Gas Storage Sets Spain Up for a ‘Significant’ Earthquake

via Escal UGS

You probably shouldn’t be able to pump 100 million cubic meters of gas into an undersea reservoir next door to a fault line and just be OK. That’s sort of like trying to lift weights with a semi-healed broken arm. Pockets in the Earth’s crust might make a handy vessel for extracted gas in ideal circumstances, but even not very active fault lines, such as the recently reawakened one under Spain’s Gulf of Valencia, are still geological weaknesses by definition. Nonetheless, a Spanish firm has been injecting gas 1.7 kilometers under the Mediterranean Sea all summer with the result being, according to the Spanish government, some 400 smallish earthquakes and the slight but real possibility of a big one.

The gas comes via Project Castor, a massive scheme to load up a 1.3 billion cubic meter depleted oil reservoir with extracted gas such that it can be stored and then piped to the Spanish energy grid. Once full, the reservoir should be enough to supply Valencia, Spain’s third-largest city at five million people, with energy for a whopping three months. The Spanish government ordered Escal UGS, the company behind Project Castor, to stop pumping the gas on Sept. 26, though it had already been stopped for 10 days by the company’s own accord. Nonetheless, just since yesterday, the region has been hit by at least 15 small quakes. It seems the damage has been done.

Spain’s Industry Minister Jose Manuel Soria says there is a “limited risk” of a significant (read: damaging) quake happening. “There is a high probability of a relationship between the injections of gas into the storage facility between June 13 and September 16 and the seismic movements on the coastal zone facing the facility,” he told a news conference. This conclusion comes courtesy of government advisers as well as the country’s geological and hydrological mining institutes.

Project Castor is mostly likely done for a very long time, if not permanently. “This halt will continue in force until there is an absolute guarantee of 100 percent safety for the whole population,” Soria said. Though that’s probably slim consolation for Valencia and neighboring Catalonia, both of which are under low level earthquake alerts. At least if the big one does hit, the quake will come with some warning.

Note that southern Spain is no stranger to manmade earthquakes. Two years ago, an earthquake near the city of Lorca caused nine deaths and dozens of injuries. That quake since been linked to fracking activity, specifically the removal of groundwater creating instability in the Earth’s crust. Meanwhile, a recent study in the journal Geology has linked wastewater storage in depleted oil reservoirs—a near perfect analog for the Spanish quakes—in the U.S. with earthquake activity in Oklahoma. In that case, the relevant wells were drilled 18 years prior to the quakes, suggestion that Valencia is in for a rocky future no matter what.

@everydayelk