Venting (Fugitive Sources / Oil and Natural Gas)

Understanding Venting and Fugitive Emissions

Venting, within the oil and gas sector, is one type of what are called Fugitive Emissions. The IPCC reporting guidelines (2006) define fugitive emissions to mean "all greenhouse gas emissions from oil and gas systems except contributions from fuel combustion. Oil and natural gas systems comprise all infrastructure required to produce, collect, process or refine and deliver natural gas and petroleum products to market. The system begins at the well head, or oil and gas source, and ends at the final sales point to the consumer. " Fugitive emissions are the catch-all: they are are defined as all emissions from the oil and gas systems, minus a few exceptions:

  • Combustion for useful heat or energy by stationary or mobile sources (which are counted in relation to the reason for stationary or mobile combustion)
  • Fugitive emissions from carbon capture and storage projects (which are counted in relation CO2 management)
  • Fugitive emissions that occur at industrial facilities other than oil and gas facilities (which are counted in the Industrial Processes and Process Use, rather than within Energy)
  • Fugitive emissions from waste disposal activities outside of the oil and gas industry (these are counted in Waste sectors rather than within the Energy sector)
All other fugitive emissions from oil and gas systems are included in this category, including the oil and gas production components of facilities that re-inject CO2 for the purposes of enhancing oil recovery.

Venting

Venting is an industry term for the controlled release of non-combusted gases into the atmosphere. The 2006 IPCC reporting guideline defines venting as comprising all engineered or intentional discharges of waste gas streams and process by-products to the atmosphere, including emergency discharges. These releases may occur on either a continuous or intermittent basis, and may include the following:

  • The use of pressurized natural gas instead of compressed air in pneumatic devices
  • Pressure relief and disposal of off-specification product during process upsets
  • Purging and blowdown events related to e.g. maintenance
  • Disposal of off-gas streams from oil and gas treatment units
  • Gas released from drilling and well testing
  • Disposal of waste-associated gas oil production facilities
  • Solution gas emissions from storage tanks, evaporation losses from e.g. process sewers, tailings ponds, even biogenic gas formation from tailings ponds
  • Discharge of CO2 extracted from refined gas

Reducing Venting Emissions

Critical Success Factors

  • Reduce the number of oil and gas wells
  • Reduce the venting of casing gas from oil and gas wells
  • Reduce the use of natural gas to drive pneumatic equipment
  • Reduce the venting of gas during equipment maintenance activities
  • Reduce the release of acid gas, which comprises mostly carbon dioxide
  • Reduce exposure of oil sands to open atmosphere
  • Reduce exposure of oil sands tailings and settling ponds to open atmosphere

Barriers

  • Alignment: Oil and gas continue to see enormous market demand.
  • Geopolitics: Comparable oil and gas operators in the US are scaling up under policies of the Trump administration.
  • Geopolitics: Canadian federal ambition is to position Canada as an energy superpower by exporting fossil fuels.
  • Cost: It is usually cheaper to venting something than to store it.
  • Scale: Historically, pneumatic equipment that vents depressurized natural gas was standard technology, and there are thousands of facilities using this technology.
  • Cost: Small remote facilities may have no convenient source of electricity to drive non-pneumatic equipment.
  • Uncertainy: there seems to be so much unreported emission of greenhouse gases that policies targeting reported emissions may not be meaningful.
  • Feasibility: There is no practical technology to prevent methane escape from oil sands mining surfaces or tailings ponds.

Possible Strategies

Description Cost / tonne CO2e
Replace gas-powered pneumatic equipment
Anything-but-gray hydrogen for the hydroconversion of bitumen
Reinject carbon dioxide back into gas-bearing formations
Various liquid carbon dioxide storage approaches
Replace gas vents with flaring systems
Somehow block the dispersion of emissions from oil sands with e.g. enormous tents

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