 21 - vibrating sieve for drilling mud; 22 - drilling fluid flow line.

Drilling- the process of destruction of rocks using special equipment - drilling equipment. There are three types of drilling:

  • Vertical drilling
  • Directional drilling

Drilling of the wells- this is the process of constructing a directed cylindrical mine in the ground, the diameter “D” of which is small compared to its length along the shaft “H”, without human access to the face. The beginning of a well on the surface of the earth is called the mouth, the bottom is called the bottom, and the walls of the well form its trunk.

Well construction cycle

Roller cone drill bit

  1. construction of ground structures;
  2. wellbore deepening, the implementation of which is possible only when performing two parallel types of work - the actual deepening and flushing of the well;
  3. formation isolation, consisting of two sequential types of work: strengthening (fastening) the wellbore with lowered pipes connected into a column, and plugging (cementing) the annular space;
  4. well development. Often, well development in combination with some other types of work (removal of the formation and fastening of the bottom-hole zone, perforation, injection and intensification of fluid inflow (outflow)) is called well injection.

1. Preparatory work for construction. Receive documents for the allocation of a forest area for deforestation and agree with the forestry department; marking out the site according to on-site coordinates; deforestation; site layout; construction of a residential village; preparation of the foundation for the drilling rig; site preparation and planning; construction of foundations for tanks at a fuel and lubricants warehouse; lining devices for fuel and lubricants warehouse; delivery of equipment and transportation.

2. Derrick installation work. Installation of equipment; installation of lines; installation of substructures, foundations and blocks; installation and lifting of the tower; commissioning works.

3. Preparatory work for drilling. Upon completion of the installation of the drilling rig and the construction of structures at the towers, the drilling rig is accepted by a special commission. The drilling foreman, together with the commission, checks the quality of work and tests the equipment; the state of labor protection is checked. Electrical lighting must be in explosion-proof luminaires; the rig must have 12 v emergency lighting; all shortcomings and comments of the commission must be eliminated before drilling. Before the start of work, the drilling rig is equipped with drilling tools, bits, casing pipes for the conductor and drill pipes, small-scale mechanization devices, instrumentation, a square hole, a supply of water, chemical reagents, etc. The drilling rig should have: residential houses, cultural booth, canteen, drying bath, room for analyzing solutions, fire-fighting equipment in place, a set of hand and auxiliary tools, a set of safety posters, first aid kits, a supply of fuel and lubricants in containers with a clear indication of the type of fuel, a warehouse for drilling tools, a warehouse for chemical reagents, a barn for collecting waste liquids, a water source. After accepting the installation from the installers, the tackle system is re-equipped, equipment is installed and small-scale mechanization objects are tested (UMK, anti-drag device, etc.). Drilling is carried out from the installation of a mast direction, installed strictly in the center with the axis of the tower. The tower is centered, then they drill to the direction - lower the pipe and cement it, connecting the top of the direction to the trench. After the direction, the centering of the tower and rotor is checked again. The center of the well is drilled into a hole for a square and lined with a pipe. The hole is drilled with a turbodrill, holding it from reactive rotation with a hemp rope in three or four wraps. One end is tied to the leg of the tower, the second is held in the hands through a block or leg of the tower. Upon completion of the preparatory work, no later than 2 days before the start-up of the drilling rig, a start-up conference is held with the participation of the expedition administration (chief engineer, chief technologist, chairman of the trade union committee, chief geologist and head of the technical department), where they get acquainted in detail with the well design, geological section, rock properties, expected complications, drilling regime. The regulatory map is reviewed and measures for accident-free and high-speed wiring are discussed. Drilling can be started if the following documents are available: a geological and technical work order (GTU), a drilling rig commissioning certificate, a regulatory map, there must be a shift log, a drilling fluid log, a labor safety log, a diesel engine operation log. The drilling rig must have: cementing equipment, logging equipment, occupational health and fire safety posters, a helipad, drinking and process water, chemical reagents and materials for drilling and cement fluids, emergency tools, drill and casing pipes.

4. Drilling a well (driving and securing). During the process of drilling a well, rock is drilled out, resulting in the formation of a wellbore, which must be secured using casing and cementation.

5. Testing wells for oil and gas flow. The column walls are perforated to access the productive horizon in order to obtain an influx of oil and gas.

6. Dismantling of drilling equipment and adjacent structures.

7. Recultivation of the allocated area. A seal is installed on the well with a sign indicating the timing of drilling the well and the name of the company performing the work. All barns are buried, garbage is burned, and scrap metal is collected for disposal. The drilling site is brought into compliance with the standards of environmental services.

Classification of wells by purpose

Wells for oil and gas can be systematized as follows:

  • structural search, the purpose of which is to establish (clarify tectonics, stratigraphy, lithology, assess the productivity of horizons) without additional construction of wells;
  • exploration, serving to identify productive objects, as well as to delineate already developed oil and gas-bearing formations;
  • mining (exploitation), intended for the extraction of oil and gas from the bowels of the earth. This category also includes injection, appraisal, observation and parametric wells;
  • injection, intended for injection of water, gas or steam into formations in order to maintain reservoir pressure or treat the near-wellbore zone. These measures are aimed at extending the period of flowing oil production or increasing production efficiency;
  • ahead of mining, used for oil and gas production while simultaneously clarifying the structure of the productive formation;
  • evaluative, the purpose of which is to determine the initial oil-water saturation and residual oil saturation of the formation (and conduct other studies);
  • control and observation, intended for monitoring the development object, studying the nature of the movement of formation fluids and changes in the gas and oil saturation of the formation;
  • supporting wells are drilled to study the geological structure of large regions in order to establish general patterns of occurrence of rocks and identify the possibility of the formation of oil and gas deposits in these rocks.

Drilling methods

Drilling method Definition
Rotational Mechanical drilling, in which a destructive force is created by continuous rotation of a rock-cutting tool with the application of an axial load
Rotary Rotary drilling, in which the drill string is rotated by a machine with a rotary type rotator
Turbine Rotary drilling, in which the rock-cutting tool is rotated by a turbo drill
Volume Rotary drilling, in which the rock-forming(?) tool is rotated by a screw (displacement) motor
Electric drill Rotary drilling, in which the rock-cutting tool is rotated by an electric drill
Diamond Rotary drilling, in which rock is destroyed by a rock-cutting tool reinforced with diamonds
Carbide Rotary drilling, in which rock is destroyed by a rock-cutting tool reinforced with hard alloys
Drobova Rotary drilling, in which rock is destroyed by shot
Shock Mechanical drilling, in which the destructive force is created by the impact of a rock-cutting tool
Shock-rope Impact drilling, in which the reciprocating motion created by the machine is transmitted to the rock cutting tool by a rope
Impact rod Impact drilling, in which the reciprocating motion created by the machine is transmitted to the rock cutting tool by drill pipes
Impact-rotational Mechanical drilling, in which the destructive force is created as a result of the combined impact of impacts and rotation of the rock-cutting tool
Water hammer Rotary impact drilling, in which impacts are imparted to the rock-cutting tool by a hydraulic hammer
Vibrating Mechanical drilling, in which the drill bit is inserted using a vibratory hammer
Hydrodynamic Drilling in which rock is destroyed by a high-pressure jet of liquid
Thermal Drilling in which rock is destroyed by thermal influence
Electrophysical Drilling in which rock is destroyed under the influence of forces resulting from an electrical discharge
Explosive Drilling in which rock is destroyed by forces resulting from an explosion
Chemical Drilling, in which rock is destroyed under the influence of reagents that enter into a chemical reaction with it
With flushing Drilling in which rock destruction products are removed by a flow of drilling fluid
With purging Drilling in which rock destruction products are removed by gas flow

Drill string

Drill string It is an assembly of drill pipes lowered into the well, fastened together with drill joints, designed to supply hydraulic and mechanical energy to the bit, to create an axial load on the bit, and also to control the trajectory of the well being drilled.

Being a drilling tool together with a bit and a downhole motor, the drill string performs the following functions:

  • transmits rotation from the rotor to the bit;
  • receives reactive torques from downhole motors;
  • supplies flushing agent to the face;
  • supplies hydraulic power to the bit and submersible hydraulic motor;
  • presses the bit into the rocks at the bottom, acting by its force of gravity (the axial load on the bit is created by part of the drill collars included in the bottom hole assembly (BHA), part of the drill collars (BC) is used to tension the drill string ( namely, for tensioning drill pipes, like a plumb line) to create perpendicularity of the entire drill string relative to the surface of the earth). (the rule of up to 75% of the weight of the BHA to create axial load on the bit and 25% to tension the drill string is valid only in some CIS countries; many customers and drilling contractors neglect this rule, putting priority on drilling);
  • provides replacement of the bit and submersible motor by transporting them to the bottom or to the surface;
  • allows for emergency and other special work in the wellbore.

Notes

Literature

  • Basarygin Yu. M., Bulatov A. I., Proselkov Yu. M. Drilling oil and gas wells. - Textbook manual for universities. - M.: Nedra-Business Center LLC, 2002. - 632 p. - ISBN 5-8365-0128-9
  • Drilling equipment. - Technical catalogue. - M.: “German Printing Factory”, 2008. - 265 p.
  • Daniel Yergin Extraction: A World History of the Struggle for Oil, Money and Power = The Prize: The Epic Quest for Oil, Money, and Power. - M.: "Alpina Publisher", 2011. - 944 p. - ISBN 978-5-9614-1252-9
  • Petroleum Engineering-Drilling and Well Completions, C. Gatlin (ed.), Prentice-Hall Inc., Englewood Cliffs, NJ (1960.
  • Lessons in Rotary Drilling, U. of Texas, Unit II, Lesson 3.
  • A Primer of Oil Well Drilling, third and fourth editions, U. of Texas.
  • Rotary Drilling Handbook, sixth edition, J.e. Brantly (ed.) Palmer Pub., New York City.

see also


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