Quality Control of DAS VSP Data in Desert Environment Using Simulations and Matching Filters
Nour Alzamil1,2, Vladimir Kazei3, Huawei Zhou1
1Department of Earth and Atmospheric Sciences, University of Houston, 4800 Calhoun Rd., Houston, TX 77004, USA.
Sensors (Basel, Switzerland)
|February 24, 2024
Summary
This study introduces a novel simulation method to evaluate distributed acoustic sensing (DAS) vertical seismic profiling (VSP) data quality in deserts without needing geophone data. The approach assesses DAS VSP data reliability using simulated waveforms and receiver signatures.
Area of Science:
- Geophysics
- Seismic Exploration
- Wellbore Geophysics
Background:
- Desert environments present challenges for vertical seismic profiling (VSP) data quality due to near-surface unconsolidated sediments and significant daily temperature fluctuations.
- Distributed acoustic sensing (DAS) VSP is a valuable technique, but its data quality assessment often relies on traditional geophone surveys, which can be impractical or unavailable.
- Rigorous quality control is essential for accurate subsurface characterization using VSP data.
Purpose of the Study:
- To develop and validate a simulation-based methodology for assessing the quality of DAS VSP data acquired in desert environments, independent of geophone data.
- To evaluate the accuracy of simulated DAS VSP data by comparing it with field measurements and assessing channel depth uncertainty.
- To propose a new quality control metric for DAS VSP data based on receiver signature analysis.
Main Methods:
- Utilized an elastic pseudo-spectral finite difference method to simulate DAS and geophone VSP data based on a 1D velocity model derived from checkshot data.
- Assessed DAS channel depth uncertainty by calibrating against formation depth using the principle of conservation of energy flux.
- Estimated source and receiver signatures using matching filters and compared simulated data with field measurements.
Main Results:
- Simulated DAS VSP data exhibited high visual similarity with field DAS first arrival waveforms, unlike simulated geophone data which failed to replicate field amplitude variations.
- Estimated source and receiver signatures from simulations were visually indistinguishable from field DAS data.
- A new quality control metric based on local variations in receiver signatures was proposed, demonstrating the potential for geophone-independent DAS VSP data quality assessment.
Conclusions:
- The simulation-based approach provides a viable method for quality control of DAS VSP data in challenging desert conditions without requiring geophone data.
- The proposed receiver signature variation metric offers a robust, geophone-free approach to assess DAS VSP data quality.
- This methodology enhances the reliability and applicability of DAS VSP for subsurface investigations in remote or difficult-to-access environments.
