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What is an oil well? What is water drilling and what types of wells are there? What is drilling.

Lecture 1

First let's define the terms:

« Borehole

wellhead "well bottom"

Well axis - «

Well walls –

Wellbore - «

Well length - axes».

Well depth – vertically".

Well diameter

Well construction

Well drilling

Well deepening

Drilling technology - «

.

900 mm to 26 mm.

Well depth up to 12260 m

Well length up to 13000

.

- Geologists - ;

During hydrocarbon exploration.

- ,

-

- Hydrogeologists – ,

- ,

- ,

-

-

History of MGRI - RGGRU

In September 1918 year, the Moscow Mining Academy was created, in which there was geological exploration faculty officially considered the founder MGRI-RGGRU.

IN 1930 year, the one-of-a-kind Moscow Geological Prospecting Institute emerged from the MGA - MGRI, Thus, MGRI-RGGRU has two years of birth - 1918 and 1930.

MGRI graduates have always occupied a worthy place in the science and practice of geological exploration, hydrogeology, engineering geology and other branches of the national economy.

From 1975 to 1989 Minister of Geology of the USSR was a graduate MGRI specialty "Reconnaissance Technology" - RT-48 (second graduation) Evgeny Alexandrovich Kozlovsky.

MGRI educational and scientific site

At the end of November 1935, MGRI was transferred from the Moscow Electromechanical College to a plot of land near the village of Ryazantsy, Zagorsky (now Sergiev Posad) district of the Moscow region. The order from MGRI read:

" §1. To improve the educational and practical work of students and conduct basic field educational practices for students: geophysical, geodetic exploration And engineering-hydrogeological, as well as to organize an experimental training and research site within NIS to carry out research and experimental work.

Since that time, training practices for students of all major specialties: geologists, hydrogeologists, geophysicists, exploration technicians, including training drilling practices, have been constantly conducted at the test site.

Since 2010, an educational and historical museum of drilling equipment has been created at the Sergiev Posad test site.

Rice. 4. Fragment of the drilling museum

Lecture 2

Methods, types and varieties of well drilling Table 1

Methods, types and varieties of drilling Drilling parameters Main Applications
Rock category by drillability Well depth up to, m Well diameter mm
Shock-rope I - XII 140 - 700 Placer exploration. Drilling for water
Drilling shallow wells without circulating cleaning agent Shallow Impact Drilling I–III 93 – 168 Engineering geology, Geological exploration (search and survey). Exploration of placer deposits. Small water supply. Explosive seismic wells. Explosive during open-pit mining in coal mines. Technical wells (in construction, mining, etc.).
Slow rotation and combined I–V 30 - 50 112 – 250
Compression drilling and screw drilling I–III 24 - 40 50 – 65
Vibration, vibration-impact and vibration-impact-rotational I – IV I - V 93 – 168
Auger I - IV (V) 60 -250
Mechanical rotary with circulation of cleaning agent Geological exploration Coreless (with solid face) I–XII Not limited 73 – 151 (250) Geological exploration wells in intervals where core is not needed
Kolonkovoe Simple projectiles Carbide I–VIII » 1500 36 - 151 It is advisable to drill hole depths of up to 200–300 m; deeper it is better to use SSC.
With STM cutters V - VIII 36 – 132
Diamond VI - XII 36 – 112
Simple projectiles with a downhole mechanism Water hammer Impact-rotational Rotational-impact VI –XI IX - XII ≈ 500 » 1500 59 – 151 59 - 76 With carbide crowns. With diamond bits against polishing of diamonds and self-jamming of the core.
Pneumatic impact Impact-rotational VI - XI » 500 (up to 1000) 76 - 300 In dry and low-water wells.
With high pressure compressor.
With downhole motor » 1500 59 - 76 To deflect the well interval during directional drilling.
Mechanical rotary with circulation of cleaning agent Special projectiles with core lifting without pipe lifting Projectiles with removable core receiver KSSK, SSK, LJNGYEAR and similar V – XI (XII) 1500 – 3500 46 – 95 (47 -145) For well depths of more than 200 - 300 m. A modern progressive option!
Projectiles (Kits) with hydro (pneumatic) transport of core or sludge KGK, KPK I - V 300 - 500 76- 250 Progressive method, but only in weak breeds. Progressive version with annular hammer for hard rocks up to 1200 m.
Operational Drilling production wells for oil and gas Rotary I - XII (with horizontal termination up to 13000m) 120 - 490 Additional exploration and production of oil, condensate and gas (Applied before 2008)
With movable rotator
Turbodrill V - XII
Hydraulic motor
Electric drill 146 - 390
Drilling water intake and hydrothermal wells I - IX 200 - 350 2000-2500 112- 350 Extraction of water, brines and hydroheat
Drilling geotechnological wells I - IX 50 -700 70 - 500 Extraction of solid minerals (uranium, sulfur, iron, etc.)
Drilling technical, scientific and auxiliary wells I - XII 10 - 12300 70 - 900
Physical methods of rock destruction Hydraulic drilling I - IV In combination with TPI mining.
Thermodynamic drilling VI–XII For drilling blast holes.
Blast drilling V - XII Effective, but dangerous.
Thermostatic melting VI - XII Experienced.
Plasma drilling VI - XII Experienced.
Electric pulse drilling IV - VII Experienced.
Laser drilling Experienced.
Cavitation drilling Experienced.
Jet Experienced.
Magnetostrictive Experienced
Ultrasonic Experienced

Lecture 3

Rice. 6

The choice of well direction is determined by the most complete solution of geological problems. The most accurate information about the formation rocks (structure, thickness of the formation) is obtained when the well intersects the formation at the cross-strike, i.e. at an angle of 90º.

When drilling a well in complex geological sections, the behavior of its axis is significantly influenced by a number of factors, primarily geological (when transitioning from rocks of one hardness to rocks of another hardness, layering, fracturing, anisotropic properties of rocks, and others), as well as technical and technological ones. As a result, the wellbore becomes bent during the drilling process, and it is very difficult or even impossible to drill a straight well in such conditions. This curvature of the borehole axis is called natural. In these cases, it is advisable to design a curved well route in advance, taking into account the factors causing curvature. Moreover, curved routes are often not only easier to implement, but also more rational than straight ones.

Since to drill a well along a given route it is necessary to use special technical means and technological methods, in this case the curvature of the well is called “ artificial curvature", and the work of executing such a route is called " directional drilling»

Curvilinear routes, like rectilinear ones, can have any direction and are distinguished into “curved with constant curvature, with variable curvature, with curvature in two directions, and combined, combining straight and curved sections. (Fig. 7)

Along with multilateral wells, exploratory drilling practice uses multilateral drilling(incorrect multilateral well), when from one site (due to the rotation of the machine rotator) several wells are drilled sequentially at different angles with one drilling rig (Fig. 9 a, b)

This solution provides a significant economic effect when drilling not very deep wells in hard-to-reach areas (Fig. 9 b) and deep oil and gas wells (Fig. 9 a), allowing savings on laying transport routes and equipment of sites, as well as reducing environmental damage.

Well route design is carried out in the following sequence:

1. The choice between single-hole and multilateral wells. In this case, first of all, economic feasibility and the need to solve geological problems play a role. Issues of environmental protection are now beginning to play a particularly important role - with every transportation and installation of a drilling rig, serious damage to nature is caused - this must be taken into account.

2. If a single-hole well is selected, its direction is determined: vertical, inclined, horizontal, rising. In terms of labor costs, they increase in the order of the (previously) named areas.

3. The next step is to determine the straightness or curvilinearity of the well route. In the simplest geological sections (with monotonous occurrence of layers or in monolithic massifs), a straight line is usually chosen. In the case when, due to geological and technological reasons, the well will be curved, it is more profitable to use natural curvature and design a curved well route. At the same time, it must be taken into account that as the intensity of well deflection increases, the difficulties of its implementation also increase (power costs and the possibility of breakage of drill pipes increase). It is generally accepted that the permissible curvature intensity is no more than 0.05 degrees/m. A curved route is designed to solve certain problems and can be more effective than a straight one. For example, when cutting steeply dipping formations with a well, a straight inclined well must be laid with a large inclination angle, which creates technical difficulties; in addition, the length of such a well will be greater than that of a curved one (L1>L2) (Fig. 10).

In the practice of production drilling, curved wells are used, the final part of which, entering the productive formation, approaches a horizontal position and runs along the formation, which increases the possibility of extracting minerals (in oil drilling such wells are called “horizontal”, but it is more correct when they are called “well with horizontal ending - s.g.o."). (Fig. 12).

Rice. 13.

SSK drills differ from simple ones in that they consist of a string of special drill pipes that have the same internal cross-section as a core pipe. A thin-walled core receiver pipe is placed in the core pipe, into which a core column enters during drilling (Fig. 13 c). After filling the core receiver with core, a special catcher is lowered from the surface on a thin cable into the drill pipe string, which captures the head of the core receiver pipe and a high-speed winch, the core receiver with the core inside drill pipes rise to the surface. Thus, instead of several hours for tripping and lifting operations when drilling deep wells, it will take several tens of minutes to recover the core from the well. Taking into account the fact that SSK shells are much more expensive than simple shells, it is more profitable to use simple shells for drilling shallow wells (up to approximately 200 - 300 meters), and for deeper ones it is more profitable to use SSK shells.

When drilling with hydraulic or pneumatic core transport, a double string of drill pipes is used. The flow of cleaning agent is supplied to the bottom through the gap between the outer and inner pipes. At the bottom, the flow turns and rises up along the internal column, bringing pieces of core or core material to the surface when drilling through clastic rocks. All 100% of the core (or core material) is brought to the surface simultaneously with the process of deepening the well. With this drilling method, no additional time is spent on core recovery, which allows for a sharp increase in productivity. However, high productivity is only possible when drilling in soft and weak rocks, where the rock is easily destroyed and mechanically removed from the bottom into the inner pipe. The second limitation of the use of KGC and KPC is the relatively small depth of the wells. Typically, well depths are up to 500 meters. Greater depths can be achieved using blowdown in combination with ring hammers and high pressure compressors (up to 2.5 MPa).

The third option for choosing types of drilling, depending on geological conditions, is associated with the use of drilling equipment (simple or special) with an additional downhole mechanism or a special core set.

In special cases the following may be used:

Mechanisms that create shock pulses on a rock cutting tool (RDT): a)) during drilling with flushing – hydraulic hammers, b) when drilling with blowing or drilling with foam – Hammers;

- downhole screw hydraulic motor;

Special core sets for obtaining conditioned core in difficult geological conditions.

Impact pulses to the bottom during rotary drilling are used to solve a number of problems:

The ability to drill vertical, strictly straight wells due to the fact that there is no need for an axial load on the drilling device; the drill bit weighs in the well like a plumb line and does not bend, as with rotary drilling with an axial load;

Increase the drilling speed due to additional impact destruction of the rock, especially during air percussion drilling, where the speed can increase by 2 - 3 times (when drilling with hydraulic percussion drilling, the speed increases slightly);

With high-frequency hydraulic shock drilling, the friction of the cutters on the rock and the core in the core pipe is significantly reduced. This allows you to combat polishing of diamond crowns and self-jamming of the core in the core pipe.

Downhole Screw Hydraulic Motor small diameter can be used when drilling both geological and exploratory oil and gas wells.

The peculiarity of the use of downhole motors is that the drill pipe string does not rotate during the drilling process, but only the rock cutting tool rotates - a bit or a core pipe with a crown. When drilling oil and gas wells, downhole motors are used very widely. When drilling exploration wells of small diameter, the power of the downhole motor is insufficient for effective drilling. However, the ability to drill without rotating a pipe string with a downhole motor is successfully used for directional drilling, when the well path needs to be deviated in the desired direction at the desired angle. A downhole motor included in the tool on a “crooked adapter” allows for high-quality control of the direction of the well path.

Special core sets for obtaining conditioned core in unfavorable geological conditions (eroded, crumbling, layered, fractured, destroyed, crushed, intermittent, etc. rocks). Due to special designs or due to special technology (reverse circulation of the washing liquid), such core sets protect the core from destruction due to erosion, rotation of the core pipe, and destruction by the crown cutters. Since obtaining a complete core is of paramount importance for geologists, this issue will be discussed in detail during practical classes.

Lecture 6

Rice. 14

6. In addition to the graphic image, the well design is determined by its code and an explanatory note justifying its parameters. Of the published methods for compiling a code for the design of geological exploration wells, the most complete and accurate is the method proposed by the Donetsk PTI.

Example of a well design description ( in Fig. 15) with a code.

Rice. 15

Ts(20) 112/108tsb(220), 93/89tsp(440...480), 76(1000)

Basic cipher designations:

132 - number indicating drilling diameter

/ - sign indicating pipe fastening

127 - the number behind the / sign indicates the diameter of the casing pipes,

(20) - the number in parentheses after the size of the casing pipes indicates the depth to which the well is cased

(440….480) - installation interval of a hidden column

Additional cipher designations:

C is a sign of cementation of the entire column. Placed behind the diameter of the casing pipes.

Cb - a sign of cementing only the shoe (lower part) of the column

TsP - a sign for cementing the shoe and the upper end of the secret casing

; - sign of well expansion. Placed before the designation of the diameter of the tool that expands the well

Designation applicable to stepped casing

" - designation of the casing string to be removed. Placed before the designation of the diameter of the casing string, after which the length of part of the string may be indicated in brackets if not all of it is removed.

The given designations cover the entire range of parameters included in the usual concept of well design or depicted on design diagrams. However, if necessary, you can enter any other additional letter indices.

In this example: - the well is drilled with a bit with a diameter of Ø 132 mm and secured with a guide pipe Ø 127 mm to a depth of 20 m. Here pipes Ø 127 mm are cemented over their entire length. Further, the drilling diameter was 112 mm to 220 m, and the well was secured to this depth with a Ø 108 mm jig. For a column with a diameter of 108 mm, only the shoe (the lower part of the column) is cemented. Further drilling is carried out with a Ø 93 mm bit to a depth of 480 m. In the interval from 440 to 480 m, the complications zone and the wellbore are secured with a secret column Ø 89 mm (the shoe and the upper part of the secret column are secured with cement). Up to a depth of 1000 m, the well has a Ø 76 mm without reinforcement.

Rice. 16

Rice. 17

Another feature of the construction of oil and gas wells is the critical importance of horizon isolation in order to exclude fluid flows from different horizons. Isolation of the annulus space of almost all casing strings is carried out by cementation. Since when drilling oil and gas wells it is necessary to isolate formations with fluids of various compositions, including aggressive ones that are dangerous if they enter productive formations and with different pressures, cementation of the annulus of casing strings is of paramount importance. Great importance is attached to the composition and quality of cement mixtures, their properties and parameters. Particular importance is attached to cementing quality control. Therefore, geophysical methods for monitoring the quality of cementation are given paramount importance. In practice, to study the technical condition of a well, the method of radioactive isotopes, the acoustic method, and the method of well thermometry are used; these methods determine the height of rise of the cement slurry in the annulus, identify places of annular circulation, and the state of contact of the cement stone with the casing pipes and rock in the walls of the well.

Fig.18


Lecture 1

What is a borehole and what is well drilling.

First let's define the terms:

« Borehole - a cylindrical hole (mining) in the earth’s crust, ice massifs and artificial structures, which is significantly larger in length than its diameter.”

The beginning of the well is called “ wellhead ", the bottom of the well (the surface of the bottom of the well) both during deepening (drilling) and at the end of deepening is called "well bottom"

Well axis - « line connecting the centers of the cross sections of the well from the mouth to the bottom.”

Well walls – "lateral surface of the well".

Wellbore - « the inner part of the well, limited by its walls.”

Well length - “the distance between the wellhead and the bottom of the well along its axes».

Well depth – “the distance between the wellhead and the bottom of the well vertically".

Well diameter – “nominal borehole diameter equal to the diameter of the rock-cutting tool

Note - The actual diameter of the well in different areas may be larger due to drilling and development of the wellbore, or smaller due to swelling of the rocks.

Well construction - (well construction), Performing the entire range of work, starting with site preparation and installation of the drilling rig and ending with reclamation of the territory after drilling, as a result of which the well is drilled, the results are obtained, and the well is abandoned or closed.

Well drilling - performance of a complex of works, starting from drilling to completion of deepening upon reaching the final depth and completion of all work in the well.

Well deepening - a drilling process in which the rock at the bottom of the well is destroyed and the bottom moves forward.

Drilling technology - « a series of sequential choices and decisions that ensure the effective execution of the process, including the choice of technical means and methods for performing the process" In a narrower sense, technology includes selection of process control methods and parameters drilling The concept of drilling mode closely corresponds to this narrow meaning.

Technical means for drilling wells - drilling equipment, drilling tools, instrumentation (instrumentation), automation and control equipment (CA and CS).

What is a borehole.

The well can be drilled not only downwards, but also obliquely and horizontally and even upwards.

The well axis can be straight or curved; (Fig.3)

The diameter of the wellbore can change in steps (Fig. 1)

The diameter of the wells can be from 900 mm to 26 mm.

Well depth up to 12260 m. (scientific Kola superdeep).

Well length up to 13000 m. (oil well on Sakhalin Island).

What is the connection between drilling wells and geologists and hydrogeologists? .

- Geologists - obtaining complete and reliable geological information;

When exploring solid minerals,

During hydrocarbon exploration.

- determination and calculation of mineral reserves,

- compilation of geological maps and sections.

- Hydrogeologists – carrying out engineering-geological research,

- obtaining hydrogeological information,

- design of water intake and observation wells,

- development of water wells.

- design and development of drainage wells.

Drilling is the process by which a cylindrical mine opening (hole, hole) is constructed due to the destruction of rocks. Most often, drilling is carried out in the earth's crust. Less common in concrete and asphalt. Drilling is used to search, study and extract minerals; blasting operations; drainage of wetlands; laying underground communications; construction of pile foundations. There is a special classification of drilling methods. The first classification is based on the nature of rock destruction. They are divided into mechanical and non-mechanical. The first type is the destructive effect of the drilling tool on the rock. The second type - the destructive impact occurs without contact of the source of impact with the rock. Mechanical drilling, in turn, is divided into rotary, impact, rotary impact and rotary impact. Rotary drilling destroys rock by rotating a tool pressed to the bottom. For this type, most often, cutting type tools (rock cutting), diamond tools, shot drilling and shot cores are used. The choice of tool type depends on the strength of the rock. Impact methods include impact drilling and impact rotary drilling (drilling with rotary hammers). Drilling can also be divided according to the type of tool used to drill. From this classification we can distinguish screw, diamond, roller and rod.

There is a division by types of drilling machines (turbine, pneumatic percussion, perforating) and by the method of drilling wells (cluster and inclined).

Drilling development and specialization is applied mainly to three fundamental areas of technology. The first area is oil and gas drilling. To do this, fairly deep wells are drilled, several kilometers deep.

The second area is wells reaching depths of hundreds of meters. Such wells are drilled in search of solid minerals. The latter area is used in construction and mining for placing explosives in rocks. The depth of such wells ranges from several meters to tens of meters.
Drilling for water is the most critical stage when the issue of drainage and water supply for a home or cottage is resolved. It is customary to begin water supply for a cottage or home with a choice regarding the water source. Usually the owner himself does this. In order to complete the following drilling steps, special equipment and experienced personnel are required. Water well drilling is a high-tech type of construction service. This requires high professionalism of the performer. The most reliable source of water supply today can be considered an artesian well. Since it is not possible to find identical sections, the process of drilling for water is associated with many random factors. And the influence of the human factor in this area is very high.

All companies - professionals in the market and specialized organizations for drilling underwater wells must have detailed and complete information about drilling methods and local geological conditions. They must submit projects that very accurately indicate the projected depths and other characteristics of the wells and water quality.

In this work, the most important thing is that the geological specifics of the area and the specific place where work on drilling water wells is being carried out strictly corresponds to the level of the technical base used. Installations related to the need for equipment and equipment for well installation work are selected taking into account the depth and other parameters of the aquifer and aquifer layers.

When constructing water wells, it is not the drilling itself that is important, but also the selection and installation of a well pump. Control automation and water supply systems running from wells to a dacha or house are also used. In our daily life, the water supply system provides us with comfort. It's hard to imagine what we would do without her. The quality, reliability and reliability of water supply equipment today is at its best. And all this thanks to improved pumps and automatic control. In order to drill a well under water, it is necessary to open the limestone horizons. This type of drilling is called limestone drilling.

There is a sand well for water. The advantages of such a well are low cost, ease of maintenance, quick installation and no need for registration and licensing of wells. All the necessary water is located at great depths and to lift it from this depth, special pumps for wells are used. Trenchless technologies are used to lay pipelines made of polyethylene or steel. Such technologies include directional drilling, under-road piercing and HDD piercing. If you have not yet gotten involved with drilling water wells, you may be wondering why they are needed at all. They are needed in order to organize an individual water supply system for a home or cottage. You will gain independence from all centralized water supply systems, incorrectly functioning automation and the eternal problem of pipeline corrosion. For the proper operation of the heating and sewage system of your home, as well as for the convenience of living, you must organize your own water well.

In order to choose the right well, you need to fully study the needs of residents and the purpose of using the well. The location for which the well is drilled plays a significant role. This could be a large house with water consumption or a small house with a garden area.

Depending on the quality of water supply, budget, and volume of water consumption, certain types of water well drilling can be distinguished. Drilling small filtered grains of sand into the horizon (drilling wells into sand) is carried out to a depth of up to 30 meters. More precisely, until the sandy horizon is reached. After this, a well is usually installed, the diameter of which is from 126 millimeters to 134 millimeters. The internal diameter of the pipe of this well ranges from 126 millimeters to 134 millimeters. This pipe consists of a pipe called casing and the capacity of which is up to 20 liters per minute.

Most often, drilling a well in sand takes about two working days. If you decide to drill a well and value for money for the water supply system of an area with low water consumption, then a shallow sand well is best for you. Also, it is suitable for a summer house or a house in which you live only in the summer or spring - autumn. Like all other wells, a sand well has its disadvantages. The main disadvantage of such a well is the very high probability of being flooded. The service life of the pipes depends on how often the well is used and on the natural potential of the horizon. In addition to drilling wells for sand, there is drilling of wells for limestone (artesian well). It consists of drilling wells to a depth of 20 meters to 210 meters to the aquifer. Drilling is carried out to the layers of limestone. Limestone wells are distinguished from other wells by their high productivity, which reaches up to 100 cubic meters per hour. Also, such wells can boast of high reliability.

As for the depth of wells for limestone, it is much greater than the depth of sand wells. But because of this, the complexity of the work increases. Drilling an artesian well usually takes about three days. If you are going to live in your house or cottage all year round, then this type of water well will suit you best. It will help you always have crystal clear water in your home. Among the main advantages of such a well are the following: a large supply of water, a significant operational life due to the stability of the aquifers of the limestone slabs. While drilling an artesian well, its walls are strengthened. This helps the well serve you from 35 to 55 years. The disadvantage of such drilling is the need for additional equipment for the water that is supplied to the well. After drilling, it is important to choose the right water treatment system. If you have installed an artesian well, then be sure that your home will always have clean drinking water for many years. Usually, wells begin to be drilled before the house is built. This will allow you to save money and your own efforts. This also significantly affects the convenience of building a house, because you will need a lot of water.

Before you start drilling, you also need to take a very responsible approach to the placement of all objects on the site. If, after all, the dacha or house was built before the water supply was organized, then there is nothing wrong with that. With the help of experienced specialists, well drilling can be done at any time during the construction of a house. In order to do all the drilling work correctly, you need professional technical equipment that allows you to perform work of absolutely varying complexity and in all weather conditions. In principle, such work can be carried out at any time of the year. Winter time is favorable for the customer in that fairly heavy and powerful machines will not damage the site. Also, the slag that is brought to the surface during drilling does not clog the territory of the building.

In advance, before choosing a place to drill a water well, you need to accurately measure 15 meters from the septic tank. If the slope of the terrain on the territory of the building is towards the well, then the distance to the septic tank must be increased to 20 meters. The distance from the foundation or fence to the well should be no closer than three meters. The drilling method is selected depending on the structure of the soil, and the working area should be 24 cubic meters.
Since a water well can be called a capital structure, the area in which water drilling will be carried out must be very carefully selected. It should be located above an aquifer, which is favorable for the subsequent operation of the well. Also, the territory of the building must be adapted for repair work. The place where the well will be located must comply with relevant environmental standards and be protected from pollution. But we must remember that not every well has the opportunity to be water-bearing. Therefore, it is necessary to approach the calculations of the location of the future well before drilling with great responsibility. Important points in drilling are: determining the type of soil, checking the area for the presence of vegetation, and analyzing the surface of the area. This analysis includes the topography, finding a suitable location for the well, a thorough check for harmful sources of pollution and the presence of water on the surface, and a study of the conditions that lie below the surface of the site.
To determine the area for drilling a water well, a highly qualified specialist travels to the place where the work is expected to be carried out. He discusses with the customer the location of the future well, checks the availability of power supply at the site and selects a place for specialized equipment, workers’ accommodation, a water carrier and a drilling rig. The next step after drilling a water well is the construction of the well itself. The purpose of constructing a well is to supply water from the well itself to the surface of the site using a special pump. The pressure of this pump should raise the water to the surface. Drilling water wells requires the installation of a caisson. It is thanks to him that the customer will be able to drink clean drinking water at any time of the year. A caisson is a metal reservoir that prevents water from freezing in winter. It also serves as an excellent protector against groundwater and other contaminants. Pipelines are laid from the caisson to the cottage or house. They are laid at a depth of 1.9 meters.

Drilling a well includes the installation of an automatic, uninterrupted pump control system and a variety of filters to clean water from unnecessary impurities.

Well, the very last, final stage in drilling water wells is the chemical analysis of water. To do this, after all the drilling work has been done, a water sample is taken from the well and a chemical analysis is performed. This analysis allows us to determine whether the water is suitable for daily use and for the normal operation of plumbing fixtures and household appliances. After all, if the water is unsuitable and contains contaminants and impurities, it will not only lead to breakdowns of plumbing, but will also cause great damage to the human body.

Well, at the end of the drilling work, all that remains is to equip it with the help of a casing. A casing is a structure that consists of pipes. These pipes are connected to each other using the threaded method. More precisely, this thread is called a conical trapezoidal thread. Depending on the type of work, ordinary welding is also used to construct casing columns. If you have completed all the stages associated with drilling wells for water, including its arrangement, then we can confidently say that the work has come to an end and you can now enjoy your personal water supply. If you did this work on your summer cottage, where you appear only at a certain time, then naturally the well will not be in working condition for a long time. After a long break (a year or more), the well must be checked. Most likely, after checking the well, it will need to restore the productivity of the aquifer well and clean it. Cleaning consists of flushing the bottom-hole zone using a water-air mixture, cleaning the filter, and there is also the possibility of replacing the casing strings.

Drilling water wells in Perm includes the steps listed above. Experienced specialists will help you when choosing a place of work and making calculations that are necessary for the proper operation of the water supply.

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


Wikimedia Foundation. 2010.

Drilling is the construction of a well, as well as the destruction of layers of the earth with the subsequent extraction of destruction products to the surface

Drilling: for water, types of drilling, types of drilling, gas

Drilling is

Drilling is construction of a well, as well as the destruction of layers of the earth with the subsequent extraction of destruction products to the surface.

— process destruction of rocks using special equipment - drilling equipment.

There are three types drilling:

Vertical drilling

Directional drilling

Horizontal drilling

Well drilling is process construction of a directed cylindrical mine working 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.

Types of water wells

1. Filter well for water in sandy horizons.

To identify the presence of an aquifer in sandy soils, exploratory drilling is first carried out.

When drilling an exploration well, there can be 3 situations:

1) Availability of water for the construction of a water well, in the presence of a layer of water-saturated sand with a thickness of > 0.8 m.

2) Availability of water for the construction of a well - when interlayering water-saturated sand and other types of clay soils.

3) Lack of aquifers.

An exploration well for water is usually drilled to a depth of 13-15 meters. The cost of exploration drilling is 1000 rubles/meter. If, during exploratory drilling, aquifers are found for the construction of a water well, price meters of exploration drilling is included in price meter of drilling a water well.

If an aquifer is discovered, a production well with a filter and casing is drilled into it to construct a well. The depth of such a well is usually 13-25 m. Drilling a well at sand produced by a combined screw and shock-rope method. When drilling, metal pipes with a threaded connection type with a diameter of 168 mm are used as an external casing (to hold the walls of the well during drilling). After installing the production casing with a filter inside the outer casing pipes, the outer pipes are removed.

The production casing of a sand well consists of three parts:

1. Working column - located from ground level to the level of the aquifer. The pipes of the working string, on the one hand, “case” the well, keeping its walls from collapsing, on the other hand, they serve to place water-lifting pipes and a pump in them.

2. Filter column - a continuation of the working column, a perforated pipe equipped with a stainless galloon mesh (0.2 - 0.315 mm).

Through a filter column, water enters the well from the thickness of water-saturated sand, and a mesh filter prevents the entry of sand particles.

3. The storage tank is a blind pipe, closed at the bottom with a plug, which serves for uninterrupted water supply (water supply).

2. Well for an aquifer in Ordovician limestones.

A limestone well is drilled into an aquifer located in limestone cracks. Limestone - rock, predominantly consisting of calcite (calcium carbonate). Drilling wells into aquifers in limestone is done with augers, which in appearance represent the working part of a corkscrew.

Unlike a sand well for water, the drilling process is less labor-intensive. When drilling a water well, no external metal pipes are required to hold the walls of the well - due to the hardness of the limestone. The depth of such a well is usually 15-40 m.

The “limestone” well consists of three parts:

1. Working column.

2. The filter column is simply a perforated pipe (perforated filter).

3. The storage tank is a blind pipe.

3. Artesian water wells for the Cambro-Ordovician, Lomonosov aquifers and the Vendian aquifer complex (Gdov horizon).

Artesian aquifers, in our region, are confined to deep-lying sandstones, which are covered on top by layers of waterproof rock (clay thickness), forming a barrier to the waters of Quaternary sediments. The water contained in the caverns of these sandstones is located at a depth under high pressure. When such an aquifer is opened by a well, the water level under pressure rushes to the surface of the earth and is usually established at a depth of 5-15 meters.

The first artesian wells, from which water rushed out under its own pressure, were drilled in France, in the province of Artois, hence the name “Artesian Well”.

Such wells have a flow rate of approximately 2-15 m3/hour and have a depth of 80 m. They are drilled for water supply to enterprises, cottage villages or detached residential buildings.

Drilling of artesian wells is carried out if the customer has a license for the right to use the subsoil plot for the purpose of geological study.

Impact-rope drilling method

The impact projectile is suspended on a rope, which is supplied from the instrumental drum. During chiselling, the projectile is raised and dropped using a balancer - the pulling mechanism of the machine, or from a winch. When dropped, the projectile falls down under its own weight, destroying the rock at the face. As the well deepens, the drilling line is released from the tool drum, feeding the bit. Having drilled a certain interval of the well, they stop chiseling and begin cleaning the face. This operation is performed with a bailer. After cleaning the well, they continue chiseling or begin to shore up the well - unstable intervals are secured with casing pipes.

Drilling is

A drilling rig for drilling drilling equipment consists of a bit, a striking rod, scissors (jasses) and a rope lock (ropsocket).

The following types of chisels are used: flat, I-beam, Z, rounding, cross, pyramidal and eccentric. The type of bit is determined by the nature of the rocks being penetrated. The angle of sharpening (attack) depends on the hardness of the drill bits rocks.

When percussion drilling of placer deposits, to drive the leading casing simultaneously with deepening the well, a driving half-rod and an impact head are additionally used as part of the projectile.

Drilling is

To remove destroyed rock from the face and when drilling layers of quicksand, a bailer tool is used in the following composition: bailer, scissors and rope lock. Sometimes a short shock rod (half rod) is added.

Bailer with a flat valve and a driving glass.

a) flat; b) I-beam; c) rounding; d) cross

The main advantage of the shock-rope method is that there is no need to supply drilling rigs with clay and water.

The main disadvantage is the low mechanical speed in easily passable rocks, the relatively high cost of casing pipes, and the method is more energy-consuming. Also, when drilling in rocks above category III in the immediate vicinity of buildings, damage to foundations is possible from the resulting vibration when the bit hits the bottom.

Rotary drilling

It has several main directions: auger, core, drilling with direct and reverse circulation, drilling with purge.

With the auger method of drilling soft and loose rocks, rock destruction at the face is carried out with a rotating bit of various designs; the destroyed rock is transported from the face to the day surface by augers, which are a single screw conveyor. When auger drilling with an annular face, magazine augers and special bits are used. This type of drilling is the most common and most versatile method of all types of shallow drilling. It is used when drilling in rocks from categories I to VI in terms of drillability, including gravel and pebbles and in rocks containing small boulders. Auger drilling is widespread due to the fact that when drilling in most rocks, the walls of the well are simultaneously secured with the rock being lifted.

Auger drilling process

The main advantage of drilling with augers is the high penetration rate.

The main disadvantage is the high energy consumption, the curvature of the wellbore, and it is impossible to drill in rocks above category VI.

Drilling is

Core drilling

In core drilling, rock destruction at the bottom is carried out by cutting an annular channel by rotating a core pipe with a drill bit placed at its end. In this case, in the central part of the face (inside the core pipe) a core is formed in the form of a column (monolith) of an undisturbed structure. After a core of sufficient length has been formed, it is torn from the massif using a core grabber installed on a core pipe immediately above the crown and raised to the surface. Often core drilling of rocks is carried out with bottom-hole circulation of the flushing fluid, less often with flushing of the wellbore with a clay solution. Instead of washing, blowing the bottom with compressed air is also used. Blowing has a number of important advantages over flushing from the point of view of exploration drilling, namely:

Drilling is

Additional moisture is excluded, as well as erosion of the core and bottom;

The possibility of contamination and moistening of the sludge, as well as the mixing of differences in sludge carried from different horizons is eliminated.

And of course, such an important point as the delivery of water to wells is excluded.

Core pipe

The main disadvantage preventing the widespread use of this method is the geological and hydrogeological limitation of drilling possibilities: bottom hole blowing is most appropriate and effective to carry out in wells that do not contain liquid water.

The main advantage is the high penetration rate in rocks from category V and above. Possibility of extracting core with an undisturbed structure to the surface.

Drilling with flushing.

Of the total volume of water well drilling, more than 85% is performed using a rotary method with flushing with industrial water or clay solution. Water, clay solutions treated with nonionic surfactants (OP-7, OP-10, etc.), water-hypane (3-5%) and carbonate solutions are used as a flushing liquid when opening aquifers. When drilling using the rotary method, two types of flushing are used: direct and reverse.

Drilling is

In direct flushing, the flushing fluid is supplied to the rock-cutting tool through the drill pipes and rises to the surface through the annular gap between the drill pipes and the walls of the well, carrying with it pieces of destroyed rock (sludge).

During backflushing, the flushing fluid enters the well through a hermetically sealed wellhead along the wellbore and rises through the drill pipes to the surface.

Well flushing scheme

a - straight; b - reverse; 1 - well walls; 2 - guide pipe; 3 - drill pipe; 4 - oil seal; 5 - drainage of flushing liquid; 6 - cover; 7 - supply of flushing liquid; 8 - adapter.

Continuous face drilling is carried out using roller bits, the type of which is selected based on the category of the rock being drilled.

Circular face drilling with direct flushing is carried out using core sets with carbide or diamond bits.

Main advantages: The drilling speed of this method in soft and medium-hard rocks at any depth is approximately 3 times higher compared to the shock-rope method. The design of a rotary drilling well is much simpler, and cost casing pipes are 40-60% less than with cable-percussion drilling. Significantly lower energy intensity and energy consumption compared to other methods.

The main disadvantage is the provision of water and clay to drilling rigs.

Drilling with blowing.

In direct circulation drilling, the processes are generally the same as in direct circulation drilling. Only instead of a solution, compressed air is supplied through the swivel seal. And the destroyed rock (sludge) is blown to the surface. Drilling is carried out with air hammers, as well as roller bits or core bits with diamond or carbide bits.

Drilling is

Well location

Since a well performs different functions than wells, when working there is no point in looking for high water and determining the optimal location. Customers, or if you are drilling for yourself, I can choose the site for the well yourself, in the place where it is convenient and will have the best effect.

This is all the more effective because there is water in almost any soil, the only question is how deep it is. Drilling rigs drill wells up to 50 meters, which gives an almost guaranteed result.

How to drill different types of soil?

The question is by no means an idle one, since there are significant differences in the technology of breaking through clay or rocky soils. Don't forget. that at different depths the soil type may change, this is worth taking into account and changing equipment and nozzles.

The most labor-intensive, slow and expensive drilling process is the development of calcareous, hard and rocky layers and soil types.

A typical mistake of beginners is that in an effort to quickly pass through an unpleasant section, the speed increases, which is why the drill “bites” and Job stops completely. On the contrary, the revolutions of the drilling equipment should be 30-40, then you will stably pass through a difficult section.

You will be able to break through strong and hard ground much easier. If you use a roller bit, a roller cutter with a rectangular tape thread.

Unfortunately, there are simply impassable areas - huge stones hidden in the thickness of the earth. In this case, it is recommended to rearrange the installation.

Clay soils are a driller's paradise; the drill breaks through such soil easily and quickly. everything goes like clockwork, moreover, nothing threatens the well, clay areas are not subject to delamination and shedding.

Sandy soils, quicksand.

Actually, it is in the sand that underground water, springs, and aquifers are located.

However, the top layer, quicksand, is not suitable for use, so such sandy layers are also passed through. The biggest difficulty is that the sand crumbles and can fill up and ruin the whole work. To avoid this, special additives are added to the circulating water - clays (natural, dry and bentonite), Stuvamax.

The most important thing is not to rush and carefully monitor the behavior of the drilling rig.

In particular, water should always flow out of the wellbore. If not, then you need to raise the rod column and use a motor pump. When building up bars, raise the columns. Pass air columns along the rods to clean the tools.

Oil and gas wells

Based on the method of impact on rocks, a distinction is made between mechanical and non-mechanical drilling. During mechanical drilling, the drilling tool directly affects the rock, destroying it, and during non-mechanical drilling, destruction occurs without direct contact with the rock from the source of impact on it. Non-mechanical methods (hydraulic, thermal, electrophysical) are under development and are not currently used for drilling oil and gas wells.

Mechanical drilling methods are divided into impact and rotary.

During impact drilling, rock destruction is carried out by bit 1 suspended on a rope (Fig. 3). The drilling tool also includes a striking rod 2 and a rope lock 3. It is suspended on a rope 4, which is thrown over a block 5 mounted on a mast (not shown). The reciprocating movement of the drilling tool is provided by the drilling rig 6.

1 - bit; 2 - shock rod; 3 - rope lock; 4 - rope; 5 - block; 6 - drilling rig.

As the well deepens, the rope is lengthened. The cylindricity of the well is ensured by turning the bit during work.

To clear the face of destroyed rock, the drilling tool is periodically removed from the well, and a bailer, similar to a long bucket with a valve in the bottom, is lowered into it. When the bailer is immersed in a mixture of liquid (formation or poured from above) and drilled rock particles, the valve opens and the bailer is filled with this mixture. When the bailer is lifted, the valve closes and the mixture is removed to the top.

After cleaning the bottom is completed, the drilling tool is lowered into the well again and drilling continues.

To avoid collapse of the well walls, a casing pipe is lowered into it, the length of which increases as the bottom deepens.

Currently, shock drilling is not used in our country when drilling oil and gas wells.

Oil and gas wells are constructed using the rotary drilling method. With this method, rocks are not crushed by impacts, but are destroyed by a rotating bit, which is subject to an axial load. Torque is transmitted to the bit or from the surface from the rotator (rotor) through the drill pipe string (rotary drilling) or from a downhole motor (turbo drill, electric drill, screw motor) installed directly above the bit.

Drilling is

A turbodrill is a hydraulic turbine driven into rotation by means of flushing fluid injected into the well. An electric drill is an electric motor protected from liquid penetration, power to which is supplied via a cable from the surface. A screw motor is a type of downhole hydraulic machine in which a screw mechanism is used to convert the energy of the flushing fluid flow into mechanical energy of rotational motion.

Based on the nature of rock destruction at the bottom, a distinction is made between continuous and core drilling. During continuous drilling, rock destruction occurs over the entire face area. Core drilling involves the destruction of rocks only along the ring in order to extract a core - a cylindrical sample of rocks along the entire or part of the length of the well. Using core selection, the properties, composition and structure of rocks, as well as the composition and properties of the fluid saturating the rock, are studied.

All drill bits are classified into three types:

cutting and shearing bits that destroy rock with blades (blade bits);

crushing and shearing bits that destroy rock with teeth located on roller cones (cone bits);

bits with cutting and abrasive action, destroying rock with diamond grains or carbide pins, which are located in the end part of the bit (diamond and carbide bits).

Drilling rig: 1 - bit; 2 - above-bit weighted drill pipe; 3 - sub; 4 - centralizer; 5 - coupling sub; 6, 7 - weighted drill pipes; 8 - sub; 9 - safety ring; 10 - drill pipes; 11 - safety sub; 12, 14 - lower and upper rod subs; 13 - leading pipe; 15 - swivel sub; 16 - swivel; 17 - riser; 18 - hose; 19 - hook; 20 - traveling block; 21 - tower; 22 - crown block; 23 - gearbox; 24 - winch; 25 - rotor; 26 - sludge separator; 27 - mud pump

Systematization of oil and gas wells according to their intended 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 well construction;

exploration, serving to identify productive objects, as well as to delineate already developed oil and gas-bearing formations;

extractive (exploitation) intended for the extraction of oil and gas from the earth subsoil. This category also includes injection, appraisal, observation and parametric wells;

injection, designed for pumping water, gas or steam into formations in order to maintain reservoir pressure or treat the bottom-hole zone. These measures are aimed at extending the period of the fountain method oil production or improving production efficiency;

advancing the extractive ones, serving for oil production and gas with simultaneous clarification of the structure of the productive formation;

assessment, 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 observational, designed to monitor the development object, study the nature of the movement of formation fluids and changes in the gas and oil saturation of the formation;

reference 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 deposits in these rocks black gold and gas.

Drilling is

Well construction cycle

The well construction cycle includes:

preparatory work;

installation of tower and equipment;

preparation for drilling;

Drilling process;

fastening the well with casing pipes and its plugging;

formation drilling and inflow testing black gold and gas.

During the preparatory work, a site for the drilling rig is selected, an access road is laid, and power supply, water supply and communications systems are installed. If the terrain is uneven, then plan a site.

Offshore well drilling

Currently, the share of black gold extracted from offshore deposits accounts for about 30% of all world production, and gas - even more. How do people get to this wealth?

The simplest solution is to drive piles into shallow water, install a platform on them, and place a drilling rig and the necessary equipment on it.

Another way is to “extend” the shore by filling the shallow water with soil. Thus, in 1926, the Bibi-Heybat Bay in the Baku region was filled up and an oil field was created in its place.

After large deposits of black gold and gas were discovered in the North Sea more than half a century ago, a bold project to drain it was born. The fact is that the average depth of most of the North Sea barely exceeds 70 m, and some parts of the bottom are covered with only a forty-meter layer of water. Therefore, the authors of the project considered it advisable, with the help of two dams - across the English Channel in the Dover area, and also between Denmark and Scotland (more than 700 km long) - to cut off a huge section of the North Sea and pump out water from there. Fortunately, this project remained only on paper.

In 1949, the first offshore oil production rig in the USSR was drilled in the Caspian Sea, 40 km from the coast. Thus began the creation of a city on steel piles, called “Oil Rocks”. However, the construction of overpasses extending many kilometers from the coast is very expensive. In addition, their construction is possible only in shallow waters.

When drilling oil and gas wells in deep seas and oceans, using stationary platforms is technically difficult and economically unprofitable. For this case, floating drilling rigs have been created that can independently or with the help of tugs change drilling areas.

There are jack-up drilling platforms, semi-submersible drilling platforms and gravity-type drilling platforms.


Investor Encyclopedia. 2013 .

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