# US 2016/0258281 A1 · Determining locations of acoustic sources around a borehole > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0258281 A1 - Document ID: US20160258281A1 - Status: Published application - Kind: A1 - Application number: 14/647,811 - Filed: 2014-07-18 - Published: 2016-09-08 - Earliest claimed: 2014-07-18 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Batakrishna MANDAL - Web page: https://patentgrep.com/patent/US20160258281A1 ## CPC - E21B 47/107: using acoustic means - E21B 47/005: Monitoring or checking of cementation quality or level - E21B 47/09: Locating or determining the position of objects in boreholes or wells {, e.g. the position of an extending arm}; Identifying the free or blocked portions of pipes - G01V 1/40: specially adapted for well-logging - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract Systems, methods, and computer-readable storage devices for determining a location of an acoustic source outside of a borehole. The method relates to indicating a radial distance to the borehole, an offset along the borehole, and an azimuthal position around the borehole, of the acoustic source. The method includes receiving acoustic signals from respective acoustic sensors spaced along a tool lowered within the borehole. Using the acoustic signals and a borehole model, stacked energies are calculated for different radial distances from the borehole. At least one of the stacked energies is translated to an indication of a radial distance of the acoustic source from the borehole. The stacked energy for a radial distance is computed by offsetting the acoustic data signals in time in accordance the borehole model, summing the offset acoustic data signals to produce a stacked signal, and evaluating energy of the stacked signal over a time window. ## Claims ### Claim 1 A method of determining a location of an acoustic source outside of a borehole, the method comprising: receiving acoustic data signals from respective acoustic sensors spaced along a tool lowered within the borehole; calculating, from the acoustic data signals, stacked energies for different radial distances from the borehole, wherein the stacked energy for each different radial distance from the borehole is computed by offsetting the acoustic data signals in time in accordance with a borehole model specifying acoustic delay to the respective acoustic sensor as a function of the radial distance from the borehole and an offset in the displacement along the borehole to the respective acoustic sensor, and summing the offset acoustic data signals to produce a stacked signal, and evaluating energy of the stacked signal over a time window; and translating at least one of the stacked energies to an indication of a radial distance of the acoustic source from the borehole. ### Claim 2 (depends on 1) The method of claim 1, wherein the borehole model is based on acoustic properties of a formation surrounding a well casing of the borehole and acoustic properties of the well casing. ### Claim 3 (depends on 1) The method of claim 1, wherein the borehole model specifies an acoustic delay that is a parabolic function of the offset in the displacement along the borehole to the respective acoustic sensor. ### Claim 4 (depends on 1) The method of claim 1, wherein the acoustic sensors are spaced at intervals of between five and seven inches. ### Claim 5 (depends on 1) The method of claim 1, wherein the translating at least one of the stacked energies to an indication of a radial distance for the acoustic source includes displaying a graph of the stacked energies as a function of the radial distance from the borehole. ### Claim 6 (depends on 1) The method of claim 1, wherein the translating at least one of the stacked energies to a radial distance for the acoustic source includes comparing the stacked energies to a threshold and finding that said at least one of the stacked energies exceeds the threshold. ### Claim 7 (depends on 1) The method of claim 1, which further includes: receiving acoustic data signals from the respective acoustic sensors when the tool is at different displacements along the borehole; calculating, from the acoustic data signals received when the tool is at each of the different displacements along the borehole, stacked energies for different radial distances from the borehole and for said each of the different displacements along the borehole, wherein the stacked energy for each different radial distance from the borehole and for said each of the different displacements along the borehole is computed by offsetting the acoustic data signals in time in accordance with the borehole model, and summing the offset acoustic data signals received when the tool is at each of the different displacements along the borehole to produce a stacked signal for said each of the different displacements along the borehole, and evaluating energy of the stacked signal for said each of the different displacements along the borehole over a time window; and translating at least one of the stacked energies to an indication of displacement of the acoustic source along the borehole. ### Claim 8 (depends on 1) The method of claim 1, wherein the acoustic sensors are also spaced around a circumference of the tool to provide groups of the acoustic sensors at different azimuthal positions around the tool and spaced along the tool, and the method further includes computing the stacked energies for the different azimuthal positions from the acoustic data signals from the respective groups of the acoustic sensors, and translating at least one of the stacked energies to an indication of an azimuthal position of the acoustic source around the borehole. ### Claim 9 A system for determining a location of an acoustic source outside of a borehole, the system comprising: a tool having acoustic sensors spaced along the tool; a processor electronically coupled to the tool to receive acoustic data signals from respective ones of the acoustic sensors; and a computer-readable storage device storing instructions that, when executed by the processor, cause the processor to perform operations comprising: receiving the acoustic data signals from the respective ones of the acoustic sensors; calculating, from the acoustic data signals, stacked energies for different radial distances from the borehole, wherein the stacked energy for each different radial distance from the borehole is computed by offsetting the acoustic data signals in time in accordance with a borehole model specifying acoustic delay to the respective acoustic sensor as a function of the radial distance from the borehole and an offset in the displacement along the borehole to the respective acoustic sensor, and summing the offset acoustic data signals to produce a stacked signal, and evaluating energy of the stacked signal over a time window; and translating at least one of the stacked energies to an indication of a radial distance of the acoustic source from the borehole. ### Claim 10 (depends on 9) The system as claimed in claim 9, wherein the borehole model is based on acoustic properties of a formation surrounding a well casing of the borehole and acoustic properties of the well casing. ### Claim 11 (depends on 9) The system as claimed in claim 9, wherein the acoustic sensors are spaced along the tool at intervals of between five and seven inches. ### Claim 12 (depends on 9) The system as claimed in claim 9, wherein the translating at least one of the stacked energies to an indication of a radial distance for the acoustic source includes displaying a graph of the stacked energies as a function of the radial distance from the borehole. ### Claim 13 (depends on 9) The system as claimed in claim 9, wherein the operations further include: receiving the acoustic data signals from the respective acoustic sensors when the tool is at different displacements along the borehole; calculating, from the acoustic data signals received when the tool is at each of the different displacements along the borehole, stacked energies for different radial distances from the borehole and for said each of the different displacements along the borehole, wherein the stacked energy for each different radial distance from the borehole and for said each of the different displacements along the borehole is computed by offsetting the acoustic data signals in time in accordance with the borehole model, and summing the offset acoustic data signals received when the tool is at each of the different displacements along the borehole to produce a stacked signal for said each of the different displacements along the borehole, and evaluating energy of the stacked signal for said each of the different displacements along the borehole over a time window; and translating at least one of the stacked energies to an indication of a displacement of the acoustic source along the borehole. ### Claim 14 (depends on 9) The system as claimed in claim 9, wherein the acoustic sensors are also spaced around a circumference of the tool to provide groups of the acoustic sensors spaced along the tool at different azimuthal positions around the tool, and the operations further include computing the stacked energies for the different azimuthal positions from the acoustic data signals from the respective groups of the acoustic sensors, and translating at least one of the stacked energies to an indication of an azimuthal position of the acoustic source around the borehole. ### Claim 15 A computer-readable storage device storing instructions which, when executed by a computing device, cause the computing device to determine a location of an acoustic source outside of a borehole by perform operations comprising: receiving acoustic data signals from respective acoustic sensors spaced along a tool lowered within a borehole; calculating, from the acoustic data signals, stacked energies for different radial distances from the borehole, wherein the stacked energy for each different radial distance from the borehole is computed by offsetting the acoustic data signals in time in accordance with a borehole model specifying acoustic delay to the respective acoustic sensor as a function of the radial distance from the borehole and an offset in the displacement along the borehole to the respective acoustic sensor, and summing the offset acoustic data signals to produce a stacked signal, and evaluating energy of the stacked signal over a time window; and translating at least one of the stacked energies to a radial distance of the acoustic source from the borehole. ### Claim 16 (depends on 15) The computer-readable storage device as claimed in claim 15, wherein the borehole model is based on acoustic properties of a formation surrounding a well casing of the borehole and acoustic properties of the well casing. ### Claim 17 (depends on 15) The computer-readable storage device as claimed in claim 15, wherein the translating at least one of the stacked energies to a radial distance for the acoustic source includes displaying a graph of the stacked energies as a function of the radial distance from the borehole. ### Claim 18 (depends on 15) The computer-readable storage device as claimed in claim 15, wherein the translating at least one of the stacked energies to a radial distance for the acoustic source includes comparing the stacked energies to a threshold and finding that said at least one of the stacked energies exceeds the threshold. ### Claim 19 (depends on 15) The computer-readable storage device as claimed in claim 15, wherein the operations further include: receiving the acoustic data signals from the respective acoustic sensors when the tool is at different displacements along the borehole; calculating, from the acoustic data signals received when the tool is at each of the different displacements along the borehole, stacked energies for different radial distances from the borehole and for said each of the different displacements along the borehole, wherein the stacked energy for each different radial distance from the borehole and for said each of the different displacements along the borehole is computed by offsetting the acoustic data signals in time in accordance with the borehole model, and summing the offset acoustic data signals received when the tool is at each of the different displacements along the borehole to produce a stacked signal for said each of the different displacements along the borehole, and evaluating energy of the stacked signal for said each of the different displacements along the borehole over a time window; and translating at least one of the stacked energies to an indication of displacement of the acoustic source along the borehole. ### Claim 20 (depends on 15) The computer-readable storage device as claimed in claim 15, wherein the acoustic sensors are also spaced around a circumference of the tool to provide groups of the acoustic sensors at different azimuthal positions around the tool and spaced along the tool, and the operations further include computing the stacked energies for the different azimuthal positions from the acoustic data signals from the respective groups of the acoustic sensors, and translating at least one of the stacked energies to an indication of an azimuthal position of the acoustic source around the borehole.