Application of Electronic Data Processing To Sonic Analysis (Sound Logging) Data Improves Interpretation

SONAN (sonic-analysis) logging resulted primarily from the research and development of a practical logging sound by McKinley et. al. of Esso Production Research Company (EPRC). McKinley primarily confined his research to the use of this system for documenting fluid flow behind cemented casing but also described the potential of this system as a flow meter. Following the publication of his findings in 1973, several service companies, including Dresser Atlas, began field testing equipment varying slightly from the EPRC designs. The variations were the result of efforts to speed up the recording of the log and to improve the ease of operations of the system and its reliability. In the time since, additional applications of this system have been noted, including its use to (1) find zones of lost circulation in drilling wells, (2) locate leak points in casing and tubing, (3) locate the source of fluid entry in uncased well bores, and (4) use this system in calculating perforation productivity profiles. McKinley also demonstrated that the data recorded could be quantitatively evaluated to determine rate of flow as well as the source. Because of the present method of data recording and the potential quantitative nature of the data, Dresser Atlas found that the processing of the field-recorded data is best performed with the aid of digital computers. Automated processing of the sound log data has been found to speed the interpretation, improve the accuracy of the interpretation and provide customers with a permanent record of our analysis for their well files. The equipment, principle of operation, several examples of the applications previously mentioned, and our processing of the data are discussed in the following pages.