C6*fitei21 



CONTINUOUS 

 VELOCITY 

 LOGGING 

 (Acoustical Logging) 



H. R. Breck, 



S. W. Schoellhorn 



and 



R. B. Baum 



As a general service to the oil industry, continuous velocity logging, or 

 acoustic logging, is approximately three years old. Even with this short period 

 of experience, many observations indicate that the continuous velocity log will 

 make valuable contributions to the information obtainable from a drilled hole. 



The first commercial continuous velocity log was run in the Stanolind's 

 Daisy Perdasofpy No. 1, Comanche County, Oklahoma, on March 6, 1954. This 

 survey was performed by Seismograph Service Corporation of Tulsa, using 

 under license agreement, the Magnolia Petroleum Company Continuous Velocity 

 Logger. In recent years Magnolia, Shell Oil Company, Humble Oil and Refining 

 Company, United Geophysical Company, and The Texas Company have pio- 

 neered in the development of velocity logging tools. Magnolia began its work 

 about 1950. Very little published information, except for that on the Magnolia 

 tool, is available on the details of the various instruments constructed. 



The Magnolia Continuous Velocity Logger now in commercial use, and more 

 commonly described as the CVL logger, consists of a transmitter and a single 

 receiver. The direct presentation, without photographic recording delay, of both 

 the interval log and the integrated travel-time curve, are unique to this system. 



SPECIFICATIONS 

 AND EQUIPMENT 



A simplified drawing of the essential com- 

 ponents of the Magnolia logger is shown in 

 Figure 21-1. The system contains a magneto - 

 strictive nickel alloy transmitter. The expansion of the alloy, when magnetized 

 by the electric current supplied from the logging truck, produces the sonic 



409 



