See also normal and lateral devices . See hydrocarbon porosity feet . If the pore pressure is higher than normal, then it supports part of the lithostatic load . Effective stress exerted by porous rock. The accumulated thickness of sandstone of a specified quality which is found within a specific interval of formation .
All stable isotopes are capable of capturing thermal neutrons .
In well logging, neutron bombardment of a formation and the subsequent capture of thermal neutrons causes excitation of certain elements. If the resulting product nucleus is a radioisotope its later decay to a stable state can be detected and the energy level of emitted gamma rays is characteristic of the specific element. The analysis of the energies of the decay gamma rays is neutron activation analysis. See capture cross section . The three possible processes are elastic scattering , inelastic scattering , and absorption .