Texas Continues to Issue Thousands of Flaring Permits

The Texas Railroad Commission continues to approve almost all applications for flaring and venting natural gas at drilling sites. As a result,  flaring and venting of natural gas in Texas during drilling operations continues to be a significant source of green-house gas emissions.   As reported here, this is in spite of rules which prohibit flaring, or burning off, natural gas at the wellhead except under a few specific conditions.  In reality nearly all applications for flaring are approved, "rubber stamped", according to some.

"Since the Railroad Commission launched a flaring exemption database in May 2021, the records include only 44 applications that were denied and more than 8,000 that were approved."

"In addition to releasing methane and other hazardous air pollutants, including volatile organic compounds, flaring contributes to ground-level ozone, which causes respiratory illness and heart disease. Flaring has also been linked to pre-term births."

Their are relatively few studies on the products of incomplete combustion during flaring. One lists these products that were detected at a flare site:

"Incomplete combustion instead produces potentially harmful compounds such as: carbon monoxide, unburned hydrocarbons, Volatile Organic Compounds (VOC’s) and sulphur compounds. These products can have effects on public health – carbon monoxide affects people with heart disease and can harm the central nervous system."

Ideally, flares produce no smoke, indicating near complete combustion of methane to CO2.  But it is not uncommon in the field to see lots of black smoke from flare stacks. In other places the lack of smoke indicates that the flare is not even lit and is emitting large volumes of methane and other volatile hydrocarbons to the atmosphere.

A 2022 report in Science includes data on what the researchers found when they flew planes through a flare plume to sample and then analyzed emissions from gas flaring.  The results are startling. Perhaps, most troubling is that many permitted flare operations do not even light the flare, instead simply venting, emitting large quantities  of methane:

"Flaring is widely used by the fossil fuel industry to dispose of natural gas. Industry and governments generally assume that flares remain lit and destroy methane, the predominant component of natural gas, with 98% efficiency. Neither assumption, however, is based on real-world observations."

 They found:

"...both unlit flares and inefficient combustion contribute comparably to ineffective methane destruction, with flares effectively destroying only 91.1% ...of (the) methane."

"This represents a fivefold increase in methane emissions above present assumptions and constitutes 4 to 10% of total US oil and gas methane emissions, highlighting a previously underappreciated methane source and mitigation opportunity."

So, flaring and venting are significant but far from all methane emissions from natural gas activities. If poor flaring and venting practices accounting for only "4-10% of total US oil and gas methane emissions", where do the other 90 to 96% of emissions come from?

The short answer is "leaks".

"Wells to Wheels": methane life-cycle analysis

“Well-to-Wheels”: GWP -Global Warming Potential

Total GHG emissions from natural gas production is far higher than just from flaring and venting. Leakage rates from each portion of the value chain (drilling, treatment, storage, pipelines and ships, abandoned wells) are far higher than EPA originally assumed.

Contrary to previous estimates of CH₄ losses from the “upstream” portions of the natural gas fuel cycle (8, 9), a recent paper by Howarth et al. calculated upstream leakage rates for shale gas to be so large as to imply higher lifecycle GHG emissions from natural gas than from coal (1). (SI Text, discusses differences between our paper and Howarth et al.) Howarth et al. estimated CH₄ emissions as a percentage of CH₄ produced over the lifecycle of a well to be 3.6–7.9% for shale gas and 1.7–6.0% for conventional gas. (boldface is mine).

The authors conclude:

"On the one hand, a shift to natural gas is promoted as climate mitigation because it has lower carbon per unit energy than coal or oil (6). On the other hand, methane (CH₄), the prime constituent of natural gas, is itself a more potent GHG than carbon dioxide (CO₂); CH₄ leakage from the production, transportation and use of natural gas can offset benefits from fuel-switching."

"Estimates of the net climate implications of fuel-switching strategies should be based on complete fuel cycles (e.g., “well-to-wheels”) and account for changes in emissions of relevant radiative forcing agents. Unfortunately, such analyses are weakened by the paucity of empirical data addressing CH₄ emissions through the natural gas supply network, hereafter referred to as CH₄ leakage.* The U.S. Environmental Protection Agency (EPA) recently doubled its previous estimate of CH₄ leakage from natural gas systems (6)."

Obviously, this is disconcerting. Have we derived any reduction in total greenhouse gas emissions by switching from coal to gas fired generation?  It is dubious, at best.

"Methane’s contribution to climate change in the short term is more potent than carbon dioxide. The oil and gas industry is the second-largest source of industrial methane emissions in the United States, after agriculture."

"The Global Warming Potential (GWP) was developed to allow comparisons of the global warming impacts of different gases."

"Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO₂)"

"Methane (CH₄) is estimated to have a GWP of 27-30 over 100 years. CH₄ emitted today lasts about a decade on average, which is much less time than CO₂. But CH₄ also absorbs much more energy than CO₂. The net effect of the shorter lifetime and higher energy absorption is reflected in the GWP. The CH₄ GWP also accounts for some indirect effects, such as the fact that CH₄ is a precursor to ozone, and ozone is itself a GHG. "

With regard to flaring and venting, regulators are well aware of the abuses in the permitting process.  

"At a Railroad Commission meeting last month, Commissioner Jim Wright chastised Callon Petroleum for flaring natural gas at a drilling site, saying it should “find a better solution.”"

"But his comment came after he voted to grant the Houston-based company a flaring permit that allows Callon to continue flaring gas at the Crockett 15 well in the Permian Basin into the seventh consecutive year."

Wright pointed out the natural gas Callon flares is “fully marketable.” He also noted the company was requesting a “sizable increase” in the amount of permitted flaring. The new permits more than double the volume of gas Callon can flare at the drilling sites, compared to previous permits.

“I find this particular situation troubling,” Wright said. “I would suggest that this operator and its vendors attempt to find a better solution to eliminate the need to keep coming back to the commission to administratively forgive the waste of our natural resources.”"

"Crockett 15, a horizontal gas well, has received 16 different flaring exceptions dating back to 2018. Between July 1, 2022 and June 30, 2023, Callon reported that over nine percent of the gas produced at the well was flared."

Aside from the emission of greenhouse gases and other noxious gases, it just doesn´t makes sense economically.  It is the epitome of short term thinking that makes it possible to flare/vent so much of this resource. The IEA reports:

"Over 140 bcm of natural gas was flared in 2021 and a further 125 bcm was vented or leaked to the atmosphere from oil and gas operations. This waste of natural gas is happening against the backdrop of tight and volatile gas markets."

"If all the gas flared in routine operations during 2021 was brought to markets today, its revenues would amount to about USD 60 billion. Capturing methane emissions could bring over USD 30 billion."

The data suggest that flaring, venting and leaks in the supply chain result in, conservatively speaking, at least 9% of total gas production.  How much is that?

"In 2022, natural gas consumption in the United States amounted to around 881 billion cubic meters, up from nearly 836 billion cubic meters one year earlier and the highest value recorded within the period of consideration. Between 1998 and 2022, natural gas consumption in the U.S. increased by almost 251 billion cubic meters."

1 kg of natural gas releases 2.75 kg of CO2 when burned. At atmospheric pressure (approx. 1 Bar) 1 cubic metre of natural gas has a mass of 0.68 kilograms.

So, 881 billion cubic meters of natural gas weighs 599 billion kgs. or 599 million tonnes and releases 1647 million tonnes of CO2. If, in order to get 599 million metric tons of gas to burn, 665 million metric tons had to have been produced if just 9%, as described here, of it was lost to leaks, incomplete flaring and venting. That 9% of 665 resulted in 59.85 million metric tons of methane released, equivalent to (GWP methane is 27 times that of CO2) 1616 million metric tons CO2, making the total emissions  3263 equivalent million metric tons of CO2. The resulting increase in GWP from methane emissions is 98%, about double.

In terms of power produced, burning natural gas emits about 200.8 g (0.0002008 tonnes) CO2 per kWh_PE. Burning soft coal  emits about 407.3 per kWh_PE (0.0004073 tonnes), a ratio of a bit less then 1::2. 

However, the conservatively estimated 9% of methane produced that is emitted to the atmosphere from ineffective flares, leaks in the supply chain and venting nearly doubles the effective GWP of the natural gas that is produced. The ratio of emissions of CO2 equivalent of natural gas production and burning, including the emissions of methane,  to burning soft coal is thus reduced to about 1::1, at the very least.  I do not have an estimate of the CO2 emissions for producing coal.  That should be taken into account.

But, it is not unreasonable to suggest that the actual GWP for the use of natural gas is, when accounting for methane releases, is very similar to that of soft coal.

One has to wonder how the natural gas industry gets away with this.  Producers of natural gas seem to have sold the idea that natural gas is far more "green" than coal.  It has taken a great deal of effort and lots of "experts" to convince the public.

Statements such as this appear in EIA documents:  Please have a look.  This page looks like it could have been lifted from an oil company  pleasant dream.

Is natural gas more polluting than coal?

Natural gas is a relatively clean burning fossil fuel,

Burning natural gas for energy results in fewer emissions of nearly all types of air pollutants and carbon dioxide (CO₂) than burning coal or petroleum products to produce an equal amount of energy.

True enough, that is, as long as it is burned nearly completely.  But it is not. Not by a long shot. Also, it should be pointed out that there are both better and worse examples than the Permian Basin of methane (mis)-management in the Oil&Gas Industry. One obvious example of even worse management of gas via leaks and flaring is Russia.

"State gas giant Gazprom is burning off, or “flaring,”about 4.34 million cubic meters of gas a day at a new liquified natural gas (LNG) facility, according to analysis of heat levels and satellite data by Rystad Energy."

Heaven knows how much is simply vented.

But the fact remains that, in effect, the burden is on the natural gas industry to prove that they have gotten us even one inch closer to Net Zero than coal has.  Until they do, their claims of being an effective "bridge fuel" to effective climate-change management are ludicrous.