Abstract: A method and system for interspersing different wait times in trainlet and partial recovery sequences is provided. The method includes introducing a nuclear magnetic resonance (NMR) tool into a wellbore penetrating a subterranean formation. The method also includes applying an NMR pulse sequence to the subterranean formation using the NMR tool, in which the NMR pulse sequence includes at least two different wait times interspersed between successive sequences of radio frequency (RF) pulses. The method also includes measuring one or more echo signals corresponding to a substance in the subterranean formation based on the applied NMR pulse sequence. The method also includes determining a distribution of a characteristic of the substance based on the measured one or more echo signals.

Abstract: A method and system for interspersing different wait times in trainlet and partial recovery sequences is provided. The method includes introducing a nuclear magnetic resonance (NMR) tool into a wellbore penetrating a subterranean formation. The method also includes applying an NMR pulse sequence to the subterranean formation using the NMR tool, in which the NMR pulse sequence includes at least two different wait times interspersed between successive sequences of radio frequency (RF) pulses. The method also includes measuring one or more echo signals corresponding to a substance in the subterranean formation based on the applied NMR pulse sequence. The method also includes determining a distribution of a characteristic of the substance based on the measured one or more echo signals.

Abstract: Various embodiments include a method for determining a viscosity for heavy oil in a formation by obtaining viscosity data and nuclear magnetic resonance (NMR) relaxation time distribution data for a plurality of oil samples. A correlation is determined between a set of viscosity data for the plurality of oil samples and an NMR relaxation time geometric mean for the plurality of oil samples. An NMR relaxation time geometric mean intrinsic value is determined based on the correlation, apparent hydrogen index, and TE. Electromagnetic energy may then be transmitted into a formation and NMR relaxation time distributions determined for oil in the formation based on secondary electromagnetic field responses associated with the electromagnetic energy. A viscosity of the oil in the formation may then be determined based a correlation between the set of viscosity data and the NMR relaxation time geometric mean intrinsic value of the distribution data.

Abstract: A technique facilitates estimation of the viscosity of heavy oil. The method comprises evaluating a sample of oil by using an infrared spectrum sensor to obtain a reference temperature based on infrared absorbance. The reference temperature can then be used to determine viscosity data on the sample at a given temperature or temperatures.

Abstract: NMR logging in a wellbore is used to monitor an oil reservoir during oil recovery by miscible displacement. Diffusivity distributions found by NMR logging indicate whether one or two phases are present and composition of residual oil. Operation of the oil recovery procedure may be maintained or modified in response to monitoring of the reservoir.

Abstract: The viscosity ? (in centipoise) of a heavy oil sample is determined according to an equation of the form ln ? ? g = - C ? ? 1 * ( T - c ? ? 246 ) c ? ? 47.10 + ( T - c ? ? 246 ) , where T is the temperature of the heavy oil, T2LM is the logarithmic mean of the T2 distribution of the sample obtainable from nuclear magnetic resonance (NMR) measurements, c?=1.0±0.05, c?=1.0±0.04, ?g is the glass transition temperature viscosity of the heavy oil and a function of T2LM, and C1 is a variable which is a constant for the heavy oil and is a function of T2LM. Both C1 and ?g are considered functions of certain NMR values associated with the heavy oil sample, with ?g and C1 preferably estimated by empirically fitting data to the equations ln T2LM=a?+b? ln ?g and ln T2LM=a?+b?C1, where a?, b?, a? and b? are constants.

Abstract: NMR logging in a wellbore is used to monitor an oil reservoir during oil recovery by miscible displacement. Diffusivity distributions found by NMR logging indicate whether one or two phases are present and composition of residual oil. Operation of the oil recovery procedure may be maintained or modified in response to monitoring of the reservoir.

Abstract: Viscosity of heavy oil is determined in situ in a formation by making nuclear magnetic resonance (NMR) measurements in the formation, and then calculating viscosity according to an equation of the form T 2 ? LM = a + b ? ( ? T ) c , where T is the temperature of the heavy oil sample, ? is the viscosity, T2LM is the logarithmic mean of the T2 distribution spectrum of the sample, and a, b, and c are non-zero constants. Typically, constant b has a value between 5 and 7 and constant c has a value between ?0.7 and ?0.5.

Abstract: A method for determining a wax appearance temperature of a fluid includes obtaining nuclear magnetic resonance (NMR) measurements of the fluid at a plurality of temperatures; deriving a NMR parameter from each of the NMR measurements; and determining the wax appearance temperature by analyzing the NMR parameter as a function of temperature. An apparatus for detecting wax appearance in a fluid includes a sample cell for holding a fluid for nuclear magnetic resonance (NMR) measurements at a plurality of temperatures; a temperature measuring device disposed proximate the sample cell; a magnet for polarizing molecules in the fluid in the sample cell; at least one radiofrequency (RF) coil for generating pulses of magnetic field and for detecting NMR signals; and circuitry for controlling and measuring the temperature of the fluid in the sample cell and for obtaining NMR measurements.

Abstract: The viscosity of a heavy oil is estimated according to a power law equation which relates the heavy oil viscosity to a function of the assumed, measured, or estimated glass transition temperature of the heavy oil and the measured temperature of the heavy oil.

Abstract: The viscosity ? (in centipoise) of a heavy oil sample is determined according to an equation of the form ln ? ? g = - C ? ? 1 * ( T - c ? ? 246 ) c ? ? 47.10 + ( T - c ? ? 246 ) , where T is the temperature of the heavy oil, T2LM is the logarithmic mean of the T2 distribution of the sample obtainable from nuclear magnetic resonance (NMR) measurements, c?=1.0±0.05, c?=1.0±0.04, ?g is the glass transition temperature viscosity of the heavy oil and a function of T2LM, and C1 is a variable which is a constant for the heavy oil and is a function of T2LM. Both C1 and ?g are considered functions of certain NMR values associated with the heavy oil sample, with ?g and C1 preferably estimated by empirically fitting data to the equations lnT2LM=a?+b?ln?g and lnT2LM=a?+b?C1, where a?, b?, a? and b? are constants.

Abstract: Viscosity of heavy oil is determined in situ in a formation by making nuclear magnetic resonance (NMR) measurements in the formation, and then calculating viscosity according to an equation of the form T 2 ? LM = a + b ? ( ? T ) c , where T is the temperature of the heavy oil sample, ? is the viscosity, T2LM is the logarithmic mean of the T2 distribution spectrum of the sample, and a, b, and c are non-zero constants. Typically, constant b has a value between 5 and 7 and constant c has a value between ?0.7 and ?0.5.

Abstract: A method for determining a wax appearance temperature of a fluid includes obtaining nuclear magnetic resonance (NMR) measurements of the fluid at a plurality of temperatures; deriving a NMR parameter from each of the NMR measurements; and determining the wax appearance temperature by analyzing the NMR parameter as a function of temperature. An apparatus for detecting wax appearance in a fluid includes a sample cell for holding a fluid for nuclear magnetic resonance (NMR) measurements at a plurality of temperatures; a temperature measuring device disposed proximate the sample cell; a magnet for polarizing molecules in the fluid in the sample cell; at least one radiofrequency (RF) coil for generating pulses of magnetic field and for detecting NMR signals; and circuitry for controlling and measuring the temperature of the fluid in the sample cell and for obtaining NMR measurements.

Abstract: A method for estimating a concentration of a substance in a test sample of formation fluid, comprising measuring an NMR parameter of a first sample of formation fluid to obtain a first measurement, adding a known quantity of the substance to the first sample to produce a modified sample, measuring the NMR parameter of the modified sample to obtain a second measurement; and determining a relation between the concentration of the substance and a function of the NMR parameter using the first and second measurements and the NMR parameter of the substance.