# US 11,078,409 B2 · Electrically conductive proppant coating and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,409 B2 - Document ID: US11078409B2 - Status: Granted - Kind: B2 - Application number: 14/278,124 - Filed: 2014-05-15 - Published: 2014-11-20 - Granted: 2021-08-03 - Earliest claimed: 2013-05-17 - Assignees: ConocoPhillips Company - Applicants: Conocophillips Company - Inventors: Joe D. Allison - Web page: https://patentgrep.com/patent/US11078409B2 ## CPC - C09K 8/805: {Coated proppants} - E21B 43/267: reinforcing fractures by propping - E21B 47/125: using earth as an electrical conductor (by electromagnetic energy E21B47/13) - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An electrically conductive proppant coating and a method for applying the coating to the proppant, whereby the coated electrically conductive proppant can determine formation characteristics, such as dimensions, orientation, and conductivity. ## Claims ### Claim 1 A method for determining geometry of a fracture in a subterranean formation, the method comprising: a. injecting a coated proppant into the fracture to cause the fracture to function as an emitting antenna while opening the fracture or holding the fracture open, the coated proppant including a proppant suspended in an electrically-conductive coating, the electrically-conductive coating (i) deposited on a proppant surface of the proppant, (ii) stabilized with an oxidizing agent, and (iii) including a mixture of carbon residue forming material and a solvent, the coated proppant carbonized and graphitized, the carbon residue forming material being petroleum pitch, the solvent being toluene, xylene, quinoline, tetrahydrofuran, tetralin, or naphthalene; b. sending, via electrical connections, a time-varying electrical signal into the fracture to charge the coated proppant, the time-varying electrical signal generated at a top surface above the fracture; c. detecting, via a plurality of surface antennas at the top surface, the time-varying electrical signal, the plurality of surface antennas spaced from each other over an area above the fracture; and d. determining the geometry of the fracture based on the time-varying electrical signal detected by the plurality of surface antennas. ### Claim 2 (depends on 1) The method according to claim 1, wherein the solvent is toluene. ### Claim 3 (depends on 1) The method according to claim 1, wherein the solvent is xylene. ### Claim 4 (depends on 1) The method according to claim 1, wherein the electrically-conductive coating is graphitized immediately after being carbonized. ### Claim 5 (depends on 1) The method according to claim 1, wherein the electrical connections extend from the surface of the fracture to a well casing. ### Claim 6 (depends on 1) The method according to claim 1, wherein the electrical connections extend to a mud pit. ### Claim 7 (depends on 1) The method according to claim 1, wherein the time-varying electrical signal is generated via a reversing DC current. ### Claim 8 (depends on 1) The method according to claim 1, wherein the time-varying electrical signal is generated via an AC current. ### Claim 9 (depends on 1) The method according to claim 1, wherein the detecting the time-varying electrical signal includes recording the time-varying electrical signal. ### Claim 10 (depends on 1) The method according to claim 1, wherein the plurality of surface antennas are spaced from each other over different parts of the fracture. ### Claim 11 (depends on 1) The method according to claim 1, wherein the oxidizing agent is a gaseous oxidizing agent. ### Claim 12 (depends on 11) The method according to claim 11, wherein the gaseous oxidizing agent is selected from a group consisting of oxygen, sulfur fumes, gaseous oxides, nitrogen oxide gas, ambient air, halogens or combinations thereof. ### Claim 13 A method for determining geometry of a fracture in a subterranean formation, the method comprising: a. injecting a coated proppant into the fracture, the coated proppant including a proppant suspended in an electrically-conductive coating material deposited on a surface of the proppant and stabilized with an oxidizing agent, the coated proppant carbonized and graphitized; b. sending a time-varying electrical signal into the fracture to charge the coated proppant; c. detecting, via a plurality of surface antennas, the time-varying electrical signal, the plurality of surface antennas spaced from each other over an area above the fracture; and d. determining the geometry of the fracture based on the time-varying electrical signal detected by the plurality of surface antennas. ### Claim 14 (depends on 13) The method according to claim 13, wherein the coating material includes a mixture of carbon residue forming material and a solvent or combination of solvents. ### Claim 15 (depends on 14) The method according to claim 14, wherein the carbon residue forming material is petroleum pitch. ### Claim 16 (depends on 14) The method according to claim 14, wherein the solvent or combination of solvents is selected from a group consisting of toluene, xylene, quinoline, tetrahydrofuran, tetralin, naphthalene or combinations thereof. ### Claim 17 (depends on 13) The method according to claim 13, wherein the coated proppant is injected into the fracture during creation of the fracture. ### Claim 18 (depends on 13) The method according to claim 13, wherein the plurality of surface antennas are spaced from each other over different parts of the fracture.