Oilfield flaring is a very visible source of greenhouse gas (GHG) emissions in oil and gas, both for the eyes and the environment. The International Energy Agency (IEA) estimates that carbon dioxide (CO2) produced by flaring accounts for roughly 5% of overall oil and gas industry GHG emissions, meaning around 265 million metric tons of CO2 in 2020 alone. And that’s without considering the invisible, unburned methane resulting from incomplete combustion during flaring.
On average, the global combustion efficiency of flares is estimated to be 92%, which in 2020 resulted in the release of approximately 8 million metric tons of unburned methane emissions on top of the CO2. If you consider methane’s GHG potential (discounting future warming at 2.5% annually) to be 50 times that of carbon dioxide, then that unburned methane is equivalent to 400 million metric tons of CO2e and more than doubles the true global warming impact of flaring. Not to mention that poor combustion efficiency also results in soot and other particulate matter that can adversely affect the health of people living nearby.
A flare at 95% efficiency has double the carbon footprint of a flare near 100%.
This is one of the main reasons why the oil and gas industry is striving to minimize flaring as much as possible. The global challenge of reducing GHG emissions and combatting climate change is driving a growing desire (and increasing pressure) to reduce—and ultimately eliminate—certain types of flaring.
The second reason is that it wastes hydrocarbons that could otherwise be used as an energy source. The World Bank estimates that 144 billion cubic meters of gas were flared at upstream oil and gas facilities worldwide in 2021. That’s enough to power the whole of sub-Saharan Africa for a year.
This means that reducing flaring emissions also plays a role in energy security and accessibility—a timely opportunity. Predictions of future cost increases and limited supply have shifted attention to coal in countries that rely on imported natural gas to meet energy demand. Meanwhile, the IEA estimates that nearly 210 billion cubic meters of natural gas could be made available to gas markets through a global effort to eliminate routine flaring and reduce methane emissions from oil and gas operations.
Meeting the challenge of providing the world with secure and accessible energy while reducing atmospheric GHG concentrations will take a generation or longer. That being said, there is potential for a quick win-win: scale down the flaring of hydrocarbons and use them to our benefit instead.
But before delving into how this can be achieved using existing technology, it’s important to have a clear picture of what kinds of flares are in operation today.
The routine, the nonroutine, and the in-between
Flaring operations are typically described as routine, nonroutine, and safety (or emergency). Routine flaring is quite persistent and can occur for several reasons. Often, it is performed when the cost of transporting the excess natural gas associated with oil and gas production to market exceeds the price for which it can be sold. In this case, eliminating the practice requires advanced techno-economic solutions that either address the former, the latter, or both. Other times, routine flaring is used to dispose of low-BTU gas (gas with less heat energy) from processing activities such as dehydration and acid gas removal.
Although it happens less frequently, a significant percentage of overall flaring activity relates to nonroutine flaring, which is intermittent and of short duration. Nonroutine flaring typically occurs in the exploration, appraisal, or development phases of a well, during operations such as well testing and cleanup. It can also occur after a well undergoes temporary maintenance or repairs. Like its routine counterpart, nonroutine flaring normally occurs because oil and/or gas being produced isn’t commercially viable due to fluid treatment requirements, lack of infrastructure, or both.
Finally, there is emergency flaring, which occurs less frequently but is essential for safe operations at oil and gas production facilities. This type of flaring can be difficult to avoid or mitigate because the frequency and duration of the activity is much harder to predict.
The primary goal: Elimination
The obvious solution to eliminate emissions from flaring is to stop flaring operations. For many cases of both routine and nonroutine flaring, this implies commercially viable solutions to get the hydrocarbon to market.
Great progress has already been made to reduce flaring activity across several traditional operations related to nonroutine flaring. When it comes to well tests, for example, new technologies and approaches such as deep transient testing on wireline can replace more traditional dynamic reservoir characterization methods such as drill stem tests (DSTs), thereby eliminating flaring in the process. During poststimulation well cleanups, on the other hand, a combination of advanced multiphase pumping technologies, multiphase metering, flow simulations, and the availability of nearby production infrastructure have proven to be effective in eliminating flaring. And the results are notable: Operators in Kazakhstan and Oman have managed to achieve emissions reductions totaling over 300,000 metric tons of carbon dioxide equivalent (CO2e) using techniques to eliminate flaring from well testing and cleanup capabilities.
Operators in Kazakhstan and Oman achieved emissions reductions of over 300,000 metric tons of carbon dioxide equivalent.
In routine flaring, and in some cases also in nonroutine flaring when there’s no production infrastructure nearby, the challenge is to find a cost-effective solution for monetizing the gas that would otherwise be flared. To address this, there has been a lot of recent innovation in “gas-to-value” technologies and processes that convert the otherwise flared gas to commodities that are either more profitable to sell or less expensive to transport, or both. Among the “value” in “gas-to-value” are compressed natural gas (CNG), liquified natural gas (LNG), specialty chemicals, liquid fuels that can be injected into pipelines, local usage, animal feed, and even powering mobile cryptocurrency mining.
If you can’t eliminate, minimize
The technical challenges of eliminating flaring are clear and, while elimination is an important goal, it’s important that flares remain as efficient as possible in the interim. As previously mentioned, methane emissions from incomplete flare combustion result in a substantially larger GHG footprint. You’d be surprised how critical every increment of a percent is when it comes to environmental impact. A flare operating at 95% efficiency, for example, has double the carbon footprint of a flare at near 100% efficiency.
The industry’s most efficient burner reaches 99.84% efficiency!
Much progress is being made in improving flare combustion efficiency. Imaging technologies that monitor flares and ensure that they operate at peak efficiency are a great example. Other high-efficiency flaring services focus on maximizing combustion efficiency. They convert more hydrocarbon to CO2 instead of releasing unburned methane or particulate matter into the air, thereby minimizing GHG emissions through design optimization. Consider this: the industry’s highest efficiency, DNV-certified burner for use with oil achieves a peak combustion efficiency of 99.84%!
More decarbonization on the horizon
Reducing flaring can be a triple win for the oil and gas industry: It can reduce global warming, reduce local pollution, and increase the amount of secure energy available for society. That opportunity has motivated the industry, and many have responded. To date, 35 governments and 54 oil companies have committed to zero routine flaring by 2030.
Moving forward, as more organizations commit to the same, the industry must collectively accelerate its efforts. The elimination of flaring emissions is a tough yet exciting challenge. It requires industry players to work in partnership to develop and deploy a wider range of solutions for profitably selling the hydrocarbon already flared today. Simultaneously, quickly shifting our flaring efficiency from 92% to 100% is a clear goal that requires its own attention, monitoring, and optimization.
Needless to say, we (as an industry) are on it.
