Oil Well Logging
Oil well logging is a technique for finding hydracarbon zones in the geological formations below the Earth's crust. As the well is being drilled, a probe that contains both an energy source (neutron or gamma ray) and a detector (photomultiplier with scintillator) is lowered into the well. The detector measures the amount of radiation that scatters back from the well's surroundings. This will indicate the porosity and permeability of the rock, and help determine whether oil can be removed. In addition to this task, the photomultiplier tube can also detect gamma rays that naturally occur in shale deposits, which in turn indicate the presence of oil or gas.