Patent ID: 8063356

Claim:
A method to compensate for the photoelectric effect in pulsed γ-γ density tools, comprising the steps of: providing a source of energetic particles and directing those energetic particles at a formation having a known photoelectric factor and electron density; capturing one or more photons either emitted or deflected from said formation with one of a first detector and a second detector, wherein said first detector is spaced a first distance from said source, said second detector is spaced a second distance from said source and a third distance separates said first detector from said second detector; measuring a first total energy of said one or more photons striking said first detector during a time interval and measuring a second total energy of said one or more photons striking said second detector during the same time interval; and disposing a first filter between said first detector and said formation effective to cause Pe sensitivity to match standoff influence thereby compensating for both effects simultaneously.