Oilfield cleaning hydrotrope: a "weapon" to help oilfields achieve efficient exploitation and clean production
Oilfield cleaning hydrotrope is a chemical agent specially used in the process of oilfield exploitation to clean oil pollution, improve crude oil recovery and reduce environmental pollution. It achieves effective cleaning and displacement of oil-based drilling fluid, oil pollution and residual crude oil in the formation by reducing the oil-water interfacial tension, emulsifying and solubilizing crude oil.
1. What is an oilfield cleaning hydrotrope?
Oilfield cleaning hydrotrope is a complex chemical formula mainly composed of surfactants, additives and solvents. Its core function is to reduce the oil-water interfacial tension, separate crude oil from the formation or equipment surface, and disperse it into the water phase, thereby achieving efficient cleaning and solubilization.
During the oilfield exploitation process, oil-based drilling fluid and crude oil often form oil films and mud cakes that are difficult to remove on the well wall and equipment surface, resulting in a decrease in cementing quality, reduced equipment efficiency, and even environmental pollution problems. The emergence of oilfield cleaning hydrotrope provides an effective chemical means to solve these problems.
2. Characteristics of oilfield cleaning hydrotropes
High solubilization ability: Oilfield cleaning hydrotropes can significantly reduce the oil-water interfacial tension, making crude oil easier to emulsify and solubilize. For example, some high-efficiency oil recovery cleaning agents can reduce the oil-water interfacial tension to the order of 10⁻³ mN/m at low concentrations.
Good wettability: By adjusting the composition of surfactants, oilfield cleaning hydrotropes can change the surface contaminated by crude oil from lipophilic to hydrophilic, thereby improving the cleaning efficiency.
Environmental friendliness: Modern oilfield cleaning hydrotropes mostly use environmentally friendly formulas, avoid the use of highly toxic or difficult-to-degrade chemicals, and reduce pollution to the environment.
Strong adaptability: This type of cleaning agent can be adjusted according to different oilfield conditions (such as temperature, mineralization, crude oil properties), and has a wide range of applicability.
Synergy: The combination of multiple surfactants and additives can produce synergistic effects, further improving the cleaning and solubilization effects.
3. Classification of oilfield cleaning hydrotropes
Oilfield cleaning hydrotropes can be divided into the following categories according to their chemical composition and mechanism of action:
(I) Anionic surfactants
Anionic surfactants are a common type of component in oilfield cleaning hydrotropes, with good emulsification and solubilization capabilities. Common anionic surfactants include:
Sodium dodecylbenzene sulfonate (C₁₂H₂₅NaOSO₃)
This is a commonly used anionic surfactant with good emulsification and dispersibility, and is widely used in oilfield cleaning agents.
Sodium octylphenol polyoxyethylene ether carboxylate
Through the introduction of polyoxyethylene ether, this surfactant has good wettability and emulsification ability, and is suitable for high temperature and high salt environments.
(II) Cationic surfactants
Cationic surfactants usually have good bactericidal and dispersibility, and are often used in compound systems to enhance the cleaning effect. Common cationic surfactants include:
Tetradecyltrimethylammonium chloride (C₁₄H₃₁NCl)
This is a typical quaternary ammonium salt cationic surfactant with good bactericidal and emulsifying properties, and is often used in the compounding of oilfield cleaning agents.
Dodecyltrimethylammonium chloride (C₁₂H₂₅NCl)
This compound has good surface activity and emulsifying ability and can be used to clean oil-based drilling fluids.
(III) Nonionic surfactants
Nonionic surfactants also occupy an important position in oilfield cleaning hydrotropes. They are characterized by good water solubility and emulsifying ability and are environmentally friendly. Common nonionic surfactants include:
Polyoxyethylene-polyoxypropylene block copolymer (PEO-PPO)
This block copolymer can achieve good wettability and emulsifying properties by adjusting the ratio of ethylene oxide and propylene oxide, and is suitable for a variety of oilfield cleaning scenarios.
Fatty alcohol polyoxyethylene ether (CₓHₓOₓ)
This type of surfactant has good emulsification and solubilization ability and is often used to clean equipment contaminated by crude oil.
(IV) Quaternary Ammonium Compounds
Quaternary ammonium salts are an important type of cationic surfactants and are widely used in oilfield cleaning hydrotropes. Their molecular structure usually contains a quaternary ammonium cation and a halogen anion. Quaternary ammonium salts have excellent surface activity, emulsification, bactericidal, antistatic and solubilizing properties, which can effectively reduce the oil-water interfacial tension and enhance the cleaning and solubilization effects.
Common quaternary ammonium salts and their applications
Cetyltrimethylammonium Chloride (CTAC)
Chemical properties
Molecular formula: C₁₉H₄₂ClN
Molecular weight: 320
Appearance: white crystalline solid or colorless to pale yellow liquid.
CTAC has many uses in oilfield cleaning hydrotropes:
Emulsification and solubilization: CTAC can effectively reduce the oil-water interfacial tension, emulsify crude oil and disperse it into the water phase, thereby improving the cleaning effect.
Bactericidal and anti-corrosion: Due to its cationic properties, CTAC has good bactericidal properties and can be used for anti-corrosion treatment of oilfield equipment.
Oilfield additives: CTAC can be used as an emulsifier for high-temperature resistant oil-in-water emulsified mud and used in the preparation of oilfield drilling fluids.
Sludge treatment: CTAC can effectively decompose and clean crude oil in sludge and reduce environmental pollution.
Dodecyltrimethylammonium Chloride
Chemical properties
Molecular formula: C₁₂H₂₅NCl
Appearance: colorless to light yellow liquid.
Application
Dodecyltrimethylammonium chloride is mainly used in oilfield cleaning agents and has the following characteristics:
Emulsification ability: It can effectively emulsify oil-based drilling fluids and crude oil, and is suitable for cleaning oil pipes and equipment surfaces.
Synergistic effect: often compounded with other surfactants to enhance the cleaning and solubilization effects.
Environmental friendliness: has good biodegradability and has little impact on the environment.
As an important component of oilfield cleaning hydrotropes, quaternary ammonium salts have become an indispensable chemical additive in oilfield exploitation and production due to their excellent chemical properties and wide application scenarios.
4. Application of oilfield cleaning hydrotropes
Oilfield cleaning hydrotropes are widely used in oilfield exploitation and production, covering multiple links from equipment cleaning to increased recovery. The following are its main application areas:
(I) Oil well cleaning and unblocking
Oil well pipe cleaning
During the oil well exploitation process, a large amount of crude oil, wax and silt will adhere to the inner wall of the oil pipe, causing the oil pipe to be blocked and reducing production efficiency. Oilfield cleaning hydrotropes can effectively remove dirt on the inner wall of the oil pipe and restore the patency of the oil pipe by chemical cleaning. For example, HM-803 oilfield injection and production well neutral unblocking agent can quickly dissolve wax and oil stains in the oil pipe through its efficient solubilization and dispersion ability, thereby improving the oil recovery efficiency of the oil well.
Oil well unblocking
During the oilfield exploitation process, the formation pores may be blocked by crude oil, wax or mud, resulting in a decrease in oil well production. Oilfield cleaning hydrotropes can be injected into the formation to reduce the oil-water interfacial tension, disperse the blockages and carry them out with the water flow, thereby restoring the permeability of the formation. For example, QJN-871 oil well neutral supramolecular cleaning agent can effectively dissolve organic and inorganic scales in the formation and improve the permeability of the oil well.
(II) Oil-based drilling fluid cleaning
Drill pipe cleaning
During the drilling process, a large amount of oil-based drilling fluid and cuttings will adhere to the surface of the drill pipe, affecting the drilling efficiency and equipment life. Oilfield cleaning hydrotropes can remove the oil-based drilling fluid from the surface of the drill pipe through chemical emulsification and disperse it into the water, thereby achieving efficient cleaning.
Drilling fluid recovery and treatment
The recovery and treatment of oil-based drilling fluid is an important part of oilfield environmental protection. Oilfield cleaning hydrotropes can solubilize the crude oil and harmful components in the discarded oil-based drilling fluid, so that it can be recycled and reused, while reducing pollution to the environment.
(III) Produced water treatment
Oil field produced water usually contains a large amount of crude oil and suspended solids, and direct discharge will cause serious pollution to the environment. Oil field cleaning hydrotrope can be used for the pretreatment of produced water. The crude oil in the water is dispersed by solubilization, which is convenient for subsequent oil removal and purification.
Filter cleaning
During the produced water treatment process, the filter material will be blocked due to the accumulation of oil and impurities, affecting the filtering effect. Oil field cleaning hydrotrope can be used to clean the filter material and restore its filtering performance.
(IV) Oil pollution cleaning and environmental protection
Sludge cleaning
A large amount of sludge is generated during the production process of oil fields. These sludges contain a large amount of crude oil and harmful substances, which pose a serious threat to the environment. Oil field cleaning hydrotrope can be used to clean the sludge. The crude oil in the sludge is separated by chemical solubilization to achieve the reduction and resource treatment of the sludge.
Equipment surface cleaning
During the long-term operation of oil field equipment, a large amount of oil and corrosion products will adhere to the surface, affecting the performance and life of the equipment. Oilfield cleaning hydrotropes can be used to clean the surface of equipment, remove oil stains and corrosion products, and extend the service life of equipment.
(V) Improved recovery rate
Oil displacement agent
Oilfield cleaning hydrotropes can be used as oil displacement agents. By reducing the oil-water interfacial tension, the residual crude oil in the formation can be more easily displaced, thereby improving the crude oil recovery rate. For example, HM-703 cleaning hydrotropes have shown good oil displacement effects in oilfield field applications and can significantly increase the production of oil wells.
Profile control agents
In the middle and late stages of oilfield development, the heterogeneity of the formation will lead to ineffective circulation of injected water and reduce the recovery rate. Oilfield cleaning hydrotropes can be compounded with profile control agents to block high permeability layers, adjust the flow rate of injected water, and improve the sweep efficiency of injected water.
(VI) Other applications
Oil tank cleaning
After long-term storage of crude oil in oil tanks, a large amount of sludge and impurities will be deposited on the tank wall and bottom, affecting the oil storage capacity and service life of the oil tank. Oilfield cleaning hydrotrope can be used to clean oil tanks, remove dirt in the oil tanks by chemical cleaning, and restore the oil storage capacity of the oil tanks.
Gathering and transportation pipeline cleaning
During the long-term operation of oilfield gathering and transportation pipelines, a large amount of crude oil, wax and impurities will adhere to the inner wall of the pipeline, affecting the pipeline's transportation capacity. Oilfield cleaning hydrotrope can be injected into the pipeline through the pipeline cleaning system, remove dirt in the pipeline through chemical cleaning and solubilization, and restore the pipeline's transportation capacity.
Oilfield Chemicals Supplier
UNPChemicals is a professional oilfield chemical manufacturer, with products covering drilling, completion, oil production, gathering and transportation, etc., and has won the trust of customers with advanced technology, strict quality control and high-quality services. We are committed to personalized solutions to help oilfields develop efficiently.