For many years, the oil and petrochemical industry has adopted the method of manual cleaning of oil tanks. Operators wash the oil tanks manually by ladders from the side wall overhaul holes. The space of the tanks is narrow, the air is not circulating, the concentration of combustible gases is high, poisoning and explosion accidents are easy to occur, the working environment is bad, and the workers are seriously damaged. The physical and mental health of the staff;
On the other hand, the filthy oil removed from the tank and the large amount of sewage produced by manual scrubbing cause environmental pollution in the tank area and the surrounding areas. At the same time, the long cleaning period (averaging two months) reduces the storage and regulation capacity of the reservoir area, which directly affects the normal production of the reservoir area. A large number of discarded bottom oils also cause waste of resources and environmental pollution. Dyed.
Compared with the traditional tank cleaning method, mechanical cleaning technology realizes the whole process of tank closed cleaning, which has the characteristics of short cleaning time, health, safety, high oil recovery rate, social and economic benefits.
(1) The whole process of closed cleaning, cleaning process personnel do not need to enter the tank, only in the external operation of cleaning equipment, control the cleaning process, construction workers do not directly contact the tank oil, gas, reduce labor intensity, improve the construction conditions.
(2) In the process of cleaning, human inert gas is injected to replace air and combustible gas, reduce the concentration of combustible gas and oxygen, and ensure the safety and reliability of mechanical cleaning operation.
(3) tank cleaning under closed conditions does not pollute the environment around the tank, and meets the requirements of environmental protection. Through oil-water circulation cleaning and oil-water separation process, the bottom oil is filtered out and then re-entered the storage and transportation system in the reservoir area. The recovery rate of the bottom oil is over 98, which improves the oil commodity rate and reduces the resource consumption.
(4) the cleaning cycle is shorter (average half a month), which can effectively improve the storehouse's storage and adjustment ability.
4. Application of oil tank cleaning in Daqing oilfield of China
With the continuous improvement of oil field production management level, higher requirements for safety, health, environmental protection and quality are put forward. Manual cleaning of storage tanks has been unable to meet the needs of modern petroleum enterprises. In view of this, China's Daqing Oilfield in 1998 to investigate and demonstrate the mechanical cleaning technology, and imported from foreign oil tank mechanical cleaning professional equipment.
In 1999, after the domestic matching transformation, the trial run, after more than two years of practice, summed up the formation of a mature mechanical cleaning process. The bottom oil of mechanical tank cleaning is calculated according to the average depth of oil storage after the bottom of the floating vessel of the tank is 0.3 M. Taking the 5X104m3 oil tank as an example, the recoverable oil amount reaches 750 t, which is all commercial crude oil. Mechanical cleaning of a 5X104m3 oil tank can bring more benefits than manual cleaning of 2.55 million yuan. In 2003, China's Daqing oilfield fully implemented the mechanical cleaning technology of oil storage tanks.
Up to 2006, the average annual cleaning of more than 30 large and small oil tanks, recovered more than 10,000 tons of commodity crude oil, reduced the annual consumption of commodity crude oil nearly 40 million yuan.
5. Oil tank cleaning is an inevitable trend.
With the large scale of crude oil storage tanks, the traditional manual cleaning operation can no longer meet the production requirements. The main reason is that manual cleaning is difficult, long cycle and so on, manual operation into the tank, may cause personnel poisoning and fire and explosion accidents. Therefore, mechanized cleaning technology of tank will replace manual cleaning. Mechanical operation instead of manual operation is an inevitable trend in the development of human society, which is irresistible.