Formation Density

Gamma

Source

Near Detector

Detector

Scattering and

Absorption

  • A chemical source generates gamma radiation that is focused into the formation.
  • Gamma rays collide with electrons in the formation and are scattered, losing energy in the process, and are finally absorbed.
  • The number and energy of gamma rays received at each of the two detectors are measured.
  • The number of gamma rays measured is a function of the density of electrons in the formation which is approximately proportional to the density of the formation.
  • By using two detectors, correction can be made for mud cake and small irregularities in borehole smoothness.

Was this article helpful?

0 0

Post a comment