# US 2024/0201406 A1 · Detecting Near-Surface Structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201406 A1 - Document ID: US20240201406A1 - Status: Published application - Kind: A1 - Application number: 18/080,958 - Filed: 2022-12-14 - Published: 2024-06-20 - Earliest claimed: 2022-12-14 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Ali Aldawood; Mohammed Almarzoug - Web page: https://patentgrep.com/patent/US20240201406A1 ## CPC - G01V 1/288: {Event detection in seismic signals, e.g. microseismics (G01V1/36 takes precedence)} - G01V 1/226: {Optoseismic systems} - G01V 1/307: {for determining seismic attributes, e.g. amplitude, instantaneous phase or frequency, reflection strength or polarity} - G01V 2210/67: Wave propagation modeling - 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 Example methods and systems for near-surface characterization through passive monitoring of rig-generated noise are disclosed. One example method includes positioning a distributed acoustic sensing (DAS) cable in a spiral configuration layout around a drilling rig, where the drilling rig includes one or more pieces of drilling rig equipment, and the DAS cable includes a fiber-optic cable. The DAS cable is interrogated using multiple distributed fiber-optic sensing (DFOS) laser pulses during a drilling operation of the drilling rig. Multiple backscattered laser pulses are received from the DAS cable after the DAS cable is interrogated using the multiple DFOS laser pulses. A respective location of each of one or more anomalies in sub-terrain around the drilling rig is determined based on the multiple backscattered laser pulses. ## Claims ### Claim 1 A method, comprising: positioning a distributed acoustic sensing (DAS) cable in a spiral configuration layout around a drilling rig, wherein the drilling rig comprises one or more pieces of drilling rig equipment, and the DAS cable comprises a fiber-optic cable; interrogating, using a plurality of distributed fiber-optic sensing (DFOS) laser pulses, the DAS cable during a drilling operation of the drilling rig; receiving a plurality of backscattered laser pulses from the DAS cable after the DAS cable is interrogated using the plurality of DFOS laser pulses; and determining, based on the plurality of backscattered laser pulses, a respective location of each of one or more anomalies in sub-terrain around the drilling rig. ### Claim 2 (depends on 1) The method of claim 1, wherein determining the respective location of each of the one or more anomalies in the sub-terrain around the drilling rig comprises: determining, based on the plurality of backscattered laser pulses, one or more gathers of seismic traces; and determining, based on the one or more gathers of seismic traces and using frequency-wavenumber (F-K) analysis, the respective location of each of the one or more anomalies. ### Claim 3 (depends on 2) The method of claim 2, wherein the method further comprises: constructing, based on the one or more gathers, a one-dimensional (1D) velocity profile of the sub-terrain around the drilling rig. ### Claim 4 (depends on 3) The method of claim 3, wherein constructing the 1D velocity profile comprises obtaining a dispersion curve from one of the one or more gathers using multichannel analysis of surface waves (MASW). ### Claim 5 (depends on 2) The method of claim 2, wherein determining the one or more gathers comprises decoding the one or more gathers using a pilot trace from a top-drive sensor at the drilling rig, and wherein the pilot trace comprises a signal representing characteristics of vibration of the one or more pieces of drilling rig equipment during the drilling operation. ### Claim 6 (depends on 1) The method of claim 1, wherein the respective location comprises a respective azimuth and offset of each of the one or more anomalies, and the respective offset is with respect to the drilling rig. ### Claim 7 (depends on 1) The method of claim 1, wherein the one or more pieces of drilling rig equipment comprise at least one of a generator, a mud pump, or a shale shaker. ### Claim 8 (depends on 1) The method of claim 1, wherein interrogating the DAS cable comprises interrogating the DAS cable using an interrogator connected to the DAS cable, and wherein the plurality of DFOS laser pulses are from the interrogator. ### Claim 9 (depends on 1) The method of claim 1, wherein the one or more anomalies in the sub-terrain around the drilling rig comprise at least one of karst, cavity, or fault. ### Claim 10 (depends on 1) The method of claim 1, wherein positioning the DAS cable in the spiral configuration layout around the drilling rig comprises positioning the DAS cable in the spiral configuration layout around the drilling rig and in a star shape configuration layout, and the star shape configuration layout comprises a plurality of radial paths that intersect at the drilling rig. ### Claim 11 A system, comprising: a distributed acoustic sensing (DAS) cable positioned in a spiral configuration layout around a drilling rig, wherein the drilling rig comprises one or more pieces of drilling rig equipment, and the DAS cable comprises a fiber-optic cable; and a control system communicably coupled to the DAS cable and configured to perform operations comprising: interrogating, using a plurality of distributed fiber-optic sensing (DFOS) laser pulses, the DAS cable during a drilling operation of the drilling rig; receiving a plurality of backscattered laser pulses from the DAS cable after the DAS cable is interrogated using the plurality of DFOS laser pulses; and determining, based on the plurality of backscattered laser pulses, a respective location of each of one or more anomalies in sub-terrain around the drilling rig. ### Claim 12 (depends on 11) The system of claim 11, wherein determining the respective location of each of the one or more anomalies in the sub-terrain around the drilling rig comprises: determining, based on the plurality of backscattered laser pulses, one or more gathers of seismic traces; and determining, based on the one or more gathers of seismic traces and using frequency-wavenumber (F-K) analysis, the respective location of each of the one or more anomalies. ### Claim 13 (depends on 12) The system of claim 12, wherein the operations further comprise: constructing, based on the one or more gathers, a one-dimensional (1D) velocity profile of the sub-terrain around the drilling rig. ### Claim 14 (depends on 13) The system of claim 13, wherein constructing the 1D velocity profile comprises obtaining a dispersion curve from one of the one or more gathers using multichannel analysis of surface waves (MASW). ### Claim 15 (depends on 12) The system of claim 12, wherein determining the one or more gathers comprises decoding the one or more gathers using a pilot trace from a top-drive sensor at the drilling rig, and wherein the pilot trace comprises a signal representing characteristics of vibration of the one or more pieces of drilling rig equipment during the drilling operation. ### Claim 16 (depends on 11) The system of claim 11, wherein the respective location comprises a respective azimuth and offset of each of the one or more anomalies, and the respective offset is with respect to the drilling rig. ### Claim 17 (depends on 11) The system of claim 11, wherein the one or more pieces of drilling rig equipment comprise at least one of a generator, a mud pump, or a shale shaker. ### Claim 18 (depends on 11) The system of claim 11, wherein interrogating the DAS cable comprises interrogating the DAS cable using an interrogator connected to the DAS cable, and wherein the plurality of DFOS laser pulses are from the interrogator. ### Claim 19 (depends on 11) The system of claim 11, wherein the one or more anomalies in the sub-terrain around the drilling rig comprise at least one of karst, cavity, or fault. ### Claim 20 (depends on 11) The system of claim 11, wherein the DAS cable is positioned in the spiral configuration layout around the drilling rig and in a star shape configuration layout, and the star shape configuration layout comprises a plurality of radial paths that intersect at the drilling rig.