DALLAS (Reuters) - Seismologists installed a new earthquake-monitoring device in the Dallas suburb of Irving this week after a series of minor tremblors rocked an area near the site of the former Dallas Cowboys football stadium.
Irving was shaken by nine quakes on Tuesday and into Wednesday, including three measuring magnitude 3.6, 3.5, and 3.1, the U.S. Geological Survey said. The quakes were the strongest in a series of about 20 minor quakes to hit around the stadium area since September.
Five smaller quakes registering between 1.6 and 2.9 were recorded on Tuesday in the suburb. Another 1.7 magnitude quake was recorded in the nearby city of Farmers Branch late on Tuesday night, according to the USGS.
There were no immediate reports of injury or damage.
But the seismic series has left residents on edge, wondering whether the situation will get worse and what has been behind an uptick in quakes over the last several years.
"The safety and security of our residents is paramount for the city of Irving," said Irving City Manager Chris Hillman.
Some residents believe the implosion of Texas Stadium in 2010 may have exacerbated problems. There is also speculation the quakes might be related to hydraulic fracturing, or "fracking," an energy extraction technique that has a long history in north Texas.
Irving, headquarters of Exxon Mobil's XTO unit that helped pioneer hydraulic fracturing in the region, has two gas wells that were fracked in 2010, according to city officials.
The study by seismologists from Southern Methodist University in Dallas is aimed at pinpointing the quakes' epicenters, said SMU seismology professor Brian Stump.
About 40 miles west of Irving, a series of small earthquakes rattled the town of Azle a year ago, causing sinkholes and cracks in house foundations. Residents blamed fracking and injection disposal wells for drilling waste as the cause, but an official finding is still pending.
Energy industry officials have said fracking is safe and causes no significant seismic damage.
LINK (VERY Informative & detailed comment by
Dubious Dawg
1
20
Having worked in the field for Chesapeake Energy Corporation for years with extensive knowledge in Hydraulic Fracturing (also known hydrofracturing, hydrofracking, fracking, or fraccing depending upon the part of the country you live in) - we always knew that fracking damaged underground aquifers because casing strings were always cracking and the cement along the length of the wellbore had gaps that could not be prevented and did not isolate the well completely from the surrounding geology. Especially when we lowered the perforating gun and fired off charges to perforate the steel casing, cement and the shale formation we thought gas and oil reserves were in. Many times, we accidentally perforated the steel casing and cement outside the shale layer and compromised the surround geology. But no one cared.
The perforating gun *always* created seismic tremors. And the cracking of the shale just didn't stop cracking after the charge was set off. Depending on depth, pressure, etc. - the cracking and seismic activity could go on for days, weeks, we even had activity at one wellbore that carried on for a month shaking.
And that mixture of water, sand and chemicals we injected into the wellbore under high pressure? That just kept the tremors going. And we broke plenty of casing strings and fractured the cement liners far outside the shale formation. Initially, the "chemical" element of the injection mix Chesapeake used (what they like to state as small in number and dilute in concentration and can be found in many household items) ... was actually petroleum distillates - paint thinners, diesel fuel, Kerosene, etc. LOTS of Ethylene glycol (anti-freeze folks). With cracked or cracking casings, under pressure, that stuff leeched out all over the place underground outside the cement insulators. Right into aquifers. We even punched through an abandoned coal mine tunnel once and that was a mess.
And yes, we were aware of existing fault lines. We bored through them. Perforated next to them. Faults that hadn't moved in thousands of years - our injection mixes lubricated them with Polyacrylamide and bingo ... suddenly those faults started slipping and became very active. We had ground actually subside or collapse under our rigs.
Anyone who tells you that this extraction process is safe for the environment, that companies like Chesapeake take every measure possible to protect drinking water and property above ground ... is feeding you a line of bull. The truth is - we didn't give a rat's butt what happened to the areas we bored. We didn't live there. We didn't drink the water. Whatever happened after we plugged, wasn't our problem ... we moved on to the next site.
As for the water that's supposed to flow back up the bore and we "supposedly" recycled 20 to 30% for reuse - let's just say, some tankers used to joke it was easier to just pull over and flush away it into a creek.
)
Posts
