Precise location data is crucial for accurate seismic interpretation. While the “4 corners” method can introduce risks, extracting coordinates directly from trace headers improves spatial accuracy, minimizing misalignment from cumulative azimuth and spacing errors.
Loading corner coordinates from load sheets and EBCDIC headers is efficient, but manual data entry raises error risks. Studies indicate that 20-30% of these errors are transpositions (e.g., “43” entered as “34”), with the rest being random digit additions or omissions.
Analyzing XY values from hundreds of thousands of 3D poststack volumes confirms that trace headers—populated directly by processing software—provide more reliable spacing and azimuth data than load sheets and EBCDIC headers, with far fewer manual-entry errors. However, trace headers can still have issues, which can often be identified and corrected automatically.
The images from the Waihapa 3D dataset included here are ©Crown Copyright, reproduced with permission from New Zealand Petroleum and Minerals (www.nzp&m.govt.nz), and are used to showcase the Bin Grid Calculator.
We’re launching a new Grid Definition Calculator, available soon for Beta testing. This tool allows users to enter or paste line, trace, and XY corner values to calculate spacings, azimuths, area, and create a grid polygon using either three corners or a Point + Spacing method. Currently, Projection (CRS) is for display only, but an upcoming feature will check corner orthogonality (90-degree angles).
Interested in Beta testing? Reach out! We welcome feedback on the interface and are especially keen on your input for handling 4-corner data from load sheets/EBCDIC headers versus XYs from trace headers.
About Don Robinson
Don Robinson has dedicated over 50 years to software development and seismic analysis. He founded Oklahoma Seismic Corporation in 1980 and co-developed the MIRA interpretation system, later acquired by Landmark Graphics in 1993. He then started Resolve GeoSciences in 1997, where he now leads the development of SeisShow and AnalyzeSE, software for analyzing and correcting SEG-Y seismic data.Connect on LinkedIn
