New study proves methane leaks around North Sea boreholes
The pictures went around the world. In April 2010, huge amounts of methane gas escaped from a well below the Deepwater Horizon platform in the Gulf of Mexico. This "blow-out" caused an explosion, in which eleven people died.
For several weeks, oil spilled from the damaged well into the ocean. Fortunately, such catastrophic "blow-outs" are rather rare. Continuous discharges of smaller amounts of gas from active or old and abandoned wells occur more frequently.
Scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of Basel now published new data in the international journal Environmental Science & Technology, indicating that gas migration along the outside of wells could be a much bigger problem than previously assumed.
This type of leakage is currently neither considered by operators nor regulators, but could be just as important as fugitive emissions through damaged wells, which are usually recognized and quickly repaired. "We estimate that gas leakage around boreholes could constitute one of the main sources of methane in the North Sea", says Dr. Lisa Vielstädte from GEOMAR, the first author of the study.
During expeditions to oil and gas fields in the central North Sea in 2012 and 2013, the scientists discovered a number of methane seeps around abandoned wells. Interestingly, the gas originates from shallow gas pockets buried less than 1,000 meters below the seabed.
They are simply penetrated when drilling into the underlying, economically interesting hydrocarbon reservoirs. "These gas pockets usually do not pose a risk to the drilling operation itself. But apparently disturbing the sediment around the well enables the gas to rise to the seafloor", explains Dr. Matthias Haeckel from GEOMAR, who initiated the study.
Seismic data from the subsurface of the North Sea further show that about one third of the boreholes perforated shallow gas pockets and may thus leak methane. "Considering the more than 11,000 wells that have been drilled in the North Sea, this results in a fairly large amount of potential methane sources", states Dr. Vielstädte who is currently based at the Stanford University in California, USA.
According to the team's calculations shallow gas migration along wells may release around 3,000 to 17,000 tonnes of methane from the North Sea seafloor per year. "This would reflect a significant contribution to the North Sea methane budget", emphasizes Dr. Haeckel.
In the ocean, methane is usually degraded by microbes, thereby locally acidifying the seawater. In the North Sea, about half of the wells are located in such shallow water depths that the methane leaking from the seabed can reach the atmosphere, where it is acting as a potent greenhouse gas - much more efficient than carbon dioxide.
"Natural gas, thus methane, is often praised as the fossil fuel that is most suitable for the transition from coal burning towards regenerative energies. However, if drilling for gas leads to such high atmospheric methane emissions, we have to rethink the greenhouse gas budget of natural gas ", summarizes Dr. Haeckel.
In order to better quantify the human impact on the methane budget of the North Sea, Kiel's research vessel POSEIDON will investigate further gas seeps in the vicinity of oil and gas wells in October.
Dr. Andreas Villwock | EurekAlert!
AWI researchers measure a record concentration of microplastic in arctic sea ice
24.04.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Climate change in a warmer-than-modern world: New findings of Kiel Researchers
24.04.2018 | Christian-Albrechts-Universität zu Kiel
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology