Checkshot survey

{
  "id": "MLC-T-OAG-000640",
  "term": "Checkshot survey",
  "field": "Oil and gas",
  "definition": "A procedure for measuring the travel time of seismic energy from the surface to a known depth in a borehole. A geophone is lowered into the well to record signals from a seismic source at the surface, establishing a direct relationship between depth and two-way travel time. These measurements are used to calibrate the time-to-depth conversion of seismic data and to correct sonic log data for drift and dispersion.",
  "subject": "Geophysics",
  "url": "https://mlchart.com/terminology/oil-and-gas/checkshot-survey/"
}