scholarly journals Blue Shift in the Spectrum of Arrival Times of Acoustic Signals Emitted during Laboratory Hydraulic Fracturing

10.5772/56448 ◽  
2013 ◽  
Author(s):  
Arcady V. ◽  
Elena Pasternak ◽  
Andrew P. ◽  
James Kear
Keyword(s):  
Hydraulic Fracturing ◽  
Blue Shift ◽  
Acoustic Signals ◽  
Arrival Times

РЕЗУЛЬТАТЫ ЭКСПЕРИМЕНТАЛЬНЫХ И ТЕОРЕТИЧЕСКИХ ИССЛЕДОВАНИЙ РАСПРОСТРАНЕНИЯ ИМПУЛЬСНЫХ СИГНАЛОВ В МЕЛКОМ МОРЕ ВДОЛЬ КРОМКИ КОНТИНЕНТАЛЬНОГО ШЕЛЬФА

2020 ◽  
Author(s):  
A.A. Golov ◽  
Yu.N. Morgunov ◽  
M.A. Sorokin ◽  
P.S. Petrov
Keyword(s):  
Field Experiments ◽  
Sound Propagation ◽  
Acoustic Signals ◽  
The Sea Of Japan ◽  
Acoustic Path ◽  
Shallow Sea ◽  
Summer Period ◽  
Arrival Times ◽  
Modal Component ◽  
Group Velocities

Анализируются результаты натурного эксперимента по распространению импульсных акустических сигналов на шельфе Японского моря в осенне-летний период 2018 года. Цель эксперимента состояла в определении времен прихода и эффективных скоростей распространения сигналов вдоль акустической трассы,ориентированной вдоль кромки шельфа. В ходе теоретического анализа и моделирования распространенияакустических колебаний для условий эксперимента разработана методика прогноза эффективных скоростейраспространения импульсных сигналов на большие расстояния в мелком море. Методика основана на усреднении групповых скоростей первой модальной компоненты сигнала по всей трассе.The purpose of the paper is to present the interpretation of field experiments, dedicated to studying the propagation of impulse acoustic signals on the shelf of the Sea of Japan in the autumn-summer period of 2018. The main goal of the experiments was to determine arrival times and effective sound velocities of the propagation of the pulsed signals in underwater acoustic path trace oriented along the edge of the continental shelf. During theoretical analysis and modeling of sound propagation, the methodology for predicting the effective propagation velocity of pulsed signals over long hauls in the shallow sea was developed. It is based on averaging of the group velocities of the first modal component of the signal over the entire path.

Microseismic and Induced Seismicity Monitoring and Tomography of the Changning-Zhaotong shale gas play in China using dense nodal arrays

2020 ◽  
Author(s):  
Wen Yang ◽  
Junlun Li ◽  
Yuyang Tan ◽  
Yaxing Li ◽  
Jiawei Qian ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Velocity Structure ◽  
Double Difference ◽  
Steady Increase ◽  
S Wave ◽  
Two Phase ◽  
Arrival Times ◽  
Seismicity Monitoring ◽  
Tomography Method

<p>With the development of shale gas in the Changning-Zhaotong play in the southern Sichuan basin of China, which is the largest shale gas prospect in China, the frequency and magnitude of earthquakes in this region have increased significantly in recent years. For example, a M5.7 earthquake occurred on December 16, 2018, and a M5.3 earthquake on January 6, 2019 in addition to many M4.0+ earthquakes in this area. Some studies argue the large magnitude earthquakes are triggered by hydraulic fracturing in for the local shale gas development, which commenced in 2011. The frequency of the earthquake occurrence has been on steady increase in the past few years that local residents often reported felt quakes. To further understand the correlation between the shale gas development and local seismic activity, we conducted a two-phase dense array seismic monitoring with about 200 Zland 3C and SmartSolo 3C 5 Hz seismic nodes, from late February to early May, 2019 for a period of 70 days. The survey consists of roughly 340 deployments at 240 sites, with an average interstation distance of 1.5 km, covering 500 km<sup>2</sup> in total. We have processed seismic records from late February to early April, 2019 (phase I), and picked some 600,000 P- and S-wave arrival times from 4385 detected local earthquakes. The earthquake hypocenters and the subsurface velocity structure of the Changning-Zhaotong area are inverted for using the double-difference tomography method. The relocation results show that the majority of hypocenters were located at depths ranging from 1.0km to 4.0km, in the proximity of the horizontal hydraulic fracturing wells. The tomographic results (< 3 km) correlate well with the known surface geological units, and most earthquakes occurred along the velocity discontinuities, likely characterizing a large hidden fault which, interestingly, is where the January 2019 M5.3 occurred. Our study is very important for understanding the seismic potentials in this area, and should provide useful information for the shale gas development in this region and other areas in China with similar geological, tectonic and stress conditions.</p>

Real-time event location using model-based estimation of arrival times and back azimuths of seismic phases

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. KS25-KS40 ◽  
Author(s):  
Nobuyasu Hirabayashi
Keyword(s):  
Hydraulic Fracturing ◽  
Real Time ◽  
Time Window ◽  
Signal To Noise Ratio ◽  
Estimation Method ◽  
Signal To Noise ◽  
Arrival Times ◽  
Event Location ◽  
Single Well ◽  
Noise Ratio

I have devised a real-time procedure for locating events using an estimation method that analyzes arrival times and back azimuths of phases. The new procedure is applicable to data acquired by local array receivers, such as those used in single-well monitoring as well as by dense receiver networks, and also to noisy waveforms, such as those observed in hydraulic fracturing monitoring if the signal-to-noise ratio is greater than approximately 6 dB. The new procedure uses coalescence microseismic mapping to obtain predictions of arrival times. Based on these predictions, arrival times were estimated by picking the maximum of the ratio of the short-term average to the long-term average of a characteristic function computed for waveforms in an appropriate time window. The estimated arrival times were used in a probabilistic location method, and the probability density function (PDF) of the event location was generated. To locate events for a local array of receivers, the PDFs of event back azimuths obtained using polarizations were combined with the traveltime data to remove directional ambiguities. I have developed this method to generate the PDF of event back azimuths using the average of polarization misfits, which are the differences of the measured and computed polarizations for trial event locations, weighted by the signal-to-noise ratio. Synthetic and field data examples of single-well monitoring of hydraulic fracturing, which required the estimation of event back azimuths in addition to arrival times, were evaluated to determine the effectiveness of the new procedure.

Shale, Quakes, and High Stakes: Regulating Fracking-Induced Seismicity in Oklahoma, USA and Lancashire, UK

2019 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Miriam R. Aczel ◽  
Karen E. Makuch
Keyword(s):  
United States ◽  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Seismic Activity ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
High Volume ◽  
The United States ◽  
Horizontal Drilling ◽  
Induced Seismic Activity

High-volume hydraulic fracturing combined with horizontal drilling has “revolutionized” the United States’ oil and gas industry by allowing extraction of previously inaccessible oil and gas trapped in shale rock [1]. Although the United States has extracted shale gas in different states for several decades, the United Kingdom is in the early stages of developing its domestic shale gas resources, in the hopes of replicating the United States’ commercial success with the technologies [2, 3]. However, the extraction of shale gas using hydraulic fracturing and horizontal drilling poses potential risks to the environment and natural resources, human health, and communities and local livelihoods. Risks include contamination of water resources, air pollution, and induced seismic activity near shale gas operation sites. This paper examines the regulation of potential induced seismic activity in Oklahoma, USA, and Lancashire, UK, and concludes with recommendations for strengthening these protections.

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