Methane escapes from the seabed of the North Sea in various places. Recent German research suggested that this mainly occurs in the vicinity of abandoned wells. Methane is a potent greenhouse gas and its release into the sea and subsequent release into the atmosphere can contribute to global warming.
The methane release would mainly be related to wells drilled in areas where shallow gas occurs. Shallow gas is when natural gas is present in the pores of the sediment that forms the top kilometer of the sea floor. An inventory by TNO shows that approximately 240 wells (out of a total of 2150 wells) have been drilled in Dutch territorial waters in the North Sea in areas where shallow gas occurs naturally.
The Dutch parliament has asked questions on this and a follow up research was planned. In this research we investigate a representative selection of these wells and also natural seep sites to quantify potential methane leakage from or along wells. We also investigate potential causes and compare whether these fluxes need to be taken into account in national policy on greenhouse gas emissions.
Together with TNO we conduct independent on-site sea-going investigations to determine whether wells are leaking methane and how much of this methane ultimately reaches the atmosphere.