Borehole compensated oxygen activation nuclear well logging
 Formations adjacent a well borehole are activated with neutrons from a pulsed neutron source in a sonde at an energy level, such as 14 MeV, to energize oxygen present in the formation and borehole, giving rise to gamma radiation from O.sup.16 (n,p)N.sup.16 reaction. Gamma radiation in the energy windows 3.25-4.00 MeV and 4.75-7.20 MeV is detected in a time gated detector and counted. Count rate contributions from the borehole and from the formation are differentiated on the basis of radial distance from the center of the sonde. In this manner, compensation for adverse effects of borehole oxygen activation on formation oxygen activation measurements of interest is achieved. Further, the neutron output intensity of the pulse neutron source may also be measured. 
Texaco Inc.
G
G01V
inventional
Dan M.
Arnold