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US 4,899,844 AGranted
Acoustical well logging method and apparatus
AssigneeAtlantic Richfield Company
InventorsKeith W. Katahara, Billy Joe Smith
Life of this patent
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Abstract
A method and tool for acoustically logging a wellbore where a transmitter simultaneously generates a plurality of separate acoustical signals having different frequencies, each effectively centered about a different resonance frequency, and then transmits the signals as a composite multi-frequency output signal having an effective broad frequency bandwidth that is capable of exciting pressure waves in a variety of different types of earthen formations.
Claims17
An acoustic well logging tool comprising
- a sonde comprising:
- a transmitter having a plurality of separate acoustic signal generating means, each of said acoustic signal generating means having a different resonance frequency and each of said acoustical signal generating means comprising a pair of transducer elements positioned diametrically-opposed to each other in said transmitter section, each of said pair of transducer elements having the same resonance frequency;
- means for simultaneously driving each of said plurality of signal generating means to thereby generate an individual acoustic signal from each of said plurality of signal generating means, each signal having a frequency bandwidth effectively centered about the respective resonance frequency of its respective signal generating means;
- and
- means for transmitting said plurality of individual signals as a composite output acoustical signal from said transmitter, said output signal having a broad frequency bandwidth extending over the effective range of said resonance frequencies of said plurality of signal generating means;
- and
- at least one receiver section means spaced from said transmitter for detecting said composite output signal from said transmitter section after said output signal has passed through a formation being logged by said tool.
4 more elements
An acoustic well logging tool comprising:
- a sonde having a transmitter section and at least one receiver section;
- said transmitter section comprising:
- a housing having a plurality of parallel horizontal passages therethrough, each passage having its ends open on diametrically-opposed sides of said housing;
- a plurality of acoustical signal generating means each having a different resonance frequency, one of said plurality of acoustical signal generating means mounted in each of said passages;
- means for simultaneously driving each of said acoustical frequency generating means to thereby generate a plurality of acoustical signals, each of which is effectively centered about its respective resonance frequency;
- an elastic sleeve mounted on said housing over said acoustic signal generating means to thereby form a space between said sleeve and said signal generating means;
- and a
- liquid filling said space.
5 more elements
Dependencies are inferred from the claim text.