A method includes generating a ranging model of a drilling wellbore to be drilled and generating a predicted signal along measured depths of the drilling wellbore based on the ranging model. The method includes performing the following operations until the drilling wellbore has been drilled to a defined depth. The following operations include drilling, with a drill string, the drilling wellbore to an increment of the defined depth and detecting, by a sensor positioned on the drill string, an electromagnetic field emanating from a target wellbore. The following operations include determining ranging measurements to the target wellbore at the increment based on the electromagnetic field and calibrating the predicted signal based on the ranging measurements. The following operations include determining ranging accuracy for all deeper depths in the wellbore and making drilling decisions or adjusting drilling operations based on the predicted ranging accuracy for deeper depths.

A method comprises determining a plurality of responses at a plurality of tilted angles for multiple coils of a collocated antenna assembly based on at least one coil parameter of the collocated antenna assembly, wherein the at least one coil parameter comprises at least one of a number of coil turns, a coil size, and a number of coils. The method includes determining crosstalk between the multiple coils at each of the plurality of tilted angles from the plurality of responses. The method includes determining a signal-to-noise ratio for each of the plurality of tilted angles based on the crosstalk. The method also includes selecting a tilted angle for the collocated antenna assembly corresponding to an optimal signal-to-noise ratio of the determined signal-to-noise ratios.

A method comprises determining a plurality of responses at a plurality of tilted angles for multiple coils of a collocated antenna assembly based on at least one coil parameter of the collocated antenna assembly, wherein the at least one coil parameter comprises at least one of a number of coil turns, a coil size, and a number of coils. The method includes determining crosstalk between the multiple coils at each of the plurality of tilted angles from the plurality of responses. The method includes determining a signal-to-noise ratio for each of the plurality of tilted angles based on the crosstalk. The method also includes selecting a tilted angle for the collocated antenna assembly corresponding to an optimal signal-to-noise ratio of the determined signal-to-noise ratios.

There is disclosed a fluid and/or material detection device (2) comprising an electromagnetic transmitter and/or receiver arrangement (4) comprising a cable (6) or transmission line that acts as an antenna (e.g., transmitter and/or receiver). The device (2) comprises a liquid level detection device and/or particulate (particulate containing fluid) detection device. At least a portion of the cable (6) is rigid/stiff, e.g., at least a portion of the cable (6) having a length of from 0.1 meters to 10 meters. The cable (6) advantageously comprises a coaxial cable or triaxial cable, a radiating cable (RC) or a leaky feeder (LF). The device (2) finds use in an enclosed structure (36), e.g., a cased borehole or well, which can be sealed or unsealed during use of the device (6). The enclosed structure (36) provides a space (34), e.g., an annulus between a production tubing and a wellbore casing or a bore of a production tubing. There is also disclosed a method of detecting and/or determination and/or measuring and/or monitoring a level and/or position of a fluid and/or material or fluid interface within the space (34), the method comprising: providing the device (2); transmitting and/or receiving an electromagnetic signal or signals from and/or at/by the device (2). The method beneficially comprises detecting, locating, establishing and/or measuring a fluid level or liquid level and/or interface of a fluid or liquid using a technique comprising: Frequency Domain Reflectometry (FDR).

A method for ranging to locate a target borehole. The method may include disposing a bottom hole assembly (BHA) into an intercept borehole, disposing a downhole tool into a reference borehole, imaging a target borehole for the intercept borehole to get a first set of measurement, imaging the target borehole from the reference borehole to get a second set of measurements, and combining the first set of measurements and the second set of measurements to determine a direction and distance to the target borehole form the intercept borehole.

Provided are systems and methods for mapping hydrocarbon reservoirs. Operations include disposing an electromagnetic (EM) transmitter and an EM receiver into first and second wellbores of first and second wells, respectively, penetrating a resistive layer of a subsurface formation bounded by first and second conductive layers. The EM transmitter and receiver each being disposed at depths proximate to intersections of the first and second wellbores and the resistive layer, respectively. The operations further including transmitting an EM signal between the EM transmitter and receiver via the resistive layer, determining transport properties associated with propagation of the EM signal from the EM transmitter to the EM receiver via the resistive layer, and determining the presence of an anomaly in at least one of the conductive layers based on the travel time.

Systems and methods for performing bed boundary detection and azimuthal resistivity logging using a logging tool with a pair of tilted receiver antennas having a midpoint on a longitudinal axis of the logging tool, a first pair of transmitter antennas symmetrically spaced from said midpoint, and a third tilted receiver antenna positioned farther from said midpoint than the transmitter antennas. Method embodiments include energizing each transmitter antenna of the first pair in a firing sequence and obtaining, responsive to the energizing, measurements with a pair of tilted receiver antennas equally spaced from said midpoint. Methods may also include obtaining, responsive to energizing of a more distant one of the first pair of transmitter antennas, measurements with a third tilted receiver antenna positioned farther from the midpoint than the transmitter antennas.

Systems and methods for performing bed boundary detection and azimuthal resistivity logging using a logging tool with a pair of tilted receiver antennas having a midpoint on a longitudinal axis of the logging tool, a first pair of transmitter antennas symmetrically spaced from said midpoint, and a third tilted receiver antenna positioned farther from said midpoint than the transmitter antennas. Method embodiments include energizing each transmitter antenna of the first pair in a firing sequence and obtaining, responsive to the energizing, measurements with a pair of tilted receiver antennas equally spaced from said midpoint. Methods may also include obtaining, responsive to energizing of a more distant one of the first pair of transmitter antennas, measurements with a third tilted receiver antenna positioned farther from the midpoint than the transmitter antennas.

A method for magnetic ranging includes switching an electromagnet deployed in a target wellbore between at least first and second states and acquiring a plurality of magnetic field measurements at a magnetic field sensor deployed on a drill string in a drilling wellbore while the electromagnet is switching. The magnetic field measurements may be sorted into at least first and second sets corresponding to the first and second states of the electromagnet. The first and second sets of magnetic field measurements are then processed to compute at least one of a distance and a direction from the drilling well to the target. The electromagnet may be automatically switched back and forth between the first and second states independently from the acquiring and sorting of the magnetic field measurements.

A diameter measurement device for measuring the diameter of a wireline cable dynamically during moving in and out of a borehole. The measurement device has a first pair of opposed shafts, a rotating roller on each shaft of said first pair of opposed shafts, a first resilient member mounted to urge at least one of the shafts of said first pair of opposed shafts toward the wireline cable to be measured, and a first intrinsic measuring unit operatively associated with the first resilient member to measure the displacement thereof. The measuring device further has at least a second pair of opposed shafts angularly displaced with respect to the first pair of opposed shafts, a rotating roller on each shaft of said second pair of opposed shafts, a second resilient member mounted to urge at least one of the shafts of said second pair of opposed shafts toward the wireline cable to be measured, and a second intrinsic measuring unit operatively associated with the first resilient member to measure the displacement thereof as the wireline cable is moved lengthwise between the rollers; each of said first and second intrinsic measuring devices outputting to a digitizer for generating digital measurements of the diameter at various positions on the circumference of and along the length of said wireline cable, which measurements are transmitted to and stored in a logging device. At least one of the first and second intrinsic measuring units can be an eddy current measurement device to measure deflection of at least one of the first and second resilient members using eddy currents.