The Identification Of Energy Peaks In Gamma-ray Spectrum Of Formations

This paper first analyzes the characteristics of the energy spectrum of the gamma-rays emitted by the natural radioactive elements in the formations. In consideration of the special response of the present gamma-ray spectrum log tool, several tests are designed and completed to research the details of the natural gamma-ray spectrum given out by the formation elements.Based on the detailed spectrum data analysis, a new concept is put forward to describe the energy peaks, which views the energy peaks in natural gamma-ray spectrum as special distributions. According to this conception, each gamma-ray energy peak can be treated as a specially designed distribution function. And then a new method is conceived in order to identify the energy peaks. That is to locate the object peak position by comparing it with a reference distribution function.The availability and efficiency of this method are both demonstrated by several examples which calculates the energy peak position channels for the potassium, uranium and thorium.At last, during the well logging process, by the advantage of identifying the energy peaks quickly and efficiently, the spectrum is stabilized with a special designed software. Thus the accuracy and stability are warranted during the logging process.