Leaky mode

{
  "id": "MLC-T-OAG-002143",
  "term": "Leaky mode",
  "field": "Oil and gas",
  "definition": "A borehole wave that is only partly trapped by the fluid column, so it loses energy by radiating into the surrounding formation as it travels. The leaky P wave is the best known example, a dispersive compressional arrival that dominates in slow formations where shear velocity is below the borehole fluid velocity. In fast formations, leaky modes follow the compressional arrival and contribute to the shear wave group in the full waveform.",
  "subject": "Formation Evaluation",
  "url": "https://mlchart.com/terminology/oil-and-gas/leaky-mode/"
}