Netherlands earthquake could lead to further gas production cuts at Groningen field
12 January 2018
On January 8, a 3.4-magnitude Richter-scale earthquake was recorded in the northern Dutch province of Groningen, the Royal Netherlands Meteorological Institute (KNMI) said in a statement. No casualties were reported but some damage to homes and buildings was reported. KNMI classified the earthquake as "induced", which means that it was caused by gas extraction.
Wellheads in the Groningen field - Image: NAM
The epicentre was about 3 km below the village of Zeerijp, north of the provincial capital of Groningen, and was the largest magnitude quake recorded in the province of Groningen since 2012 when a 3.6-magnitude quake hit the village of Huizinge.
NAM, a Royal Dutch Shell and Exxon Mobil joint venture that operates the Groningen field, has been extracting gas from the site since the 1960s. This process is responsible for virtually all the many earthquakes recorded in the province, according to KNMI.
On January 10, a NAM spokesman said that in the light of the earthquake, the company will propose reducing output at Groningen by shutting down some of the field’s production clusters.
Dutch Minister of Economic Affairs Eric Wiebes said that because of the damage caused by these incidents, output at Groningen should be reduced “by as much as possible” during the current government term through 2021.
The Dutch government has lowered gas production several times in recent years, as decades of gas extraction have led to dozens of earthquakes every year in the region, causing damage to thousands of buildings and homes.
The new coalition government under Prime Minister Mark Rutte has already agreed to reduce output to around 20 billion cubic metres (bcm) by 2021, from a current 21.6 bcm and down from 39.4 bcm in production year 2015-16.
Wiebes is responsible for natural gas extraction within the government. After lobbying from green groups and residents, he was given one year to come up with solid reasons why output should remain at this high level by the Council of State.
According to Dutchnews.nl, since the quakes began, some 75,000 complaints have been made about damage and the bill for research, shoring up property and damage claims against NAM have reached an estimated €1.3bn so far.
In 2015, a report by the Dutch Safety Board concluded that all the organisations involved ignored the danger of earthquakes caused by gas extraction at the Groningen gas field for decades. The correlation between gas extraction and earthquakes was clear in 1993, but “the risks to residents were not recognised” until 2013, the report said.
The board’s year-long inquiry concluded that the Economy Ministry, State Supervision of Mines and NAM, the Shell-Exxon Mobil joint venture which operates the gas field, worked collectively to maximise production.
“The parties concerned considered the safety risk to the population to be negligible and thus disregarded the uncertainties surrounding this risk assessment,” it said. They “failed to act with due care for citizen safety in Groningen.”
The extraction of gas reduces pressure in the gas reservoir and causes compaction in the reservoir sandstone, which causes earthquakes. As more gas was extracted – the field is about two-thirds empty now – pressure changes deep underground become more severe and unpredictable. Nearly 1,000 man-made earthquakes, ranging from 0.1 to 3.6 on the Richter scale, have occurred in Groningen since the early 1990s.
A 3.4 magnitude earthquake is not usually a major event, but because the earthquakes take place at the shallow depth of 3km, and many Groningen buildings are built on soft clay, the damage caused is greater than their small Richter-scale magnitudes suggest.
The total cost of damage repairs, structural improvements to buildings, and compensation for home value decreases was estimated at €6.5bn in 2015. Around 35,000 homes were said to be affected, parliament was told.
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