What You Should Know About Oilfield Demulsifier 

What is  crude oil demulsifier?

Crude oil demulsifier refers to a chemical agent developed for dehydration and desalination of crude oil emulsions. It mainly achieves the purpose of dehydration by destroying and affecting the strength of the emulsion interface film or replacing the interface film to destabilize the emulsion.

Mechanism and properties of crude oil demulsifier

The droplets of oil-water emulsions produced by oil wells are distributed with natural emulsifiers, such as colloids, asphaltene, organic matter, etc. These substances are often combined with silt and clay, inorganic salts, wax, etc. to form a film at the oil-water interface. The greater the mechanical strength, the smaller the droplet diameter, and the more stable the oil-water emulsion. The essence of demulsification of crude oil demulsifier is to make the crude oil demulsifier adsorb to the oil-water interface and displace the original emulsifier (soap, colloid, etc.) from the oil-water interface, but it does not form a strong protective film, that is, the original solid powder (such as asphaltene particles or microcrystalline wax) is completely mixed with crude oil or water, and enters the phase that mixes it, thereby destroying the protective layer, and the dispersed layers approach each other and aggregate to become larger, and finally achieve the process of oil-water separation. The properties of crude oil demulsifier are mainly reflected in two aspects: diffusion adsorption and wetting film formation. For a certain emulsified crude oil. If a certain crude oil demulsifier has good performance in these two aspects, then this crude oil demulsifier will have a good demulsification effect on this emulsified crude oil.

(1) Diffusion adsorption The diffusion adsorption of crude oil demulsifier refers to the speed and adsorption capacity of crude oil demulsifier molecules entering the oil-water emulsion and diffusing to the oil-water interface film. If it has good diffusion and adsorption, its membrane destruction effect is sufficient and complete, which is manifested in macroscopically as less dosage, faster dehydration speed and larger dehydration amount. It is precisely because crude oil demulsifiers have great differences in diffusion and adsorption for different crude oil emulsions that the influence of crude oil demulsifiers on the stability of emulsions is different, resulting in the emergence of a wide variety of crude oil demulsifiers.

(2) Wetting and film-forming properties After the crude oil demulsifier molecules enter the oil-water interface, whether they can effectively destroy the interfacial film is the key to demulsification, which is specifically manifested in the ability of crude oil demulsifiers to wet and reverse the asphaltene, paraffin and other solid particles on the interfacial film, occupy and replace the original interface to re-film and thus reduce the strength of the original emulsified film. Therefore, the stronger the wetting ability of the crude oil demulsifier, the better its demulsification and dehydration properties.

Oil-water emulsions need to be separated efficiently and quickly to increase crude oil production or facilitate further refining, and to dissolve impurities in the separated water.

Deshi group's demulsifiers are generally divided into two types: oil-soluble and water-soluble, and in different concentrations. When added to the produced fluid, our demulsifiers migrate to the water/oil interface, destroying or weakening the rigid film and enhancing water droplet coalescence. They operate at low dosages and show high efficiency at lower operating temperatures while providing rapid precipitation and minimal oil entrainment.

Deshi Group offers a wide range of demulsification formulations to help achieve production and environmental goals. There are demulsifiers for desalting, demulsifiers for high waxy crude oil, demulsifiers for dense crude oil, demulsifiers for EOR, demulsifiers for high water content crude oil, and inverse demulsifiers.

Application of Demulsifiers

Demulsifiers are widely used in the oil and gas industry to solve the problem of water-in-oil or water-in-oil emulsions formed during crude oil extraction, storage and transportation, and natural gas production. These emulsions can cause a variety of problems such as reduced oil flow, increased viscosity, corrosion and equipment fouling. The following are the main applications of demulsifiers:

1、Crude Oil Production

In oil wells, water often mixes with oil to form a water-in-oil emulsion. Demulsifiers are added to the production fluid to break up the emulsion so that the oil and water can be separated more effectively in a separation vessel or storage tank.

2、Enhanced Oil Recovery (EOR)

Techniques such as waterflooding introduce large amounts of water into an oil reservoir to push the oil toward production wells. The resulting emulsion requires demulsifiers to separate the water from the oil for disposal or re-injection.

3、Storage and Transportation

Crude oil may form emulsions when stored or transported in tanks or pipelines. Adding demulsifiers helps prevent these emulsions from forming or break them up if they do form, thereby maintaining fluidity and preventing potential blockages.

4、Storage and Transportation

Crude oil may form emulsions when stored or transported in tanks or pipelines. Adding demulsifiers helps prevent these emulsions from forming or break them up if they do form, thereby maintaining fluidity and preventing potential blockages.

5、Gas Processing

Natural gas streams may contain condensate and water, which form emulsions. Demulsifiers are used to separate water from natural gas streams to protect downstream processing equipment and recover valuable condensate.

What is the main role of demulsifiers in oil and gas production?

Demulsifiers are chemical additives used primarily in the oil and gas industry to separate emulsions of water and oil. During the production process, water is often entrained in the oil, forming a stable mixture or emulsion. This condition may occur naturally due to the geological conditions of the reservoir or due to enhanced oil recovery techniques such as water injection.

Emulsified water can hinder the refining process and reduce the quality of crude oil products. It can also cause corrosion and scaling of pipelines and processing equipment, leading to increased maintenance costs and reduced efficiency.

The main role of demulsifiers is to break the emulsion, allowing the oil and water to coalesce into different phases, which can then be easily separated. Demulsifiers generally work by reducing the interfacial tension between the oil and water droplets, providing a surfactant that helps break the emulsion. This allows for more efficient processing and transportation of crude oil, minimizing waste and optimizing production.

The choice of demulsifier depends on the characteristics of the emulsion, such as the type of crude oil, the salinity of the water, and the temperature at which the separation occurs. Proper dosage and timing are essential for effective demulsification. Demulsifiers are an essential component of downstream petroleum processing, ensuring effective separation of oil and water prior to further refining and use.

Is  demulsifier a surfactant?

Demulsifiers can be classified as surfactants when they contain a hydrophobic tail and a hydrophilic head, which are characteristic of surfactants. Surfactants are compounds that reduce the surface tension between two liquids or between a liquid and a solid. In the case of oil and water emulsions, demulsifying surfactants work by adsorbing at the oil-water interface, thereby reducing the interfacial tension and promoting the coalescence of the emulsion droplets, allowing them to separate.

However, not all demulsifiers are surfactants. Some demulsifiers work by mechanisms that do not involve changing surface tension. These can include polymers that increase the viscosity of the continuous phase, which helps the droplets separate, or molecules that complex with emulsifiers, thereby destabilizing the emulsion. Therefore, while many demulsifiers are surfactants, the term "demulsifier" is not synonymous with "surfactant." It refers to any chemical that can be used to break an emulsion, whether it works by reducing surface tension or some other mechanism.

How do demulsifiers chemically break emulsions in produced water?

Demulsifiers chemically break emulsions in produced water by breaking the interfacial tension between the oil droplets and the water phase. The process involves several steps:

Adsorption: When a demulsifier is introduced into an emulsion, it selectively adsorbs to the surface of the oil droplets. This is because the demulsifier's chemical structure is designed to be amphiphilic, meaning it has both a hydrophilic portion (attracts water) and a hydrophobic portion (attracts oil).

Reducing interfacial tension: The adsorbed demulsifier molecules change the surface properties of the oil droplets, which reduces the interfacial tension between the oil and water phases. This reduction in tension makes it easier for the two liquids to separate.

Can demulsifiers be used for both water-in-oil and water-in-oil emulsions?

Demulsifiers are designed to effectively treat both water-in-oil and oil-in-water emulsions. The choice of demulsifier depends on the specific characteristics of the emulsion, including the composition of the oil and water phases, the nature of the emulsifier, and the conditions under which the emulsion is formed and exists.

For water-in-oil emulsions, demulsifiers typically work by reducing the surface tension at the oil/water interface, promoting coalescence of the oil droplets, thereby separating them from the water phase. These demulsifiers typically contain surfactants that adsorb to the oil droplets, thereby reducing the interfacial tension.

For water-in-oil emulsions, demulsifiers work similarly to water-in-oil emulsions in reducing interfacial tension, but they preferentially adsorb to water droplets. This facilitates the aggregation and coalescence of water droplets, thereby separating them from the oil phase.

Chemical companies often offer multifunctional demulsifiers that are effective for both types of emulsions. The effectiveness of a demulsifier depends largely on its ability to interact with the emulsion interface and overcome the forces that stabilize the emulsified state.

To ensure optimal performance, demulsifier selection is often preceded by laboratory testing to determine the agent that is best suited for a particular emulsion. Factors such as pH, temperature, salinity, and the presence of other chemicals in the system are taken into account to tailor the demulsifier to the specific application.

Are environmental factors important to consider when selecting a demulsifier?

Yes, there are several environmental factors to consider when selecting a demulsifier:

Biodegradability: It is important to select a demulsifier that is readily biodegradable, so that its presence in the environment is minimized. Demulsifiers that break down quickly can reduce the risk of long-term ecological impacts.

Toxicity: Demulsifiers should have low toxicity to aquatic organisms to avoid harm to ecosystems when produced water is discharged into water bodies.

Biological accumulation potential: Demulsifiers with low bioaccumulation potential are preferred to prevent the accumulation of chemicals in the food chain and wildlife.

Environmental regulations: It is essential to comply with local, national, and international environmental regulations. This includes understanding legal requirements for the use and discharge of chemicals in produced water.

Impact on reuse and disposal: Demulsifiers should not adversely affect the reuse of treated water, nor should they make the disposal process more complicated or environmentally harmful.

Eco-labels and certifications: Some demulsifiers may be certified through eco-labeling schemes, indicating that they meet certain environmental standards, which can serve as a guiding factor in selection.

Green Chemistry Principles: Considering green chemistry principles in the design and selection of demulsifiers can lead to more sustainable choices that reduce hazardous materials and energy consumption.

End-of-Life Management: Ensuring there is a management plan at the end of the demulsifier’s life cycle, including appropriate disposal or recycling options, can help minimize environmental impact.

Risk Assessment: A thorough risk assessment of a demulsifier’s potential environmental impact can inform decisions about whether it is suitable for use.

By considering these factors, operators can select demulsifiers that will effectively meet their operational needs while minimizing environmental impact.

How do the molecular weight and structure of demulsifiers affect their effectiveness?

The molecular weight and structure of demulsifiers play a crucial role in determining their effectiveness. The molecular structure affects the interaction of the demulsifier with the oil-water interface, affecting the ability to reduce interfacial tension and promote droplet coalescence.

Molecular weight:

● Demulsifiers with higher molecular weights generally have longer hydrophobic chains that adsorb more tightly at the interface, thereby improving demulsification by enhancing the stability of the formed oil droplets and reducing the chance of re-emulsification.

● However, too high a molecular weight can lead to reduced solubility and slower adsorption kinetics, which may reduce overall efficiency.

Hydrophobic-Hydrophilic Balance:

● The effectiveness of a demulsifier depends largely on the balance between its hydrophobic and hydrophilic parts. This balance is often called HLB (Hydrophilic-Lipophilic Balance) and should match the characteristics of the emulsion.

● For water-in-oil emulsions, higher HLB values ​​are generally desired, indicating that a stronger hydrophilic component can adsorb to the oil droplets.

● Conversely, for water-in-oil emulsions, lower HLB values ​​are required, indicating that more hydrophobic demulsifiers can adsorb onto water droplets.

Surface activity:

● The ability of a demulsifier to reduce interfacial tension is directly related to its surface activity. Molecules that can easily diffuse to the oil-water interface will reduce tension more effectively.

● Molecular weight and structure affect the ability of the demulsifier to locate at the interface, thereby affecting its surface activity.

Thermodynamic compatibility:

● Demulsifiers must be thermodynamically compatible with the emulsified system to effectively reduce interfacial tension, and the molecular structure should be able to interact well with the emulsion components.

Solubility:

● Solubility in both the water and oil phases is critical for the demulsifier to reach the interface and adsorb. Molecular structure affects solubility, and there is usually a compromise between solubility and surface activity.

Adsorption kinetics:

● The rate of adsorption of a demulsifier at an interface is affected by its molecular structure. The faster the adsorption, the faster the demulsification.

Taking all these factors into account, demulsifier design requires a delicate balance between achieving the correct HLB, ensuring good surface activity, maintaining appropriate solubility, and optimizing adsorption kinetics. The molecular structure of the demulsifier must be carefully selected to suit the specific characteristics of the emulsion being treated.

What are the safety precautions and handling recommendations for demulsifiers?

Demulsifiers are chemicals used to break emulsions in oil and water systems and must be handled carefully to ensure operator safety and environmental protection. Here are some safety precautions and handling recommendations:

Personal Protective Equipment (PPE): Always wear appropriate personal protective equipment when handling demulsifiers. This includes gloves, goggles, a long-sleeved shirt, and sometimes a face mask or respirator, depending on the nature and potential hazards of the chemical.

Material Safety Data Sheet (MSDS): Before using any demulsifier, review the MSDS to learn about the chemical's properties, hazards, and recommended exposure limits.

Proper Storage: Store demulsifiers in their original containers, clearly labeled, away from sources of ignition, heat, and direct sunlight. Ensure that the storage area is well ventilated and safe.

Disposal: Follow proper waste disposal procedures as outlined in the MSDS and local regulations. Do not discharge demulsifiers into waterways or sewage systems.

Handling: When transferring demulsifiers, use a closed system to prevent spills and exposure. If a spill occurs, follow the spill response procedure and use absorbent materials to contain the leak.

Emergency Showers and Eyewash Stations: Ensure that emergency showers and eyewash stations are readily accessible in case of accidental contact.

Training: Provide training to all personnel handling demulsifiers covering proper handling techniques, risks associated with the chemical, and emergency response procedures.

Respiratory Protection: Use appropriate respiratory protection if there is a risk of inhalation of dust or vapor.

Avoid Contamination: Do not allow demulsifiers to come in contact with food or beverages. Wash hands before eating, drinking, or smoking.

Medical Care: If the substance comes into contact with the skin or eyes, immediately flush the exposed area with plenty of water for at least 15 minutes. If symptoms persist or if there is any question about the severity of the exposure, seek medical attention.

By following these precautions and recommendations, operators can minimize the risks associated with handling demulsifiers and maintain a safe work environment. Always refer to the specific MSDS for detailed safety information on the demulsifier being used.

What is reverse demulsifier？

Reverse Demulsifier is a composite of non-ionic organic high molecular polymers. The product has multiple chain links and excellent bridging flocculation ability. It can quickly connect the oil droplets dispersed in the water, aggregate and float to separate the oil and water. The product is widely used in the de-oiling and clarification of oily wastewater from oilfield production fluids.

2. Technical Indicators Of Reverse Demulsifier

Appearance                  Homogeneous liquid

PH value                        5-6

Water solubility               Miscible with water without stratification

Freezing point, ℃        ≤-10

Relative oil removal rate, %     ≥80

3. Application of Reverse Demulsifier

Reverse Demulsifier is used in oilfield wastewater treatment; the product is composed of organic high molecular polymers, has the characteristics of high branching degree, high surface activity, strong bridging flocculation ability, and has a significant removal effect on oil in wastewater. It is widely used in oilfield produced liquid separation and wastewater treatment. When used, it is directly injected into the sewage pipeline with a metering pump at the sewage station, and the specific situation can be determined according to the on-site conditions.

What is demulsifer for crude oil？

Oil demulsifier is compounded by different types of polyether. The product has the characteristics of low dosage, high dehydration rate, smooth oil-water interface, less oil in sewage, etc. It is highly targeted at crude oil with complex properties such as low-temperature crude oil demulsification, heavy oil and extra-heavy oil demulsification, and tertiary production liquid emulsified crude oil demulsification. Some products have good desalination effect. The products are produced strictly in accordance with the control requirements of GB/T19001 quality management system.

2. Technical indicators of oilfield demulsifier

Appearance: uniform liquid, free of impurities

PH: 7-8

Viscosity, 25℃ ＜300mPa.s

Freezing point, ℃ ≤-35

Density (20℃), g/cm3 0.98-1.08

Dehydration performance: dehydration rate is greater than 95% of the standard sample

3. Application of demulsifier for crude oil

Chemical demulsifier is mainly used for demulsification and dehydration of produced fluid from crude oil production in oil fields. Different products are suitable for chemical dehydration of produced fluids with different properties in different blocks of oil fields. The products have the advantages of small dosage, high dehydration rate, clear dehydrated water, and uniform oil-water interface, which can meet the requirements of oil-water separation of different produced fluids in complex fault block oil fields. The products are also used for crude oil desalination and salt washing in refineries.

 Demulsifier Case

High wax content and low temperature demulsification case in Changqing Oilfield:

The crude oil in a block of Changqing Oilfeld has wax content of 15% -22%, water content of about 25%, freezing point of 18℃, wax precipitation point of 36 ℃ and demulsification temperature of 30℃. in order to reduce energy consumption, the field production process requires rapid and complete demulsification under the condition of demulsification temperature below 30℃. According to the site requirements, the company developed and produced a DS-1 demulsifier which can realze low temperaure rapid demulsification.Compared wth XC-1 demulsifier used in block stations, the water content of crude oil after demulsification was less than 1% at 27℃.which has obvious advantage in demulsification effect and meets the requirement  of field production.

Reverse Demulsifier Case

Reverse demulsifier treatment case for wastewater of Shengli Oilfield:

The water content of produced fluid in a certain block of Shengli Oilfeld is about 95%, and the daily treatment capacity of combined station is about 20000m³. After tertiary recovery, the oil content of produced liquid sewage is about 3000mg / L (production requirement≤ 30mg / L) and the conlent of suspended solids is about 600mg / L (produclion requirement ≤ 30mg /L), which causes great burden on the back-end sewage treatment of combined station. According to the field process, our company developed DSJ-212 reverse demulsifier. After indoor experimental verificaion and field pilot test, according to the field 30ppm dosing concentration requirements the oil content of sewage was reduced to 8mg /L, and the suspended solid content was reduced to 6mg / L. Our company's reverse demulsifier has good compatibility with the demulsifer in use on site, which fully meets the requirements of site water qualty index.

 Deshi Chemicals has a variety of oilfield chemicals. Demulsifier and reverse demulsifier are relatively mature products. We are very familiar with the oil quality of Saudi Arabia and can send samples directly. If you want to know the demulsifier price or more information, you can contact us at any time.