# US 12,110,789 B2 · Electromagnetic downlink while drilling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,789 B2 - Document ID: US12110789B2 - Status: Granted - Kind: B2 - Application number: 17/247,445 - Filed: 2020-12-11 - Published: 2021-06-17 - Granted: 2024-10-08 - Earliest claimed: 2019-12-13 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Pavel Annenkov; Melisa Lourdes Ramirez Tovar; Robert Tennent; Sam Soundar; Jiuping Chen; Liang Sun; Richard Hunter; Wei Zhou - Web page: https://patentgrep.com/patent/US12110789B2 ## CPC - E21B 47/13: by electromagnetic energy, e.g. radio frequency - E21B 7/18: Drilling by liquid or gas jets, with or without entrained pellets (E21B7/14 takes precedence) - G01V 3/30: operating with electromagnetic waves - 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 Communication between the surface and a downhole location, such as a bottomhole assembly and/or an RSS is performed by electromagnetic downlink. Electromagnetic signals are transmitted from the surface through the formation at a frequency of 8 Hz or greater. Electromagnetic signals are transmitted and received while drilling or during drilling activities. In this manner, information and instructions may be transmitted to the BHA while drilling. ## Claims ### Claim 1 A method for downhole communication, comprising: Providing an oil-based fluid to a bottomhole assembly; selecting a frequency of at least 8 Hz for an electromagnetic signal based, in part, on the oil-based fluid; transmitting the electromagnetic signal from a surface location without interrupting downhole drilling activities, wherein the downhole drilling activities comprise removing material from a wellbore; receiving the electromagnetic signal downhole at a bottomhole assembly while performing the downhole drilling activities; and demodulating the electromagnetic signal at the bottomhole assembly while performing the downhole drilling activities. ### Claim 2 (depends on 1) The method of claim 1, wherein transmitting the electromagnetic signal includes transmitting instructions for the bottomhole assembly or transmitting information to the bottomhole assembly. ### Claim 3 (depends on 2) The method of claim 2, comprising changing at least one drilling parameter of the bottomhole assembly based on the transmitted instructions. ### Claim 4 (depends on 1) The method of claim 1, wherein receiving the electromagnetic signal includes receiving the electromagnetic signal at a rotary steerable system of the bottomhole assembly. ### Claim 5 (depends on 1) The method of claim 1, wherein the downhole drilling activities comprise drilling formation of the wellbore, reaming formation of the wellbore, or cutting casing of the wellbore. ### Claim 6 (depends on 1) The method of claim 1, wherein transmitting the electromagnetic signal includes transmitting the electromagnetic signal while maintaining a volumetric flow rate of a drilling fluid. ### Claim 7 A method for downhole communication, comprising: providing an oil-based fluid to a bottomhole assembly; selecting a frequency of at least 8 Hz for an electromagnetic signal based in part on the oil-based fluid; transmitting the electromagnetic signal from a surface location; and receiving the electromagnetic signal downhole at an uphole location of a length of drill pipe of the bottomhole assembly; insulating the length of drill pipe of the bottomhole assembly from the formation with the oil-based fluid; and transmitting the electromagnetic signal to a gap sub of the bottomhole assembly. ### Claim 8 (depends on 7) The method of claim 7, wherein transmitting the electromagnetic signal includes transmitting at a bit rate of greater than 1 bit per second. ### Claim 9 (depends on 8) The method of claim 8, wherein transmitting the electromagnetic signal includes transmitting at a bit rate of greater than 8 bits per second. ### Claim 10 (depends on 7) The method of claim 7, wherein transmitting the electromagnetic signal includes transmitting instructions for the bottomhole assembly. ### Claim 11 (depends on 10) The method of claim 10, comprising receiving the instructions and changing at least one drilling parameter of the bottomhole assembly. ### Claim 12 (depends on 7) The method of claim 7, comprising demodulating the electromagnetic signal. ### Claim 13 (depends on 12) The method of claim 12, wherein demodulating the electromagnetic signal includes filtering noise from the electromagnetic signal. ### Claim 14 (depends on 7) The method of claim 7, wherein transmitting the electromagnetic signal includes transmitting a plurality of electromagnetic signals at a plurality of frequencies. ### Claim 15 A method for downhole communication, comprising: performing drilling activities comprising drilling, reaming, or milling using an oil-based fluid; selecting a frequency of at least 8 Hz for an electromagnetic signal based, in part, on the oil-based fluid while performing the drilling activities, transmitting the electromagnetic signal from a surface location to a bottomhole assembly; while performing the drilling activities, receiving the electromagnetic signal downhole at the bottomhole assembly; and demodulating the electromagnetic signal at the bottomhole assembly. ### Claim 16 (depends on 15) The method of claim 15, wherein transmitting the electromagnetic signal includes transmitting at a frequency of greater than 8 Hz. ### Claim 17 (depends on 15) The method of claim 15, wherein performing the drilling activities includes tripping drill pipe into a wellbore or tripping drill pipe out of the wellbore. ### Claim 18 (depends on 15) The method of claim 15, wherein demodulating the electromagnetic signal includes demodulating the electromagnetic signal with a signal-to-noise ratio of greater than 1:1.