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A Demonstration of Time-Lapse Imaging Using Ultra-High-Frequency Seismic Reflection Data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 3rd Applied Shallow Marine Geophysics Conference, Sep 2018, Volume 2018, p.1 - 5
Abstract
Time-lapse seismic imaging has improved our capability to measure and understand dynamic processes in the subsurface. However, there are very few examples using ultra-high-frequency (kHz-range) seismic data. Exacting requirements for navigation can be prohibitive for acquiring coherent, true-3D volumes and residual errors manifest as noise in time-lapse differences making it challenging to interpret real subsurface changes.
By updating the acquisition and processing workflows for the 3D Chirp, an ultra-high-frequency sub-bottom profiler, initial results illustrate high amplitude and navigation repeatability. Post-processing was used to improve the capability and performance of real-time kinematic GPS, coupled with high-accuracy inertial measurements to yield centimetre-level absolute positioning in a range of operating conditions. A comparison of seismic reflection volumes acquired over the same area at high and low tide reveals a normalized RMS difference of 16.1% and demonstrates the capability for direct quantitative monitoring of the shallow subsurface at decimeter-resolution.