Cement evaluation through dual-string pipes

Abstract

A method for cement evaluation through dual-string pipes comprising the steps of: i) acquiring waveforms data using a cement bond logging tool; ii) processing the acquired waveforms data to eliminate one or more potential DC offsets; iii) selecting a first receiver to further process the processed acquired waveforms data in a common-receiver domain; iv) performing in-situ calibration using the processed acquired waveforms data from the common-receiver domain to identify free-pipe and wall-bonded waveforms; v) calculating normalized amplitudes from monopole waveforms and azimuthal waveforms obtained from the free-pipe and wall-bonded waveforms to determine bond index and generate cement map; and vi) calculating statistical averages and variances using the calculated normalized amplitude to generate a final presentation.

What is claimed is: 
     
         1 . A method for cement evaluation through dual-string pipes comprising the steps of
 i) acquiring waveforms data using a cement bond logging tool;   ii) processing the acquired waveforms data to eliminate one or more potential DC offsets;   iii) selecting a first receiver to further process the processed acquired waveforms data in a common-receiver domain;   iv) performing in-situ calibration using the processed acquired waveforms data from the common-receiver domain to identify free-pipe and wall-bonded waveforms;   v) calculating normalized amplitudes from monopole waveforms and azimuthal waveforms obtained from the free-pipe and wall-bonded waveforms to determine bond index and generate cement map; and   vi) calculating statistical averages and variances using the calculated normalized amplitude to generate a final presentation.   
     
     
         2 . The method of  claim 1 , wherein a second or more receivers can also be chosen for further processing of the processed acquired waveforms in a common-receiver domain followed by the remaining steps. 
     
     
         3 . The method of  claim 1 , wherein the one or more potential DC offsets is any constant and non-zero amplitudes. 
     
     
         4 . The method of  claim 1 , wherein the in-situ calibration is done using an algorithm. 
     
     
         5 . A system for autonomous restriction navigation comprising, the system comprising:
 a processor;   memory accessible to the processor;   processor-executable instructions stored in the memory and executable by the processor to instruct the system to:
 i) acquire waveforms data using a cement bond logging tool; 
 ii) process the acquired waveforms data to eliminate one or more potential DC offsets; 
 iii) select a first receiver to further process the processed acquired waveforms data in a common-receiver domain; 
 iv) perform in-situ calibration using the processed acquired waveforms data from the common-receiver domain to identify free-pipe and wall-bonded waveforms; 
 v) calculate normalized amplitudes from monopole waveforms and azimuthal waveforms obtained from the free-pipe and wall-bonded waveforms to determine bond index and generate cement map; and 
 vi) calculate statistical averages and variances using the calculated normalized amplitude to generate a final presentation. 
   
     
     
         6 . The system of  claim 5 , wherein a second or more receivers can also be chosen to further process the processed acquired waveforms in a common-receiver domain followed by the remaining steps. 
     
     
         7 . The system of  claim 5 , wherein the one or more potential DC offsets is any constant and non-zero amplitudes. 
     
     
         8 . The system of  claim 5 , wherein the in-situ calibration is done using an algorithm.