The Study Of Spectral Analysis Of Natural Gamma Ray Spectralog

Natural Gamma Ray Spectralog (SGR) is an important nuclear log method,and real spectral analysis is a pivotal compose of the surface processing system in SGR . The low confidence levels are leaded ,because of the inherent low resolution , strong statistical fluctuation and low signal noise ratio.The Direct Demodulation method is an advanced technique in the word to solve modulation equation interatively under physical constrains.It has a high sensitivity and spatial resolution than the traditional methods,and can compress the noise effect effectively.This thesis,based on the data of China Offshore Oil Logging Company SGR calibration Facility,performed preliminary research on the DD method in gamma-ray log.The results are:(1) The normal count pate spectrums are obtained form the test pits,the four traditional algorithms methods are tested,which offer credible basis for algorithm selecting.(2) The main idea of DD method is introduced.For the first time in Shengli Oil Logging Company,the Point-Spread-Funtion of Natural Gamma Ray Spectroscopy tool is obtained.The contents of radionuclide in calibration pits are obtained . The DD methed in gamma-ray log is established.