Prospecting for hydrocarbons deep on the ocean floor
Despite substantial progress, Europe cannot yet meet all its energy demand using renewable resources. Until it can, fossil fuels will continue to be an important source of energy. But that doesn’t mean Europe can’t use cleaner forms of fossil fuels. “European economies and citizens require energy that is sustainable, affordable, and that has a secure and reliable supply,” says Jens Kallmeyer, a geomicrobiologist at the Helmholtz Centre for Geosciences(opens in new window).
Natural gas ticks all the boxes
Not only does natural gas produce fewer emissions than other fossil fuel-based energy, it is also a resource that can be found right here in Europe. The challenge is that Europe is a densely populated continent, which makes prospecting for energy reservoirs challenging. “Balancing energy prospection and production with the responsible management of environmental resources will remain a challenge in the years ahead,” adds Kallmeyer. Helping to strike such a balance is the EU-funded PROSPECTOMICS(opens in new window) project.
Innovative ways to detect inconspicuous hydrocarbon sites
Prospecting for oil and gas reservoirs in European waters is restricted by tight environmental regulations, and deep drilling can be prohibitively expensive. Instead, the PROSPECTOMICS project decided to explore the surface of the ocean floor. According to Kallmeyer, who serves as the lead principal investigator, every oil and gas reservoir leaks to some degree. The upward flowing hydrocarbons can leave multiple geological manifestations at the surface as they provide an energy source for life on the sea floor. While visible natural seeps have been previously used for hydrocarbon prospecting, not all seepage reaches the ocean floor. “In the subsurface, low levels of hydrocarbon seepage can cause an invisible shift in microbial community structure and metabolic processes with no visible surface manifestation,” explains Kallmeyer. “Our goal is to develop innovative ways to detect these inconspicuous sites.” That detection will happen using state-of-the-art ‘omics’ techniques and detailed biogeochemistry. “By combining environmental ‘omics’ with contextual knowledge of the chemical surroundings, we’ll be able to analyse sediment samples from the upper three metres of the sea floor,” notes Kallmeyer.
Vast amounts of data being analysed by machine learning
The use of these techniques has generated vast amounts of data, requiring analysis via machine learning and predictive models. However, due to a significant delay caused by the COVID-19 pandemic, the project has only started digging into this data. That being said, the project has made some important findings. For example, it discovered that even if the hydrocarbons leaking from these reservoirs have been completely consumed below the sampling depth, the microbes in the recovered sediment cores still reflect the increased input of chemical energy.
Hydrocarbon exploration with minimal environmental disturbance
Although there is more work to be done, the PROSPECTOMICS project has created a true multi-omics dataset with absolute parallel samples and allowing for direct comparisons. “This has never been achieved before in such resolution,” says Kallmeyer. As a result, the project team is confident they are well positioned to design a biology-based tool for rapid and minimally invasive screening of even minor hydrocarbon seepage in marine sediments. “By providing a set of biological ‘fingerprints’, our tool can help guide hydrocarbon exploration with minimal environmental disturbance and to detect minor leakage in pipelines,” concludes Kallmeyer.
