Acoustic Logging Tool

Abstract

A downhole acoustic logging tool for improved noise reduction incorporates a receiver electronics section located in proximity to the receiver or receivers that shields the received signals from direct transmitter interference. The tool additionally allows for local storage and processing of receiver data.

What is claimed is: 
     
         1 . An acoustic logging tool configured as an elongated sonde for conducting investigations in a wellbore, the tool comprising:
 an acoustic transmitter disposed on an upper end of the tool;   a transmitter electronics section disposed on an upper end of the tool and in communication with the transmitter;   a sound isolating attenuator disposed on the tool downhole from the acoustic transmitter;   a first receiver disposed on the tool downhole from the sound isolating attenuator;   a second receiver disposed on the tool downhole from the first receiver;   a receiver electronics section separate from the transmitter electronics section; and   wherein the receiver electronics section is also disposed on the tool downhole from the sound isolating attenuator and adjacent at least one of the receivers.   
     
     
         2 . The acoustic logging tool of  claim 1 , wherein the acoustic logging tool is a cement bond logging tool (CBLT). 
     
     
         3 . The acoustic logging tool of  claim 1 , wherein the receiver electronics section is in between the first and second receivers. 
     
     
         4 . The acoustic logging tool of  claim 1 , wherein at least one of the first or second receivers is comprised of a radial receiver. 
     
     
         5 . The acoustic logging tool of  claim 1 , wherein at least one of the first or second receivers is comprised of a multi-receiver array. 
     
     
         6 . The acoustic logging tool of  claim 1 , wherein the receiver electronics section is contained within a pressure control housing. 
     
     
         7 . The acoustic logging tool of  claim 1 , wherein the receiver electronics section is configured to store receiver data. 
     
     
         8 . The acoustic logging tool of  claim 1 , wherein the receiver electronics section is configured to process receiver data. 
     
     
         9 . The acoustic logging tool of  claim 1 , wherein the first and second receivers are located at three foot and five foot downhole from the transmitter. 
     
     
         10 . The acoustic logging tool of  claim 1  further comprising an additional transmitter and third and fourth receivers wherein the third and fourth receivers repeat the spacing of the first and second receivers. 
     
     
         11 . An acoustic logging tool configured as an elongated sonde for conducting investigations in a wellbore, the tool comprising:
 an acoustic transmitter disposed on an upper end of the tool;   a transmitter electronics section disposed on an upper end of the tool and in communication with the transmitter;   a sound isolating attenuator disposed on the tool downhole from the acoustic transmitter;   a first receiver disposed on the tool downhole from the sound isolating attenuator;   a second receiver disposed on the tool downhole from the first receiver;   a receiver electronics section separate from the transmitter electronics section disposed downhole from the sound isolating attenuator; and   wherein the total length of the acoustic logging tool is less than 95 inches.   
     
     
         12 . The acoustic logging tool of  claim 11 , wherein the acoustic logging tool is a cement bond logging tool (CBLT). 
     
     
         13 . The acoustic logging tool of  claim 11 , wherein the receiver electronics section is also disposed on the tool adjacent at least one of the receivers. 
     
     
         14 . The acoustic logging tool of  claim 13 , wherein the receiver electronics section is in between the first and second receivers. 
     
     
         15 . The acoustic logging tool of  claim 11 , wherein at least one of the first or second receivers is comprised of a radial receiver. 
     
     
         16 . The acoustic logging tool of  claim 11 , wherein at least one of the first or second receivers is comprised of a multi-receiver array. 
     
     
         17 . The acoustic logging tool of  claim 11 , wherein the receiver electronics section is contained within a pressure control housing. 
     
     
         18 . The acoustic logging tool of  claim 11 , wherein the receiver electronics section is configured to store receiver data. 
     
     
         19 . The acoustic logging tool of  claim 11 , wherein the receiver electronics section is configured to process receiver data. 
     
     
         20 . The acoustic logging tool of  claim 11 , wherein the first and second receivers are located at three foot and five foot downhole from the transmitter.