Abstract: Logging tools and methods for obtaining a three-dimensional (3D) image of the region around a borehole. In at least some embodiments, a 3D imaging tool rotates, transmitting pulses that are approximately a nanosecond long and measuring the time it takes to receive reflections of these pulses. Multiple receivers are employed to provide accurate triangulation of the reflectors. In some cases, multiple transmitters are employed to obtain compensated measurements, i.e., measurements that compensate for variations in the receiver electronics. Because reflections occur at boundaries between materials having different dielectric constants, the 3D imaging tool can map out such boundaries in the neighborhood of the borehole. Such boundaries can include: the borehole wall itself, boundaries between different formation materials, faults or other discontinuities in a formation, and boundaries between fluids in a formation.

Abstract: Various methods and tools optically analyze downhole fluid properties in situ. Some disclosed downhole optical radiometry tools include a tool body having a sample cell for fluid flow. A light beam passes through the sample cell and a spectral operation unit (SOU) such as a prism, filter, interferometer, or multivariate optical element (MOE). The resulting light provides a signal indicative of one or more properties of the fluid. A sensor configuration using electrically balanced thermopiles offers a high sensitivity over a wide temperature range. Further sensitivity is achieved by modulating the light beam and/or by providing a reference light beam that does not interact with the fluid flow. To provide a wide spectral range, some embodiments include multiple filaments in the light source, each filament having a different emission spectrum. Moreover, some embodiments include a second light source, sample cell, SOU, and detector to provide increased range, flexibility, and reliability.

Abstract: A processor accepts sensor data about a geological formation from a sensor. The sensor data is such that processing the sensor data using a processing technique to estimate a parameter of the geological formation without a constraint, whose value is not yet known, produces a plurality of non-unique estimates of the parameter. The processor accepts more than two time-displaced images of fluid sampled from the geological formation. The time displacements between the images are substantially defined by a mathematical series. The processor processes the images to determine the constraint. The processor processes the sensor data using the processing technique constrained by the constraint to estimate the parameter of the geological formation. The processor uses the estimated parameter to affect the drilling of a well through the geological formation.

Abstract: Determining a parameter associated with a formation corrected for neutrons produced. At least some of the illustrative embodiments are methods including: disposing a logging tool within a borehole, the borehole penetrates a formation; producing neutrons by a neutron source within the logging tool; detecting neutrons produced by the neutron source, the detecting by a neutron detector; creating an indication of a number of neutrons produced by the neutron source, the indication based only on neutrons detected that have not interacted with other elements before entering the neutron detector; obtaining a count rate of a gamma detector responsive to the production of neutrons by the neutron source; and determining a parameter associated with the formation based on the count rate and on the indication of the number of neutrons produced.

Abstract: Determining a parameter associated with a formation corrected for neutrons produced. At least some of the illustrative embodiments are methods including: disposing a logging tool within a borehole, the borehole penetrates a formation; producing neutrons by a neutron source within the logging tool; detecting neutrons produced by the neutron source, the detecting by a neutron detector; creating an indication of a number of neutrons produced by the neutron source, the indication based only on neutrons detected that have not interacted with other elements before entering the neutron detector; obtaining a count rate of a gamma detector responsive to the production of neutrons by the neutron source; and determining a parameter associated with the formation based on the count rate and on the indication of the number of neutrons produced.

Abstract: A processor accepts sensor data about a geological formation from a sensor. The sensor data is such that processing the sensor data using a processing technique to estimate a parameter of the geological formation without a constraint, whose value is not yet known, produces a plurality of non-unique estimates of the parameter. The processor accepts more than two time-displaced images of fluid sampled from the geological formation. The time displacements between the images are substantially defined by a mathematical series. The processor processes the images to determine the constraint. The processor processes the sensor data using the processing technique constrained by the constraint to estimate the parameter of the geological formation. The processor uses the estimated parameter to affect the drilling of a well through the geological formation.

Abstract: Various methods and tools optically analyze downhole fluid properties in situ. Some disclosed downhole optical radiometry tools include a tool body having a sample cell for fluid flow. A light beam passes through the sample cell and a spectral operation unit (SOU) such as a prism, filter, interferometer, or multivariate optical element (MOE). The resulting light provides a signal indicative of one or more properties of the fluid. A sensor configuration using electrically balanced thermopiles offers a high sensitivity over a wide temperature range. Further sensitivity is achieved by modulating the light beam and/or by providing a reference light beam that does not interact with the fluid flow. To provide a wide spectral range, some embodiments include multiple filaments in the light source, each filament having a different emission spectrum. Moreover, some embodiments include a second light source, sample cell, SOU, and detector to provide increased range, flexibility, and reliability.

Abstract: Logging tools and methods for obtaining a three-dimensional (3D) image of the region around a borehole. In at least some embodiments, a 3D imaging tool rotates, transmitting pulses that are approximately a nanosecond long and measuring the time it takes to receive reflections of these pulses. Multiple receivers are employed to provide accurate triangulation of the reflectors. In some cases, multiple transmitters are employed to obtain compensated measurements, i.e., measurements that compensate for variations in the receiver electronics. Because reflections occur at boundaries between materials having different dielectric constants, the 3D imaging tool can map out such boundaries in the neighborhood of the borehole. Such boundaries can include: the borehole wall itself, boundaries between different formation materials, faults or other discontinuities in a formation, and boundaries between fluids in a formation.