The student in the Department of Chemical Engineering and Petroleum Industries, Abu Dhar Saeed, wrote a scientific article entitled (Preparation of Crude Oil Before Refining Operations) and under the supervision of the teaching teacher in the department, Ms. Fatima Uday Ali Majdi, and the content of the article was:
Preparing crude oil before filtering operations
Crude oil, when extracted from the well, contains varying amounts of gas dissolved under the influence of pressure and temperature inside the well. It also contains a certain amount of water and salts, and in many cases this mixture is an oil emulsion.
The associated gas is a mixture of hydrocarbon compounds with a chemical composition similar to the chemical composition of oil, so the ability to dissolve them in it is considered good, and the ability to dissolve vapors of light compounds from oil in the gas is also good.
Therefore, the process of removing gas from oil requires ensuring that the largest quantity of it is removed while at the same time not escaping excess amounts of hydrocarbon compounds with the gas. Under normal conditions, the oil and gas emitted into it cannot be stored together, nor can they be transported together. Likewise, the amount of oil cannot be determined precisely.
The dangers resulting from its leakage from containers and pipes containing it include (explosion, fire).
Therefore, before the oil reaches the warehouses, several operations take place on it.
First: the gas isolation process
It is the process by which petroleum hydrocarbon gases are separated or isolated for the purpose of utilizing them in the petroleum and petrochemical industry while preserving the largest possible amount of light fraction particles (light hydrocarbons) to remain with the crude oil. A severe drop in pressure from the well to the gas isolation station will lead to separation. Gases from oil inside the insulators are therefore designed to eliminate methane, ethane and propane gases and keep light hydrocarbons.
The purpose of gas isolation stations is:
1- Converting the oil produced from high-pressure reservoirs to normal atmospheric pressure while preserving the precious heavy hydrocarbon liquids dissolved in the crude oil and releasing
Only light hydrocarbons.
2- Removal of water and other liquids such as sand, clay and solids.
Second: The process of removing salts
What is meant by salts is sodium chloride
Which was not present in the oil, neither in the formation stages, nor in the reservoir, nor even in...
Drilling stages before production
The crude oil present in the reservoir does not contain water, but rather is isolated from it and accumulates
In a layer below the crude oil, and when oil is produced from that layer, water moves and comes out with
Oil and during the movement of oil and water inside the well, then to the wellhead, then the flow pipe
And the valves to the isolation stations, the reservoir water becomes in two forms
Free water is isolated as soon as the mixture of oil and water enters the buffer or tank, i.e. when...
It has a chance to precipitate, but the water in the oil is in the form of small droplets
It does not precipitate easily as it requires additional processes to separate these droplets from the oil
Using wet oil processing units note that these small droplets of water
It is surrounded by crude oil, so the emulsion, which is highly stable, does not cause
Corrosion in tanks or production pipes, but its effect appears clear in oil heaters or
Heat exchangers and also cause the tubes to close
Small particles as a result of the deposition of salts on them in order to carry out treatment must be identified
Emulsifiers, their types, composition, formation factors, and stability