Earlier this week the Copernicus OBSERVER published an article about the improved abilities to track methane emissions from the oil and gas extraction industry from space. This capacity practically did not exist five years ago, but space and instrument technology have made big leaps since, partially thanks to Dutch instruments and Dutch science.
What is hydraulic fracturing?
Hydraulic fracturing, or fracking, is an extraction technique that enables the exploitation of new gas and oil reserves in subterranean shale deposits. It involves the fracturing of deep underground bedrock formations by a pressurised liquid. The process involves the high-pressure injection of ‘fracking fluid’ (primarily water, containing sand or other proppants suspended with the aid of chemical thickening agents) into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine will flow more freely. When the hydraulic pressure is removed from the well, small grains of hydraulic fracturing proppants (either sand or aluminium oxide) hold the fractures open.
Increasing energy demands, improvements in extraction techniques, and the emphasis on national energy independence have driven the growth of hydraulic fracturing worldwide. In some parts of the world concerns about the environmental impact of this technique have slowed or stopped its use, but in other regions, hydraulic fracturing is a common method of oil and gas extraction.
The environmental effects of unconventional oil and gas extraction are the subject of a strong debate among local citizens, legislators, government regulatory bodies, and the oil and gas industry. Claims that hydraulic fracturing causes harmful atmospheric emissions, groundwater and soil pollution, and earthquakes, have not been decisively addressed because of the absence of systematic analysis and monitoring of the impact of hydraulic fracturing. Natural gas is known as a clean fuel, emitting fewer greenhouse gases than alternatives such as coal. However, unmonitored methane leakage from hydraulic fracturing sites may counteract the benefits of natural gas use.
Research shows that natural gas is cleaner than coal when burned to generate electricity, producing about half the carbon dioxide that coal does. But if methane gets into the atmosphere before it is burned it can warm the planet more than 80 times as much as the same amount of carbon dioxide over a 20-year period.
The largest methane leak ever recorded, by Dutch Scientists
In February 2018, a blowout happened at a natural gas well run by an Exxon Mobil subsidiary in Belmont County, Ohio. This incident did not make many headlines and was quickly forgotten. Almost two years later, scientists from the New York-based Environmental Defense Fund and the Netherlands Institute for Space Research (SRON) got together to investigate the incident, using data from the new Sentinel 5P satellite, that had been launched shortly before the event. Their results were published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) and made headlines around the world. It is one of many new breakthrough publications based on Copernicus Sentinel-5P data.
The satellite’s measurements showed that in the 20 days it took for Exxon to plug the well in Ohio, about 120 metric tons of methane was released into the atmosphere every hour. The blowout leaked more of this potent greenhouse gas in 20 days than most European nations do in a year from their entire oil and gas industries.
Dutch Tropomi Instrument on Sentinel-5P
Methane is invisible to the human eye but can be detected spectroscopically. Like any gas, it absorbs light at specific frequencies. With a spectrometer mounted on a satellite it is possible to analyse light reflected from Earth for signs of the gas. Spectrometers come in many shapes and sizes, as do the satellites that carry them. The Tropomi instrument on board the Sentinel-5P satellite can also detect spectral signs of other polluting gases, such as nitrogen dioxide, sulphur dioxide and carbon monoxide. The Sentinel-5P satellite was launched in October 2017, complementing other Sentinel satellites in the Copernicus programme. Its detector has an extensive view, looking at a strip of Earth 2,600 km wide with a resolution of 7 km x 5.5 km for methane.
Fracking in Europe
In the first decades of the 21st century, fracking was extensively used in several European nations, including Denmark, Lithuania, Romania and the United Kingdom. The biggest country using hydraulic fracturing has been Poland , which has seen more shale exploration than any other European country. Poland’s shale-gas reserves are estimated to hold about 5,295 billion cubic metres (bcm) of technically recoverable gas, the most shale gas of any country in Europe. If all of this gas could be extracted, it would be equivalent to 325 years of Poland’s current gas consumption. Despite this potential however, many of the world’s major gas companies have abandoned projects in Poland, Denmark and Romania after exploration proved disappointing. (source)
Despite several years of exploratory drilling there are no commercial shale-gas wells in Europe at present. Tests of the continent’s shale potential have been limited, and results to date have generally yielded little shale gas reserves. It also remains highly uncertain how much gas would be recoverable using current technologies, and even more difficult to forecast how much could be profitably extracted. Moreover, geologists know relatively little about the potential of shale-rock formations in Europe because there has been limited onshore drilling compared with the United States.
Fracking has also been banned in many countries including in France, Germany, Bulgaria, and the Netherlands, further limiting fracking exploration at a European level. Moreover, even in countries where fracking is permitted, fears remain over safety of the practice. For example, in the UK where fracking is permitted, two small earthquakes near Blackpool in northern England in 2011 associated with fracking exploration, led the government to place a year-long moratorium on further fracking (Inman, 2016). Separately, within the UK, Northern Ireland, Scotland and Wales, as devolved governments, have all issued bans on fracking exploration. Owing to these issues, fracking in Europe is therefore a considerable way off from commercial exploitation.