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U.S. Department of Energy
Office of Scientific and Technical Information

Method and apparatus for acoustic cement bond logging

Patent ·
OSTI ID:5736483
A logging instrument is caused to traverse a cased earth borehole periodically emitting and receiving acoustic energies, such instrument generating an electrical signal containing one or more electrical alternations representative of the received acoustic energies, and such alternations having an amplitude generally functionally related to the attentuation of the acoustic energies as they traverse the casing within the borehole. A significant portion of these alternations is determined and digitized, and the individual digitized values therein summed together to yield a functional representation of the signal area of the alternations of a predetermined polarity within the significant portion. This signal area is then compared to the area which would be indicated if the casing were free of cement bonding, the comparison yielding an indication of the relative degree of bonding of cement to the casing within the borehole.
Assignee:
Dresser Industries, Inc.
Patent Number(s):
US 4551823
OSTI ID:
5736483
Country of Publication:
United States
Language:
English