Helpful information. Oil well drilling process Well construction cycle

Drilling is the impact of special equipment on soil layers, as a result of which a well is formed in the ground through which valuable resources will be extracted. The process of drilling oil wells is carried out in different directions of work, which depend on the location of the soil or rock formation: it can be horizontal, vertical or inclined.

As a result of the work, a cylindrical void in the form of a straight trunk, or well, is formed in the ground. Its diameter may vary depending on the purpose, but it is always less than the length parameter. The beginning of the well is located on the soil surface. The walls are called the trunk, and the bottom of the well is called the bottom.

Key milestones

If medium and light equipment can be used for water wells, then only heavy equipment can be used for drilling an oil well. The drilling process can only be carried out using special equipment.

The process itself is divided into the following stages:

• Delivery of equipment to the site where the work will be carried out.
• The actual drilling of the mine. The process includes several works, one of which is deepening the shaft, which occurs through regular washing and further destruction of the rock.
• To prevent the wellbore from being destroyed and clogging it, the rock layers are strengthened. For this purpose, a special column of interconnected pipes is laid into the space. The space between the pipe and the rock is fixed with cement mortar: this work is called plugging.
• The last job is mastery. The last layer of rock is opened there, a bottom-hole zone is formed, and the mine is perforated and fluid is drained.

Site preparation

To organize the process of drilling an oil well, it will also be necessary to carry out a preparatory stage. If development is carried out in a forest area, it is required, in addition to completing basic documentation, to obtain consent for the work from the forestry enterprise. Preparation of the site itself includes the following steps:

1. Cutting down trees on the site.
2. Dividing the zone into separate parts of the land.
3. Drawing up a work plan.
4. Creation of a settlement to house the workforce.
5. Preparing the foundation for a drilling station.
6. Carrying out markings at the work site.
7. Creation of foundations for the installation of tanks in a warehouse with flammable materials.
8. Arrangement of warehouses, delivery and debugging of equipment.

After this, it is necessary to begin preparing the equipment directly for drilling oil wells. This stage includes the following processes:

• Installation and testing of equipment.
• Wiring lines for power supply.
• Installation of bases and auxiliary elements for the tower.
• Installing the tower and raising it to the desired height.
• Debugging of all equipment.

When the equipment for drilling oil wells is ready for operation, it is necessary to obtain a conclusion from a special commission that the equipment is in good condition and ready for work, and the personnel have sufficient knowledge of safety rules for this kind of production. When checking, it is clarified whether the lighting devices have the correct design (they must have an explosion-resistant casing), and whether lighting with a voltage of 12V is installed along the depth of the shaft. Remarks regarding performance and safety must be taken into account in advance.

Before starting work on drilling a well, it is necessary to install a pit, bring in pipes to strengthen the drill shaft, a bit, small special equipment for auxiliary work, casing pipes, instruments for measurements during drilling, provide water supply and resolve other issues.

The drilling site contains accommodation facilities for workers, technical premises, a laboratory building for analyzing soil samples and the results obtained, warehouses for equipment and small working tools, as well as medical care and safety equipment.

Features of drilling an oil well

After installation, the processes of re-equipping the traveling system begin: during this work, equipment is installed, and small mechanical means are tested. Installing the mast opens the process of drilling into the soil; the direction should not diverge from the axial center of the tower.

After the alignment is completed, a well is created according to the direction: this process means installing a pipe to strengthen the trunk and filling the initial part with cement. After setting the direction, the alignment between the tower itself and the rotor axes is adjusted again.

Drilling for a pit is carried out in the center of the trunk, and during the work, casing is done using pipes. When drilling a hole, a turbo drill is used; to adjust the rotation speed, it is necessary to hold it with a rope, which is fixed on the tower itself, and physically held by the other part.

A couple of days before the launch of the drilling rig, when the preparatory stage has passed, a conference is held with the participation of members of the administration: technologists, geologists, engineers, drillers. Issues discussed at the conference include the following:

• Layout of strata in an oil field: a layer of clay, a layer of sandstone with water carriers, a layer of oil deposits.
• Design features of the well.
• Rock composition at the research and development point.
• Taking into account possible difficulties and complicating factors that may arise when drilling an oil well in a particular case.
• Review and analysis of the standard map.
• Consideration of issues related to trouble-free wiring.

Documents and equipment: basic requirements

The process of drilling an oil well can begin only after a number of documents have been completed. These include the following:

• Permission to start operating the drilling site.
• Map of standards.
• Journal on drilling fluids.
• Journal on ensuring labor safety at work.
• Accounting for the functioning of diesel engines.
• Shift log.

To the main mechanical equipment and consumables that are used in the process of drilling a well, The following types include:

• Equipment for cementing, the cement mortar itself.
• Safety equipment.
• Logging mechanisms.
• Process water.
• Reagents for various purposes.
• Water for drinking.
• Pipes for casing and actual drilling.
• Helicopter pad.

Well types

In the process of drilling an oil well, a shaft is formed in the rock, which is checked for the presence of oil or gas by perforating the shaft, which stimulates the influx of the desired substance from the productive area. After this, the drilling equipment is dismantled, the well is sealed indicating the start and end dates of drilling, and then the garbage is removed and the metal parts are disposed of.

At the beginning of the process, the trunk diameter is up to 90 cm, and by the end it rarely reaches 16.5 cm. During the work, the construction of a well is done in several stages:

1. Deepening the bottom of a well, for which drilling equipment is used: it crushes the rock.
2. Removing debris from the mine.
3. Secure the trunk with pipes and cement.
4. Work during which the resulting fault is examined and productive locations of oil are identified.
5. Descent of depth and its cementing.

Wells can vary in depth and are divided into the following types:

• Small (up to 1500 meters).
• Medium (up to 4500 meters).
• Deep (up to 6000 meters).
• Ultra-deep (more than 6000 meters).

Drilling a well involves crushing a solid rock formation with a chisel. The resulting parts are removed by washing with a special solution; The depth of the mine becomes greater when the entire face area is destroyed.

Problems during oil drilling

While drilling wells, you may encounter a number of technical problems that will slow down or make work almost impossible. These include the following phenomena:

• Destruction of the trunk, collapses.
• Discharge of liquid into the soil for flushing (removing parts of rock).
• Emergency conditions of equipment or mine.
• Errors in drilling the barrel.

Most often, wall collapses occur due to the fact that the rock has an unstable structure. A sign of a collapse is increased pressure, greater viscosity of the fluid used for flushing, as well as an increased number of pieces of rock that come to the surface.

Liquid absorption most often occurs when the underlying formation completely absorbs the solution. Its porous system or high degree of absorbency contributes to this phenomenon.

During the process of drilling a well, the projectile, which moves clockwise, reaches the bottom and rises back. The drilling of the well reaches the bedrock formations, into which cutting up to 1.5 meters occurs. To prevent the well from being washed out, a pipe is immersed at the beginning, which also serves as a means of carrying the flushing solution directly into the trench.

The drill bit, as well as the spindle, can rotate at different speeds and frequencies; this indicator depends on what types of rocks need to be punched and what diameter of the crown will be formed. The speed is controlled by a regulator, which regulates the level of load on the bit used for drilling. During the work, the necessary pressure is created, which is exerted on the walls of the face and the cutters of the projectile itself.

Well drilling design

Before starting the process of creating an oil well, a project is drawn up in the form of a drawing, which outlines the following aspects:

• Properties of the discovered rocks (resistance to destruction, hardness, degree of water content).
• The depth of the well, its angle of inclination.
• The diameter of the shaft at the end: this is important to determine the extent to which it is affected by the hardness of the rock.
• Well drilling method.

Designing an oil well must begin with determining the depth, the final diameter of the shaft itself, as well as the level of drilling and design features. Geological analysis allows us to resolve these issues, regardless of the type of well.

Drilling methods

The process of creating a well for oil production can be carried out in several ways:

• Shock-rope method.
• Work using rotary mechanisms.
• Drilling a well using a downhole motor.
• Turbine type drilling.
• Drilling a well using a screw motor.
• Drilling a well using an electric drill.

The first method is one of the most well-known and proven methods, and in this case the shaft is pierced with chisel blows, which are carried out at certain intervals. The blows are made through the influence of the weight of the chisel and the weighted rod. The lifting of the equipment occurs due to the balancer of the drilling equipment.

Working with rotary equipment is based on the rotation of the mechanism using a rotor, which is placed at the wellhead through drilling pipes that perform the function of a shaft. Drilling small wells is done through the participation of a spindle motor in the process. The rotary drive is connected to a cardan and a winch: this device allows you to control the speed at which the shafts rotate.

Drilling with a turbine is carried out by transmitting rotating torque to the column from a motor. The same method allows you to transfer hydraulic energy. With this method, only one energy supply channel operates at the level before the face.

A turbo drill is a special mechanism that converts hydraulic energy in solution pressure into mechanical energy, which ensures rotation.

The process of drilling an oil well consists of lowering and lifting the column into the shaft, as well as holding it suspended. A column is a prefabricated structure made of pipes that are connected to each other using special locks. The main task is to transfer different types of energy to the bit. In this way, movement is carried out, leading to the deepening and development of the well.

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 .

Drilling is the procedure of breaking rocks using special drilling equipment. Drilling, like many other technologies, has several directions.

The drilling process involves breaking up rocks using drilling equipment, resulting in a well.

These directions depend on the position of the rock formation:

• vertical;
• oblique directional;
• horizontal.

The process of laying a directed cylindrical shaft in the ground is called drilling. Subsequently, this channel is called a well. Its diameter should be less than its length. The wellhead (beginning) is located on the surface. The bottom and walls of the well are called the bottom and the wellbore, respectively.

Preparation for the process

When drilling wells, first:

The drilling process is impossible without special drilling equipment.

1. Drilling equipment is brought to the drilling site.
2. Then the drilling process begins. It consists of deepening the wellbore by flushing it and drilling.
3. In order to avoid the collapse of the walls of wells, separation of layers is carried out - work to strengthen the layers of the earth. To do this, pipes are lowered into the drilled ground and laid, which are connected into columns. Then the entire space between the pipes and the ground is cemented (packed).
4. The last stage of work is called well development. It includes opening the last layer, installing the near-wellbore zone, as well as perforation and inducing outflow.

In order to start drilling again, it is necessary to carry out preparatory work.

First, documents are drawn up allowing the felling and clearing of the forest, but for this you need to obtain the consent of the forestry department. When preparing a site for drilling, the following work is carried out:

Before you start drilling wells, you need to clear the area of ​​trees.

• division of zones into sections according to coordinates;
• cutting down trees;
• layout;
• construction of a workers' settlement;
• preparing the base for the drilling rig;
• preparation and marking of the site;
• installation of foundations for tanks at a fuel and lubricants warehouse;
• arrangement of warehouse enclosure, preparation of equipment.

The next stage of work is the preparation of tower installation equipment. For this:

• install equipment;
• installation of lines;
• installation of substructures, foundations and blocks;
• installation and lifting of the tower;
• commissioning works.

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Preliminary work

After the drilling machine is installed, a special commission arrives to check the equipment, technology and quality of work.

When the drilling rig is ready, pre-drilling work begins. As soon as the drilling machine is installed and the construction of the structures is completed, the drilling rig is inspected by a special commission. The foreman of the drilling team, accepting the commission, together with it monitors the quality of work, checks the equipment and compliance with labor protection.

For example, according to the method of execution, lamps must be in an explosion-proof casing; emergency lighting at 12 V must be distributed throughout the mine. All comments made by the commission must be taken into account before the start of drilling work.

Before drilling begins, the equipment is equipped with the appropriate equipment: a square hole, drill pipes, a bit, small-scale mechanization devices, casing pipes for the conductor, instrumentation, water, etc.

The drilling rig should have houses for living, a gazebo, a dining room, a bathhouse for drying things, a laboratory for analyzing solutions, equipment for extinguishing fires, auxiliary and working tools, safety posters, first aid kits and medicines, storage for drilling equipment, and water.

After the drilling rig has been installed, a series of work begins on re-equipping the traveling system, during which equipment is installed and small-scale mechanization equipment is tested. Drilling technology begins with the installation of a mast. Its direction must be set exactly in the center of the tower axis.

After centering the tower, drilling is carried out according to the direction. This is lowering the pipe to strengthen the wells and filling its upper end, which should coincide in direction with the gutter, with cement. After the direction in the process of drilling wells has been established, the alignment between the axes of the rotor and the tower is checked again.

In the center of the well, a square hole is drilled and lined with a pipe in the process. Drilling the well hole is carried out with a turbo drill, which is held by a hemp rope to prevent too rapid rotation. One end of it is attached to the leg of the tower, and the other is held in the hands through a block.

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Completion

After the preparatory work, 2 days before the launch of the drilling rig, a conference is organized where the entire administration (chief engineer, technologist, chief geologist, etc.) participates. The conference discusses:

Scheme of the structure of geological rocks at the site of oil discovery: 1 – clays, 2 – water-saturated sandstones, 3 – oil deposit.

• well structure;
• rock structure at the location of the geological section;
• complications that may arise during the drilling process, etc.;
• then consider the regulatory map;
• work on trouble-free and high-speed wiring is discussed.

The drilling process can begin upon completion of the following documents:

• geological and technical work;
• permission to put the drilling rig into operation;
• regulatory map;
• logbook;
• journal on drilling fluids;
• occupational safety journal;
• accounting for diesel engines.

The following types of mechanisms and materials can be used at the drilling rig:

• cementing equipment;
• posters with messages about safety and labor protection;
• logging equipment;
• drinking water and technical;
• Helipad;
• cement mortars and drilling mortars;
• chemical reagents;
• casing pipes and drilling pipes.

Well drilling is a method of cutting down rock to form a mine. Such mines (wells) are tested for the presence of oil and gas. To do this, the wellbore is perforated to provoke an influx of oil or gas from the productive horizon. Then the drilling equipment and all derricks are dismantled. A seal is installed on the well indicating the name and date of drilling. After this, the garbage is destroyed, all barns are buried, and the scrap metal is disposed of.

Typically, at first the maximum diameter of the wells does not exceed 900 mm. At the end it rarely reaches 165 mm. The drilling process consists of several processes during which the wellbore is constructed:

• the process of deepening the bottom of wells by painting rocks with a drilling tool;
• removal of broken rock from their well shaft;
• well bore fastening;
• carrying out geological and geophysical work to study fault rocks and discover productive horizons;
• lowering and cementing depth.

Depending on the depth of the well, there are the following types:

• shallow – 1500 m deep;
• medium – depth up to 4500 m;
• deep – 6000 m;
• ultra-deep – over 6000 m.

The drilling process is the breaking of rocks with drill bits. The broken parts of this rock are cleaned out with a stream of washing (liquid) solution. The depth of the wells increases as the face is destroyed over the entire area.

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Complications that arise

The collapse of the well walls can occur due to the unstable structure of the rock.

During the process of drilling a well, some complications may arise. It can be:

• mine wall collapses;
• absorption of washing liquid;
• accidents;
• inaccurate borehole drilling, etc.

Landslides can occur due to the unstable structure of the rock. Their sign can be:

• high blood pressure;
• the viscosity of the flushing fluid is too strong;
• too much debris when washing the mine.

Absorption of the washing solution occurs due to the fact that the solution poured into the shaft is completely sucked into the formation. This usually happens when the formations have a porous structure or high permeability.

Drilling is a process in which a rotating projectile is brought to the bottom and then raised again. In this case, the wells are drilled to the bedrock, cutting 0.5-1.5 m. After this, a pipe is lowered into the mouth to prevent erosion and so that the flushing liquid, leaving the well, falls into the trench.

The rotational speed of the drill bit and spindle depends on the physical properties of the rocks, the diameter and type of the drill bit. The rotation speed is controlled by a feed regulator, which creates the desired load on the bit. At the same time, it creates a certain pressure on the projectile cutters and the walls of the face.

Before you start drilling a well, you need to draw up its design drawing, which indicates:

• physical properties of rocks: their hardness, stability and water saturation;
• well depth and inclination;
• final well diameter, which is affected by rock hardness;
• drilling methods.

Drawing up a well design begins with choosing its depth, diameter at the end of drilling, drilling angles, and structure.

The depth of mapping wells depends on geological analysis followed by its mapping.

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 the 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 route.

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.

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

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