Multi-Receiver Quality Factor From an Array Sonic Log

This work deals with the extraction of attenuation attributes from compressional waves picked up from an array sonic log acquired in a real well. To achieve this goal, an algorithm was developed based on spectral ratio analysis of recorded waves, which replaces the traditional artificial reference by a reference sample obtained from the well log. The main attenuation attribute considered was the quality factor Q. The results show values for Q factor in accordance with those related in the literature, as well in a good correlation with all petrophysical logs of the well, especially those physical properties related to fluid saturation, like oil-water contact recognition. A new approach for attenuation visualization is proposed based on a continuous map of quality factor as a function of depth and offset. The proposed method offers new independent and reliable information at very low additional costs, since it is derived from an already available data.