Another myth busted with new methane research
June 2nd, 2017
New research from the CSIRO has confirmed fugitive methane (CH4) emissions from Australian coal seam gas well completions to be “virtually zero”.
The CSIRO report, Methane Emissions from CSG Well Completion Activities, commissioned by the Department of the Environment and Energy measured methane emissions at nine well completions and one well workover at two CSG sites in the Surat Basin in Queensland.
The findings are an independent reinforcement of what the industry has been reporting for years – that methane emissions from CSG wells are and can be kept very low.
The measurements found total methane emissions from well completions were low, ranging “from virtually zero to a maximum of 373kg CH4” for the entire completion process – and importantly, that no further emissions were detected on completed wells after they had been fitted with the wellhead.
And while the report acknowledges the results came from a small sample size, the results are reflective of a greater demand for data and evidence to drive the debate about industry – not the usual fiction and mistruths relied on by activist groups on this issue.
The report authors also looked at emissions from a workover well in Queensland, which showed quite different results, for different reasons.
For the well workover, methane emissions were much higher than the completions, totalling more than 21 tonnes of methane over the duration of the process.
The report notes:
“Most of this gas was released during the clean-out phase of the operation which in this case, involved injecting compressed air into the well during the process.”
The process is more usually completed using water injection which significantly reduces the emission of methane.
“The bulk of the workover-related emissions, however, were again linked to the use of compressed air in the well.
“Not all workovers require compressed air for the clean-out so the results from this well are unlikely to be indicative of workover emissions more broadly.
“During workovers where compressed air flushing is not used and the well is kept filled with liquid, gas would probably be contained by the hydrostatic pressure of the well fluid with correspondingly lower emissions. However, this is yet to be confirmed by field measurements.”
The evidence is in: fugitive methane emissions from Australian CSG well completions are low.