Distributed Acoustic Sensing in Geophysics. Группа авторов

DISCUSSION 15.8. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 16 Using Distributed Acoustic Sensing (DAS) for Multichannel Analysis of Surface Waves (MASW) 16.1. INTRODUCTION 16.2. DAS MEASUREMENT PRINCIPLES 16.3. STUDY AREA AND EQUIPMENT LAYOUT 16.4. LARGE SHAKER SEISMIC SOURCE 16.5. DAS AND GEOPHONE SENSORS 16.6. MULTICHANNEL ANALYSIS OF SURFACE WAVES (MASW) 16.7. SURFACE-WAVE DISPERSION ANALYSIS RESULTS 16.8. DISCUSSION 16.9. SUMMARY AND CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 17 A Literature Review: Distributed Acoustic Sensing (DAS) Geophysical Applications Over the Past 20 Years 17.1. INTRODUCTION 17.2. FBG‐BASED QDAS GEOPHYSICAL APPLICATIONS 17.3. VARIOUS DAS GEOPHYSICAL APPLICATIONS 17.4. SOME THOUGHTS ON RECENT ADVANCES AND FUTURE APPLICATIONS 17.5. CONCLUSION ACKNOWLEDGMENTS REFERENCES

      12  INDEX

      13  End User License Agreement

      List of Tables

      1 Chapter 6Table 6.1 Fields Trials of Active‐Source DAS Seismic Applications by Shell ...

      2 Chapter 9Table 9.1 Plane Wave Particle Displacements and Velocities.Table 9.2 Plane Wave Particle Velocity,

, Point‐Wise Axial Strain Rate,

, ...Table 9.3 Cross‐Correlations of Measurements at (x₁, y₁, z₁) in the

Direc...Table 9.4 Horizontal Particle Velocity and Point‐Wise Axial Strain Rate Res...

      3 Chapter 10Table 10.1 Local Earthquake Recorded by the SFSO DAS Array.Table 10.2 Estimates of Relative Amplitudes of the Data Generated by Five L...

      4 Chapter 12Table 12.1 Comparison of Specifications of Geophone and DAS Arrays.Table 12.2 CMM Algorithm Parameters Used in This Study.

      5 Chapter 13Table 13.1 Acquisition Parameters for the May 2017 Field Trial.Table 13.2 Acquisition Parameters for the November 2017 Field Trial.Table 13.3 Offset VSP Processing Flow.

      6 Chapter 15Table 15.1 Upper and Lower Bounds of MC Sampling for Inversion Parameters.Table 15.2 Location and American Petroleum Institute (API) Identification Nu...

      7 Chapter 16Table 16.1 Parameters Used in SWAMI Inversion.

      8 Chapter 17Table 17.1 Review and Introduction for DAS Applications.Table 17.2 FBG‐Based qDAS Applications in Geophysics.Table 17.3 DAS Principle, Instrument, Installation, Tests, and Advance.Table 17.4 DAS‐VSP (Borehole Seismic) Applications.Table 17.5 DAS in Downhole Surveillance and Flow Monitoring.Table 17.6 DAS in Monitoring Hydraulic Fracturing and Microseismicity.Table 17.7 DAS in CCS and CO ₂ Injection Monitoring.Table 17.8 DAS in Surface Seismic Exploration.Table 17.9 DAS in Geothermal System, Mining, and Mineral Exploration.Table 17.10 DAS Monitoring for Safety and Security.Table 17.11 DAS for Seismology, Fault, and Deformation.Table 17.12 DAS Data Exchange, Management, Processing, and Deep Learning.

      List of Illustrations

      1 Chapter 1Figure 1.1 Operation principle of distributed acoustic sensing.Figure 1.2 COTDR.Figure 1.3 DAS schemas: MOD—intensity and frequency modulator; AOM—acousto‐o...Figure 1.4 DAS optical setup. Distance is proportional to flytime.Figure 1.5 COTDR response (Equation 1.6) shown in the left panel of the simu...Figure 1.6 Intensity changes are irregular along distance but harmonic along...Figure 1.7 Comparison of DAS theoretical response (Equation 1.13) with simul...Figure 1.8 Comparison of first and second order tracking algorithms for DAS....Figure 1.9 The left‐hand panel shows modeling of raw DAS acoustic data (Equa...Figure 1.10 Illustration of two time‐consecutive measurements when DAS outpu...Figure 1.11 Acoustic measurements using DAS: The left panel represents strai...Figure 1.12 Comparison of DAS spectral response with that from a 10 m sensor...Figure 1.13 Low spatial frequency gain in DAS by using long interferometer....Figure 1.14 DAS with linear optical cable is more sensitive to P‐wave in VSP...Figure 1.15 2D spectral representation on upgoing and downgoing acoustic wav...Figure 1.16 Normalized SNR curve (SNR vs. frequency) for a 3000 m/s wave spe...Figure 1.17 Sensing optical fiber cable deployments.Figure 1.18 The left‐hand panel shows a single shot of raw acoustic data; th...Figure 1.19 Comparison of DAS performance with SM and MM optical fiber.Figure 1.20 Directionality of DAS response: The left and central panels repr...Figure