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Project Overview (Presented at the Global Methane Forum, 2018)

Background: Methane Emissions from Energy Production

Methane gas accounts for approximately 25% of human-caused global warming and is 84 times more effective as a greenhouse gas (GHG) than carbon dioxide, over a period of 20 years. The oil and gas sector produces approximately 44% of Canada鈥檚 methane emissions, with methane representing 15% of Canada鈥檚 GHG emissions. In light of Canada鈥檚 international commitments to combat climate change, regulations have been established to reduce methane emissions from the oil and gas sector by 40-45% from 2012 levels by the year 2025. Ottawa has proposed a regulatory plan regarding equipment leaks, venting, pneumatic devices, compressors and well completions.

Why Methane Emissions from Legacy Sites Matters in the Maritime Provinces

In the Maritimes, legacy sites represent the main methane emission threat as most upstream industry (oil and gas) development predates modern regulation.

Wells

• New Brunswick: 85% 0f 302 drilled onshore wells sit in a suspended or abandoned state, and 60% of that total were abandoned over 70 years ago.
• Nova Scotia: fewer than 1% of the wells drilled are still in production.
• In both provinces: the majority of wells were decommissioned before proper well abandonment procedures were developed and enforced.

Improper well sealing can lead to well bore leakage and gas migration, which involves uncontrolled migration of thermogenic gas and oil. This could lead to methane emissions to

• shallow groundwater
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• the atmosphere as a potent greenhouse gas

Mines

• The Nova Scotia government has documented approximately 7000 historic coal mine openings, including 1922 pits, shafts, adits and slopes (NSDNR, 2016).
• Methane liberation declines after mining activity ceases, yet abandoned mines can emit methane at a near-steady rate for an extended period of time if not flooded.
• Studies of abandoned mines conducted in the US found negligible emissions were detected from several flooded mines, while others emitted over 500 000 ft^{3 听}of methane per day.

As such, legacy sites in the Maritimes may have been emitting persistently for over a century and could be excellent targets for permanent mitigation.听

Our Research: Gas Seepage Project (GaSP)

In order to achieve a better understanding of the methane dynamics at legacy oil and gas wells in Nova Scotia and New Brunswick, an innovative and multi-discinplinary approach was taken. The Gas Seepage Project (GaSP) was developed, and research was completed in 2017-18.

GaSP is the first multi-stakeholder project completed in the Atlantic Provinces evaluating methane emissions from legacy oil and gas extraction sites. This short-term, multifaceted project involved individuals from universities, consulting firms and commercial enterprises, and represents a collaboration of approximately 30 researchers.

Project methodology spanned several disciplines and combined well-documented techniques used to estimate methane fluxes between geological reservoirs, groundwater and soil conduits, and the atmosphere (ex. groundwater sampling, static chambers) with innovative, new technology and approaches (drone-based surveys, autonomous methane sensors).

To learn more about the GaSP project, please visit the project webpage.

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