# US 7,609,065 B2 · System and method for locating an anomaly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,065 B2 - Document ID: US7609065B2 - Status: Granted - Kind: B2 - Application number: 11/270,707 - Filed: 2005-11-09 - Published: 2006-03-23 - Granted: 2009-10-27 - Earliest claimed: 2003-11-05 - Assignees: Shell Oil Company - Inventors: Erik Banning; Teruhiko Hagiwara; Rich Ostermeier - Web page: https://patentgrep.com/patent/US7609065B2 ## CPC - G01V 3/30: operating with electromagnetic waves - 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 method and a system are provided for allowing determination of a direction and distance from a tool to anomaly in a formation. The apparatus for performing the method includes at least one transmitter and at least one receiver. An embodiment of the method includes transmitting electromagnetic signals from the at least one transmitter through the formation near the wellbore and detecting responses at the at least one receiver induced by the electromagnetic signals. The method may further include determining the direction from the device to the anomaly based on the detected responses. The method may also include calculating at least one of an apparent azimuth angle and an apparent dip angle based on the responses, monitoring the at least one calculated apparent angle over time, and determining the direction to the anomaly after the at least one monitored apparent angle deviates from a zero value. ## Claims ### Claim 1 A method for determining a direction to an anomaly in a formation near a wellbore using a device comprising at least one transmitter for transmitting electromagnetic signals and at least one receiver for detecting transient responses induced by the electromagnetic signals, the method comprising: calculating at least one of an apparent azimuth angle and an apparent dip angle based on the transient responses obtained by transmitting the electromagnetic signals through the formation near the wellbore and detecting the transient responses at the at least one receiver; monitoring the at least one calculated apparent angle over time; and determining the direction to the anomaly from the at least one calculated apparent angle after the at least one monitored apparent angle deviates from a zero value. ### Claim 2 (depends on 1) The method of claim 1, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along at least two axes. ### Claim 3 (depends on 1) The method of claim 1, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along three axes. ### Claim 4 (depends on 1) The method of claim 1, wherein calculating the at least one angle comprises relating responses in a device coordinate system to responses in an anomaly coordinate system. ### Claim 5 (depends on 1) The method of claim 1, further comprising detecting a presence of the anomaly when the at least one calculated apparent angle reaches a non-zero value. ### Claim 6 (depends on 1) The method of claim 1, further comprising calculating the direction to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 7 (depends on 1) The method of claim 1, further comprising determining a distance to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 8 (depends on 1) The method of claim 1, further comprising calculating both the apparent azimuth angle and the apparent dip angle based on the responses. ### Claim 9 A computer readable medium storing computer executable instructions for performing a method for determining a direction to an anomaly in a formation near a wellbore, in a system comprising a device with at least one transmitter for transmitting electromagnetic signals and a receiver for detecting transient responses induced by the electromagnetic signals, the method comprising: calculating at least one of an apparent azimuth angle and an apparent dip angle based on the transient responses obtained by transmitting the electromagnetic signals through the formation near the wellbore and detecting the transient responses at the at least one receiver; monitoring the at least one calculated apparent angle over time; and determining the direction to the anomaly from the at least one calculated apparent angle after the at least one monitored apparent angle deviates from a zero value. ### Claim 10 (depends on 9) The computer readable medium of claim 9, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along at least two axes. ### Claim 11 (depends on 9) The computer readable medium of claim 9, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along three axes. ### Claim 12 (depends on 9) The computer readable medium of claim 9, wherein calculating the at least one angle comprises relating responses in a device coordinate system to responses in an anomaly coordinate system. ### Claim 13 (depends on 9) The computer readable medium of claim 9, wherein the computer readable medium further stores instructions for detecting a presence of the anomaly when the at least one calculated apparent angle reaches a non-zero value. ### Claim 14 (depends on 9) The computer readable medium of claim 9, wherein the computer readable medium further stores instructions for calculating the direction to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 15 (depends on 9) The computer readable medium of claim 9, wherein the computer readable medium further stores instructions for determining a distance to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 16 The system of computer readable medium 9, wherein the computer readable medium further stores instructions for calculating both the apparent azimuth angle and the apparent dip angle based on the responses. ### Claim 17 A system for determining a direction to an anomaly in a formation near a wellbore, the system comprising: at least one transmitter for transmitting electromagnetic signals through the formation near the wellbore; at least one receiver for detecting transient responses induced by the electromagnetic signals; and a computer readable medium storing instructions for: calculating at least one of an apparent azimuth angle and an apparent dip angle based on the transient responses; monitoring the at least one calculated apparent angle over time; and determining the direction to the anomaly from the at least one calculated apparent angle after the at least one monitored apparent angle deviates from a zero value. ### Claim 18 (depends on 17) The system of claim 17, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along at least two axes. ### Claim 19 (depends on 17) The system of claim 17, wherein calculating at least one of the apparent azimuth angle and apparent dip angle comprises evaluating responses along three axes. ### Claim 20 (depends on 17) The system of claim 17, wherein calculating the at least one angle comprises relating responses in a device coordinate system to responses in an anomaly coordinate system. ### Claim 21 (depends on 17) The system of claim 17, wherein the computer readable medium further stores instructions for detecting a presence of the anomaly when the at least one calculated apparent angle reaches a non-zero value. ### Claim 22 (depends on 17) The system of claim 17, wherein the computer readable medium further stores instructions for calculating the direction to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 23 (depends on 17) The system of claim 17, wherein the computer readable medium further stores instructions for determining a distance to the anomaly when the at least one calculated apparent angle reaches an asymptotic value. ### Claim 24 (depends on 17) The system of claim 17, wherein the computer readable medium further stores instructions for calculating both the apparent azimuth angle and the apparent dip angle based on the responses.