Abstract: A method for generating a log of a value of a property of a fluid in an earth formation versus depth includes: obtaining a plurality of samples of drilling fluid that are entrained with a formation gas and correlating each sample to a depth in a borehole from which the formation gas was entrained in the drilling fluid; extracting the formation gas from each sample to provide a plurality of gas samples; analyzing each formation gas sample to provide a chemical composition of each formation gas sample in the plurality of formation gas samples; and determining a property value of the fluid in the earth formation versus depth using the chemical composition of each formation gas sample in the plurality of formation gas samples to provide the log.

Abstract: A method for processing nuclear magnetic resonance (NMR) measurement data includes receiving, with a processor, NMR measurement data obtained from an NMR tool, the NMR measurement data having an echo train affected by a motion artifact, wherein the motion artifact is related to a magnetic field magnitude that varies in a volume of interest due to a motion of the NMR tool. The method further includes reducing, with the processor, an effect on the NMR measurement data of the motion artifact by using a correcting inversion method that models the motion artifact to provide a corrected transverse relaxation time constant (T2) distribution, the correcting inversion method having a multiplicative term having a term that includes at least one local maximum and an optional decay term.

Abstract: A method for estimating a property of a subsurface material includes conveying a carrier through a borehole penetrating the subsurface material and performing an NMR measurement in a volume of interest in the subsurface material using an NMR tool having an antenna disposed at the carrier. The method further includes receiving with the antenna a short build-up signal due to a short magnetization build-up time of the NMR measurement, an echo-train signal with short polarization time due to the NMR measurement, and an echo-train signal with long polarization time due to the NMR measurement. The method further includes inverting, simultaneously, the short build-up signal, the short-polarization-time echo-train signal, and the long-polarization-time echo-train signal using a processor to estimate the property; and transmitting a signal comprising the property to a signal receiving device.

Abstract: A method for generating a log of a value of a property of a fluid in an earth formation versus depth includes: obtaining a plurality of samples of drilling fluid that are entrained with a formation gas and correlating each sample to a depth in a borehole from which the formation gas was entrained in the drilling fluid; extracting the formation gas from each sample to provide a plurality of gas samples; analyzing each formation gas sample to provide a chemical composition of each formation gas sample in the plurality of formation gas samples; and determining a property value of the fluid in the earth formation versus depth using the chemical composition of each formation gas sample in the plurality of formation gas samples to provide the log.

Abstract: A method for processing nuclear magnetic resonance (NMR) measurement data includes receiving, with a processor, NMR measurement data obtained from an NMR tool, the NMR measurement data having an echo train affected by a motion artifact, wherein the motion artifact is related to a magnetic field magnitude that varies in a volume of interest due to a motion of the NMR tool. The method further includes reducing, with the processor, an effect on the NMR measurement data of the motion artifact by using a correcting inversion method that models the motion artifact to provide a corrected transverse relaxation time constant (T2) distribution, the correcting inversion method having a multiplicative term having a term that includes at least one local maximum and an optional decay term.

Abstract: A method for processing nuclear magnetic resonance (NMR) measurement data includes: receiving, with a processor, NMR measurement data obtained from an NMR tool, the NMR measurement data being affected by a motion artifact and having a first echo train obtained with a long polarization time TWET and a second echo train obtained with a short polarization time TWTL that is shorter than TWET; and at least one of (i) reducing, with a processor, an effect on the NMR measurement data of the motion artifact using the first echo train and the second echo train and (ii) identifying, with a processor, the motion artifact using the first echo train and the second echo train; wherein the motion artifact is related to a magnetic field magnitude that varies in a volume of interest due to a motion of the NMR tool.

Abstract: A method for estimating a property of a subsurface material includes conveying a carrier through a borehole penetrating the subsurface material and performing an NMR measurement in a volume of interest in the subsurface material using an NMR tool having an antenna disposed at the carrier. The method further includes receiving with the antenna a short build-up signal due to a short magnetization build-up time of the NMR measurement, an echo-train signal with short polarization time due to the NMR measurement, and an echo-train signal with long polarization time due to the NMR measurement. The method further includes inverting, simultaneously, the short build-up signal, the short-polarization-time echo-train signal, and the long-polarization-time echo-train signal using a processor to estimate the property; and transmitting a signal comprising the property to a signal receiving device.

Abstract: A method for processing nuclear magnetic resonance (NMR) measurement data includes: receiving, with a processor, NMR measurement data obtained from an NMR tool, the NMR measurement data being affected by a motion artifact and having a first echo train obtained with a long polarization time TWET and a second echo train obtained with a short polarization time TWTL that is shorter than TWET; and at least one of (i) reducing, with a processor, an effect on the NMR measurement data of the motion artifact using the first echo train and the second echo train and (ii) identifying, with a processor, the motion artifact using the first echo train and the second echo train; wherein the motion artifact is related to a magnetic field magnitude that varies in a volume of interest due to a motion of the NMR tool.

Abstract: Method and apparatus for estimating a parameter of interest of an earth formation using a model based on NMR data, imaging data, and NMR tool response characteristics. The method may include constructing a model of the earth formation. The method may also include constructing a predictive model for estimating the parameter of interest. The apparatus may include an NMR tool and at least one processor configured to estimate the parameter of interest. The apparatus may also include an imaging tool configured to acquire the imaging data.

Abstract: Method and apparatus for estimating a parameter of interest of an earth formation using a model based on NMR data, imaging data, and NMR tool response characteristics. The method may include constructing a model of the earth formation. The method may also include constructing a predictive model for estimating the parameter of interest. The apparatus may include an NMR tool and at least one processor configured to estimate the parameter of interest. The apparatus may also include an imaging tool configured to acquire the imaging data.