# US 7,612,565 B2 · Apparatus and system for well placement and reservoir characterization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,612,565 B2 - Document ID: US7612565B2 - Status: Granted - Kind: B2 - Application number: 12/204,996 - Filed: 2008-09-05 - Published: 2008-12-25 - Granted: 2009-11-03 - Earliest claimed: 2005-06-28 - Assignees: Schlumberger Technology Corporation - Inventors: Jean Seydoux; Emmanuel Legendre; Reza Taherian - Web page: https://patentgrep.com/patent/US7612565B2 ## CPC - G01V 3/28: using induction coils - 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 resistivity array having a modular design includes a transmitter module with at least one antenna, wherein the transmitter module has connectors on both ends adapted to connect with other downhole tools; and a receiver module with at least one antenna, wherein the transmitter module has connectors on both ends adapted to connect with other downhole tools; and wherein the transmitter module and the receiver module are spaced apart on a drill string and separated by at least one downhole tool. Each transmitter and receiver module may comprise at least one antenna coil with a magnetic moment orientation not limited to the tool longitudinal direction. A spacing between the transmitter and receiver module may be selected based on expected reservoir thickness. ## Claims ### Claim 1 A modular downhole apparatus to determine a formation property, the apparatus being incorporated into a drill string comprising one or more downhole tools and drill pipe, the drill pipe being of the same or various lengths, the modular downhole apparatus comprising: a first module comprising a first drill collar having one or more antennas mounted thereon or therein, wherein the first module has connectors on both ends and is removeably connected to the drill string; and a second module comprising a second drill collar having one or more antennas mounted thereon or therein, wherein the second module has connectors on both ends and is removeably connected to the drill string; wherein a first dipole moment of one of the one or more antennas of the first module intersects a first module longitudinal axis at a first angle; wherein a second dipole moment of one of the one or more antennas of the second module intersects a second module longitudinal axis at a second angle; and wherein the first and second angles are equal. ### Claim 2 (depends on 1) The modular downhole apparatus of claim 1, wherein the first and second angles are non-longitudinal. ### Claim 3 (depends on 2) The modular downhole apparatus of claim 2, wherein the first and second dipole moments are azimuthally offset from one another. ### Claim 4 (depends on 1) The modular downhole apparatus of claim 1, wherein one of the modules has an antenna having a third dipole moment that intersects the longitudinal axis of that module at a third angle that is not equal to the first angle. ### Claim 5 (depends on 1) The modular downhole apparatus of claim 1, wherein at least one of the modules comprises a conventional resistivity tool. ### Claim 6 (depends on 1) The modular downhole apparatus of claim 1, wherein one or more of the one or more antennas in one or both of the modules comprises a transceiver. ### Claim 7 (depends on 1) The modular downhole apparatus of claim 1, wherein one or more of the one or more antennas in one of the modules transmits a signal and one or more of the one or more antennas in the other module receives the signal. ### Claim 8 (depends on 1) The modular downhole apparatus of claim 1, wherein the one or more antennas of one or both of the modules comprise transmitter antennas and receiver antennas. ### Claim 9 (depends on 1) The modular downhole apparatus of claim 1, wherein one or more of the one or more antennas of one of the modules is disposed proximate to or within a drill bit. ### Claim 10 (depends on 1) The modular downhole apparatus of claim 1, wherein one of the modules includes a drill bit. ### Claim 11 (depends on 1) The modular downhole apparatus of claim 1, wherein one of the modules is part of a logging-while-drilling resistivity tool. ### Claim 12 (depends on 1) The modular downhole apparatus of claim 1, further comprising one or more additional modules, each additional module having one or more antennas, wherein each additional module has connectors on both ends and is removeably connected to the drill string. ### Claim 13 (depends on 1) The modular downhole apparatus of claim 1, wherein one or more of the one or more antennas in one or both of the modules comprises a solenoid coil approximating a magnetic dipole. ### Claim 14 (depends on 1) The modular downhole apparatus of claim 1, wherein the one or more antennas on the first module comprise a plurality of antennas having dipole moments that intersect the first module longitudinal axis at the first angle, and the one or more antennas on the second module comprise a plurality of antennas having dipole moments that intersect the second module longitudinal axis at the second angle. ### Claim 15 (depends on 1) The modular downhole apparatus of claim 1, wherein the formation property is one or more of a horizontal resistivity, a vertical resistivity, a formation resistivity, a formation factor, a fluid saturation, a dip angle, a dip azimuth angle, a porosity, a distance to bed boundary, a formation conductivity tensor, or a permeability. ### Claim 16 A modular downhole apparatus to determine a formation property, the apparatus being incorporated into a drill string comprising one or more downhole tools and drill pipe, the drill pipe being of the same or various lengths, the modular downhole apparatus comprising: a first module comprising a first drill collar having one or more antennas mounted thereon or therein, wherein the first module has connectors on both ends and is removeably connected to the drill string; and a second module comprising a second drill collar having one or more antennas mounted thereon or therein, wherein the second module has connectors on both ends and is removeably connected to the drill string; wherein a first dipole moment of one of the one or more antennas of the first module intersects a first module longitudinal axis at a first angle; wherein a second dipole moment of one of the one or more antennas of the second module intersects a second module longitudinal axis at a second angle; and wherein the first and second angles are unequal. ### Claim 17 (depends on 16) The modular downhole apparatus of claim 16, wherein the first and second angles are non-longitudinal. ### Claim 18 (depends on 17) The modular downhole apparatus of claim 17, wherein the first and second dipole moments are azimuthally offset from one another. ### Claim 19 (depends on 16) The modular downhole apparatus of claim 16, wherein one of the modules has an antenna having a third dipole moment that intersects the longitudinal axis of that module at a third angle that is equal to neither the first angle nor the second angle. ### Claim 20 (depends on 16) The modular downhole apparatus of claim 16, wherein at least one of the modules comprises a conventional resistivity tool. ### Claim 21 (depends on 16) The modular downhole apparatus of claim 16, wherein one or more of the one or more antennas in one or both of the modules comprises a transceiver. ### Claim 22 (depends on 16) The modular downhole apparatus of claim 16, wherein one or more of the one or more antennas in one of the modules transmits a signal and one or more of the one or more antennas in the other module receives the signal. ### Claim 23 (depends on 16) The modular downhole apparatus of claim 16, wherein the one or more antennas of one or both of the modules comprise transmitter antennas and receiver antennas. ### Claim 24 (depends on 16) The modular downhole apparatus of claim 16, wherein one or more of the one or more antennas of one of the modules is disposed proximate to or within a drill bit. ### Claim 25 (depends on 16) The modular downhole apparatus of claim 16, wherein one of the modules includes a drill bit. ### Claim 26 (depends on 16) The modular downhole apparatus of claim 16, wherein one of the modules is part of a logging-while-drilling resistivity tool. ### Claim 27 (depends on 16) The modular downhole apparatus of claim 16, further comprising one or more additional modules, each additional module having one or more antennas, wherein each additional module has connectors on both ends and is removeably connected to the drill string. ### Claim 28 (depends on 16) The modular downhole apparatus of claim 16, wherein one or more of the one or more antennas in one or both of the modules comprises a solenoid coil approximating a magnetic dipole. ### Claim 29 A method to determine a formation property, the method comprising: providing a modular apparatus incorporated into a drill string comprising one or more downhole tools and drill pipe, the drill pipe being of the same or various lengths; the modular apparatus comprising a first module comprising a first drill collar having one or more antennas mounted thereon or therein, wherein the first module has connectors on both ends and is removeably connected to the drill string; a second module comprising a second drill collar having one or more antennas mounted thereon or therein, wherein the second module has connectors on both ends and is removeably connected to the drill string; wherein a first dipole moment of one of the one or more antennas of the first module intersects a first module longitudinal axis at a first angle; a second dipole moment of one of the one or more antennas of the second module intersects a second module longitudinal axis at a second angle; and the first and second angles are equal; using the first and second modules to make measurements; and using the measurements to determine the formation property. ### Claim 30 (depends on 29) The method of claim 29, further comprising using the formation property to steer a drill bit. ### Claim 31 A method to determine a formation property, the method comprising: providing a modular apparatus incorporated into a drill string comprising one or more downhole tools and drill pipe, the drill pipe being of the same or various lengths; the modular apparatus comprising a first module comprising a first drill collar having one or more antennas mounted thereon or therein, wherein the first module has connectors on both ends and is removeably connected to the drill string; a second module comprising a second drill collar having one or more antennas mounted thereon or therein, wherein the second module has connectors on both ends and is removeably connected to the drill string; wherein a first dipole moment of one of the one or more antennas of the first module intersects a first module longitudinal axis at a first angle; a second dipole moment of one of the one or more antennas of the second module intersects a second module longitudinal axis at a second angle; and the first and second angles are unequal; using the first and second modules to make measurements; and using the measurements to determine the formation property. ### Claim 32 (depends on 31) The method of claim 31, further comprising using the formation property to steer a drill bit.