Questerre Energy

Mike's Blog

Jan
11

Shock waves

Ecocrats are sending out shock waves from Ohio.  Some water injection wells in Ohio are believed to have induced seismic activity.  Induced seismic is a term for seismic activity caused by humans.  Earthquake is a common name for seismic activity. The headlines are that fracing caused earthquakes in Ohio.    Let's forget for a moment that the news was water disposal wells may have caused earthquakes but the headlines said fracing did.   We aren't shocked at all by things like that anymore.   I have news that is really shocking:  hydraulic fractures are earthquakes!  The whole idea of hydraulic fracturing is to induce seismic activity.   It wouldn't be much of a fracturing operation that didn't induce seismic activity by fracturing some rock. Just Google 'induced seismic'.  It turns out induced seismic activity is pretty common stuff.  A farmer's tractor working in a field, trucks going down the road, hydraulic fracturing - well, you get the idea.   Almost all induced seismic is too small for people to feel including the hydraulic fracturing variety.  So the issue is not whether something causes an earthquake.  The issue is whether it causes a noticeable earthquake. In Ohio the biggest earthquake was reported to be 4.0 on the Richter scale.  That's big enough for people to feel which is noticeable.  If it had been ten times stronger or a Richter 5.0 then it could have caused damage which is significant.  As a comparison, a major earthquake like Fukushima was almost 100,000 times stronger than the biggest earthquake in Ohio. Human activities in the past that have caused noticeable earthquakes are:  hydroelectric dams (including the Manic-3 reservoir close to Baie-Comeau), mining operations, oil and gas production, geothermal, water disposal wells, and hazardous liquid waste disposal wells.   Other activities that people are concerned might cause noticeable earthquakes include hydraulic fracturing and CO2 sequestration.   Of interest, there have been major earthquakes of over 7.0 on the Richter scale caused by geo-thermal and hydro-electric dams. It isn't a bad idea to understand the geology before carrying out activities that have the potential to cause noticeable earthquakes.   Areas of fault instability can have this risk. Wait a minute:  there is a recent study of fault stability in the St. Lawrence Lowlands [link to study].  It discusses the issues of induced seismic and also puts in to context the issue for the St. Lawrence Lowlands.  It is a collaboration of Quebec based experts and experts from industry who provided much of the geological data.  I blogged my surprise about how there was no mention of this important issue in the media when the study was press released and presented at the oil and gas conference in Quebec. There was no mention of it either when there were headlines about fracing causing earthquakes in Ohio.   IF I was more surprised about that I would be shocked.

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