Energy Research Improves Sour Gas and Natural Gas Liquids Understanding in BC’s Northeast

Vancouver, BC – July 20, 2022 – Research results published by Geoscience BC provide a new understanding of the distribution and nature of hydrogen sulphide ‘sour gas’ and location of natural gas liquids in British Columbia’s Northeast Region.

The multi-year, multi-partner study sought to understand why sour gas only affects some wells in the region’s Montney, Doig and Duvernay formations – the source of the majority of the natural gas produced in BC. Numerous theories had been previously proposed, and the report concludes that the cause is most likely from sulphate that had migrated through faults and fractures into the Montney from deeper zones.

Sour gas is natural gas that contains measurable amounts of H2S. If sour gas is present in the subsurface, it creates health, environmental and economic risks while drilling, producing, or treating the gas.

Isotopic analysis of the sulphur in the sour gas largely demonstrated a match with Triassic rocks containing anhydrite. This sulphate-rich mineral has migrated (while in solution) to the Montney Formation rocks that host hydrocarbons. The reaction between the hydrocarbons and sulphate led to formation of the sour gas.

In addition to tracing the source of the gas, the new study includes maps that can aid risk-analysis for sour gas. The study also used detailed workflows and modelling to map the nature and distribution of natural gas liquids associated with the Montney Play.  Natural gas liquids are a class of hydrocarbons that include products like propane, butane and condensate.

Geoscience BC Manager, Energy and Water Randy Hughes said: "Being able to map and better understand the source of the sour gas, as well as better predict the distribution of natural gas liquids can assist operators and regulators in better decision-making around the development of new wells.”

Industry partners in the Distribution, Origin, and Implications of Hydrogen Sulphide in Unconventional Reservoir Rocks in Western Canada with Insights into the Stratigraphic Zonation and Lateral Variability of Producible Hydrocarbon Liquids project included AGAT, Chevron Canada, Crew Energy, EnCana/Ovintiv, Pacific Canbriam and Saguaro Resources.

Accessing information

To view the reports and maps, visit the project page or view the information on Geoscience BC's Earth Science Viewer online mapping application.

 

View project page          View project in Earth Science Viewer

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For more information, please contact:

Richard Truman

Geoscience BC

604-662-4147 / 778-929-1662

truman@geosciencebc.com