9 September, 2025

Corrosion Monitoring Methods in Pipelines: Best Practices for the Oil & Gas Industry

Introduction

Corrosion is one of the most critical threats to pipeline integrity in the oil and gas industry. It can lead to leaks, equipment failures, environmental disasters, and costly downtime. To ensure safe and efficient operations, companies must implement robust corrosion monitoring methods.

At NND Oil & Gas, we specialize in helping energy companies detect, analyze, and mitigate corrosion before it becomes a serious issue. In this blog, we explore the most effective corrosion monitoring methods used in pipelines and how they contribute to asset longevity and safety.

Why Corrosion Monitoring Is Essential

Pipelines in the oil and gas sector are exposed to a wide range of corrosive environments, including moisture, chemicals, CO₂, H₂S, and microbial activity. Left unchecked, corrosion can:

1. Cause pipeline ruptures
2. Endanger human lives and ecosystems
3. Lead to legal and regulatory penalties
4. Increase maintenance and repair costs
5. Reduce pipeline lifespan

Monitoring corrosion proactively is not just good practice – it’s a regulatory and operational necessity.

Key Corrosion Monitoring Methods in Pipelines

Here are the top methods used across the oil & gas industry:

1. Visual Inspection

Overview:
The simplest form of monitoring, visual inspection involves manual observation of pipeline surfaces using the naked eye or specialized equipment like drones and robotic crawlers.

Pros:

1. Low-cost
2. Immediate feedback
3. Can detect obvious surface damage

Cons:

1. Limited to external surfaces
2. Doesn’t detect internal or early-stage corrosion

2. Ultrasonic Testing (UT)

Overview:
Ultrasonic waves are used to measure wall thickness and detect material loss due to corrosion.

Pros:

1. Accurate wall thickness measurement
2. Detects internal and external corrosion
3. Non-destructive

Cons:

1. Requires skilled operators
2. May need surface preparation

3. Electrical Resistance (ER) Probes

Overview:
ER probes measure metal loss over time by monitoring the change in electrical resistance.

Pros:

1. Real-time corrosion rate monitoring
2. Suitable for harsh environments

Cons:

1. Requires data logging systems
2. Limited by probe placement

4. Linear Polarization Resistance (LPR)

Overview:
LPR sensors measure the rate of corrosion electrochemically, ideal for water-based environments.

Pros:

1. Fast response time
2. Effective in aqueous environments

Cons:

1. Not suitable for dry gas pipelines
2. Requires continuous monitoring

5. Coupon Monitoring

Overview:
Corrosion coupons are metal samples inserted into the pipeline system and periodically removed for analysis.

Pros:

1. Simple and cost-effective
2. Provides historical corrosion data

Cons:

1. Time-delayed results
2. Does not give real-time monitoring

5. Smart Pigging

Overview:
Smart pigs are intelligent devices inserted into pipelines that scan for corrosion, cracks, and wall thinning as they move through the system.

Pros:

1. Internal inspection of long pipeline sections
2. High-resolution data
3. Identifies exact corrosion locations

Cons:

1. Expensive
2. Requires pipeline shutdown during deployment

Choosing the Right Method

The best corrosion monitoring strategy depends on several factors:

1. Pipeline location (onshore, offshore, buried, subsea)
2. Product transported (oil, gas, multiphase)
3. Pipeline age
4. Budget and operational constraints
5. Regulatory requirements

At NND Oil & Gas, we help you design and implement a custom corrosion monitoring program tailored to your operational and environmental conditions.

Benefits of a Robust Corrosion Monitoring System

Implementing a comprehensive monitoring system delivers measurable value:

1. Extends pipeline service life
2. Enhances operational safety
3. Minimizes unplanned downtime
4. Supports regulatory compliance
5. Optimizes maintenance schedules
6. Reduces total cost of ownership

Conclusion

Corrosion is inevitable—but failure is not. By leveraging the right monitoring technologies and working with experienced partners like NND Oil & Gas, operators can stay ahead of corrosion, maintain pipeline integrity, and ensure safe, compliant operations.