Oil is a combustible, oily liquid, ranging in color from light brown (almost transparent) to dark brown (almost black). Density is divided into light, medium and heavy.
It is currently impossible to imagine the modern world without oil. It is the main source of fuel for various vehicles, raw materials for the production of various consumer goods, medicines and other things. How is oil extracted?
Development
Oil, along with natural gas, accumulates in porous rocks called reservoirs. They may be different. A good reservoir is considered to be a layer of sandstone, which is located between layers of clay and shale. This eliminates the leakage of oil and gas from underground tanks.
As soon as minerals are discovered, an assessment of their reserves in the reservoir, quality is carried out and a method is developed for the safe extraction and transportation to the processing plant. If it is estimated that oil and gas production in a given field is economically viable, installation of production equipment begins.
Features of oil production
In natural reservoirs where oil is extracted, it is in a wet state. Typically, a flammable liquid is mixed with gas and water. Often they are under high pressure, under the influence of which oil is displaced to unequipped wells. This may cause problems. Sometimes the pressure is so low that it requires the installation of a special pump.
The oil production process can be divided into three stages:
- The movement of fluid in the reservoir towards the well. It is carried out due to a natural or artificially created pressure difference.
- The movement of fluid along the well - from the bottom to the mouth.
- Collection of oil with gas and water on the surface, their separation, refining. And then the liquid is transported to the processing plants.
There are various methods of oil production, which depend on the type of mineral deposit (land, seabed), type of reservoir, and depth. Also, the method may change as the natural reservoir is emptied. It is worth noting that offshore oil production is a more complex process, since it requires the installation of underwater installations.
Natural prey
How is oil extracted? To do this, use the force of pressure, natural or created artificially. The operation of a well with reservoir energy is called a fountain. In this case, under the pressure of groundwater, gas, oil rises up, without requiring additional equipment. However, the fountain method is used only for primary mining, when the pressure is significant and is able to raise the liquid up. In the future, it is necessary to use additional equipment to fully pump oil.
The fountain method is the most economical. To adjust the oil supply, special fittings are installed, which seals the wellhead, controls the volume of the supplied substance.
After primary production, secondary and tertiary methods are used to maximize the use of the field.
Primary, secondary and tertiary methods
With the natural method of oil production, a phased method is used:
- Primary. The fluid comes under the influence of high pressure in the reservoir, which is formed from groundwater, gas expansion, etc. With this method, the oil recovery factor (CIN) is about 5-15%.
- Secondary. This method is used when natural pressure is no longer enough to lift oil through the well. In this case, the secondary method is applied, which consists in supplying energy from outside. In this capacity is injected water, associated or natural gas. Depending on the reservoir rocks and oil characteristics, the recovery factor in the secondary method reaches 30%, and the total value is 35-45%.
- Tertiary. This method consists in increasing the mobility of oil to increase its return. One way is TEOR, by which viscosity is reduced by heating fluid in the formation. For this, water vapor is most often used. Less commonly used is partial burning of oil in situ, directly in the formation itself. However, this method is not very effective. To change the surface tension between oil and water, special surfactants (or detergents) can be introduced. The tertiary method can increase the CIN by another 5-15%. This method is used only if oil production remains profitable. Therefore, the application of the tertiary method depends on oil prices and the cost of its extraction.
Mechanized way: gas lift
If energy for raising oil is supplied from outside, then this method of production is called mechanized. It is divided into two types: compressor and pump. Each of the methods has its own characteristics.
The compressor is also called gas lift. This method involves injecting gas into a well where it mixes with oil. As a result, the density of the mixture decreases. Downhole pressure also decreases, becomes lower than reservoir pressure. All this leads to the movement of oil to the surface of the earth. Sometimes gas under pressure is supplied from neighboring formations. This method is called "uncompressed gas lift."
In old fields, an airlift system is also used, in which air is used. However, this method requires the burning of petroleum gas, and the pipeline has a low resistance to corrosion.
Gas lift for oil production is used in Western Siberia, Western Kazakhstan, Turkmenistan.
Mechanized way: using pumps
With the pumping method, pumps are lowered to a certain depth. Equipment is divided into various types. The most common are sucker rod pumps.
Consider how oil is extracted in this way. The principle of operation of such equipment is as follows. Pipes are lowered into the well, inside which are located a suction valve and a cylinder. In the latter, a plunger with a discharge valve is installed. The movement of oil is carried out due to the reciprocating movement of the plunger. At the same time, the suction and discharge valves alternately open and close.
The performance of sucker rod pumps is approximately 500 cc. m / day at a well depth of 200-400 m, and at a depth of 3200 m - up to 20 cubic meters. m / day.
Rodless sediments can also be used for oil production. In this case, electrical energy is supplied to the equipment through the wellbore. A special cable is used for this. Another type of energy-carrying flow (coolant, compressed gas) can also be used.
In Russia, the centrifugal type of electric pump is more often used. With the help of such equipment, most of the oil is produced. When using electric pumps on the ground, it is necessary to install a control station and a transformer.
Mining in the countries of the world
It was examined how oil is extracted from natural reservoirs. It is worth familiarizing with the pace of development. Initially, until the mid-70s, oil production doubled almost every decade. Then the pace of development became not so active. The volume of oil that was pumped from the beginning of production (from the 1850s) to 1973 amounted to 41 billion tons, almost half of which was in 1965-1973.
Today, the largest world oil producers are countries such as Saudi Arabia, Russia, Iran, the USA, China, Mexico, Canada, Venezuela, and Kazakhstan. These countries are the main ones on the “black gold” market. It is worth noting that oil production in the United States is not in the top positions, but the country bought large deposits in other states.
The largest oil and gas basins in which oil and gas are produced are the Persian Gulf, the Gulf of Mexico, the South Caspian, Western Siberia, Algeria Sahara and others.
Oil reserves
Oil is a non-renewable resource. The volume of known deposits is 1200 billion barrels, and unexplored - approximately 52-260 billion barrels. Total oil reserves, taking into account its modern consumption, will be enough for about 100 years. Despite this, the plans of Russia to increase production of "black gold".
The countries with the highest oil production are:
- Venezuela.
- Saudi Arabia.
- Iran.
- Iraq.
- Kuwait.
- UAE
- Russia.
- Libya.
- Kazakhstan.
- Nigeria.
- Canada.
- USA.
- Qatar.
- China.
- Brazil.
Oil in Russia
Russia is one of the leading countries in oil production. It is not only widely used in the country itself, a significant part is exported to various countries. Where is oil extracted in Russia? The largest deposits today are in the Khanty-Mansi Autonomous Okrug, Yamalo-Nenets Autonomous Okrug and the Republic of Tatarstan. These regions account for more than 60% of the total volume of produced fluid. Also, the Irkutsk region and the Republic of Yakutia are places where oil is produced in Russia, showing excellent results in increasing volumes. This is due to the development of a new export direction Siberia - Pacific Ocean.
Oil prices
The price of oil is formed from the ratio of supply and demand. However, in this case there are some peculiarities. Demand remains virtually unchanged and has little effect on price dynamics. Of course, it is growing every year. But the main factor in pricing is supply. A slight decrease leads to a sharp jump in value.
With the increase in the number of cars and similar equipment, the demand for oil is increasing. But the deposits are gradually drying up. All this, according to experts, will ultimately lead to an oil crisis, when demand far exceeds supply. And then prices will skyrocket.
It is also worth noting that the price of oil is one of the most important political instruments in the global economy. Today it is about 107 dollars per barrel.