Database of offshore non-producing oil and gas wells for quantifying methane emissions potential  

Methane emissions from offshore non-producing oil and gas wells (OGWs) at the global scale remain poorly understood. Most published studies on offshore non-producing OGWs have focused on the North Sea, and there are questions as to whether these findings can be extrapolated at the global scale. One important consideration for offshore OGW methane emissions into the atmosphere is the extent to which methane biodegrades in seawater above OGWs, for which the vertical extent of the water column is viewed as a key factor. Additionally, there is a lack of consensus on whether the knowledge from onshore wells is transferable to offshore wells, as well as how best to quantify emissions to the atmosphere, including practical limitations of current technologies. Therefore, we are developing a database of offshore wells globally, including water depth data, to facilitate analysis of potential for methane emissions and its mitigation. An accompanying literature review will identify knowledge gaps related to methane emissions from offshore non-producing wells, their role in national emissions estimates, and quantification approaches. Our results will be helpful in the understanding of potential contributions of offshore non-producing OGWs to methane emissions to the atmosphere, thereby informing methane mitigation strategies and policies.