A method and a system for measuring downhole fluid properties. The downhole fluid sampling tool may comprise at least one probe and at least one passageway that passes through the at least one probe and into the downhole sampling tool. The method may comprise drawing a wellbore fluid through the at least one probe and through the at least one passageway, obtaining a first channel measurement of the wellbore fluid, obtaining at least a second channel measurement, clustering channel data from a plurality of channel measurements comprising the first channel measurement and the at least second channel measurement, and measuring a phase through a plurality of channels. The method may further comprise separating a plurality of phase signals based on the phase measured through the plurality of channels, labeling the wellbore fluid, assigning the plurality of phase signals to specific phases of a multi-phase fluid, and estimating a fluid property.

A method that includes deploying a casing with a multi-electrode configuration over a dielectric layer in a downhole environment. The method also includes collecting electromagnetic (EM) measurements using the multi-electrode configuration, and processing the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall. A related system includes a casing deployed downhole, the casing having a multi-electrode configuration and a dielectric layer between the casing and the multi-electrode configuration. The system also includes a controller for directing collection of EM measurements using the multi-electrode configuration, and a processor that processes the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall.

A method that includes deploying a casing with a multi-electrode configuration over a dielectric layer in a downhole environment. The method also includes collecting electromagnetic (EM) measurements using the multi-electrode configuration, and processing the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall. A related system includes a casing deployed downhole, the casing having a multi-electrode configuration and a dielectric layer between the casing and the multi-electrode configuration. The system also includes a controller for directing collection of EM measurements using the multi-electrode configuration, and a processor that processes the EM measurements to obtain a characterization of fluids in an annulus between the casing and a borehole wall.

Systems and methods for obtaining a calibrated permittivity dispersion measurements of a subsurface formation by measuring an impedance of the subsurface formation using a borehole imager at a first one or more frequencies; measuring a permittivity of the subsurface formation using a reference tool at a second one or more frequencies; calculating a first dispersion curve of the permittivity of the subsurface formation based at least in part on the measured impedance of the subsurface formation at the first one or more frequencies; extrapolating the permittivity of the subsurface formation to the second one or more frequencies using the calculated first dispersion curve of the permittivity of the subsurface formation; calibrating the permittivity of the subsurface formation based at least in part on the extrapolated permittivity of the subsurface formation and the measured permittivity of the subsurface formation; and generating a second dispersion curve of the permittivity of the subsurface formation based at least in part on one or more of the calibrated permittivity of the subsurface formation at the first one or more frequencies and the measured permittivity of the subsurface formation at the second one or more frequencies.

The disclosure provides a well integrity monitoring tool for a wellbore, a method, using a nuclear tool and an EM tool, for well integrity monitoring of a wellbore having a multi-pipe configuration, and a well integrity monitoring system. In one example, the method includes: operating a nuclear tool in the wellbore to make a nuclear measurement at a depth of the wellbore, operating an EM tool in the wellbore to make an EM measurement at the depth of the wellbore, determining a plurality of piping properties of the multi-pipe configuration at the depth employing the EM measurement, determining, employing the piping properties, a processed nuclear measurement from the nuclear measurement, and employing the processed nuclear measurement to determine an integrity of a well material at the depth and within an annulus defined by the multi-pipe configuration.

The disclosure provides a well integrity monitoring tool for a wellbore, a method, using a nuclear tool and an EM tool, for well integrity monitoring of a wellbore having a multi-pipe configuration, and a well integrity monitoring system. In one example, the method includes: operating a nuclear tool in the wellbore to make a nuclear measurement at a depth of the wellbore, operating an EM tool in the wellbore to make an EM measurement at the depth of the wellbore, determining a plurality of piping properties of the multi-pipe configuration at the depth employing the EM measurement, determining, employing the piping properties, a processed nuclear measurement from the nuclear measurement, and employing the processed nuclear measurement to determine an integrity of a well material at the depth and within an annulus defined by the multi-pipe configuration.

A method for performing a modified two point flux approximation scheme is disclosed. The method includes: obtaining a first pressure value for a first neighbor cell and a second pressure value for a second neighbor cell, where the first neighbor cell has a first value of a reservoir property and the second neighbor cell as a second value of the reservoir property; determining a first weight using the first pressure value and a second weight using the second pressure value; calculating a third value of the reservoir property as a weighted average of the first value and the second value; and applying the third value to the first neighbor cell.

A method for performing a modified two point flux approximation scheme is disclosed. The method includes: obtaining a first pressure value for a first neighbor cell and a second pressure value for a second neighbor cell, where the first neighbor cell has a first value of a reservoir property and the second neighbor cell as a second value of the reservoir property; determining a first weight using the first pressure value and a second weight using the second pressure value; calculating a third value of the reservoir property as a weighted average of the first value and the second value; and applying the third value to the first neighbor cell.

Raw signal measurements can be received by sensors in a wellbore. Borehole effects can affect the raw signal measurements. The raw signal measurements can be converted into ratio signals having attenuation and phase shift. An apparent resistivity can be determined from the ratio signals. Mud resistivity can be determined based on apparent resistivity, at least part of the raw signal measurements, and the borehole size. A true resistivity can be determined based on the mud resistivity and at least part of the ratio signals. The raw signal measurements and the ratio signals can be updated based on the true resistivity. Steps can be repeated to determine a corrected true resistivity. Based on the true resistivity value and updated raw signal measurements and ratio signals, an operating characteristic of a well tool can be caused to be adjusted.

Raw signal measurements can be received by sensors in a wellbore. Borehole effects can affect the raw signal measurements. The raw signal measurements can be converted into ratio signals having attenuation and phase shift. An apparent resistivity can be determined from the ratio signals. Mud resistivity can be determined based on apparent resistivity, at least part of the raw signal measurements, and the borehole size. A true resistivity can be determined based on the mud resistivity and at least part of the ratio signals. The raw signal measurements and the ratio signals can be updated based on the true resistivity. Steps can be repeated to determine a corrected true resistivity. Based on the true resistivity value and updated raw signal measurements and ratio signals, an operating characteristic of a well tool can be caused to be adjusted.