|
| |
|
|
Source mechanisms of microseismic events induced by hydraulic fracturing
Staněk, František ; Eisner, Leo (advisor) ; Cornet, Francois (referee) ; Šílený, Jan (referee)
Understanding economic success of unconventional production from shales requires an explanation of the relationship between induced seismicity and hydraulic fracturing. This thesis deals with observing and analyzing synthetic and real microseismic monitoring data acquired during hydraulic fracturing. The thesis is based on observation and analyses of source mechanisms of induced microseismic events that have recently become regularly inverted and interpreted in the oil and gas industry. The results of analyses are interpreted with the geomechanical model of the relationship between hydraulic fracturing and induced seismicity. The study of source mechanisms starts with detailed analyses of spatial distribution of full moment tensor inversion stability. It was mapped based on synthetically computed condition numbers in the vicinity of different monitoring arrays including dense arrays at the surface and sparse arrays with sensors in the boreholes. Stability of inversion was tested under several conditions, mainly dependency on size and geometry of monitoring array and level of noise in the data. In this part of the thesis it is shown that dense surface arrays may provide very stable inversion of source mechanisms which may be interpreted. The study shows that an increasing percentage of non-shear...
|
|
|
Statistical analysis of natural and induced seismicity catalogues
Mazanec, Martin ; Eisner, Leo (advisor) ; Adamová, Petra (referee)
The main goal of this thesis is to analyze the statistical properties of seismic catalogues of natural and induced seismicity, identify similarities and differences. We compare statistical temporal and magnitude information contained in different types of earthquake catalogues. Six seismostatistical criteria used for identification of natural swarms and mainshock- aftershock earthquake sequences are applied to 10 different catalogues of natural and induced seismicity. We did not find a method to reliably distinguish between natural and induced seismicity based only on temporal and magnitude information contained in catalogues. We show that induced seismicity catalogues are similar to natural earthquake swarms. We report how the set of 6 criteria presented here can be used for distinguishing between mainshock-aftershock sequences and swarm seismicity. We also show that none of the tested criteria can be used independently for distinguishing between different types of seismicity.
|
|
|
Source mechanisms of microseismic events induced by hydraulic fracturing
Staněk, František ; Eisner, Leo (advisor)
Understanding economic success of unconventional production from shales requires an explanation of the relationship between induced seismicity and hydraulic fracturing. This thesis deals with observing and analyzing synthetic and real microseismic monitoring data acquired during hydraulic fracturing. The thesis is based on observation and analyses of source mechanisms of induced microseismic events that have recently become regularly inverted and interpreted in the oil and gas industry. The results of analyses are interpreted with the geomechanical model of the relationship between hydraulic fracturing and induced seismicity. The study of source mechanisms starts with detailed analyses of spatial distribution of full moment tensor inversion stability. It was mapped based on synthetically computed condition numbers in the vicinity of different monitoring arrays including dense arrays at the surface and sparse arrays with sensors in the boreholes. Stability of inversion was tested under several conditions, mainly dependency on size and geometry of monitoring array and level of noise in the data. In this part of the thesis it is shown that dense surface arrays may provide very stable inversion of source mechanisms which may be interpreted. The study shows that an increasing percentage of non-shear...
|
|
|
Source mechanisms of microseismic events induced by hydraulic fracturing
Staněk, František ; Eisner, Leo (advisor)
Understanding economic success of unconventional production from shales requires an explanation of the relationship between induced seismicity and hydraulic fracturing. This thesis deals with observing and analyzing synthetic and real microseismic monitoring data acquired during hydraulic fracturing. The thesis is based on observation and analyses of source mechanisms of induced microseismic events that have recently become regularly inverted and interpreted in the oil and gas industry. The results of analyses are interpreted with the geomechanical model of the relationship between hydraulic fracturing and induced seismicity. The study of source mechanisms starts with detailed analyses of spatial distribution of full moment tensor inversion stability. It was mapped based on synthetically computed condition numbers in the vicinity of different monitoring arrays including dense arrays at the surface and sparse arrays with sensors in the boreholes. Stability of inversion was tested under several conditions, mainly dependency on size and geometry of monitoring array and level of noise in the data. In this part of the thesis it is shown that dense surface arrays may provide very stable inversion of source mechanisms which may be interpreted. The study shows that an increasing percentage of non-shear...
|
|
|
Source mechanisms of microseismic events induced by hydraulic fracturing
Staněk, František ; Eisner, Leo (advisor) ; Cornet, Francois (referee) ; Šílený, Jan (referee)
Understanding economic success of unconventional production from shales requires an explanation of the relationship between induced seismicity and hydraulic fracturing. This thesis deals with observing and analyzing synthetic and real microseismic monitoring data acquired during hydraulic fracturing. The thesis is based on observation and analyses of source mechanisms of induced microseismic events that have recently become regularly inverted and interpreted in the oil and gas industry. The results of analyses are interpreted with the geomechanical model of the relationship between hydraulic fracturing and induced seismicity. The study of source mechanisms starts with detailed analyses of spatial distribution of full moment tensor inversion stability. It was mapped based on synthetically computed condition numbers in the vicinity of different monitoring arrays including dense arrays at the surface and sparse arrays with sensors in the boreholes. Stability of inversion was tested under several conditions, mainly dependency on size and geometry of monitoring array and level of noise in the data. In this part of the thesis it is shown that dense surface arrays may provide very stable inversion of source mechanisms which may be interpreted. The study shows that an increasing percentage of non-shear...
|
|
|
Statistical analysis of natural and induced seismicity catalogues
Mazanec, Martin ; Eisner, Leo (advisor) ; Adamová, Petra (referee)
The main goal of this thesis is to analyze the statistical properties of seismic catalogues of natural and induced seismicity, identify similarities and differences. We compare statistical temporal and magnitude information contained in different types of earthquake catalogues. Six seismostatistical criteria used for identification of natural swarms and mainshock- aftershock earthquake sequences are applied to 10 different catalogues of natural and induced seismicity. We did not find a method to reliably distinguish between natural and induced seismicity based only on temporal and magnitude information contained in catalogues. We show that induced seismicity catalogues are similar to natural earthquake swarms. We report how the set of 6 criteria presented here can be used for distinguishing between mainshock-aftershock sequences and swarm seismicity. We also show that none of the tested criteria can be used independently for distinguishing between different types of seismicity.
|
|
|
Earthquake catalogue of completeness for eastern USA
Arnetová, Kateřina ; Eisner, Leo (advisor) ; Kolář, Petr (referee)
The subject of this thesis is the completeness of the seismic catalogs in eastern and central parts of the USA. In the last couple of years, there were some new seismic events that raised questions about their origin. Ellsworth (2013) believes that this trend is due to induced phenomena. In this work I have tried to elucidate their origin by calculating the magnitude of completeness of the seismic catalog. For the calculation, I used two seismic catalogs, ANSS catalog and Combined catalog provided by Dr. Ellsworth. The calculation was performed using three statistical methods: MAXC, GFT and BSTAB. To complement the results, continual calculation of the magnitude of completeness by GFT has been employed for both catalogs. Calculations have proved that the magnitude of completeness of both catalogs hasn't reached the value Mc = 3 or greater since 1970, but the drop came in later years. Seismic networks were not sensitive enough to capture seismic magnitude of M = 3 or larger in all cases. Continual calculation has demonstrated that the magnitude of completeness falls below Mc = 3 in such data selection, which includes the seismic events observed after introducing a denser network of portable stations USArray. The results make it evident that the increased number of seismic events in the eastern and...
|
|
| |
|
| |
guest ::
