Abstract: An apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a time-dependent ratio of information obtained from at least one neutron detector through the exposure of the earth formation to a radiation source, particularly a pulsed nuclear source. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method. Also, an apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a first component and a second component of an information set obtained using a single radiation detector.

Abstract: An apparatus for estimating porosities of a formation includes: a borehole conveyable pulsed neutron generator to emit a pulse of high energy neutrons; a short spaced neutron detector to provide a count rate as a function of time; a long spaced neutron detector to provide a count rate as a function of time; a timing gate to synchronize a timing of neutrons detected by the detectors with respect to the neutron pulse; and a processor. The processor is configured to determine epithermal count rates and thermal count rates for the detectors based on timing of detection of neutrons with respect to the neutron pulse and calculate a first ratio of short to long spaced detector epithermal count rates and a second ratio of short to long spaced detector thermal count rates. The processor estimates an epithermal porosity using the first ratio and a thermal porosity using the second ratio.

Abstract: An apparatus for estimating porosities of a formation includes: a borehole conveyable pulsed neutron generator to emit a pulse of high energy neutrons; a short spaced neutron detector to provide a count rate as a function of time; a long spaced neutron detector to provide a count rate as a function of time; a timing gate to synchronize a timing of neutrons detected by the detectors with respect to the neutron pulse; and a processor. The processor is configured to determine epithermal count rates and thermal count rates for the detectors based on timing of detection of neutrons with respect to the neutron pulse and calculate a first ratio of short to long spaced detector epithermal count rates and a second ratio of short to long spaced detector thermal count rates. The processor estimates an epithermal porosity using the first ratio and a thermal porosity using the second ratio.

Abstract: An apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a time-dependent ratio of information obtained from at least one neutron detector through the exposure of the earth formation to a radiation source, particularly a pulsed nuclear source. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method. Also, an apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a first component and a second component of an information set obtained using a single radiation detector.

Abstract: An apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a time-dependent ratio of information obtained from at least one neutron detector through the exposure of the earth formation to a radiation source, particularly a pulsed nuclear source. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method. Also, an apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a first component and a second component of an information set obtained using a single radiation detector.

Abstract: An apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a time-dependent ratio of information obtained from at least one neutron detector through the exposure of the earth formation to a radiation source, particularly a pulsed nuclear source. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method. Also, an apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a first component and a second component of an information set obtained using a single radiation detector.