The first globally consistent survey of gas flaring has been conducted using satellite data, and a series of national and global estimates of gas flaring volumes have been produced covering a twelve-year period spanning 1995 through 2006.
The survey, which was commissioned and funded by the World Bank’s Global Gas Flaring Reduction partnership (GGFR), was executed by scientists at the US National Oceanic and Atmospheric Administration.
When crude oil is brought to the surface from several kilometers below, gas associated with such oil extraction usually comes to the surface as well. If oil is produced in areas of the world which lack gas infrastructure or a nearby gas market, a significant portion of this associated gas may be released into the atmosphere, un-ignited (vented) or ignited (flared).
Gas flaring estimates, which were produced for sixty countries or areas around the world, show that global gas flaring has remained largely stable over the past twelve years, in the range of 150 to 170 BCM.
According to the satellite data, in 2006 oil producing countries and companies burned about 170 billion cubic meters (bcm) of natural gas worldwide or nearly five trillion cubic feet. That’s equivalent to 27% of total U.S. natural gas consumption and 5.5% of total global production of natural gas for the year. If the gas had been sold in the United States instead of being flared, the total US market value would have been about $40 billion. Gas flaring also emits some 400 million tons of carbon dioxide (CO2) emissions.
“Gas flaring not only harms the environment by contributing to global warming but is a huge waste of a cleaner source of energy that could be used to generate much needed electricity in poor countries around the world,” says Bent Svensson, manager of the Bank’s GGFR partnership. “In Africa alone about 40 billion cubic meters of gas are burned every year, which if put to use could generate half of the electricity needed in that continent.”
Flaring or burning of gas is widely used to dispose of natural gas liberated during oil production and processing when this occurs in remote areas far from potential users, where there is often no infrastructure on site to make use of the gas. In recent years, however, renewed efforts are being made to eliminate flaring, such as re-injecting it into the ground to boost oil production, converting it into liquefied natural gas for shipment, transporting it to markets via pipelines, or using it on site for generation of electricity.
“This study proves that it is possible to monitor gas flaring from space and make reasonable and independent estimates of the volume being wasted,” says Christopher Elvidge a scientist with NOAA’s National Geophysical Data Center (NGDC) and lead author of the study. “In the past, the only way to track gas flaring was through official estimates, but now those days are over. These independent figures should help governments and companies alike to get a better sense of how much gas they are actually flaring.”
Since this is the first study of gas flaring using satellite observations, scientists warn that these preliminary results should be used with caution, as there still are several sources of error and uncertainty, including variations in flare efficiency, misidentification of flares, non-continuous sampling, and environmental effects.
According to the satellite observations, 22 countries have increased gas flaring over the past 12 years. These include: Azerbaijan, Chad, China, Equatorial Guinea, Ghana, Iraq, Kazakhstan, Kyrgyzstan, Mauritania, Myanmar, Oman, Philippines, Papua New Guinea, Qatar, Russia (excluding Khanty Mansiysk region), Saudi Arabia, South Africa, Sudan, Thailand, Turkmenistan, Uzbekistan, and Yemen.
On the other hand, the satellite observations show that 16 countries have decreased gas flaring from 1995 to 2006, including Algeria, Argentina, Bolivia, Cameroon, Chile, Egypt, India, Indonesia, Libya, Nigeria, North Sea, Norway, Peru, Syria, UAE and USA (offshore).
And nine countries have had largely stable gas flaring across those 12 years. These include Australia, Ecuador, Gabon, Iran, Kuwait, Malaysia, Khanty-Mansiysk (Russian Federation), Romania, and Trinidad.
The authors used low-light imaging data from the U.S. Air Force Defense Meteorological Satellite Program to assess the volumes of gas burned in flares, which are visible in observations of nighttime lights under cloud-free conditions. Current and planned satellite sensors will continue to provide data suitable for estimating gas flaring volumes for decades to come. GGFR encourages on-site monitoring as well to help track changes in gas flaring volumes and to report progress in reducing flaring.