Tracing environmental impacts associated with shale gas production with novel integration of isotopologue thermometry and noble gases

With recent government green light for Lancashire fracking, concerns have arisen over the potential environmental impacts associated with drilling and shale gas production. One issue is whether fracking would introduce elevated hydrocarbon gas levels in drinking-water wells in the area of fracking. Several studies suggested that shale gas drilling could lead to fugitive gas contamination in a subset of drinking-water wells near drill sites, while others argue that methane is natural and unrelated to shale gas development. Much of this debate results from a lack of geochemical tracers that can constrain simultaneously the source, timing, and mechanism of hydrocarbon migration into shallow aquifers.

The stable carbon (13C/12C) and hydrogen (D/H) isotopic composition of methane are traditional tools to identify the origin of methane in nature and trace fugitive gases from shale gas production. However, methane with different origins often yield overlapping isotopic compositions, which make such data inconclusive. Clumped methane has been validated as a thermometer, it is particularly useful to trace origin of methane gas, but the full potential and range of uses is yet to be developed. In contrast, noble gases have long been proven as a versatile tool in the investigation of origin and physical processes occurring in natural gas and hydrocarbon systems. This project will combine noble gases and clumped methane as a new set of tracers for identifying the origin and migration processes of stray gases from shale gas production.

Beyond academia, the main beneficiaries are

Oil and gas industry - Understanding the sources and migration pathways of methane gas and assess the environmental impacts associated with hydrocarbon production, particularly shale gas exploration and extraction.

UK mass spectrometer companies - Further developing the laser technology proposed in this work, as laser systems rival traditional mass spectrometry capability at a fraction of the cost.

Local schools and community - The subject matter of this proposal may be of particular interest to the local community around Lancaster University where shale gases and fracking are a local concern. There will be technique development progress web pages within Lancaster University where scientific overview, objectives and updates can be posted. Public understanding and knowledge transfer activities will be organised for local schools and general public.

Wider public community - New findings are anticipated in this project and journalistic interests will be generated. Both the Lancaster University and NERC press offices will be used, as well as media in China to communicate the achievements of this project. There are further plans to provide material for use in interaction with schools both in the Northwest of UK and shale gas producing areas in China. Results of general interest will be posted on the Lancaster isotope geochemistry website.