Ohio quake 'linked to wells': expert

A seismological expert has claimed that an earthquake on New Year's Eve in Ohio did not occur naturally and may have been caused by high-pressure liquid injection at wells in the US state's shale play, according to a report.

Ohio's Department of Natural Resources (DNR) has suspended operations at the five deep well sites in Youngstown where injection of wastewater used in hydraulic fracturing was taking place prior to the quake, which registered 4.0 on the Richter scale, according to Reuters.

The tremor was felt in north-east Ohio, western Pennsylvania and Ontario, Canada, according to the Ohio Seismic Network's (OSN) website, citing reports of minor damage, including cracked plaster and glassware falling from shelves.

The OSN said it was the 11th earthquake in a sequence that began on 17 March last year at Youngstown, where D&L Energy has reportedly been injecting drilling brine 9200 feet underground, with 352,780 barrels, or 56 million litres, injected at the site through the end of the third quarter of 2011, according to DNR data. The OSN said the previous quakes ranged between 2.1 and 2.7 in magnitude.

Won-Young Kim, a research professor of seismology geology and tectonophysics at the Lamont-Doherty Earth Observatory at Columbia University, told Reuters in an interview on Tuesday that circumstantial evidence suggests a link between the earthquake and the high-pressure well activity.

"We know the depth (of the quake on Saturday) is two miles (3.2 kilometres) and that is different from a natural earthquake," said Kim, who has been hired to advise the Ohio administration.

Data collected from four seismographs set up in November in the area confirm a connection between the quakes and water pressure at the well, Kim said.

"There is circumstantial evidence to connect the two - in the past we didn't have earthquakes in the area and the proximity in the time and space of the earthquakes matches operations at the well," he said.

According to Kim, this is not the first time Ohio tremors have been linked to human activities. "We have several examples of earthquakes from deep well disposal in the past," Kim said.

A quake of 4.2 magnitude in Ashtabula, Ohio, on 26 January 2001, was believed to be due to deep-well injection, he said. And in 1987 there was an incident with a correlation to high pressure deep well injection, he said.

The earth tremors have also apparently opened up a rift between the state government and Democrat Representative for Youngstown, Robert Hagan, who Bloomberg reported is calling for a ban on all hydraulic fracturing and injection well activity "until we can conclude it's safe".

While the state is investigating the causes of the quakes, Ohio Governor John Kasich is a strong supporter of oil and gas exploration of its shale play and a spokesman for the governor said the latest tremor would not halt production.

"We are not going to stand by and let someone drive a stake through the heart of what could be an economic revival in Eastern Ohio," spokesman Rob Nichols said.

Both Kasich and the DNR consider the quakes isolated occurrences and said operations would continue at the state's other 177 disposal without disrupting shale gas development that may generate thousands of jobs, Nichols said.

The state could announce a preliminary decision on Wednesday whether to continue the suspension of the Youngstown wells.

Head of the DNR's oil and gas division, Rick Simmers, said D&L had agreed to bring in tanks to pull out water from the wells to reduce pressure and lower the risk of more seismic activity.

D&L's chief executive Ben Lupo failed to respond to a request from Bloomberg for comment.

Ohio's Utica shale play is attracting substantial investment with China's Sinopec announcing a $2.2 billion farm-in deal with Devon Energy that also covers other areas of the US while Total of France has agreed to acquire a 25% stake in the acreage from Chesapeake Energy and EnerVest for $700 million.

Tom Stewart, executive vice president of the Ohio Oil & Gas Association, said it supports the temporary halt to injections near Youngstown but added the quake was "a rare and isolated event that should not cast doubt about the effectiveness" of the wells.

However, Kim said that even though the wells have stopped pumping water into the rock, the area might not have experienced its last earthquake.

"It could take a couple of years for the earthquakes to go away. The migration of the fluid injected into the rock takes a long time to leave," Kim said.

Upstream Online - Steve Marshall - 04 January 2012