# US 10,119,389 B2 · Drilling collision avoidance apparatus, methods, and systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,389 B2 - Document ID: US10119389B2 - Status: Granted - Kind: B2 - Application number: 14/432,647 - Filed: 2013-12-27 - Published: 2016-09-15 - Granted: 2018-11-06 - Earliest claimed: 2013-12-27 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Burkay Donderici - Web page: https://patentgrep.com/patent/US10119389B2 ## CPC - E21B 47/09: Locating or determining the position of objects in boreholes or wells {, e.g. the position of an extending arm}; Identifying the free or blocked portions of pipes - E21B 7/04: Directional drilling - E21B 43/305: {comprising at least one inclined or horizontal well} - E21B 47/02: Determining slope or direction - E21B 47/0228: using electromagnetic energy or detectors therefor - E21B 47/13: by electromagnetic energy, e.g. radio frequency - G01V 3/20: operating with propagation of electric current - 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 Apparatus, systems, and methods may include a magnetic dipole transmitter to be located in a ranging well. A voltage measurement device can include a plurality of probes where each probe is to be located on one of a target well, the ranging well or a surface of a geological formation comprising the ranging well and the target well. A controller coupled to the voltage measurement device calculates a distance or relative direction between the target well and the ranging well based on a voltage difference between the plurality of probes. The distance/direction can be used to control drilling operations. Additional apparatus, systems, and methods are disclosed. ## Claims ### Claim 1 A system comprising: a first magnetic dipole transmitter located in a ranging well; a second magnetic dipole transmitter located in the ranging well, wherein the second magnetic dipole transmitter is radially, axially, or azimuthally separated from the first magnetic dipole transmitter; a voltage measurement device comprising a plurality of probes wherein each probe is conductively coupled to one of a target well, the ranging well, or a geological formation, and wherein a first probe of the plurality of probes is conductively coupled to the target well and a second probe of the plurality of probes is conductively coupled to the geological formation; and a controller coupled to the voltage measurement device to calculate a distance or relative direction between the target well and the ranging well based on a ratio of voltage difference measurements measured by the plurality of probes, wherein the voltage difference measurements are induced by the first magnetic dipole transmitter and the second magnetic dipole transmitter. ### Claim 2 (depends on 1) The system of claim 1, wherein the first probe is connected to a wellhead of the target well. ### Claim 3 (depends on 1) The system of claim 1, wherein the plurality of probes is connected to axially separated points in the target well. ### Claim 4 (depends on 1) The system of claim 1, wherein the plurality of probes is connected to axially separated points in the ranging well. ### Claim 5 (depends on 4) The system of claim 4, wherein the plurality of probes is connected to a bottom hole assembly (BHA) and separated from the BHA by a gap sub. ### Claim 6 (depends on 1) The system of claim 1, wherein the second magnetic dipole transmitter has a magnetic moment in an opposite direction from a magnetic moment of the first magnetic dipole transmitter. ### Claim 7 (depends on 6) The system of claim 6, wherein the second magnetic dipole transmitter is a substantially equal distance from an axial centerline of the ranging well and in a substantially opposite direction when compared to the first magnetic dipole transmitter, and wherein calculating the distance comprises calculating the distance based on a first ratio. ### Claim 8 A method for ranging between a ranging well and a target well, the method comprising: activating a first magnetic dipole transmitter in the ranging well; activating a second magnetic dipole transmitter in the ranging well, wherein the second magnetic dipole transmitter is radially, axially, or azimuthally separated from the first magnetic dipole transmitter; sensing a voltage difference between a pair of probes, wherein a first probe of the pair of probes is conductively coupled to the target well, and wherein a second probe of the pair of the pair of probes is conductively coupled to a geological formation; and determining at least one of a distance or a relative direction between the ranging well and the target well based on a ratio of voltage difference measurements measured by the pair of probes, wherein the voltage difference measurements are induced by the first magnetic dipole transmitter and the second magnetic dipole transmitter. ### Claim 9 (depends on 8) The method of claim 8, further comprising adjusting a drilling operation direction based on at least one of the distance or the relative direction. ### Claim 10 (depends on 8) The method of claim 8, wherein the second magnetic dipole transmitter has a magnetic moment in an opposite direction compared to a magnetic moment of the first magnetic dipole transmitter. ### Claim 11 (depends on 10) The method of claim 10, wherein the second magnetic dipole transmitter is simultaneously active with the first magnetic dipole transmitter. ### Claim 12 (depends on 8) The method of claim 8, further comprising generating an alternating current on the target well with the second magnetic dipole transmitter. ### Claim 13 (depends on 11) The method of claim 11, further comprising generating an alternating current on the target well with three or more magnetic dipole transmitters. ### Claim 14 (depends on 10) The method of claim 10, wherein activating the first magnetic dipole transmitter comprises transmitting a signal from one of: a 3-dipole transmitter, a 4-dipole transmitter, or an 8-dipole transmitter. ### Claim 15 (depends on 9) The method of claim 9, wherein activating the first magnetic dipole transmitter comprises transmitting the alternating current from the first magnetic dipole transmitter coupled to a bottom hole assembly, a drilling assembly, or a wireline tool disposed within the ranging well. ### Claim 16 A method for ranging between a ranging well and a target well, the method comprising: lowering a first magnetic dipole transmitter into the ranging well; lowering a second magnetic dipole transmitter into the ranging well, wherein the second magnetic dipole transmitter is radially, axially, or azimuthally separated from the first magnetic dipole transmitter; generating an alternating current on the target well with at least one of the first magnetic dipole transmitter and the second magnetic dipole transmitter; sensing a voltage difference between a pair of probes, wherein a first probe of the pair of probes is conductively coupled to a geological formation and a second probe of the pair of probes is conductively coupled to the target well; and determining at least one of a distance or a relative direction between the ranging well and the target well based on a ratio of voltage difference measurements measured by the pair of probes, wherein at least one of the voltage difference measurements are indicative of the alternating current. ### Claim 17 (depends on 16) The method of claim 16, further comprising coupling the second probe of the pair of probes to a wellhead of the target well. ### Claim 18 (depends on 16) The method of claim 16, further comprising locating a second pair of probes at axially separated points in the target well. ### Claim 19 (depends on 16) The method of claim 16, further comprising locating a second pair of probes at axially separated points in the ranging well. ### Claim 20 (depends on 16) The method of claim 16, further comprising locating a second pair of probes in a bottom hole assembly (BHA) wherein the pair of probes are separated by a gap sub. ### Claim 21 (depends on 16) The method of claim 16, further comprising a second pair of probes that are part of a wireline tool. ### Claim 22 (depends on 16) The method of claim 16, further comprising sensing an absolute voltage between the pair of probes based on the alternating current on the target well. ### Claim 23 (depends on 7) The system of claim 7, wherein calculating the distance further comprises calculating the distance based on an angular orientation of the target well. ### Claim 24 (depends on 23) The system of claim 23, wherein the first ratio comprises a first trigonometric function of the angular orientation and a second trigonometric function of the angular orientation. ### Claim 25 (depends on 24) The system of claim 24, wherein the distance is calculated as a product of the first ratio multiplied by a second ratio of measurements. ### Claim 26 (depends on 25) The system of claim 25, wherein the distance is calculated as: r = Δ ⁢ ⁢ x ⁢ ⁢ cos ⁡ ( 2 ⁢ ⁢ θ ) cos ⁢ ⁢ ( θ ) ⁢ ( V Hy ⁢ ⁢ 2 + V Hy ⁢ ⁢ 1 2 ) V Hy ⁢ ⁢ 2 - V Hy ⁢ ⁢ 1 , wherein r is the distance, θis the angular orientation, VHy1 is a measurement measured by the first magnetic dipole transmitter, VHy2 is a measurement measured by the second magnetic dipole transmitter, and Δx is a position change of the first magnetic dipole transmitter during measurement of VHy1. ### Claim 27 (depends on 1) The system of claim 1, wherein the second probe is connected to a surface of the geological formation. ### Claim 28 (depends on 8) The method of claim 8, wherein the first probe of the plurality of probes is connected to a wellhead of the target well. ### Claim 29 (depends on 16) The method of claim 16, wherein the second probe is connected to a surface of the geological formation.