Methods of oil and gas production presentation. Development of oil and gas fields

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Oil

Oil is a natural oily flammable liquid consisting of a complex mixture of hydrocarbons and some other organic compounds. The color of oil is red-brown, sometimes almost black, although sometimes slightly yellow-green and even colorless oil is found; has a specific odor and is common in sedimentary rocks of the Earth. Today, oil is one of the most important minerals for humanity.

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Chemical composition

In terms of chemical composition and origin, oil is close to natural combustible gases, ozokerite, and asphalt. These fossils are collectively called petrolites. Petrolites belong to an even larger group of so-called caustobiolites - combustible minerals of biogenic origin, which also include fossil solid fuels.

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Oil formation

Oil formation is a staged, very long (usually 50-350 million years) process that begins in living matter. A number of stages are distinguished: Sedimentation - during which the remains of living organisms fall to the bottom of water basins; Biochemical; protocatagenesis; mesocatagenesis or the main phase of oil formation (PHP) is the lowering of a layer of organic residues to a depth of 3-4 km, with a temperature rise of up to 150 °C. In this case, organic substances undergo thermocatalytic destruction, resulting in the formation of bituminous substances that make up the bulk of micro-oil. Next, the oil is distilled off due to the pressure drop and the emigration of micro-oil into sandy reservoir layers, and through them into traps; apocatagenesis of kerogen or main phase of gas formation (MFG); I.M. Gubkin also identified the stage of destruction of oil fields.

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Oil refining

Physico-chemical purification is carried out using solvents that selectively remove undesirable components from the product being purified. During adsorption purification, unsaturated hydrocarbons, resins, acids, etc. are removed from petroleum products. Adsorption purification is carried out by contacting heated air with adsorbents or filtering the product through adsorbent grains. Catalytic purification is hydrogenation under mild conditions, used to remove sulfur and nitrogen compounds.

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Distillation and application

Due to the rapid development of the chemical and petrochemical industries in the world, the need for oil is increasing not only to increase the production of fuels and oils, but also as a source of valuable raw materials for the production of synthetic rubbers and fibers, plastics, surfactants, detergents, plasticizers, additives, dyes, etc. (more than 8% of world production). Among the starting materials obtained from oil for these industries, the most widely used are: paraffin hydrocarbons - methane, ethane, propane, butanes, pentanes, hexanes, as well as high molecular weight (10-20 carbon atoms per molecule); naphthenic; aromatic hydrocarbons - benzene, toluene, xylenes, ethylbenzene; olefin and diolefin - ethylene, propylene, butadiene; acetylene. Oil is unique precisely because of its combination of qualities: high energy density (thirty percent higher than that of the highest quality coals), oil is easy to transport (compared to gas or coal, for example), and finally, it is easy to obtain a lot of the above-mentioned products from oil. The depletion of oil resources, rising prices and other reasons have led to an intensive search for substitutes for liquid fuels.

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Natural gas

Natural gas is a mixture of gases formed in the bowels of the earth during the anaerobic decomposition of organic substances. Natural gas is a mineral resource. Natural gas in reservoir conditions (conditions of occurrence in the bowels of the earth) is in a gaseous state - in the form of separate accumulations (gas deposits) or in the form of a gas cap of oil and gas fields, or in a dissolved state in oil or water. Under standard conditions (101.325 kPa and 20 °C), natural gas is only in the gaseous state. Natural gas can also be in a crystalline state in the form of natural gas hydrates.

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Chemical composition

The main part of natural gas is methane (CH4) - from 92 to 98%. Natural gas may also contain heavier hydrocarbons - homologues of methane: ethane (C2H6), propane (C3H8), butane (C4H10). as well as other non-hydrocarbon substances: hydrogen (H2), hydrogen sulfide (H2S), carbon dioxide (CO2), nitrogen (N2), helium (He).

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In science, it has long been believed that accumulations of hydrocarbons with a molecular weight of more than 60 exist in the earth’s crust in a liquid state, and lighter ones in a gaseous state. However, Russian scientists have discovered the property of natural gas, under certain thermodynamic conditions, to transform into a solid state in the earth’s crust and form gas hydrate deposits. This phenomenon was recognized as a scientific discovery and entered into the State Register of Discoveries of the USSR under No. 75 with priority from 1961. The gas turns into a solid state in the earth's crust, combining with formation water at hydrostatic pressures (up to 250 atm) and relatively low temperatures (up to 295°K). Gas hydrate deposits have an incomparably higher concentration of gas per unit volume of porous medium than in conventional gas fields, since one volume of water, when it passes into the hydrate state, binds up to 220 volumes of gas. The zones where gas hydrate deposits are located are concentrated mainly in areas of permafrost, as well as under the bottom of the World Ocean.

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Application

Natural gas is widely used as a fuel in residential, private and apartment buildings for heating, water heating and cooking; as fuel for cars (gas fuel system of a car), boiler houses, thermal power plants, etc. Now it is used in the chemical industry as a feedstock for the production of various organic substances, for example, plastics. In the 19th century, natural gas was used in the first traffic lights and for lighting (gas lamps were used)

Development of mineral deposits is a system of organizational and technical measures for the extraction of minerals from the subsoil. The system of development of oil fields and deposits is understood as a form of organizing the movement of oil in layers to production wells. The oil field development system is determined by: - ​​the procedure for putting operational facilities of a multi-layer field into development; - well placement grids at sites, the pace and order of their commissioning; - ways to regulate the balance and use of reservoir energy.

Well placement grid Well grid is the nature of the relative arrangement of production and injection wells at an operational facility, indicating the distances between them (grid density). Wells are located on a uniform grid and an uneven grid (mainly in rows). Meshes are shaped like square, triangular and polygonal. Well pattern density refers to the ratio of oil-bearing area to the number of producing wells. The mesh density is determined taking into account specific conditions. Since the late 50s, the fields have been exploited with a grid density of (30÷60)・104 m2/well.

Stages of field development A stage is a period of the development process, characterized by a certain natural change in technological and technical and economic indicators. Typical dynamics of the rate of oil production Tdn, liquid Tj and water cut of products n in under water pressure mode, highlighting development stages

The first stage is the development of an operational facility with an intensive increase in oil production to the maximum specified level (the increase is approximately 1 ¸ 2% per year of balance reserves); rapid increase in the existing well stock to 0.6 ¸ 0.8 from the maximum; a sharp decrease in reservoir pressure; low water cut of products n in (water cut of products reaches 3 ¸ 4% with an oil viscosity of no more than 5 m. Pa ・s and 35% with increased viscosity); achieved current oil recovery factor Kn (about 10%). The duration of the stage depends on the industrial value of the deposit and is 4 ¸ 5 years; the end of the stage is taken to be the point of sharp inflection of the oil production rate curve Tdn (the ratio of the average annual oil production to its balance reserves).

The second stage is maintaining a high level of oil production with a more or less stable high level of oil production (the maximum rate of oil production is within 3 ¸ 17%) for 3 ¸ 7 years or more for fields with low-viscosity oils and 1 ¸ 2 years for fields with high viscosity oils. viscosity; an increase in the number of wells, as a rule, to a maximum due to the reserve fund; an increase in the water cut of the product nв (the annual increase in water cut is 2 ¸ 3% with low oil viscosity and 7% or more with high viscosity; at the end of the stage the water cut ranges from several to 65%); shutting down a small number of wells due to watering and transferring many to mechanized oil production; the current oil recovery factor Kn, amounting to 30 ¸ 50% by the end of the stage.

The third stage is a significant decrease in oil production by a decrease in oil production (on average by 10-20% per year for low-viscosity oils and by 3-10% for high-viscosity oils); oil withdrawal rate at the end of stage 1¸ 2.5%; a decrease in the well stock due to shutdown due to production watering, and the transfer of almost the entire well stock to the mechanized production method; progressive water cut of products nв up to 80-85% with an average increase in water cut of 7-8% per year, and with greater intensity for fields with high-viscosity oils; increasing the current oil recovery factors Kn at the end of the stage to 50 ¸ 60% for fields with an oil viscosity of no more than 5 m Pa・s and up to 20 ¸ 30% for fields with oils of high viscosity; total liquid withdrawal of 0.5 - 0¸ 9 volumes from balance oil reserves. This stage is the most difficult and complex for the entire development process; its main task is to slow down the rate of decline in oil production. The duration of the stage depends on the duration of the previous stages and ranges from 5 to 10 years or more.

The fourth stage is the final stage with low, slowly decreasing rates of oil withdrawal Tdn (on average about 1%); high rates of liquid withdrawal Tj (water-oil factors reach 0.7 - 7 m3/m3); high, slowly increasing water cut of products (annual growth is about 1%); a sharper than at the third stage decrease in the operating well stock due to watering (the well stock is approximately 0.4 ¸ 0.7 of the maximum, sometimes decreasing to 0.1); selection during the stage of 10 ¸ 20% of balance oil reserves. The duration of the fourth stage is comparable to the duration of the entire previous period of deposit development, amounts to 15–20 years or more, and is determined by the limit of economic profitability, i.e., the minimum flow rate at which the operation of wells is still profitable. The profitability limit usually occurs when the product water cut is approximately 98%.

Type of energy used Depending on the type of energy used to move oil, there are: - systems for developing oil deposits under natural conditions, when only natural reservoir energy is used (i.e. development systems without maintaining reservoir pressure); -development systems with the maintenance of reservoir pressure, when methods are used to regulate the balance of reservoir energy by artificially replenishing it.

Placement of production and injection wells in the field During contour flooding, water is pumped into the formation through injection wells located outside the external oil-bearing contour along the perimeter of the deposit at a distance of 100-1000 m. Production wells are located inside the oil-bearing contour in rows parallel to the contour. The total volume of liquid withdrawn is equal to the amount of water injected into the reservoir. It is used at sites with productive formations that are thinly divided in thickness, have relatively high hydraulic conductivity, and with a small width of deposits (up to 4-5 km, and with the most favorable strata structure, even more)

Placement of production and injection wells in the field In large fields, intra-circuit flooding is used - cutting injection rows into separate production blocks. For 1 ton of extracted oil, it is necessary to inject 1.6 - 2 m3 of water. They are mainly used at sites with large oil-bearing areas (hundreds of square kilometers or more).

Placement of production and injection wells in the field Area waterflooding is used as a secondary method of oil production when developing oil deposits in non-pressure modes, when reservoir energy reserves are largely consumed and there is a significant amount of oil in the subsurface. Water is pumped into the reservoir through a system of injection wells located evenly throughout the reservoir. Normal water consumption is 10 - 15 m 3 per 1 ton of oil.

Development systems with gas injection into the reservoir can be used in two main options: gas injection into elevated parts of the reservoir (into the gas cap), area gas injection. Successful gas injection is possible only at significant inclination angles of homogeneous formations (gravitational separation of gas and oil is improved), low reservoir pressure (injection pressure is usually 15-20% higher than reservoir pressure), proximity of reservoir pressure and saturation pressure of oil with gas, or the presence of a natural gas cap , low viscosity oil. In terms of economic efficiency, the development system with gas injection into the reservoir is significantly inferior to waterflooding, and therefore has limited application.

Methods of operating wells in Russia All known methods of operating wells are divided into the following groups: 1) flowing, when oil is extracted from wells by self-flow; 2) compressor (gas lift) - using the energy of compressed gas introduced into the well from the outside; 3) pumping - oil extraction using various types of pumps. The choice of method for operating oil wells depends on the magnitude of reservoir pressure and the depth of the formation.

Flowing operation of oil wells The process of raising a gas-liquid mixture to the surface can occur: both due to the natural energy Wп of liquid and gas arriving at the bottom of the well, and due to the energy Wу introduced into the well from the surface. Energy balance equation: W 1 + W 2 + W 3 = Wп + Wи, W 1 – energy for lifting liquid and gas from the bottom to the wellhead; W 2 – energy consumed by the gas-liquid mixture when moving through wellhead equipment; W 3 – energy carried away by a stream of liquid and gas beyond the wellhead; if Wi = 0, then the operation is called fountain; when Wi > 0, operation is called mechanized oil production.

Src="http://present5.com/presentation/62225307_92047586/image-16.jpg" alt=" FLOWING CONDITION PPL > Ρ × G × H. In most cases, together"> УСЛОВИЕ ФОНТАНИРОВАНИЯ PПЛ > Ρ × G × H. В большинстве случаев вместе с нефтью в пласте находится газ, и он играет главную роль в фонтанировании скважин. Пластовый газ делает двойную работу: в пласте выталкивает нефть, а в трубах поднимает. РОЛЬ ФОНТАННЫХ ТРУБ Смесь нефти и газа, движущаяся в скважине, представляет собой чередование прослоев нефти с прослоями газа: чем больше диаметр подъемных труб, тем больше надо газа для подъема нефти. Поэтому перед освоением скважины оборудуют лифтовыми трубами условным диаметром от 60 до 114 мм, по которым происходит движение жидкости и газа в скважине.!}

Development and commissioning of flowing wells Development and commissioning of flowing wells is carried out by reducing the pressure on the formation by: 1) sequentially replacing the clay solution in the well with a liquid and a gas-liquid mixture of lower density (clay solution → water → oil); 2) the use of nitrogen or inert gas (by displacing part of the liquid from the well, by aerating it); 3) swabbing.

Christmas tree fittings 1 - column head; 2 - pipe head; 3 - fountain tree; 4 adjustable fitting; 5 pneumatic controlled valve. a set of devices mounted at the mouth of a flowing well to seal it, suspend lift columns and control the flow of well production. The Christmas tree must - withstand high pressure, - make it possible to measure pressure both in the lift pipes and at the outlet of the well, - allow the release or injection of gas during well development. F. a. includes column and pipe heads, fountain tree and manifold.

Column head located at the bottom. parts of F. a. , serves to suspend casing strings, seal interpipe spaces and control the pressure in them. The pipe head is mounted on the column head and is used to suspend and seal elevator columns with concentricity. or parallel descent into the well. The fountain tree is installed on the pipe head and serves to distribute and regulate the flow of products from the well. It consists of shut-off valves (valves, ball or conical valves), control devices (fittings of constant or variable cross-section) and fittings (coils, tees, crosses, covers). Manifold binds F. a. with pipelines. Elements of F. a. connected by flanges or clamps. For sealing internal cavities use elastic cuffs, external connections - rigid rings (steel). The drive of the locking devices is manual, at high pressure pneumatic or hydraulic with local, remote or automatic. management. When the well production pressure deviates from the specified limits or in the event of a fire at the well, shut-off devices are automatically closed. The pressure in all cavities is controlled by pressure gauges. . For lowering instruments and other equipment into a working well at F. a. install a lubricator - a pipe with a gland device for a rope or cable, in which the equipment lowered into the well is located. Working pressure F. a. 7 -105 MPa, center flow area. locking device 50 -150 mm. F. a. wells of offshore deposits with underwater mouths have special designs for remote assembly and management.

Gas-lift operation of oil wells During gas-lift operation, the missing amount of gas to lift the liquid is pumped into the well from the surface. If the incoming reservoir energy, characterized by the gas factor, is supplemented with the energy of gas pumped into the well from the surface, artificial flowing occurs, which is called gas lift, and the operating method is gas lift (compressor). The scope of gas lift is high-yield wells with high bottomhole pressures, - wells with high gas factors and bottomhole pressures below saturation pressure, - sand wells (containing sand in the product) wells, as well as wells operated in hard-to-reach conditions (for example, flooding, floods, swamps, etc.).

Gas lift (air lift) is a system consisting of a production (casing) pipe string and tubing lowered into it, in which the liquid is lifted using compressed gas (air). This system is sometimes called a gas (air) lift. The method of operating wells is called gas lift. According to the supply scheme, depending on the type of source of the working agent - gas (air), they distinguish: - compressor and non-compressor gas lift, and according to the operating scheme - continuous and periodic gas lift.

The principle of gas lift operation: High-pressure gas is injected into the annulus, as a result of which the liquid level in it will decrease and in the tubing will increase. When the liquid level drops to the lower end of the tubing, compressed gas will begin to flow into the tubing and mix with the liquid. As a result, the density of such a gas-liquid mixture becomes lower than the density of the liquid coming from the formation, and the level in the tubing will increase. The more gas is introduced, the lower the density of the mixture will be and the higher the height it will rise. With the continuous supply of gas into the well, the liquid (mixture) rises to the mouth and pours out to the surface, and a new portion of liquid constantly enters the well from the formation. Depending on the number of rows of pipes being lowered, lifts can be single- or double-row. In the direction of gas injection - annular and

The flow rate of a gas lift well depends on the amount and pressure of gas injection, the depth of tubing immersion in the liquid, their diameter, liquid viscosity, etc. a) single-row lift of a ring system b) single-row lift of a central system. c) double-row lift of the ring system. d) two-row central system. e) one and a half row lift.

Advantages of the gas lift method: · simplicity of design (there are no pumps in the well); · location of technological equipment on the surface (facilitates its observation and repair), ensuring the possibility of withdrawing large volumes of liquid from wells (up to 1800 ÷ 1900 t/day); · the ability to operate oil wells with heavy watering and high sand content, ease of regulation of well flow rate. Disadvantages of the gas lift method: high capital costs; low efficiency; increased consumption of tubing, especially the use of double-row lifts; a rapid increase in energy consumption to lift 1 ton of oil as well production decreases over time of operation. Ultimately, the cost of producing 1 ton of oil using the gas-lift method is lower due to low operating costs, so it is promising.

Topic 1.5. Oil and gas development and production

Operating modes of deposits

Hard pressure mode

Elastic-water pressure regime

Gas pressure mode

Dissolved gas mode

Gravity mode

Methods for increasing oil recovery and well productivity.

Methods for maintaining reservoir pressure

Edge flooding method

In-circuit flooding method

Method of injecting gas into the gas cap of an oil reservoir

Methods that increase the permeability of the formation and bottomhole zone

Mechanical methods that increase the permeability of the formation and bottomhole zone

Chemical methods that increase the permeability of the formation and bottomhole zone

Physical methods that increase the permeability of the formation and near-wellbore zone

Methods for enhancing oil recovery and gas recovery of formations

Operation of oil and gas wells Methods of well operation

Collection and preparation of oil and gas for transport.

Oil production

Oil production is a branch of the economy engaged in the extraction of natural minerals - oil. Oil production is a complex production process that includes geological exploration, drilling wells and their repair, purification of extracted oil from water, sulfur, paraffin and much more.

Russia has one of the world's largest potential fuel and energy resources. About 13% of the world's proven oil reserves are concentrated on 13% of the Earth's territory, in a country where less than 3% of the world's population lives. Since Russia is rich in oil reserves, there are certain mechanisms for oil production, refining and transportation.

Methods of oil production: fountain (fluid is released due to pressure difference). gas lift installation of an electric centrifugal pump (ECP). EVN installation of an electric screw pump (ESVN) SRP (rod pumps). other.

Flowing method of oil production: Flowing production of wells, as noted above, is one of the most effective methods of oil production, especially in new areas.

Advantages of flowing oil production: - simplicity of well equipment; -lack of energy supply to the well from the surface; - the ability to regulate the operating mode of the well within a wide range; -convenience of performing well and reservoir studies using almost all modern methods; -possibility of remote control of the well; - significant duration of the well's overhaul period (MRP), etc. Diagram of an oil gusher: 1 - packer (oil seal); 2 - fountain fittings; 3 - pipeline for oil outflow to storage; 4 - surface casing (conductor); 5 - cement; 6 - intermediate (technical) casing; 7 - production casing; 8 - pump-compressor string; 9 - extractable fluid.

Gas-lift oil production: With the gas-lift method of operation, the missing energy is supplied from the surface in the form of compressed gas energy through a special channel. Gas lift is divided into two types: compressor and non-compressor. With compressor gas lift, compressors are used to compress associated gas, and with non-compressor gas lift, gas from a gas field under pressure or from other sources is used.

Advantages of gas-lift oil production: simplicity of well equipment and ease of maintenance; -efficient operation of wells with large borehole deviations; -operation of wells in high-temperature formations and with a high gas factor without complications; - the ability to carry out the entire range of research work to monitor the operation of the well and field development; -full automation and telemechanization of oil production processes; -long between-repair periods of well operation against the backdrop of high reliability of the equipment and the entire system as a whole; - the possibility of simultaneously and separately exploiting two or more layers with reliable control over the process; - ease of combating the deposition of paraffin, salts and corrosion processes; - simplicity of work on underground maintenance of a well, restoring the functionality of underground equipment for lifting well production. The nature of gas lift oil production: Gas lift scheme

ESP (Electric centrifugal pump) is the most widely used apparatus for mechanized oil production in Russia. ESP - centrifugal, submersible pump. The need to operate an ESP in a well imposes restrictions on the diameter of the pump. Most of the centrifugal pumps used for oil production do not exceed 103 mm (5A pump size). At the same time, the length of the ESP assembly can reach 50 m. The main parameters that determine the operating characteristics of the pump are: nominal flow rate or productivity (m3/day) developed pressure at the nominal flow rate (m) pump rotation speed (rpm)

Deep (well) rod pumps (DSP) are the most common type of pumps designed for lifting liquid from oil wells. Design features The pumps consist of a solid fixed cylinder with extensions, a movable plunger, discharge and suction valves and a lock. The extensions are screwed onto the cylinder, one on each side. The presence of extensions allows the plunger to be pulled out of the cylinder during pump operation, which prevents deposits on the inner surface of the cylinder, which eliminates jamming of the plunger and creates favorable conditions during repairs. Live pump parts are made of high-alloy steels and alloys, which ensures long-term trouble-free operation of the pumps. The tightness of the fit of the pumps, threaded connections, and the complete interchangeability of all pump parts are ensured by the high precision of their manufacture. In terms of connecting dimensions and threads, all pumps are modified for domestic downhole equipment.

According to analysts at Amoco, the Persian Gulf states contain two-thirds of all world oil reserves. The Persian Gulf states provided 22.8% of all oil imports to the United States in 2001. Oil fields have been explored in Iraq, containing 112.5 billion barrels of oil. According to the B P Statistical Review of World Energy, Iraq has the second largest oil reserves in the world, second only to Saudi Arabia (261.8 billion barrels). Kuwait's reserves are estimated at 98.6 billion barrels, Iran - 89.7, Russia - 48.6. At the same time, the cost of Iraqi and Saudi oil is the lowest in the world.

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Oil and gas.

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Oil is a complex multicomponent mutually soluble mixture of gaseous, liquid and solid hydrocarbons of various chemical structures with the number of carbon atoms up to 100 or more with an admixture of heteroorganic compounds of sulfur, nitrogen, oxygen and some metals.

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The main part of oil consists of three groups of hydrocarbons - alkanes, arenes and naphthenes.

Chemically, oil is a complex mixture of hydrocarbons, divided into two groups - heavy and light oil. Light oil contains approximately two percent less carbon than heavy oil, but correspondingly more hydrogen and oxygen.

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Alkanes (hydrocarbons, saturated hydrocarbons, paraffins) are the most chemically stable. Their general formula is СnH(2n+2).

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Naphthenes include alicyclic hydrocarbons of the composition CnH2n, CnH (2n-2) and CnH (2n-4). Oil contains mainly cyclopentane C5H10, cyclohexane C6H10 and their homologues. Arenas (aromatic hydrocarbons). They are significantly poorer in hydrogen, the carbon/hydrogen ratio in arenes is the highest, much higher than in oil in general.

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Oil resources and deposits

World recoverable oil reserves are estimated at 141.3 billion tons. These reserves, given current oil production volumes, will last for 42 years. Of these, 66.4% are located in the countries of the Near and Middle East.

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In addition to the carbon part, oil contains an asphalt-resin component, porphyrins, sulfur and an ash part. Non-hydrocarbon components of oil include resins and asphaltenes, which play a very important role in the chemical activity of oil.

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It can be added that the geological neighbor of oil, natural gas, is also a substance with a complex composition. Most of all - up to 95% by volume - is methane in this mixture. Ethane, propane, butanes and other alkanes are also present. A more thorough analysis revealed small amounts of helium in natural gas.

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The use of natural gas began a long time ago, but at first it was carried out only in places where it naturally comes to the surface. In Dagestan, Azerbaijan, Iran and other eastern regions.

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For many centuries, people have used such gifts of nature, but these cases cannot be called industrial development. Only in the mid-19th century did natural gas become a technological fuel, and one of the first examples was glass production, organized on the basis of the Dagestan Ogni deposit.

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Application.

Oil and gas are unique and exceptionally useful resources. Their processed products are used in almost all industries, in all types of transport, in military and civil construction, agriculture, energy, in everyday life, etc. A variety of chemical materials are produced from oil and gas, such as plastics, synthetic fibers, rubbers , varnishes, paints, road and construction bitumen, detergents and many others. etc.