Patent US5917660A successfully refreshed from Google Patents.
EP0136027A2
Expired / Lapsed
EP
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Acoustic well logging device for detecting compressional and shear waves
Assignee: Mobil Oil AS
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Filing: 1984-08-13
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Granted: —
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Expires: 2004-08-13
Abstract
Abstract A borehole logging system employs a compressional wave transmitter (17) and a shear wave transmitter (18). The transmitter (17, 18) are alternately fired to impart compressional and shear waves into the formations surrounding the borehole. A bender-type receiver (10), spaced apart from the transmitters (17, 18) in the borehole is alternately gated so that voltages generated across a pair of piezoelectric planar surfaces therein are subtracted during the expected time period of symmetrical motion of the receiver (19) to provide a compressional wave output and added during the expected arrival time period of unsymmetrical motion of the receiver (19) to provide a shear wave output.
Inventors
- 👤 Joseph Zemanek, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:22
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/40; G01V1/44; G01H; G01H11/00; G01H11/06; G01H11/08; Y; Y10; Y10S; Y10S367/00; Y10S367/911; Y10S367/912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
A well logging device for continuously logging both the compressional and shear wave transmission characteristics of formations surrounding a borehole comprising: a) a multidirectional acoustic transmitter for imparting compressional waves into the formations surrounding the borehole, b) a point source acoustic transmitter for imparting shear waves into the formations surrounding the borehole, c) means for triggering said transmitters to alternately impart said compressional and shear waves into said formations, d) a receiver mounted on said logging device in spaced relation from said transmitters, said receiver comprising a bender-type transducer having opposed unrestricted piezoelectric planar surfaces, oriented along the longitudinal axis of said tool, and e) means for configuring the output of said receiver in response to said trigger means so that the voltages produced across each of said piezoelectric planar surfaces are combined for symmetrical motion following the generation of a compressional wave by said multidirectional acoustic transmitter and for unsymmetrical motion following the generation of a shear wave by said point source acoustic transmitter.
Claim 2
Dependent Claim
165 words
A well logging device for continuously logging both the compressional and shear wave transmission characteristics of formations surrounding a borehole comprising: a) a multidirectional acoustic transmitter for imparting compressional waves into the formations surrounding the borehole, b) a point source acoustic transmitter for imparting shear waves into the formations surrounding the borehole, c) means for triggering said transmitters to alternately impart said compressional and shear waves into said formations, d) a receiver mounted on said logging device in spaced relation from said transmitters, said receiver comprising a bender-type transducer having opposed unrestricted piezoelectric planar surfaces, oriented along the longitudinal axis of said tool, and e) means for configuring the output of said receiver in response to said trigger means so that the voltages produced across each of said piezoelectric planar surfaces are combined for symmetrical motion following the generation of a compressional wave by said multidirectional acoustic transmitter and for unsymmetrical motion following the generation of a shear wave by said point source acoustic transmitter.
Claim 3
Dependent Claim
117 words
The well logging device of Claim 1 wherein said means for configuring the output of said receiver comprises: a) means for gating the voltages produced across each of said piezoelectric planar surfaces of said receiver during the expected time period of symmetrical motion of said receiver, b) means for subtracting said voltages gated during the expected time of said symmetrical motion to produce a compressional wave output, c) means for gating the voltages produced across each of said piezoelectric planar surfaces of said receiver during the expected time period of unsymmetrical motion of said receiver, and d)means for adding said voltages gated during the expected time period of said unsymmetrical motion to produce a shear wave output.
Claim 4
Dependent Claim
109 words
The well logging device of Claim 2 wherein the means for gating said receiver for producing the desired compressional wave output comprises: a) a delay means initiated by the triggering of said multidirectional acoustic transmitter and producing a delay pulse extending for a time period expected for the generated compressional wave to travel through the formation to said receiver, and b) gating means responsive to the termination of said delay pulse for applying the voltages produced across each of said piezoelectric planar surfaces of said receiver to said configuring means for combining said voltages into a compressional wave during the expected time period for symmetrical motion of said receiver.
Claim 5
Dependent Claim
109 words
The well logging device of Claim 2 wherein the means for gating said receiver for producing the desired shear wave comprises: a) a delay means initiated by the triggering of said point source acoustic transmitter and producing a delay pulse extending for a time period expected for the generated shear wave to travel through the formation to said receiver, and b) gating means responsive to the termination of said delay pulse for applying the voltages produced across each of said piezoelectric planar surfaces of said receiver to said configuring means for combining said voltages into a shear wave during the expected time period for unsymmetrical motion of said receiver.
References Cited (Backward Citations)
No citation records indexed.
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