Oilfield Chemical Demulsifiers
Oilfield Chemicals Demulsifiers, commonly referred to as Demulsifiers, are specialized chemical agents used in the oil and gas industry to separate emulsions, particularly water-in-oil emulsions, that form during crude oil production. These emulsions, where water droplets are dispersed in oil, are stabilized by natural emulsifiers like asphaltenes, resins, and waxes. If not addressed, they can increase viscosity, cause corrosion, and complicate oil-water separation. Oil demulsification using demulsifiers ensures that water is efficiently removed from crude oil, enhancing production, transportation, and refining processes.
What Are Demulsifiers?
Demulsifiers are surface-active compounds designed to break emulsions by reducing interfacial tension, displacing stabilizing agents, and promoting the coalescence of dispersed water droplets. In oilfield applications, the primary focus is on Demulsifiers for Water-in-Oil emulsions, where water is the dispersed phase within a continuous oil phase. These are often called crude oil demulsifiers. However, Reverse Demulsifiers exist for oil-in-water emulsions, though they are less common in upstream operations. The goal of oilfield demulsification is to produce dry, high-quality crude oil suitable for further processing.
In the later stages of oilfield exploitation, crude oil emulsions are predominantly oil-in-water (O/W) systems, often coexisting with multiple emulsions and microemulsions. The produced liquid exhibits several challenging characteristics: high water content, free water containing oil and impurities, a deep degree of emulsification in water-containing crude oil, and significant difficulties in dehydration. To tackle these issues effectively, a new type of demulsifier is essential. This demulsifier must possess a water-soluble, intelligently linked structure that is easy to disperse in crude oil and demonstrates good permeability, enabling it to reduce the oil content in desalted wastewater. Specifically, block copolymer demulsifiers are highlighted for this purpose. To ensure faster dehydration speeds and the maximum dehydration effect, the molecular design of these demulsifiers should incorporate an appropriate block sequence and chain segment length.
Main Application Scenarios
Main Application Scenarios
Demulsifiers play a vital role across multiple stages of oil production and processing:
- --- Production: During extraction, water co-produced with crude oil forms emulsions. Demulsifiers separate this water to meet transportation standards.
- --- Transportation: Emulsions increase crude oil viscosity, hindering pipeline flow. Demulsifiers reduce viscosity by removing water.
- --- Refining: In refineries, demulsifiers eliminate water and salts from crude oil, preventing equipment corrosion and ensuring product quality.
- --- Heavy Oil Production: Heavy oil demulsifiers or heavy crude oil demulsifiers are critical for breaking stable emulsions in viscous, dense crude oils.
And the main challenges of emulsions we need to stress are following:
▶ Low-temperature crude oil demulsification
▶ Heavy oil and ultra-heavy oil demulsification
▶ Tertiary produced liquid emulsified crude oil demulsification
Main waste water MULSIONS
Main waste water MULSIONS
- Each manufacturing plant has its own unique wastewater. However, despite the industry, oily wastewater can be broken down into 4 categories. Thus, no matter how unique the water is, it is going to fall into at least one of these categories. Understanding which category of oily wastewater your plant produces will help lead to using the correct treatment equipment and chemicals. Emulsions For this kind of oily wastewater, droplets of oil are dispersed throughout water. Water is the dispersion medium and is in the continuous phase, while oil is in the dispersion phase. The oil must be removed from the water for the water to meet discharge requirements. This is typically done using demulsifiers, which allow for the coalescence and removal of the oil droplets. In the case of emulsions, the oil contained in the water is typically waste oil; therefore, product quality and preserving the water is more important than the product quality of the oil. Inverse Emulsions Inverse emulsions are the opposite of emulsions. This type of oily wastewater refers to droplets of water dispersed within oil droplets. In this case, the water is a byproduct of producing the oil and thus must be removed from the oil. It is especially important to completely dehydrate the oil droplets in order for refineries to meet crude oil requirements. This is typically accomplished with reverse emulsion breakers, which assist in the separation of water from oil. Total Dissolved Solids This kind of oily wastewater has small particles dispersed throughout. The main characteristic is the particles are not able to be filtered out with filter paper. Eventually, the particles will settle to the bottom under the natural influence of gravity. However, this is a time-consuming method of treatment and isn't ideal for a plant trying to maintain productivity standards. Suspended Solids Similar to colloidal suspension, suspended solids consist of particles in the water. Typically, suspended solids are floating in the water, rather than dispersed. These particles are usually larger and therefore quicker to settle out than colloidal suspension. Since the particles are larger, they can be filtered out much easier. However, treatment often still requires coagulants and flocculants to speed up the process.
And the main challenges of emulsions we need to stress are following:
▶ Low-temperature crude oil demulsification
▶ Heavy oil and ultra-heavy oil demulsification
▶ Tertiary produced liquid emulsified crude oil demulsification
Mechanism of Resin and TOFA Components in Demulsifiers
Mechanism of Resin and TOFA Components in Demulsifiers
TOFA (Tall Oil Fatty Acid) Components: Derived from the paper industry, TOFA acts as a surfactant, reducing interfacial tension between oil and water. This facilitates water droplet coalescence, accelerating separation. TOFA often works synergistically with other components to boost demulsifier efficacy.
Demulsifiers are usually mixtures of surfactants, including alkoxylated resins, polyethers and fatty acid derivatives.
EO/PO block copolymer is a common nonionic surfactant, which is made by block polymerization of ethylene oxide (EO) and propylene oxide (PO) and is widely used in demulsifier formulations. High fatty acid (tofa) is the fatty acid component of tall oil, derived from by-products in wood pulp production. It contains long-chain fatty acids such as oleic acid and linoleic acid and is often used in the synthesis of resins or surfactants.
The EO part provides hydrophilicity, and the PO part provides lipophilicity. When tofa is added, its long-chain fatty acids further enhance lipophilicity. This amphiphilicity enables the resin to be effectively distributed at the oil-water interface, interfering with the stabilizing effect of natural emulsifiers (such as asphaltenes and resins) and promoting the coalescence of water droplets. The addition of tofa will reduce the HLB value, making the resin more suitable for processing W/O emulsification, as the demulsifier needs to dissolve in the oil phase and migrate to the interface.
However, an excessively high tofa ratio may cause the resin to be overly lipophilic, reducing its effective adsorption at the interface. If the proportion is too low, the resin may become overly hydrophilic and difficult to enter the oil phase.
Therefore, YouzhuChem suggest that the optimized ratio of tofa needs to be determined through experiments based on the specific conditions of the emulsion (such as oil-water ratio, salinity, and temperature).
Demulsifiers are usually mixtures of surfactants, including alkoxylated resins, polyethers and fatty acid derivatives.
EO/PO block copolymer is a common nonionic surfactant, which is made by block polymerization of ethylene oxide (EO) and propylene oxide (PO) and is widely used in demulsifier formulations. High fatty acid (tofa) is the fatty acid component of tall oil, derived from by-products in wood pulp production. It contains long-chain fatty acids such as oleic acid and linoleic acid and is often used in the synthesis of resins or surfactants.
The EO part provides hydrophilicity, and the PO part provides lipophilicity. When tofa is added, its long-chain fatty acids further enhance lipophilicity. This amphiphilicity enables the resin to be effectively distributed at the oil-water interface, interfering with the stabilizing effect of natural emulsifiers (such as asphaltenes and resins) and promoting the coalescence of water droplets. The addition of tofa will reduce the HLB value, making the resin more suitable for processing W/O emulsification, as the demulsifier needs to dissolve in the oil phase and migrate to the interface.
However, an excessively high tofa ratio may cause the resin to be overly lipophilic, reducing its effective adsorption at the interface. If the proportion is too low, the resin may become overly hydrophilic and difficult to enter the oil phase.
Therefore, YouzhuChem suggest that the optimized ratio of tofa needs to be determined through experiments based on the specific conditions of the emulsion (such as oil-water ratio, salinity, and temperature).
Solvents Used for Diluting Demulsifiers
Solvents Used for Diluting Demulsifiers
Demulsifiers are typically diluted to ensure uniform application. Common solvents include:
- Hydrocarbons: Diesel, kerosene, or aromatic solvents like xylene, compatible with crude oil.
- Alcohols: Isopropyl alcohol (IPA) or methanol, often used for Water-Soluble Demulsifiers.
- Glycols: Ethylene or propylene glycol, suited for specific formulations.
The solvent choice depends on the demulsifier’s solubility, crude oil type, and operational conditions.
Injection Points and Methods for Demulsifiers
Injection Points and Methods for Demulsifiers
Demulsifiers are applied at various stages:
- Downhole: Injected into the wellbore to treat emulsions as they form.
- Wellhead: Added at the surface to address emulsions before processing.
- Separation Facilities: Introduced in separators or treaters to enhance phase separation.
- Pipelines: Injected during transportation to improve flow and reduce viscosity.
Application methods include:
- Continuous Injection: A steady demulsifier stream is added to the fluid flow.
- Batch Treatment: Periodic addition in larger doses, often in storage tanks or separators.
The demulsifiers can be added in various ways: By injection through a bore hole at high pressure, by injection at the collection point at low to medium pressure or by injection into the storage tank – intermittent metering at low pressure.
Evaluating Demulsifier Performance
Evaluating Demulsifier Performance
Performance is assessed using key metrics:
- Water Separation Efficiency: Percentage of water removed within a set time.
- Oil Quality: Residual water and salt levels in treated oil, meeting pipeline or refinery standards.
- Separation Speed: Time taken for emulsion breaking and phase separation.
- Dosage Efficiency: Amount of demulsifier needed for effective separation (lower is better).
- Stability: Consistency across varying temperatures, pressures, and crude compositions.
Bottle tests are a standard method, trialing demulsifiers on emulsion samples to observe separation behavior.
01
/
Emulsion Type and Composition
Type of Emulsion: Identify whether the emulsion is water-in-oil (W/O) or oil-in-water (O/W). This is essential because demulsifiers are formulated to target specific emulsion types, and selecting the correct one depends on this determination.
Composition: Analyze the oil and water phases for components such as natural surfactants, solids (e.g., clay or sand), or other impurities. These can stabilize the emulsion, so understanding their presence helps in choosing a demulsifier that can counteract these stabilizing agents effectively.
02
/
Emulsion Stability
Aging: Check the age of the emulsion. Fresh emulsions may differ from aged ones due to changes in viscosity or component oxidation, which can affect demulsification difficulty and the type of demulsifier needed.
Temperature: Record the temperature at which the emulsion was formed and will be tested. Temperature impacts emulsion stability and demulsifier performance, with higher temperatures often aiding separation if the demulsifier is suitable.
03
/
Physical Properties
Viscosity: Measure the emulsion’s viscosity. High viscosity can slow separation by resisting droplet coalescence, requiring a demulsifier that effectively lowers interfacial tension.
Droplet Size: Evaluate the size of the dispersed phase droplets. Smaller droplets are more stable and harder to break, often needing a more potent demulsifier to promote coalescence.
04
/
Chemical Properties
pH and Salinity: Assess the pH and salinity of the water phase. These factors can affect demulsifier efficiency, particularly if it relies on ionic interactions, so the demulsifier must be compatible with these conditions.
Presence of Solids: Determine if solids are present, as they can stabilize the emulsion at the oil-water interface. A demulsifier with properties to handle solids, such as flocculation or dispersion, may be required.
05 /
Demulsifier Characteristics
Demulsifier Characteristics
Compatibility: Ensure the demulsifier matches the emulsion’s chemistry. For example, water-soluble demulsifiers suit O/W emulsions, while oil-soluble ones are better for W/O emulsions.
Dosage: Find the optimal dosage through preliminary tests. Too little or too much demulsifier can reduce separation efficiency, making this step critical.
06 /
Testing Conditions
Testing Conditions
Mixing Method: Use a consistent mixing technique to blend the demulsifier into the emulsion without causing further emulsification. Proper mixing ensures the demulsifier reaches the interface effectively.
Temperature Control: Keep the testing temperature consistent, ideally matching field conditions or optimizing separation. Temperature affects both the separation rate and demulsifier performance.
07 /
Performance Metrics
Performance Metrics
Separation Rate: Observe how quickly the emulsion separates after adding the demulsifier. A faster rate is preferable, but it should align with effective separation.
Water Quality: Check the clarity and quality of the separated water. Clear water with minimal oil content indicates successful demulsification, while murky water suggests incomplete results.
Notable Brands and Manufacturers of Demulsifiers
Notable Brands and Manufacturers of Demulsifiers
Several prominent demulsifier manufacturers supply oilfield demulsifiers:
- Schlumberger (M-I SWACO): Offers solutions for diverse crude types and conditions.
- Baker Hughes: Provides tailored demulsifiers, including heavy oil demulsifiers.
- Nalco Champion (Ecolab): Known for a broad range of oilfield chemicals, including demulsifiers.
- Clariant
https://www.clariant.com/en/Solutions/Products/2014/10/30/12/58/PHASETREAT
: Focuses on sustainable, high-performance demulsifiers. - BASF: Supplies demulsifiers for heavy crude oil demulsifiers and water-in-oil emulsions.
- Croda: Specializes in surfactant-based demulsifiers.
These brands often customize formulations to address specific oilfield challenges.
YouzhuChem has designed its' demulisifers and reverse demulsifiers for crude oil dehydration and desalination, field trials in wells have been conducted to gauge the effectiveness of the chosen solution. The specialized products have been used with excellent results in various parts of world.
The Demulisifiers are formed by polymerizing ethylene oxide and propylene oxide in a mixed state under alkaline condition using phenol resin, polybasic alcohol, polyethylene polyamine as a starting the agent.
They get the advantages:
▶ Easy to disperse in crude oil.
▶ Easy to dilute.
▶ Easy to use.
And please tell the specification of your crude emulsions, our Demulsifier UBPro-411 is Insoluble in water, suitable for some early production crude process.
Contact us
To send us your specification so that we can offer you’re the product accordingly.You can consult the representatives of YouzhuCHEM to learn about the relevant additive schemes, injection points and injection dosages.
Oilfield Chemicals Demulsifiers are indispensable for efficient oil demulsification, enabling the separation of water from crude oil across production stages. Whether Oil-Soluble Demulsifiers for water-in-oil emulsions or Water-Soluble Demulsifiers for niche applications, their composition and application methods are tailored to optimize performance, supported by leading demulsifier manufacturers. Understanding their mechanisms and evaluation criteria ensures effective use in the oilfield.