自然伽马能谱测井(NGS)就是对井内岩石中自然存在的放射性核素在核衰变过程中放射出来的伽马射线进行能谱分析,由不同的能量的伽马射线强度确定地层中铀、钍和钾各自的含量及相互组合分布情况,从而评价地层的泥质含量、粘土矿物类型及寻找高放射性储集层等问题。 Natural gamma ray spectroscopy (NGS) is the energy spectrum analysis of the gamma rays radiated from nuclear radionuclides naturally present in the well during nuclear decay. The gamma ray intensities of different energies determine the amount of uranium , Thorium and potassium content and the mutual combination of distribution, so as to assess the formation of clay content, clay mineral types and to find high-radiation reservoirs and other issues.