Start Date
December 2013

Background
In late 2013 a two-step proposal was presented to the CCQTA membership. Step 1 involved the development of a method for measuring specific contaminants (CO₂, O₂, H₂S) in crude. Step 2 would focus on methods to monitor on a regular basis for these or other contaminants. Monitoring for these gases was deemed important to both pipelines and railcars.

The project was launched late in December 2013 and became a CCQTA sponsored project in 2016.

Milestones as of August 2023

• AITF/Enbridge present modified TM0172M method. 2014
  
• The initial gas chromatography test method development work for CO₂, O₂, H₂S undertaken by Canmet Energy was unsuccessful however in 2015 AITF (InnoTech) agreed to take over method development work. 2015
  
• Omnicon/Enbridge/IPL developed test method and results presented for O₂ measurement in condensates & other hydrocarbons by optical probe in pressurized streams. 2016
  
• Draft corrosivity evaluation protocol presented combining multiple tests to evaluate different parameters contributing to corrosion. 2016
  
• Enbridge presented a proposal for the development of a corrosion assessment model for oxygen in hydrocarbon. 2017
  
• Innotech completed GC HPLIS direct injection test method for measuring for O₂ and CO₂ with H₂S capability in development. 2018
  
• Completed O₂ and CO₂ sampling program on the Enbridge Norlite system. Results were presented at the December 2018 CCQTA meeting. 2018
  
• Decision at March 2020 meeting to discontinue efforts to add H₂S separation and detection to the scope of the current O₂ and CO₂ method.
  
• Enbridge sponsored sampling and testing campaign on both the Norlite diluent system as well as Edmonton terminal crudes (MSW, WDB and SYN) has concluded. Samples were collected for both O₂ and CO₂ as well as H₂S, water content and sediment. Study results were presented at the March 2021 project meeting.
  
• Results of the 2021 sampling campaign were presented at the March 2022 project meetings.
  
• The target for this sampling campaign is to gather samples of crude oil that would represent the maximum concentration of CO₂ that could be expected. Regions that have active EOR (tertiary recovery) using CO₂ flooding are anticipated to have the highest concentrations.
  
• At the March 2022 meeting, preliminary OLI modeling results on a CO₂/Oil/Water system was presented. The modeling work was intended to estimate the impact of CO₂ on in-situ water pH and if transmission pipelines are at risk from CO₂ related corrosion.
  
• The initial model over predicted the CO₂ partial pressure however, even with over predicted values the corrosion rate was very low.
  
• A comparison was also made between fresh water and water containing chlorides and bicarbonate. The additional of bicarbonate lowered the corrosion rate by ~100 x.
  
• The second set of samples collected in 2022 showed similar CO₂ results for WCS and CL however the MD result was significantly higher (1800 wppm vs 800 wppm previously). Equation of State (EOS) simulations using the MD composition showed beyond 1800 wppm CO₂ the vapor pressure of the crude would exceed atmospheric pressure and would no longer be stabilized.
  
• Revised OLI modeling was conservatively performed at 2000 wppm CO₂.
  
• At the September 2022, the results of latest sampling, testing and OLI modeling were presented. These results confirmed the findings of the earlier work, that CO₂ at levels found in stabilized crude oil are at or below the NACE 1 mpy threshold in the presence of bicarbonate.
  

• The final report for this project was released in May 2023. The full report and an abbreviated version are both available under the projects directory of the CCQTA website. This report has not been released publically.
  
• This project is now closed.