Marine Seismic First Line QC Service
EPI recommends that all seismic and navigation data are subjected to independent analysis and verification prior to commencement of all marine seismic operations, at specific stages (start of survey, re-configuration) and prior to deliverables being archived.
An integrated deep-dive into data integrity, formats and quality is undertaken to ensure that data is being recorded and delivered according to industry standards.
To this end we offer the following services:
1. Navigation First Line QC
- Navigation
Check P2 and P1 data formats, analysis of positioning networks, verify headers, check geodetic parameters, process raw data and compare to P1.
- Spread
Examine geometry and stability of spread, examine contract tolerance adherence of spread, & deviation of various nodes from preplot.
- Source
Verify shot flags/fired status; examine depths, pressures, volumes and timing delays; examine separations, laybacks and tow skew & examine seismic RMS attributes for source balance.
- Streamers
Examine separations at every offset; examine depth at every offset; examine bird wing data for angles and steering forces; examine RMS noise attributes at each receiver.
2. Seismic First Line QC
- Read/Verify nav merged SEG-Y
- Read/Verify raw SEG-D
- Check seismic data can be read and reformatted and the data looks as expected.
- Check all SEG-Y header mappings.
- For every header the following is also checked where appropriate: Min/max values, Min/Max increments, Number of zero samples, Check for NaNs for floating point numbers, Maximum number of consecutive traces with the same value.
- Check the EBCDIC header for SEG-Y standard conformance and completeness/accuracy of contents.
EPI provides a secure file transfer facility (SFTP) via dedicated server where a client or contractor can upload data for verification, alternatively we can download data from a client’s server.
Turnaround is typically 24 hours from receipt of sample data and a comprehensive report is provided highlighting any areas of concern. All analysis is performed by highly experienced processors using state of the art software.
