METHOD FOR DETERMINING FLUID TYPE AND LITHOLOGY OF SUBTERRANEAN FORMATIONS

摘要

Disclosed herein in a method for determining the lithology of and the types of fluid contained within a subterranean formation. In the practice of this invention, high energy neutrons bombard the formation matrix and formation fluids. Induced gamma rays from inelastic scattering reactions are indicative of the type of fluid in the formation, and induced gamma rays from neutron capture reactions are indicative of the lithology of the formation matrix. Among other things, this technique permits differentiation between water-saturated limestones and oil-bearing sandstones. Also disclosed herein is a method for detecting the presence of natural gas within a subterranean formation.