?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=https%3A%2F%2Fepisodesplatform.eu%2Feprints%2F1288%2F&rft.title=Examination+of+Possibly+Induced+Seismicity+from+Hydraulic%0D%0AFracturing+in+the+Eola+Field%2C+Garvin+County%2C+Oklahoma&rft.creator=Holland%2C+Austin+A.&rft.subject=Source+size+distribution&rft.subject=Eola+Field&rft.subject=Conventional+hydrocarbon+extraction&rft.subject=Unconventional+hydrocarbon+extraction&rft.description=On+January+18%2C+2011%2C+The+Oklahoma+Geological+Survey+(OGS)+received+a+phone+call+from+a+resident+living+south+of+Elmore+City%2C+in+Garvin+County%2C+Oklahoma%2C+that+reported+feeling+several+earthquakes+throughout+the+night.+The+reporting+local+resident+had+also+offered+that+there+was+an+active+hydraulic+fracturing+project+occurring+nearby.+Upon+examination+there+were+nearly+50+earthquakes%2C+which+occurred+during+that+time.+After+analyzing+the+data+there+were+43+earthquakes+large+enough+to+be+located%2C+which+from+the+character+of+the+seismic+recordings+indicate+that+they+are+both+shallow+and+unique.+The+earthquakes+range+in+magnitude+from+1.0+to+2.8+Md+and+the+majority+of+earthquakes+occurred+within+about+24+hours+of+the+first+earthquake.+Careful+attention+and+significant+effort+was+put+into+obtaining+the+most+accurate+locations+possible+and+gaining+a+reasonable+estimate+in+the+error+in+locations.+The+nearest+seismic+station+is+35+km+away+from+where+the+earthquakes+occurred.+Formal+errors+in+location+are+on+the+order+100-%C2%AD%E2%80%90500++m+horizontally+and+about+twice+that+for+depth.+Examination+of+different+velocity+models+would+suggest+that+the+uncertainties+in+earthquake+locations+should+be+about+twice+the+formal+uncertainties.+The+majority+of+earthquakes+appear+to+have+occurred+within+about+3.5+km+of+the+well+located+in+the+Eola+Field+of+southern+Garvin+County.+The+Eola+Field+has+many+structures%2C+which+may+provide+conduits+for+fluid+flow+at+depth.+The+well+is+Picket+Unit+B+well+4-%C2%AD%E2%80%9018%2C+and++about+seven+hours+after+the+first+and+deepest+hydraulic+fracturing+stage+started+the+earthquakes+began+occurring.++It+was+possible+to+model+95%25+of+the+earthquakes+in+this+sequence++using+a+simple+pore+pressure+diffusion+model+with+a+permeability+of+about+250+mD+(milliDarcies).+While+this+permeability+may+be+high+it+is+less+than+those+reported+for+highly+fractured+rock.+The+strong+correlation+in++time+and+space++as+well+as+a+reasonable+fit++to+a++physical++model+suggest+that+there+++is+a+possibility+these+earthquakes+were+induced+by+hydraulic-%C2%AD%E2%80%90fracturing.+However%2C+the+uncertainties+in+the+data+make+it+impossible+to+say+with+a+high+degree+of+certainty+whether+or+not+these+earthquakes+were+triggered+by+natural+means+or+by+the+nearby+hydraulic-%C2%AD%E2%80%90fracturing++operation.&rft.publisher=OKLAHOMA+GEOLOGICAL+SURVEY&rft.date=2011&rft.type=Reports&rft.type=NonPeerReviewed&rft.identifier=++Holland%2C+Austin+A.++(2011)+Examination+of+Possibly+Induced+Seismicity+from+Hydraulic+Fracturing+in+the+Eola+Field%2C+Garvin+County%2C+Oklahoma.++Technical+Report.+OKLAHOMA+GEOLOGICAL+SURVEY%2C+Oklachoma%2C+USA.+++++&rft.relation=http%3A%2F%2Fwww.ogs.ou.edu%2Fpubsscanned%2Fopenfile%2FOF1_2011.pdf