The 12 stage filtration system is widely used in the oilfield sewage treatment system. Because the oilfield development is in the middle and late stage, the water content of produced fluid is as high as 90, and the filtration system is generally heavily loaded, so the cleaning and regeneration of filter material is an important factor to ensure that the sewage treatment meets the standard. Limited by the site conditions, the filter material is mostly cleaned at room temperature. Therefore, the development of high-performance room temperature water-based filter material cleaning agent is very important for sewage treatment to meet the standard, save energy, reduce energy consumption and protect the environment.
Filter material cleaning agent is a kind of agent for cleaning the surface of filter material, which takes water as solvent, surfactant that can still play a stable role in oil and impurity removal at medium and low temperature as the main component, supplemented by alkaline detergent aid, dispersant, anti secondary sedimentation agent, defoamer, organic detergent and rust inhibitor. Water based cleaning agent, which replaces oil with water, has the advantages of high efficiency, low consumption, non combustion, non volatilization and reducing pollution.
The theory of water based cleaning and the formulation of cleaning agents are common in various professional journals. However, the comprehensive properties such as cleanability, foam, oil removal, impurity removal and rust resistance of specific products can not meet the requirements of use. Therefore, the development and research of normal temperature water based cleaning agents is particularly urgent and necessary.
Development principle of filter material cleaning agent
- In general, the dirt adsorbed on the surface of the filter material is composed of oil, suspended impurities, bacteria and their products, ferrous sulfide, iron oxide, scale and polymers for tertiary oil recovery.
- Cleaning mechanism of filter material cleaning agent the cleaning process of filter material surface is a complex and comprehensive physical and chemical process. Between the filter material and the dirt interface, the cleaning agent increases the auxiliary expansion coefficient between the dirt and the cleaning solution surface through the functions of wetting, dispersion, dissolution, shrinkage, emulsification, chelation and saponification, so that the dirt can be stripped and suspended in the cleaning solution to achieve the purpose of cleaning.
- Formula combination principle non-ionic surfactant has wide acid-base adaptability and excellent oil cleaning performance, so it has become one of the surfactants in the formula of water-based detergent.
However, the existence of cloud point of non-ionic surfactant limits its application temperature range. Only near the cloud point temperature can non-ionic surfactants play a good cleaning effect.
Therefore, the focus of developing room temperature cleaning agents is to find non-ionic surfactants with cloud point in the room temperature range (025c).
At the same time, the addition of cleaning additives (especially salt products) will further reduce the actual cloud point of surfactant, so it can ensure the normal cleaning effect of cleaning agent at room temperature and meet the actual use requirements.
In order to improve and enhance the comprehensive performance of the cleaning agent, chemical technology dispersion additives and water-based antirust agents need to be added.
Stability performance criteria
- Room temperature stability: place at room temperature for 7 days and observe the solution state. Experimental results: stable, no stratification.
- High temperature stability: put 50ml stock solution into 50ml measuring cylinder with plug, put it into 60 ± 2 C water bath after plugging, take out the measuring cylinder after 6h, cool it to room temperature for inspection, and investigate the cleaning performance of stock solution after high temperature test. Experimental results: stable and no stratification; The cleaning performance is confirmed to be unchanged after the experiment.
- Low temperature stability: put the stock solution after high-temperature head test into the low-temperature refrigerator, take out the measuring cylinder after maintaining for 1H at 18 ± 3C, and pour the test solution for 5 times for observation after the test solution is restored to room temperature and maintained for 1H.
It was placed at different low temperatures to determine the freezing point of the solution and investigate the cleaning property of the stock solution after the low temperature experiment.
Experimental results: after placing for 1h, the solution is not layered, and the state after dumping is the same as that before the experiment. The cleaning performance is confirmed to be unchanged by experiment.
- Low temperature and low foam. Even if used in agitation backwashing, there will be no spillover phenomenon.
- Efficient degreasing. Due to the use of special surfactant, the oil removal efficiency is greatly improved. The oil can be completely removed after backwashing for 10min.
- Good compatibility. The product is cleaned and degreased at room temperature, with low corrosion rate and little impact on the subsequent treatment system.
- Excellent economy. Low temperature and low ratio use concentration greatly reduce the production cost and improve the economic benefit.
- Environmental protection. It has the characteristics of low service temperature, low ratio and no volatilization, and effectively maintains and improves the on-site operation environment.