Engineering Assessment - Internal Corrosion Hazard Profiling

NACE - ICDA Step 2 - Indirect Inspection (IDI)

Q-ICDA is our technical algorithm that pin-points the most probable locations for internal corrosion based upon post-processing of raw pipeline flow modelling data with consideration of internal corrosion deterioration mechanisms. 

Accurately Pin-Points Corrosion Locations

Q-ICDA algorithms are the foundation of NACE - ICDA standard methods, and proven against in-line inspection data as a reliable method for pin-pointing the most probable corrosion locations along a pipeline to exhibit significant corrosion damage >50% wall loss.

Risk-Aligned Mitigation Guidance

Q-ICDA hazard assessment algorithms provide the foundation for risk-based mitigation guidance for field, operation and chemical teams.


Q-ICDA anchors performance-based integrity management

Q-ICDA Positions Field Teams to Manage Change

The 25-year Legacy of Q-ICDA

Q-ICDA is the foundation of the NACE - ICDA methods.

NACE - ICDA is a simplification of Q-ICDA.

A Practical Demonstration of Q-ICDA

Field teams are positioned to adjust mitigation schedules appropriate to changes in the corrosion hazard profile that occur during periods of reduced flow rates.

Q-ICDA fits within NACE - Step 2 - Indirect Inspection (IDI)


Q-ICDA is our Engineering Assessment Method within NACE - ICDA - Step 2 - Indirect Inspection (IDI)

  • Application of pipeline modelling to establish the likelihood of failure due to internal corrosion deterioration mechanism(s) along the pipeline route;
  • Identify the most cost-effective measures required to reduce the risk to an acceptable level; and,
  • Provide the basis for a Cost Benefit Analysis to be completed prior to undertaking activities to verify the integrity of a pipeline.

Q-ICDA Aligns with NACE - ICDA Project Structure

Q-ICDA Provides an Enhanced Assessment vs NACE - ICDA

INGAA Internal Corrosion Committee Adopted Q-ICDA in 2002

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Important work for the most critical pipeline infrastructure

High-Risk Oil & Gas Gathering Systems

High-Risk Oil & Gas Gathering Systems

High-Risk Oil & Gas Gathering Systems


Create a rigorous Pipeline Integrity Plan that considers the corrosion profile and mitigation response for the highest-risk oil and gas pipelines, with consideration of potential environmental impact and business losses.

Crude Oil & NGL Shipping Pipelines

High-Risk Oil & Gas Gathering Systems

High-Risk Oil & Gas Gathering Systems


Characterize the operating conditions that can lead to oil-water slippage in crude oil sales pipelines, and subsequent accumulation of stagnant water traps; potential locations for corrosion along the pipeline.

Gas Transmission Pipelines

High-Risk Oil & Gas Gathering Systems

Gas Transmission Pipelines


Although the chance of internal corrosion is considered a very unlikely occurrence, the probability of corrosion may not be nil.  It is important to consider the implications of episodic upsets to upstream processing facilities, and to establish the appropriate mitigation response by application of Q-ICDA within a formal integrity management plan.

NACE - ICDA - Step 2 - IDI including Q-ICDA

Q-ICDA creates a hazard assessment profile along the entire pipeline route, with consideration the over-life integrity implications of steady-state, and upset operating conditions.

This innovative combination of fluid hydraulic data with corrosion mechanism algorithms embedded into the Q-ICDA method is well supported by industry and has formed the basis for the NACE - ICDA technical standard.

Q-ICDA integrates into NACE - ICDA projects to provide the basis for hazard assessment, and integrity management plans proven to deliver long-term reliable operation.

Q-ICDA algorithms transform flow data into corrosion profile


Consideration of Corrosion from Steady-State Conditions, and from Ingress of Fugitive Fluids

Quantitative Internal Corrosion Direct Assessment (Q-ICDA)  incorporates Pipeline Fluid Flow Data to Establish Corrosion Rate & Corrosion Pitting Profiles along the Pipeline.

Post-processing algorithms applied onto raw pipeline modelling data transforms water-film transport properties into a corrosion damage profile

Q-ICDA calculates lifetime cumulative metal wall-loss


Cumulative Pipeline Corrosion Over Entire Operating Lifetime by Allocating Corrosion Rates According to Defined Range of Operating Eras (Periods)

Application of corrosion rates onto most probable locations (MPL's) of corrosion damage creates an estimate of expected over-life corrosion damage along the pipeline.


Digital Elevation Mapping

  • Considers the implication of pipeline elevation profile on the fluid flow dynamics;
  • Consideration of water-film transport to form detrimental stagnant water traps; possible locations of low pH corrosive regions.


Compositional Fluid Flow Pipeline Modelling Simulation

  • Application of pipeline fluid simulation models to provide characterization of three-phase (gas / oil / water) movement;
  • Fluid simulation data interpreted to identify regions of potential stagnant water hold-up;
  • Potential pH profile within identified water traps is established as foundation of corrosion rate profiles.


Sophisticated Pipeline Models + Understanding of Corrosion Mechanisms Delivers a Reliable Corrosion Damage Profile

  • Providing Field, Operations Teams with an Enhanced Analysis for Developing Mitigation, Monitoring and Inspection Plans for High-Risk Pipelines;
  • Potential corrosion damage profile has proven equivalent to performing an in-line inspection.

Q-ICDA mitigation guidance assures alignment with IC hazards


Mitigation guidance chart used as a reference for Field, Operations

  • Considers implications of corrosion rate profile with changing water-film transport at a range of production operating conditions; and,
  • Assures Field, Operations teams are always positioned to adjust mitigation schedules appropriate to changes in the corrosion hazard profile.

Q-ICDA Project Deliverable

A sample Q-ICDA project deliverable is attached for a 600 mile crude oil gathering network transporting 750,000 bbl/day to a large regional refinery complex.

Q-ICDA positions field teams to anticipate changes to the corrosion hazard severity, and to modify their maintenance schedules to; 1) prevent the growth of pre-existing corrosion damage; and, 2) prevent new corrosion from initiating.

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Count on Q-ICDA to pin-point critical corrosion locations


Pin-Point Locations of Corrosion Damage

  • Q-ICDA corrosion damage profiles position the owner to schedule cost effective integrity validation inspections.


Q-ICDA has a Proven Track Record

  • 90% of all defects < 50% wall loss characterized within two-joints of pipe; and,
  • 100% of all critical defects >50% wall loss characterized within a single joint of pipe as validated vs actual in-line inspection data.

Q-ICDA applied since 1994 & underpins NACE - ICDA standard


Contact Us to Discuss how Q-ICDA can Complement your Work

Q-ICDA within NACE - ICDA projects identifies pipelines most probable to corrode, pin-point locations most likely to exhibit corrosion damage, and provides risk-based mitigation guidance for field, operations and chemical teams.

David Richardson, P.Eng.

Trusted Pipeline Advisor

(403) 880-2835