Vanconol® ET-102 Surface Gathering and Transportation Corrosion Inhibitor

1.  Product Overview

During oil and gas field development and gathering processes, multiple corrosive factors such as H₂S, CO₂, dissolved oxygen, bacteria, and high-salinity produced fluids coexist, significantly accelerating the corrosion and deterioration of metal pipelines and equipment.

Vanconol® ET-102 is a self-developed alkyl imidazoline adsorption-film type corrosion inhibitor that effectively addresses corrosive media including dissolved oxygen, H₂S, CO₂, and chloride ions, while also suppressing under-deposit localized corrosion. The product is non-toxic, environmentally friendly, and heavy-metal-free, specifically designed for oil and gas surface gathering and transportation systems.

2. 📊 Key Product Parameters

2.1 Physicochemical Specifications

Parameter	Specification	Test Method
Appearance	Yellow transparent liquid	Visual inspection
Water solubility	Water-dispersible, no phase separation	GB/T 6324.1
Density d₂₀ (g/cm³)	0.9 – 1.1	GB/T 13378
pH (10% aqueous solution)	≤ 8	SH/T 0069
Kinematic viscosity (mm²/s, 40℃)	< 80	GB/T 265
Pour point (℃)	≤ −10	GB/T 3435
Corrosion inhibition efficiency (electrochemical method, %)	≥ 80	GB/T 35509-2017
Corrosion inhibition efficiency (static weight loss method, %)	≥ 70	GB/T 35509-2017

Chemical Composition: Composite blend of alkyl imidazoline corrosion inhibitor + specialty surfactants + synergists

2.2 Measured Corrosion Inhibition Performance Data

The following data were obtained from third-party laboratory evaluations of oil and gas field corrosion inhibitors (N80 steel substrate):

Test No.	Application	Dosage	Test Method	Test Conditions	Corrosion Inhibition Efficiency	Corrosion Rate	Standard Requirement
ET-102-①	Produced water	30 ppm	Atmospheric static	Salinity 62,400 mg/L, CO₂ saturated, 50℃, 7 days	96.16%	—	≥ 70% ✓
ET-102-②	Gathering/transportation	200 ppm	High-pressure static	Salinity 62,400 mg/L, CO₂ partial pressure 0.8 MPa, total pressure 2 MPa, 50℃, 7 days	90.62%	0.52 mm/a	> 75% ✓
ET-102-③	Gathering/transportation	200 ppm	High-pressure dynamic	Salinity 62,400 mg/L, CO₂ partial pressure 0.8 MPa, total pressure 4 MPa, 50℃, 7 days, 150 rpm	96.00%	0.27 mm/a	> 75% ✓

Key Findings: All three measured corrosion inhibition efficiencies significantly exceed standard requirements. Under atmospheric static conditions, an efficiency of 96.16% was achieved at a dosage of just 30 ppm; under high-pressure dynamic conditions, the corrosion rate was as low as 0.27 mm/a. These results confirm ET-102’s excellent corrosion inhibition performance in gathering and transportation service conditions.

3. 🛠️ Mechanism of Action

The corrosion inhibition mechanism of ET-102 is based on the dual action of chemical adsorption film formation and electrochemical inhibition:

3.1 Adsorption Film Formation

Heteroatoms such as N atoms within the molecule and metal-anchoring groups rapidly adsorb onto active sites on the metal surface via coordinate bonds, forming a dense monomolecular adsorption film. The adsorption film exhibits the following characteristics:

• Density: The imidazole ring planes align parallel to the metal surface, with intermolecular van der Waals forces enabling tight molecular packing

• Selectivity: Preferential adsorption at anodic active regions, blocking the anodic dissolution process of Fe → Fe²⁺ + 2e⁻

• Stability: Maintains adsorption strength under high-temperature (≥ 50℃) and high-salinity conditions without significant desorption

3.2 Electrochemical Inhibition

The adsorption film simultaneously affects both cathodic and anodic processes of corrosion electrochemistry:

• Cathodic inhibition: Reduces the diffusion rate of H⁺ toward the metal surface, slowing the cathodic hydrogen evolution reaction (2H⁺ + 2e⁻ → H₂↑)

• Anodic inhibition: Blocks direct contact between corrosive media (Cl⁻, H₂S, CO₂) and the metal surface, suppressing anodic dissolution

• Synergistic effects: Specialty surfactants reduce interfacial tension, while synergists enhance the stability of the adsorption film under high-temperature, high-pressure conditions

3.3 Correlation of Measured Data with Mechanism

Service Condition	Measured Efficiency	Mechanistic Interpretation
Atmospheric static, 30 ppm	96.16%	Under static conditions the adsorption film achieves complete surface coverage, enabling high inhibition efficiency even at low dosages
High-pressure static (2 MPa), 200 ppm	90.62%	High-pressure CO₂ increases the corrosion driving force; efficiency decreases slightly but remains well above standard requirements
High-pressure dynamic (4 MPa, 150 rpm), 200 ppm	96.00%	Shear forces do not disrupt the adsorption film; instead, enhanced mass transfer of the inhibitor improves efficiency

4. 📋 Application Guide

4.1 Applicable Scenarios

Scenario	Typical Conditions	Suitability
Surface gathering pipelines	CO₂/H₂S coexistence, salinity ≤ 80,000 mg/L	✓ Recommended
Gathering station equipment	Temperature 40–80℃, water-bearing	✓ Recommended
Produced water reinjection systems	High salinity, CO₂-containing	✓ Suitable
Downhole (oil wells)	High temperature, high pressure, H₂S-containing	⚠️ ET-101 (well-specific type) recommended

4.2 Recommended Dosage

Service Condition	Recommended Dosage	Remarks
Conventional gathering (temperature ≤ 65℃)	≥ 15 ppm	Calculated based on produced water volume
High-temperature gathering (temperature > 65℃)	≥ 75 ppm (active matter)	High temperature accelerates corrosion; higher dosage required
Highly corrosive media (H₂S + CO₂ coexistence)	Determined by laboratory testing	Simulated water quality coupon testing recommended

Dosage Determination Principle: The optimal dosage varies with corrosive media content, temperature, flow rate, and water quality of the produced water.It is strongly recommended that laboratory simulation testing (static coupon or electrochemical methods) be conducted prior to field application to determine a cost-effective dosage.

4.3 Usage Instructions

1. Pre-operation inspection: Verify the product in the drum is in a uniformly flowable state; if solidified, pre-heat until fluid (water-bath heating recommended, temperature not exceeding 60℃)

2. Dosage calculation: Calculate the total required amount based on produced water volume × recommended dosage

3. Dilution: May be diluted as needed on-site; softened water is recommended for dilution; transfer the calculated amount into a dedicated container and meter it into the system

4. Injection method: Continuous injection via metering pump or batch dosing is acceptable; injection at the pump station inlet or upstream of the mixer is recommended to ensure thorough mixing

5. ⚠️ Safety and Storage

• Packaging: Plastic drums, net weight 220 L per drum; custom packaging available upon request

• Storage and transport: Protect from sunlight, heat, moisture, and impact; store in a clean, cool, and dry warehouse

• Residual product: Reseal immediately after use to prevent evaporation and moisture absorption

• Shelf life: One year under ambient storage conditions

• Safety: The product is non-toxic, environmentally friendly, and heavy-metal-free; standard protective gloves and safety goggles are recommended during handling

6. ❓ Frequently Asked Questions (FAQ)

Q1: What is the difference between ET-102 and ET-101? How do I choose?

A: Both are alkyl imidazoline corrosion inhibitors but are designed for different applications:

• ET-101 is a well-specific type designed for downhole high-temperature, high-pressure environments without H₂S (measured 82.53% efficiency at 60℃/30 ppm)

• ET-102 is a surface gathering/transportation type suitable for produced water and gathering systems, capable of handling CO₂/H₂S coexistence (measured 96.16% efficiency at 50℃/30 ppm)

Selection should be based on the application: downhole → ET-101; surface gathering/produced water → ET-102.

Q2: How does ET-102 perform under high-pressure dynamic conditions?

A: Under CO₂ partial pressure of 0.8 MPa, total pressure of 4 MPa, and 150 rpm agitation, a measured corrosion inhibition efficiency of 96% was achieved at 200 ppm, with a corrosion rate of 0.27 mm/a — significantly better than the industry standard (> 75%). Dynamic shear forces do not disrupt the adsorption film; on the contrary, improved mass transfer further enhances the inhibition efficiency.

Q3: Can ET-102 be used in combination with scale inhibitors?

A: Yes. ET-102 is a pure corrosion inhibitor and does not contain scale inhibition components. If scaling risk also exists in the system (e.g., high calcium/magnesium produced water), combining with a scale inhibitor is recommended, or alternatively, Vanconol® ET-103 (an integrated scale/corrosion inhibition product) can be selected.

Q4: How do I determine the optimal cost-effective dosage?

A: The optimal dosage depends on corrosive media concentration, temperature, flow rate, and water quality. Recommended procedure:

1. Collect a field produced water sample

2. Conduct static coupon tests in the laboratory (gradient dosages: 15/30/50/75/100 ppm)

3. Determine the economic inflection point from the efficiency-versus-dosage curve

7. 📞 Technical Support

For further information, product samples, or on-site technical support, please contact the Vanconol® technical service team.