Bulk-density logging with fast neutron-induced gamma rays

The authors used computer simulations and experiments to evaluate a new method of logging earth formations for bulk density. This method promises to produce good density logs acquired in difficult borehole conditions because it furnishes a much greater depth of investigation into the formation than the conventional gamma-gamma method. Their evaluation indicates the method is most suitable for logging in vadose zone formations, above the water table, where moisture content is relatively low.