Seismic Data Reconstruction Process

The seismic section conversion process consisted of three main stages:

  • Image preparation
  • Image conversion
  • Quality control.

Image preparation

Digital images vary greatly in their quality and their input into conversion software requires certain aspects are corrected. There are many issues that can arise from poor images and it can require a number of stages to get them to a stage where automatic trace picking works reliably. The most common stages are:

  • Remove white dots from scanned image caused by scanning set up see image below for an example
  • Adjust image output to capture maximum detail
  • QC image for any anomalies

Image conversion

The software package has many options for handling input data due to the varied nature of scanned images. The basic steps are detailed below:

  • Square and straighten image to ensure traces are horizontal for picking
  • Remove time lines
  • QC traces to ensure that all traces have been picked; add in traces where necessary
  • QC traces to ensure that trace tracks over complete plot; make adjustments where necessary
  • Set the first and last trace Shot Point range; data taken from plot
  • Ensure that the trace/shot point relationship is an integer
  • Filter traces using Time Variable Bandpass Filter
  • Load navigation data into file
  • Populate EBCDIC header
  • Rename data file to standard format
  • Generate EBCDIC header dump

Quality Control

It is a relatively simple process to run an image through conversion software; however, without the correct steps being taken along the way the output data can be meaningless. As such as well as checks during the process we also perform stringent quality control procedures on all files at the end of the process as follows:

  • Create a histogram plot of amplitudes of the traces to check the relative Peak/Trough amplitude levels and ensure that there are no erroneous readings
  • Produce a frequency vs amplitude plot, check for noise outside of the original processed bandpass filter ranges
  • Check pre/post filtered images against one another
  • Check navigation values through the plot match with ASCII data
  • Compare original image with SEGY image
  • The image above is a screen capture from the converted SEGY file
  • The image above is a screen capture from the original TIF file