# US 2014/0191120 A1 · Fiberoptic Systems and Methods for Formation Monitoring > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191120 A1 - Document ID: US20140191120A1 - Status: Published application - Kind: A1 - Application number: 13/736,324 - Filed: 2013-01-08 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Halliburton Energy Services, Inc. ("HESI") - Applicants: Halliburton Energy Services, Inc. ("Hesi") - Inventors: Burkay DONDERICI; Etienne M. Samson; Michel J. LEBLANC - Web page: https://patentgrep.com/patent/US20140191120A1 ## CPC - G01V 3/34: Transmitting data to recording or processing apparatus; Recording data - E21B 47/135: using light waves, e.g. infrared or ultraviolet 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) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A disclosed formation monitoring system includes a casing that defines an annular space within a borehole. An array of electromagnetic field sensors is positioned in the annular space and configured to communicate with the surface via a fiberoptic cable. A computer coupled to the fiberoptic cable receives said measurements and responsively derives the location of any fluid fronts in the vicinity such as a an approaching flood front to enable corrective action before breakthrough. A disclosed formation monitoring method includes: injecting a first fluid into a reservoir formation; producing a second fluid from the reservoir formation via a casing in a borehole; collecting electromagnetic field measurements with an array of fiberoptic sensors in an annular space between said casing and said borehole, said array communicating measurements to a surface interface via one or more fiberoptic cables; and operating on said measurements to locate a front between the first and second fluids. ## Claims ### Claim 1 A formation monitoring system that comprises: a casing that defines an annular space within a borehole; an array of electromagnetic field sensors in the annular space; an optical waveguide that conveys optical signals to and from the array of electromagnetic field sensors; and a computer coupled to the optical waveguide to receive optical signals from the array of electromagnetic field sensors, wherein the computer operates on the received optical signals to calculate at least one parameter associated with an approaching flood front. ### Claim 2 (depends on 1) The system of claim 1, wherein the at least one parameter comprises a flood front location. ### Claim 3 (depends on 1) The system of claim 1, wherein the computer measures the at least one parameter at different times. ### Claim 4 (depends on 3) The system of claim 3, further comprising a valve that controls a flow rate from at least one production zone in said borehole, wherein the computer provides a new setting for said valve based at least in part on said at least one parameter. ### Claim 5 (depends on 3) The system of claim 3, further comprising a pump that controls a flow rate to at least one zone in an injection well, wherein the computer provides a new pump rate for said pump based at least in part on said at least one parameter. ### Claim 6 (depends on 3) The system of claim 3, further comprising a valve that controls a flow rate to at least one injection zone, wherein the computer provides a new setting for said valve based at least in part on said at least one parameter. ### Claim 7 (depends on 1) The system of claim 1, further comprising a power source coupled to the casing to generate a distribution of current flow into formations penetrated by said borehole. ### Claim 8 (depends on 7) The system of claim 7, wherein the power source is electrically connected to said casing above ground. ### Claim 9 (depends on 7) The system of claim 7, wherein the power source is electrically connected to a tool suspended on a cable, control line, tubing, or coiled tubing inside the casing. ### Claim 10 (depends on 7) The system of claim 7, wherein the power source is electrically connected to a casing in a second borehole. ### Claim 11 (depends on 7) The system of claim 7, wherein the power source is electrically connected to a tool suspended on a cable, control line, tubing, or coiled tubing in a second borehole for cross-well monitoring. ### Claim 12 (depends on 7) The system of claim 7, wherein at least one of said electromagnetic field sensors measures a radial electric field component. ### Claim 13 (depends on 1) The system of claim 1, wherein the optical waveguide comprises a fiberoptic cable. ### Claim 14 (depends on 13) The system of claim 13, wherein the fiberoptic cable includes one or more electrical conductors coupled to a power source to generate a distribution of current into formations penetrated by said borehole. ### Claim 15 (depends on 13) The system of claim 13, wherein the fiberoptic cable includes one or more electrical conductors that are uninsulated near regions of interest and insulated in other regions to direct current said regions of interest. ### Claim 16 (depends on 13) The system of claim 13, further comprising a second fiberoptic cable coupled to electromagnetic field sensors in the annular space that are in an axial range overlapping with an axial range of the array of electromagnetic sensors coupled to the optical waveguide. ### Claim 17 (depends on 1) The system of claim 1, further comprising at least one electric dipole source antenna positioned in the annular space. ### Claim 18 (depends on 1) The system of claim 1, further comprising at least one magnetic dipole source antenna positioned in the annular space. ### Claim 19 (depends on 1) The system of claim 1, the computer derives a multidimensional model of formation resistivity or conductivity based at least in part on said received optical signals to track a flood front location as a function of time. ### Claim 20 A formation monitoring method that comprises: injecting a first fluid into a reservoir formation; producing a second fluid from the reservoir formation via a casing in a borehole; collecting electromagnetic field measurements with an array of fiberoptic sensors in an annular space between said casing and said borehole, said array communicating measurements to a surface interface via one or more fiberoptic cables; and operating on said measurements to locate a front between the first and second fluids. ### Claim 21 (depends on 20) The method of claim 20, further comprising repeating said collecting and operating to track the front as a function of time. ### Claim 22 (depends on 20) The method of claim 20, further comprising reducing production from one or more zones upon detecting said front near said borehole. ### Claim 23 (depends on 20) The method of claim 20, further comprising reducing injection into one or more zones upon detecting said front near said borehole. ### Claim 24 (depends on 20) The method of claim 20, further comprising injecting an electrical current into the reservoir formation via said casing. ### Claim 25 (depends on 20) The method of claim 20, further comprising generating an electromagnetic field via an electrical dipole source in said annular space. ### Claim 26 (depends on 20) The method of claim 20, further comprising generating an electromagnetic field via a magnetic dipole source in said annular space.