# US 2017/0285206 A1 · System and methodology for estimating formation elastic properties using decomposed and undecomposed signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285206 A1 - Document ID: US20170285206A1 - Status: Published application - Kind: A1 - Application number: 15/474,371 - Filed: 2017-03-30 - Published: 2017-10-05 - Earliest claimed: 2016-03-31 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Naoki Sakiyama; Denis Syresin - Web page: https://patentgrep.com/patent/US20170285206A1 ## CPC - G01V 1/50: Analysing data - G01V 2210/6242: Elastic parameters, e.g. Young, Lamé or Poisson - G01V 2210/626: with anisotropy - 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 A technique facilitates estimating elastic properties of formations by exciting a wavefield and acquiring the signal with and without azimuthal decompositions. For example, the elastic properties may be estimated by exciting a multipole wavefield and acquiring the signal with and without the azimuthal decomposition. The technique is effective for estimating elastic properties of azimuthally homogeneous and heterogeneous formations including isotropic and anisotropic formations. ## Claims ### Claim 1 A method for evaluating a formation, comprising: exciting a multipole wavefield; acquiring an acoustic signal with and without azimuthal decomposition; and using the acoustic signal acquired to estimate elastic properties of the formation. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein using comprises using the acoustic signal to estimate elastic properties of isotropic formations. ### Claim 3 (depends on 1) The method as recited in claim 1, wherein using comprises using the acoustic signal to estimate elastic properties of anisotropic formations. ### Claim 4 (depends on 1) The method as recited in claim 1, wherein using comprises using the acoustic signal to estimate elastic properties of azimuthally homogeneous formations. ### Claim 5 (depends on 1) The method as recited in claim 1, wherein using comprises using the acoustic signal to estimate elastic properties of azimuthally heterogeneous formations. ### Claim 6 (depends on 1) The method as recited in claim 1, wherein using comprises calculating formation properties using each of the axial array receiver waveforms of a plurality of azimuthally distributed axial array waveforms. ### Claim 7 (depends on 1) The method as recited in claim 1, wherein using comprises performing acoustic signal processing at different frequency bands and time windows. ### Claim 8 (depends on 1) The method as recited in claim 1, wherein using comprises mapping formation properties with respect to azimuth around a wellbore to evaluate formation heterogeneity and anisotropy. ### Claim 9 (depends on 1) The method as recited in claim 1, wherein using comprises estimating elastic properties in the form of compressional (P) and shear (S) slownesses. ### Claim 10 (depends on 1) The method as recited in claim 1, wherein exciting comprises employing monopole excitations and dipole excitations, including unipole excitations. ### Claim 11 (depends on 1) The method as recited in claim 1, wherein acquiring comprises acquiring the signal with a sonic logging tool. ### Claim 12 (depends on 1) The method as recited in claim 1, wherein acquiring comprises acquiring the signal with a sonic logging tool having an array of transmitters and an array of receivers including azimuthally distributed receivers. ### Claim 13 A method, comprising: providing a sonic logging tool with a plurality of transmitters and a plurality of receivers; conveying the sonic logging tool downhole into a borehole; operating the plurality of transmitters to excite a multipole wavefield; acquiring an acoustic signal via the plurality of receivers, the acoustic signal being acquired with and without azimuthal decomposition; using the acoustic signal acquired to estimate elastic properties of the formation; and mapping the formation based on the estimate of elastic properties. ### Claim 14 (depends on 13) The method as recited in claim 13, wherein using comprises using the acoustic signal to estimate elastic properties of isotropic formations. ### Claim 15 (depends on 13) The method as recited in claim 13, wherein using comprises using the acoustic signal to estimate elastic properties of anisotropic formations. ### Claim 16 (depends on 13) The method as recited in claim 13, wherein using comprises using the acoustic signal to estimate elastic properties of azimuthally homogeneous formations. ### Claim 17 (depends on 1) The method as recited in claim 1, wherein using comprises using the acoustic signal to estimate elastic properties of azimuthally heterogeneous formations. ### Claim 18 A system for evaluating a formation, comprising: a tool having: a plurality of acoustic transmitters to excite a multipole wavefield; a plurality of acoustic receivers to acquire acoustic signals with and without azimuthal decomposition; and a processing system configured to process the acoustic signals with and without azimuthal decomposition to estimate elastic properties of the formation. ### Claim 19 (depends on 18) The system as recited in claim 18, wherein the tool is a sonic logging tool. ### Claim 20 (depends on 19) The system as recited in claim 19, wherein the processing system outputs a map of the formation based on the estimate of elastic properties.