# US 2014/0152456 A1 · Failure Point Diagnostics in Cable Telemetry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152456 A1 - Document ID: US20140152456A1 - Status: Published application - Kind: A1 - Application number: 13/705,124 - Filed: 2012-12-04 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Alex Olson; Nalin Weerasinghe; Milos Milosevic; Kun Wang; Motohiro Nakanouchi; Kenji Endo; Yuichi Kobayashi; Hiromasa Nishisaka - Web page: https://patentgrep.com/patent/US20140152456A1 ## CPC - G01V 3/18: specially adapted for well-logging - E21B 47/12: Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling - 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 Methods and systems for failure point diagnostics in cable telemetry at a wellsite. The methods involve providing a system includes a cable operatively coupling between a surface modem and a downhole modem that is operatively coupled to a downhole toolstring of one or more downhole tools via a toolbus. The methods further involve generating a plurality of test signals, sequentially applying the test signals across one or more test loops in the cable telemetry system, and generating a failure point alert when at least one of the test signals fails in at least one of the test loops. The failure point alert identifies which component of the cable telemetry system caused the test signal to fail. ## Claims ### Claim 1 A method for failure point diagnostics in cable telemetry at a wellsite, comprising: providing a cable telemetry system comprising a cable operatively coupling between a surface modem and a downhole modem that is operatively coupled to a downhole toolstring of one or more downhole tools via a toolbus; generating a plurality of test signals; sequentially applying the test signals across one or more test loops in the cable telemetry system; and generating a failure point alert when at least one of the test signals fails in at least one of the test loops, wherein the failure point alert identifies which component of the cable telemetry system caused the test signal to fail. ### Claim 2 (depends on 1) The method according to claim 1, further comprising beginning the sequentially applying based on one of: an automatic start, reaching a threshold head voltage, and a manual command from a user. ### Claim 3 (depends on 1) The method according to claim 1, further comprising displaying the failure point alert in real time. ### Claim 4 (depends on 1) The method according to claim 1, further comprising logging the failure point alert. ### Claim 5 (depends on 1) The method according to claim 1, wherein the failure point alert further indicates a type of failure at the component of the cable telemetry system that caused the test signal to fail. ### Claim 6 (depends on 1) The method according to claim 1, further comprising providing a surface acquisition front-end operatively coupled to the surface modem; wherein a first test loop of the one or more test loops comprises a signal loop internal to the surface acquisition front-end. ### Claim 7 (depends on 1) The method according to claim 1, wherein a second test loop of the one or more test loops comprises a signal loop making a round trip over the cable. ### Claim 8 (depends on 1) The method according to claim 1, wherein a third test loop of the one or more test loops comprises a signal loop making a round trip over the toolbus. ### Claim 9 (depends on 1) The method according to claim 1, further comprising providing a controller in the downhole modem, wherein a fourth test loop of the one or more test loops comprises a signal loop internal to the controller of the downhole modem. ### Claim 10 (depends on 1) The method according to claim 1, further comprising periodically, repeating the sequentially applying during operation of the cable telemetry system, and generating one or more of the failure point alerts for a plurality of points in time during operation of the cable telemetry system. ### Claim 11 A system for failure point diagnostics in cable telemetry at a wellsite, comprising: a cable defining a first round trip test loop, operatively coupling between a surface modem, comprising a first internal test loop, and a downhole modem, comprising a second internal test loop, that is operatively coupled to a downhole toolstring of one or more downhole tools via a toolbus defining a second round trip test loop; a surface computer, operatively coupled to the surface modem, that generates a plurality of surface test signals; a surface acquisition front-end, operatively coupled to the surface computer, that comprises a third internal test loop; wherein the surface computer is configured to sequentially apply the plurality of test signals across the first, second and third internal test loops and generate a failure point alert when at least one of the plurality of test signals fails in at least one of the test loops identifying which component of the cable telemetry system caused the test signal to fail. ### Claim 12 (depends on 11) The system according to claim 11, wherein the surface computer generates a failure point alert when one of the plurality of test signals fails in one of the first and second round trip test loops and the first, second, and third internal test loops indicating failure at one or more of the surface acquisition front-end, the cable, the downhole module, the toolbus, and at least one of the one or more downhole tools. ### Claim 13 (depends on 11) The system according to claim 11, wherein the surface computer further comprises an output module that displays the failure point alert. ### Claim 14 (depends on 11) The system according to claim 11, wherein the surface computer further comprises a log memory that stores the failure point alert. ### Claim 15 (depends on 11) The system according to claim 11, wherein the failure point alert further indicates a type of failure at the component of the cable telemetry system caused the test signal to fail.