Petroleum has mostly been recovered by oil drilling. Drilling is carried out after studies of structural geology, sedimentary basin analysis, and reservoir characterisation. Recent developments in technologies have also led to exploitation of other unconventional reserves such as oil sands and oil shale.
Once extracted, oil is refined and separated, most easily by distillation, into numerous products for direct use or use in manufacturing, such as gasoline (petrol), diesel and kerosene to asphalt and chemical reagents used to make plastics, pesticides and pharmaceuticals. Petroleum is used in manufacturing a wide variety of materials, and it is estimated that the world consumes about 100 million barrels (16 million cubic metres) each day.
The five largest oil producing countries in the world are : Venezuela (18.2%) , saudi Arabia (16.2%) , Canada (10.4%) , Iran (9.5%) , Iraq (8.7%) . Also, Qatar, having 37,000 square kilometers in its territorial waters, and Iran also having 14,000 square kilometers in its territorial waters, are the largest holders of gas condensates in the world (common reservoir) and the refining of gas condensates is much more economical and of higher quality than crude oil because the gas condensates has only a very large amount of gas , gasoline and very little kerosine and gasoil and low sulfur. For your information, pay attention to the greatness of these numbers: Note: 1 km³ = 1,000,000,000 m³ = 1 Billion m³ = 1 Trillion Liters & 1 crude oil barrel = 42 US gallons or 159 litres, or 35 imperial gallons.
Gas condensate includes compounds heavier than butane, which are liquid in atmospheric conditions. After stabilizing the vapor pressure and adjusting the dew point, these valuable compounds are transferred to the tanks and after storage, they are offered to the world markets.
Natural gas extracted from gas reservoirs mainly contains a considerable amount of gas condensate. Especially when the volume of gas withdrawal from the tank is large.
Gas condensate is a liquid hydrocarbon stream that exists in natural gas deposits and is found as sediment in extracted gas and is mainly composed of pentane and heavier hydrocarbons (+C5) and has low sulfur and is usually free of various types of It is metals and almost half of it is naphtha. Unlike butane and propane, gas condensates do not require special conditions to remain liquid and can be converted into kerosene, gasoline, jet fuel, etc. in different ways.
Compared to the crude oil refinery, in the gas condensate refinery, the conversion and refining processes are less, so its investment cost is half of the investment cost of the crude oil refinery.
The South Pars gas field is one of the largest gas resources in the world, located on the common border between Iran and Qatar in the Persian Gulf and 105 km from the southern coast of Iran. Studies show that it contains more than 14 trillion cubic meters of natural gas and more than 18 billion barrels of gas condensate, and 200 thousand barrels of gas condensate are produced daily by phases one to five of this field.
Petroleum production can be extremely profitable and was important for economic development in the 20th century, with some countries, so called "oil states", gaining significant economic and international power because of their control of oil production. Petroleum is a complex mixture of hydrocarbons that occur on Earth in liquid, gaseous, or solid form.
The term is often restricted to the liquid form, commonly called crude oil. But, as a technical term, petroleum also includes natural gas and the viscous or solid form known as bitumen, which is found in tar sands.
Crude oil, Gas Condensate, petroleum products, lubricants are a very important part of the projects and activities of the YEKTA oil& gas company. The type of crude oil, how the processes of converting it into petroleum products, how to modify some of their standard specifications have always increased the level of experience and awareness of the company's experts.
very Important note :
1. Crude oil and gas condensate have only specifications.They never have standard specifications.
2. All petroleum products from crude oil and gas condensate refining , without exception, have standard specifications around the world . Because many of them are used worldwide.for example :commercial jet fuels or gasolines and trading.
Of course, for domestic consumption, a separate standard may be followed.
Crude oil refining process:
* Semi-final products: H2,C1,C2,C3,nC4,iC4,Penthane ,natural gas, liquefied petroleum gases, light naphtha( L.S.R.G), heavy naphtha( H.S.R.G) , ORD : One Run Distillation : the same heavy naphtha , kerosine , gasoil , LLC , HLC , ISO Feed , fresh feed ,fuel oil , bitumen , sulfure
* Final products: Natural Gas (general use) , LPG (capsule) , car gasolines , aviation gasolines , JP4 , JP5 , JP8, kerosine , ATK s , Gasoils , lubricants material for base oil ,AW s , Fuel oils , Bitumen ,sulfure
Gas condensate refining process: The final products are Euro standards: NG , LPG , gasolines, kerosines , gasoils
Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. The rise in importance was due to the invention of the internal combustion engine, the rise in commercial aviation, and the importance of petroleum to industrial organic chemistry, particularly the synthesis of plastics, fertilizers, solvents, adhesives and pesticides.
More than 4000 years ago, according to Herodotus and Diodorus Siculus, asphalt was used in the construction of the walls and towers of Babylon; there were oil pits near Ardericca (near Babylon), and a pitch spring on Zacynthus. Great quantities of it were found on the banks of the river Issus, one of the tributaries of the Euphrates. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society.
As you can see in the two figures above, in the production process in an oil refinery, most petroleum products are semi-finished and after removing non-standard items and mixing in the refinery planning unit, they become the final product and are sent to the market.
At up photo ,Please note the geometry and type of crude oil & petroleum products tanks, why they are different?
The needs of the market and consumers are different for each of the oil products. For this reason, it is necessary to produce more used products. The need for gasoline and diesel as fuel used in light and heavy vehicles is very high. Therefore, the goal of the refinery is to produce as many of these products as possible with acceptable quality.
In this field, refineries use auxiliary processes such as cracking, hydrocracking, reforming, etc. to convert heavier products into light products such as gasoline.
The crude oil entering the refinery is first entered into the salting equipment so that the salts in it are completely removed from it.
Next, the crude oil passes through a number of heat exchangers for preheating. These heat exchangers actually transfer the heat from the production products of the distillation tower to the incoming crude oil. During this heat transfer, the temperature of crude oil reaches about 280˚C.
At this stage, crude oil must enter the furnace for complete heating. After leaving the furnace, the temperature of crude oil reaches about 350˚C. At this stage, the crude oil is practically two-phase and is a combination of liquid and vapor phase
After reaching the right temperature, the crude oil must enter the distillation tower. The distillation tower is a cylinder with a high height and consists of a number of trays. The number of trays in the atmospheric distillation tower is between 30 and 60 trays. These trays are installed at different points of the tower in terms of height, and the oil cuttings are collected and removed according to their boiling distance (the range between the initial and final boiling point), at their appropriate height and tray.
The temperature at the top of the atmospheric distillation tower is 70°C and at the bottom is 350°C. Lighter oil fractions exit from the upper parts of the tower and heavier fractions from the bottom of the tower. The outflows from the distillation tower are in vapor form and after passing through the condensers, they turn into liquid form.
Usually, along with each cut of oil, some lighter material is also removed from the distillation tower. This can lower the flash point (the first temperature at which the fuel ignites) of the product.
In order to correct this, the cuttings from the distillation tower are sent to a small stripping tower. Oil cuttings in the stripping tower are exposed to steam and lighter materials are separated from them.
In the atmospheric distillation tower, some heavier materials remain, which have a high boiling point. If the temperature of the distillation tower is raised to distill these substances, it causes the thermal breakdown of the molecules and the formation of coke. Therefore, to prevent this, the remaining materials of the atmospheric tower are sent to the vacuum distillation tower.
The vacuum distillation tower has a lower pressure than the atmosphere and about 10 to 45 mm of mercury, and the increase in temperature in it does not cause the formation of coke.
In the atmospheric distillation tower, some heavier materials remain, which have a high boiling point.
If the temperature of the distillation tower is raised to distill these substances, it causes the thermal breakdown of the molecules and the formation of coke. Therefore, to prevent this, the remaining materials of the atmospheric tower are sent to the vacuum distillation tower.
The vacuum distillation tower has a pressure lower than the atmosphere and about 10 to 45 mm of mercury, and increasing the temperature in it does not cause the formation of coke.
The atmospheric residue enters a furnace before entering the vacuum tower. In the furnace, some water vapor is injected into the stream to make the incoming feed more fluid and reduce the formation of coke.
The temperature of the flow after leaving the furnace is between 380°C and 450°C depending on the type of feed. At this stage, the flow enters the vacuum distillation tower. The vacuum distillation tower has a very large diameter of about 9 meters and about 8 to 20 trays are used in its structure.
A number of ejectors are connected to the vacuum distillation tower in order to reduce the pressure.
The incoming flow to the vacuum tower is vaporized due to the increase in temperature and different cuts are collected in their own special trays. Finally, the vapors coming out of the vacuum distillation tower are liquefied after passing through the condensers and come out as products of the vacuum tower.
Some of these products are used directly and some others are sent to other refinery units such as cracking, reforming, etc. to change properties and improve quality.
Other products that have a high demand for production are a variety of oils and lubricants.
Refineries provide feed for oil making units by performing physical and chemical changes on the outlet cuts of distillation towers.