# US 10,502,854 B2 · Real-time adaptive minimum phase wavelet generation for downhole tools > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,854 B2 - Document ID: US10502854B2 - Status: Granted - Kind: B2 - Application number: 15/312,748 - Filed: 2016-04-28 - Published: 2017-07-20 - Granted: 2019-12-10 - Earliest claimed: 2015-05-22 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Batakrishna Mandal; Yinghui Lu - Web page: https://patentgrep.com/patent/US10502854B2 ## CPC - G01V 1/50: Analysing data - E21B 47/00: Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) - E21B 47/005: Monitoring or checking of cementation quality or level - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An example method may include selecting a proposed pulse. A minimum phase wavelet may be generated based, at least in part, on the proposed pulse. A pulse signal within a wellbore may be generated based, at least in part, on the minimum phase wavelet. An echo signal corresponding to the pulse signal from at least a portion of the wellbore may be received, wherein the echo signal is indicative of a wellbore property. ## Claims ### Claim 1 A method comprising: selecting a proposed pulse; generating a minimum phase wavelet, at least in part, by calculating a real cepstrum of the proposed pulse; generating a pulse signal within a wellbore based, at least in part, on the minimum phase wavelet; and receiving an echo signal corresponding to the pulse signal from at least a portion of the wellbore, wherein the echo signal is indicative of a wellbore property. ### Claim 2 (depends on 1) The method of claim 1, wherein the minimum phase wavelet has the same spectral magnitude as the proposed pulse. ### Claim 3 (depends on 1) The method of claim 1, wherein the spectral magnitude of the proposed pulse is determined based, at least in part, on one or more real-time wellbore conditions. ### Claim 4 (depends on 1) The method of claim 1, wherein calculating the real cepstrum of the proposed pulse comprises calculating an inverse discrete Fourier transform of a log spectral magnitude of the proposed pulse. ### Claim 5 (depends on 4) The method of claim 4, wherein calculating the real cepstrum of the proposed pulse further comprises filtering the proposed pulse. ### Claim 6 (depends on 1) The method of claim 1, further comprising the steps of: selecting a second proposed pulse based, at least in part, on the echo signal; and repeating the generating and receiving steps for the second proposed pulse. ### Claim 7 (depends on 6) The method of claim 6, wherein a spectral magnitude of the second proposed pulse is determined based, at least in part, on the echo signal. ### Claim 8 (depends on 6) The method of claim 6, wherein the echo signal is digitized by an analog to digital converter prior to the selection of the second proposed pulse. ### Claim 9 (depends on 6) The method of claim 6, further comprising repeating the selecting, generating, and receiving steps in a feedback loop. ### Claim 10 (depends on 1) The method of claim 1, wherein the echo signal is indicative of at least one of a casing thickness, a casing impedance, a casing slowness, a casing reflectance, and a casing characteristic frequency. ### Claim 11 (depends on 1) The method of claim 1, wherein the echo signal is indicative of at least one of a cement layer thickness, a cement layer impedance, a cement layer slowness and a cement layer reflectance. ### Claim 12 (depends on 1) The method of claim 1, wherein the pulse signal is generated by a downhole tool comprising a transducer. ### Claim 13 (depends on 12) The method of claim 12, wherein the downhole tool comprises a rotating head to which the transducer is coupled. ### Claim 14 A method comprising: selecting a proposed pulse; generating a minimum phase wavelet based, at least in part, on the proposed pulse, wherein a signal energy of the minimum phase wavelet is more concentrated than a signal energy of the proposed pulse; generating a pulse signal within a wellbore based, at least in part, on the minimum phase wavelet; and receiving an echo signal corresponding to the pulse signal reflecting from a wellbore casing, wherein the echo signal is indicative of a characteristic frequency of the wellbore casing; selecting a second proposed pulse based, at least in part, on the characteristic frequency of the wellbore casing; generating a second minimum phase wavelet based, at least in part, on the second proposed pulse; generating a second pulse signal within the wellbore based, at least in part, on the second minimum phase wavelet; and receiving a second echo signal corresponding to the second pulse signal reflecting from the wellbore casing, wherein the second echo signal is indicative of the characteristic frequency of the wellbore casing. ### Claim 15 (depends on 14) The method of claim 14, further comprising repeating the selecting, generating, and receiving steps in a feedback loop. ### Claim 16 A system comprising: a downhole tool; a transducer coupled to the downhole tool; and a controller communicably coupled to the transducer and configured to select a proposed pulse; generate a minimum phase wavelet, at least in part, by calculating a real cepstrum of the proposed pulse; cause the transducer to generate a pulse signal within a wellbore based, at least in part, on the minimum phase wavelet; and cause the transducer to receive an echo signal corresponding to the pulse signal from at least a portion of the wellbore, wherein the echo signal is indicative of a wellbore property. ### Claim 17 (depends on 16) The system of claim 16, wherein the downhole tool comprises a rotating head to which the transducer is coupled.