# US 2017/0285213 A1 · Tuned probe style propagation resistivity tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285213 A1 - Document ID: US20170285213A1 - Status: Published application - Kind: A1 - Application number: 15/476,512 - Filed: 2017-03-31 - Published: 2017-10-05 - Earliest claimed: 2016-03-31 - Assignees: Pulse Directional Technologies Inc. - Applicants: Pulse Directional Technologies Inc. - Inventors: KARL EDLER; STEVE BRAISHER - Web page: https://patentgrep.com/patent/US20170285213A1 ## CPC - G01V 3/30: operating with electromagnetic waves - E21B 17/16: Drill collars - E21B 49/00: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or 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) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Tools and methods for measuring resistivity are provided. The tool for measuring resistivity in a formation comprises a receiver module comprising a first electromagnetic signal receiver and a second electromagnetic signal receiver; a first electromagnetic signal transmitter removably coupled to one longitudinal end of the receiver module; a second electromagnetic signal transmitter removably coupled to the other longitudinal end of the receiver module; and each of the first and the second electromagnetic signal receivers configured to receive electromagnetic signals propagating in the formation from the first and the second electromagnetic signal transmitters. ## Claims ### Claim 1 1) A tool for measuring resistivity in a formation comprising: a receiver module comprising a first electromagnetic signal receiver and a second electromagnetic signal receiver; a first electromagnetic signal transmitter removably coupled to one longitudinal end of the receiver module; a second electromagnetic signal transmitter removably coupled to the other longitudinal end of the receiver module; and each of the first and the second electromagnetic signal receivers configured to receive electromagnetic signals propagating in the formation from the first and the second electromagnetic signal transmitters. ### Claim 2 (depends on 1) 2) The tool of claim 1 wherein the electromagnetic signal transmitters comprise transmitter coils. ### Claim 3 (depends on 1) 3) The tool of claim 1 wherein the electromagnetic signal receivers comprise receiver coils. ### Claim 4 (depends on 4) 4) The tool of claim 4 wherein the receiver module comprises a male portion configured for removable coupling to a female portion of the first electromagnetic signal transmitter. ### Claim 5 (depends on 4) 5) The tool of claim 4 wherein the receiver module comprises a female portion configured for removable coupling to a male portion of the second electromagnetic signal transmitter. ### Claim 6 (depends on 4) 6) The tool of claim 4 comprising bow-springs between the electromagnetic signal transmitter and the receiver module that are electrically connected to the drill collar. ### Claim 7 (depends on 4) 7) The tool of claim 4 wherein the drill collar comprises at least one cut-out configured to allow electromagnetic signals to be transmitted into the formation from the ### Claim 8 (depends on 4) 8) The tool of claim 4 comprising at least one grounding spring contact positioned within the tool, the grounding spring contact configured to block electromagnetic signals produced by the first and second electromagnetic signal transmitters propagating within the tool. ### Claim 9 (depends on 8) 9) The tool of claim 8 wherein the at least one grounding spring contact engages a ground shield of a wiring harness positioned along a longitudinal axis of the tool. ### Claim 10 (depends on 8) 10) The tool of claim 8 wherein the at least one grounding spring contact comprises a circular spring electrically grounding one side of the tool containing electronics. ### Claim 11 (depends on 8) 11) The tool of claim 8 wherein the at least one grounding spring contact comprises a conical spring. ### Claim 12 (depends on 8) 12) The tool of claim 8 wherein the transmitter coils and the receiver coils are covered by a metal shield having a series of slits and the slits and the bow-springs are configured to block electromagnetic signals produced by the first and second electromagnetic signal transmitters propagating between the tool and the drill collar. ### Claim 13 (depends on 4) 13) The tool of claim 4 wherein the tool is a probe-style tool that is not mechanically locked to the drill collar. ### Claim 14 (depends on 1) 14) The tool of claim 1 wherein the electromagnetic signal receiver comprises a coil connected to a double-tuned and impedance-matched circuit that interfaces the coil to a fully differential low noise amplifier. ### Claim 15 (depends on 14) 15) The tool of claim 14 wherein the electromagnetic signals received by the electromagnetic signal receivers are processed to remove noise. ### Claim 16 (depends on 15) 16) The tool of claim 15 wherein noise removal comprises cancelling out start phases of the electromagnetic signal receivers and adding a constant phase. ### Claim 17 17) A method for configuring a tool for measuring resistivity in a formation, the method comprising the steps of: measuring a first electromagnetic signal transmitted by a first electromagnetic signal transmitter using a first electromagnetic signal receiver and a second electromagnetic signal receiver in a receiver module, and generating a first calculation from such measurements, the first electromagnetic signal transmitter removably coupled to one longitudinal end of the receiver module; measuring a second electromagnetic signal transmitted by a second electromagnetic signal transmitter using the first electromagnetic signal receiver and the second electromagnetic signal receiver in the receiver module, and generating a second calculation from such measurements, the second electromagnetic signal transmitter removably coupled to the other longitudinal end of the receiver module; combining the first calculation and the second calculation to generate a combined calculation; and configuring the tool using the combined calculation. ### Claim 18 (depends on 17) 18) The method of claim 17 wherein each of the first calculation and the second calculation comprises a first and a second magnitude ratio and combining the first calculation and the second calculation to generate a combined calculation comprises combining the first and the second magnitude ratio using geometric means to generate a combined magnitude ratio calculation. ### Claim 19 (depends on 17) 19) The method of claim 17 wherein each of the first calculation and the second calculation comprises a first and a second phase shift and combining the first calculation and the second calculation to generate a combined calculation comprises combining the first and the second phase shift using arithmetic means to generate a combined phase shift calculation. ### Claim 20 (depends on 18) 20) The method of claim 18 comprising: calculating a first phase shift using the measurements of the first electromagnetic signal and a second phase shift using the measurements of the second electromagnetic signal; and combining the first phase shift and the second phase shift using arithmetic means to generate a combined phase shift calculation; and, wherein calibrating the resistivity tool using the combined calculation, comprises using the combined phase shift calculation and the combined magnitude ratio calculation.