Enhancing Borehole Resonance Signal For Through Tubing Cement Evaluation

Abstract

A method comprising: transmitting an acoustic signal into at least part of a conduit string, measuring a return signal from at least part of the conduit string, computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal. Additionally, a system may be included and/or paired with the method. The system comprising: a transmitter configured to transmit an acoustic signal into at least part of a conduit string, a receiver configured to measuring a return signal from at least part of the conduit string, an information handling system configured for: computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.

What is claimed is: 
     
         1 . A method comprising:
 transmitting an acoustic signal into at least part of a conduit string;   measuring a return signal from at least part of the conduit string;   computing one or more amplitudes of a resonance signal from the return signal; and   forming a depth resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.   
     
     
         2 . The method of  claim 1 , further comprising decomposing the return signal to form a decomposed waveform, forming the resonance signal by implementing a filter with at least the decomposed waveform, and determining a resonance mode of the return signal. 
     
     
         3 . The method of  claim 2 , wherein the filter is a band pass filter and the band pass filter is formed from at least on the resonance mode of the return signal. 
     
     
         4 . The method of  claim 2  further comprising subtracting a baseline signal from the decomposed waveform. 
     
     
         5 . The method of  claim 4 , wherein the baseline signal is a fully bounded return signal or a free pipe return signal. 
     
     
         6 . The method of  claim 2 , wherein decomposing is based on at least the resonance mode. 
     
     
         7 . The method of  claim 2 , further comprising forming at least one time-frequency window and performing wavelet analysis on the decomposed waveform. 
     
     
         8 . The method of  claim 1 , further comprising forming a time segment from early time arrivals, wherein the early time arrivals comprise resonance and non-resonance signals. 
     
     
         9 . The method of  claim 1 , further comprising forming a time segment from late time arrivals, wherein the late time arrivals comprise only resonance signals. 
     
     
         10 . The method of  claim 1 , wherein one or more amplitudes are computed by root-mean squared amplitude, peak-to-peak amplitude or from wavelet convolution or Hilbert transform. 
     
     
         11 . The method of  claim 1 , further comprising determining a cut-off time by at least a length of return waveform, tubing and casing diameters, degree of eccentricity, or transmitter-receiver (TR) offset. 
     
     
         12 . The method of  claim 11 , further comprising taking a portion of the return signal after a cut-off time. 
     
     
         13 . The method of  claim 1 , further comprising forming a cement bond quality with at least the depth resonance amplitude log. 
     
     
         14 . A system comprising:
 a transmitter configured to transmit an acoustic signal into at least part of a conduit string;   a receiver configured to measuring a return signal from at least part of the conduit string;   an information handling system configured for:
 computing one or more amplitudes of a resonance signal from the return signal; and 
 forming a depth resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal. 
   
     
     
         15 . The system of  claim 14 , wherein the information handling system is further configured to decompose the return signal and form the resonance signal by implementing a filter with at least a decomposed waveform. 
     
     
         16 . The system of  claim 14 , wherein the information handling system is further configured to take a portion of the return signal after a cut-off time. 
     
     
         17 . The system of  claim 14 , wherein the information handling system is further configured to subtract a baseline signal from the decomposed waveform. 
     
     
         18 . A non-transitory storage computer-readable medium storing one or more instructions that, when executed by a processor, cause the processor to:
 obtain a return signal from a receiver configured to measure the return signal from at least part of a conduit string;   compute one or more amplitudes of a resonance signal from the return signal; and   form a depth resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.   
     
     
         19 . The non-transitory storage computer readable medium of  claim 18 , wherein the one or more instructions, that when executed by the processor, further cause the processor to take a portion of the return signal after a cut-off time. 
     
     
         20 . The non-transitory storage computer readable medium of  claim 18 , wherein the one or more instructions, that when executed by the processor, further cause the processor to form a decomposed waveform from the return signal and subtract a baseline signal from the decomposed waveform.