1. What is oilfield equipment protection corrosion inhibitor?

Oilfield equipment protection corrosion inhibitor is a chemical agent specifically used to slow down the corrosion of oilfield equipment. In the process of oilfield mining, gathering and transportation, oil and water treatment, etc., equipment is often damaged by contact with corrosive media such as acidic gases (such as carbon dioxide, hydrogen sulfide), salts, and microorganisms. Corrosion inhibitors form a protective film on the metal surface to prevent corrosive media from contacting the metal, thereby extending the service life of the equipment. This anti-corrosion method does not require changing the properties of metal components and has the advantages of economy, strong adaptability, and high efficiency.

2. Characteristics of oilfield equipment protection corrosion inhibitor

Oilfield equipment protection corrosion inhibitor has the following significant characteristics:

High efficiency: Even at low concentrations, it can significantly reduce the corrosion rate. For example, some high-efficiency corrosion inhibitors can reduce the corrosion rate to an extremely low level at a concentration of 0.2%.

Strong adaptability: It can be applied to a variety of corrosive environments, including complex conditions such as high temperature, high pressure, and high salt. For example, some corrosion inhibitors can effectively control corrosion under high salt concentration and carbon dioxide saturation conditions.

Easy operation: Just add the corrosion inhibitor to the corrosive medium without large-scale modification of the equipment. For example, the corrosion inhibitor is injected into the annular space of the oil casing by a pump, and the corrosion inhibitor forms a protective film on the metal surface to play a protective role.

Environmental protection: With the improvement of environmental protection requirements, new corrosion inhibitors are developing in the direction of low toxicity and pollution-free.

3. Classification of corrosion inhibitors for oilfield equipment protection

(I) Imidazoline

Imidazoline corrosion inhibitor is a common heterocyclic corrosion inhibitor. Its molecular structure contains an imidazoline ring and a long hydrocarbon chain. The typical molecular formula is: C_nH_2n+1−N(CH₂CH₂OH)−C₅H₆N₂ This corrosion inhibitor adsorbs on the metal surface through the nitrogen atom on the imidazoline ring to form a dense protective film. It has good adsorption properties for a variety of metals (such as carbon steel, copper, etc.), and can effectively prevent acidic gases (such as H₂S, CO₂) from corroding metals. For example, EC1020A is an imidazoline mixed in heavy aromatic naphtha, which can effectively control H₂S-HCl-H₂O type corrosion in the low-temperature part of the tower top.

(II) Proprietary surfactant blend

The surfactant blend corrosion inhibitor is a corrosion inhibitor made of a variety of surfactants. Its composition is complex, usually including anionic, cationic and non-ionic surfactants. This corrosion inhibitor prevents the corrosive medium from contacting the metal by forming a multi-layer adsorption film on the metal surface. Its molecular structure contains multiple polar groups, which can strongly electrostatically adsorb to the metal surface. For example, 7461-102 corrosion inhibitor is made of coal tar pyridine kettle slag, industrial alcohol and leveling agent 102, among which leveling agent 102 is a non-ionic surfactant with emulsification, solubilization, dispersion stability and wetting properties.

(III) Oligomeric ester quat Polyester quaternary ammonium

Polyester quaternary ammonium corrosion inhibitor is a cationic surfactant, which contains multiple quaternary ammonium groups in its molecular structure. The typical molecular formula is: [R−N(CH₃)₃Cl]_n, where R is a long hydrocarbon chain. Polyester quaternary ammonium corrosion inhibitor forms a uniform protective film by electrostatic adsorption of anions on the metal surface through its cationic group. It performs well in high-temperature acidification operations and can effectively prevent rapid corrosion of metals.

(IV) Alkyl phosphate ester Phosphate ester

Phosphate ester corrosion inhibitor is an organic phosphoric acid corrosion inhibitor, which contains phosphoryl groups in its molecules and can react with metal ions to form insoluble complexes that cover the metal surface and play an anti-corrosion effect. Its typical molecular formula is: R−PO(OH)₂, where R is a long hydrocarbon chain. Phosphate ester corrosion inhibitor performs well in aqueous corrosion environments and can effectively prevent uniform and local corrosion of metal surfaces.

4. Application of corrosion inhibitors for oilfield equipment protection

Corrosion inhibitors for oilfield equipment protection are widely used in all aspects of oilfields:

Drilling process: corrosion inhibitors are added to prevent corrosion of drill pipes. For example, some oil-soluble water-dispersed surfactant corrosion inhibitors can be used to control the corrosion of the inner surface of the drill pipe.

Acidification operation: polyester quaternary ammonium corrosion inhibitors can effectively protect oil pipes. For example, after EC1020A corrosion inhibitor is injected into the atmospheric tower top distillation line, it can effectively control the corrosion of the low-temperature part of the tower top.

Oil-water treatment link: imidazoline corrosion inhibitors can be used to prevent uniform corrosion of equipment. For example, the 2SY92-1 oil well corrosion inhibitor used in Zhongyuan Oilfield can effectively control corrosion under high salt concentration and carbon dioxide saturation conditions.

Oil tanks, pipelines and other equipment: phosphate corrosion inhibitors can be used for long-term corrosion protection. For example, some organic phosphate corrosion inhibitors perform well in oilfield gathering and transportation systems.

Supplier of corrosion inhibitor

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.