SYSTEMS AND METHODS FOR ANALYZING CASING BONDING IN A WELL USING DIFFERENTIAL SENSING
Implementations described and claimed herein provide systems and methods for isolation detection. In one implementation, an acoustic signal is obtained. The acoustic signal is captured at a set of acoustic receivers deployed in a structure in a subterranean surface. A differential acoustic signal is produced from the acoustic signal captured at the set of acoustic receivers. A symmetry within a portion of the structure is determined based on a value of the differential acoustic signal. At least one isolation region is detected within the structure based on the symmetry.
1 . A method for isolation detection in a wellbore, the method comprising:
obtaining an acoustic signal, the acoustic signal captured at a set of acoustic receivers deployed in a structure in a subterranean surface;
producing a differential acoustic signal from the acoustic signal captured at the set of acoustic receivers; and
determining a symmetry within a portion of the structure based on a value of the differential acoustic signal.
2 . The method of claim 1 , wherein the symmetry is determined to be symmetrical when the value of the differential acoustic signal is zero.
3 . The method of claim 1 , wherein the symmetry is determined to be asymmetrical when the value of the differential acoustic signal is non-zero.
4 . The method of claim 1 , wherein the acoustic signal is an axial acoustic signal propagating in at least one axial direction, the symmetry including an axial symmetry.
5 . The method of claim 1 , wherein the acoustic signal is a radial acoustic signal propagating in at least one radial direction, the symmetry including a radial symmetry.
6 . The method of claim 1 , wherein the structure includes a production tube deployed in a casing of a wellbore having a cement layer.
7 . The method of claim 1 , further comprising:
detecting at least one isolation region within the structure based on the symmetry.
8 . The method of claim 1 , wherein acoustic waves propagate from at least one acoustic transmitter and are received at the set of acoustic receivers as the acoustic signal.
9 . The method of claim 1 , wherein the set of acoustic receivers includes two acoustic receivers spaced equidistant from an acoustic transmitter.
10 . The method of claim 1 , wherein the differential acoustic signal is produced by summing signals received by each of the set of acoustic receivers in a differential amplifier.
11 . The method of claim 1 , wherein the set of acoustic receivers are coupled in reverse polarity, operably offsetting to produce a cumulative receiver output, the cumulative receiver output being the differential acoustic signal.
12 . One or more tangible non-transitory computer-readable storage media storing computer-executable instructions for performing a computer process on a computing system, the computer process comprising:
obtaining an acoustic signal, the acoustic signal captured at a set of acoustic receivers deployed in a structure in a subterranean surface;
producing a differential acoustic signal from the acoustic signal captured at the set of acoustic receivers; and
determining a symmetry within a portion of the structure based on a value of the differential acoustic signal.
13 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the symmetry is determined to be symmetrical when the value of the differential acoustic signal is zero.
14 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the symmetry is determined to be asymmetrical when the value of the differential acoustic signal is non-zero.
15 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the acoustic signal is an axial acoustic signal propagating in at least one axial direction, the symmetry including an axial symmetry.
16 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the acoustic signal is a radial acoustic signal propagating in at least one radial direction, the symmetry including a radial symmetry.
17 . The one or more tangible non-transitory computer-readable storage media of claim 12 , further comprising:
detecting at least one isolation region within the structure based on the symmetry.
18 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the set of acoustic receivers includes two acoustic receivers spaced equidistant from an acoustic transmitter.
19 . The one or more tangible non-transitory computer-readable storage media of claim of claim 12 , wherein the differential acoustic signal is produced by summing signals received by each of the set of acoustic receivers in a differential amplifier.
20 . The one or more tangible non-transitory computer-readable storage media of claim 12 , wherein the set of acoustic receivers are coupled in reverse polarity, operably offsetting to produce a cumulative receiver output, the cumulative receiver output being the differential acoustic signal.