According to aspects of the present disclosure, systems and methods for measuring fluid resistivity are described herein. An example system may include a non-conductive tube. The non-conductive tube may be filled with a fluid, such as a formation fluid or drilling fluid, whose resistivity needs to be determined. A transmitter may be disposed around an outer surface of the non-conductive tube. A first receiver may be disposed around the outer surface of the non-conductive tube, and a second receiver may be positioned within a bore of the non-conductive tube. The transmitter may generate a primary electromagnetic field in a fluid within the tube, which may in turn generate an eddy current and a secondary electromagnetic field. The first and second receivers may be used to identify the eddy current and the resistivity of the fluid.

According to aspects of the present disclosure, systems and methods for measuring fluid resistivity are described herein. An example system may include a non-conductive tube. The non-conductive tube may be filled with a fluid, such as a formation fluid or drilling fluid, whose resistivity needs to be determined. A transmitter may be disposed around an outer surface of the non-conductive tube. A first receiver may be disposed around the outer surface of the non-conductive tube, and a second receiver may be positioned within a bore of the non-conductive tube. The transmitter may generate a primary electromagnetic field in a fluid within the tube, which may in turn generate an eddy current and a secondary electromagnetic field. The first and second receivers may be used to identify the eddy current and the resistivity of the fluid.

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.

An interactive display of results obtained from the inversion of logging data is produced by obtaining and inverting the logging data using a Monte-Carlo inversion. An interactive plot having a percentile scale plotted against a location parameter is produced and a particular percentile is selected using the interactive plot. A cross-section plot for the particular percentile using the results of the Monte-Carlo inversion is produced. The particular percentile can be a curve representing a best-fit solution or a polyline representing selected solutions. Background color/shading can be displayed on the interactive plot to indicate user-defined constraints have been applied. Uncertain features can be plotted on a corresponding cross-section display using fading. Clusters of solutions that are substantially equally likely, given the measurements at a particular drill location, can be identified and plotted. A cross-section constructed from the layered models belonging to a particular cluster can be overlaid on another cross-section.

An interactive display of results obtained from the inversion of logging data is produced by obtaining and inverting the logging data using a Monte-Carlo inversion. An interactive plot having a percentile scale plotted against a location parameter is produced and a particular percentile is selected using the interactive plot. A cross-section plot for the particular percentile using the results of the Monte-Carlo inversion is produced. The particular percentile can be a curve representing a best-fit solution or a polyline representing selected solutions. Background color/shading can be displayed on the interactive plot to indicate user-defined constraints have been applied. Uncertain features can be plotted on a corresponding cross-section display using fading. Clusters of solutions that are substantially equally likely, given the measurements at a particular drill location, can be identified and plotted. A cross-section constructed from the layered models belonging to a particular cluster can be overlaid on another cross-section.

Various embodiments include systems and methods that operate to provide reservoir imaging. The systems and methods can include a number of transmitter antennas and a number of receiving antennas arranged to operate as one or more multi-pole antennas, controlled to generate high resolution cross-well formation images. Additional apparatus, systems, and methods are disclosed.

Various embodiments include systems and methods that operate to provide reservoir imaging. The systems and methods can include a number of transmitter antennas and a number of receiving antennas arranged to operate as one or more multi-pole antennas, controlled to generate high resolution cross-well formation images. Additional apparatus, systems, and methods are disclosed.

A method for obtaining full tensor gain compensated propagation measurements includes processing a full tensor voltage measurement to obtain a fully gain compensated tensor quantity. An electromagnetic logging tool including at least first and second axially spaced transmitters and at least first and second axially spaced receivers is rotated in a subterranean borehole. A plurality of voltage measurements are acquired while rotating to obtain a full tensor voltage measurement which is in turn processed to obtain the fully gain compensated tensor quantity.

A method for obtaining full tensor gain compensated propagation measurements includes processing a full tensor voltage measurement to obtain a fully gain compensated tensor quantity. An electromagnetic logging tool including at least first and second axially spaced transmitters and at least first and second axially spaced receivers is rotated in a subterranean borehole. A plurality of voltage measurements are acquired while rotating to obtain a full tensor voltage measurement which is in turn processed to obtain the fully gain compensated tensor quantity.

A system for detecting the depth of an antenna embedded in the card body of a smart card includes a milling device for forming a cavity in the card body, a test device disposed in close proximity to the card body, a vector network analyzer (VNA) for measuring a linear characteristic of the test device, and a control device for regulating operation of the milling device in view of data collected by the VNA. In use, the VNA generates a test signal and measures the degree of signal reflection from the test device. Under normal conditions, the VNA observes a spike in forward return loss at the natural resonant frequency of the open antenna circuit. However, at the instant that the milling device contacts the antenna, a notable variance in the degree of signal reflection is observed which indicates that the proper antenna depth has been reached.