Reducing challenges related to reservoir souring in province's offshore
Drs. Helen Zhang, Kelly Hawboldt and Amy Hsiao, professors in Memorial’s Faculty of Engineering and Applied Science, along with Drs. Penny Morrill and Christina Bottaro of the Faculty of Science, recently established a $3.4 million collaborative research partnership with Suncor Energy Inc. to identify the mechanisms, impacts and potential solutions related to offshore reservoir souring.
To enhance oil and gas production, sea water containing naturally occurring sulphate is injected into the reservoir. The seawater, combined with any sulphur compounds already present in the petroleum, can cause various sulphur compounds to form that are corrosive in nature. This results in increased costs due to platform equipment corrosion, water-handling systems, and transporting and processing the oil.
The multidisciplinary research focuses on the delineation and management of the sulphur cycle, corrosion control and improved production. The researchers are combining their expertise to take a comprehensive approach to the issue of reservoir souring, which is an important step in developing production methods to maximize the extraction of petroleum from the reservoir. Although there is ongoing research in Western Canada in the challenges of onshore reservoir souring, this is the first in Canada where the focus is offshore.
Dr. Hsiao’s research focuses on the challenges associated with the characterization and prediction of corrosion of carbon steel, similar low alloy steels and novel corrosion-resistant alloys in sour acid gas environments. She is establishing a H2S Standards and Materials Research and Testing facility for investigating the interaction of these metallic surfaces and structures in various oil and gas production conditions.
“This lab will be the first of its kind in Canada, and it is noteworthy that it will be here at Memorial,” she said. “Suncor’s initiative to address this topic will result in important developments in the prediction of long-term offshore asset integrity and the optimization of monitoring procedures. The potential for meaningful results and understanding of the corrosion phenomena that is being observed in offshore operations is great. I am also thrilled to be part of this great mix of strong, enthusiastic researchers.”
Dr. Hawboldt, with Dr. Bottaro, is studying the chemical sources of souring (seawater, production chemicals etc.), the behaviour of these sulphur compounds in the production system and mitigation methods to prevent souring.
“Dr. Bottaro and I are working closely with the other researchers on this project to get a full understanding of sulphur chemistry,” said Dr. Hawboldt. “In particular, we are combining the biological souring process and the chemistry souring process to get a full understanding of how the process initiates and propagates.
“Suncor’s vision was to integrate researchers from different backgrounds for this very purpose, to get a complete understanding of the process and, thereby, develop solutions. To be involved at such an early stage in the process and working with Suncor to address a challenge, and to see one’s work being applied to a real industry problem, is particularly exciting for a researcher”
Dr. Zhang, with Dr. Morrill, is investigating the interactions between sulphate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB), and examining possible offshore reservoir souring inhibition due to nitrate/nitrite injection.
“SRB are responsible for the majority of bacterial problems in oil production, and reservoir souring can be directly caused by SRB as a byproduct of respiration,” explained Dr. Zhang. “The application of nitrates/nitrites could be very effective for reservoir souring control by promoting NRB, consuming nutrients that SRB require to grow, thus inhibiting SRB activity.
“I am very happy to work with my peers on this multidisciplinary research. By investigating optimal growth conditions for NRB to inhibit microbial sulphate reduction in closed nitrate/nitrite enrichment experiments, we will help Suncor tackle SRB‐triggered reservoir souring problems and, thus, reduce operational challenges in offshore oil and gas operations.”