Abstract: Methods for analyzing a reservoir in a formation containing hydrocarbon fluid are described. Information characterizing the formation is collected and applied to a formation simulator that is provided with a modified Darcy's law equation that accounts for at least one of gas adsorption/desorption, various modes of diffusive transport, and non-Darcy flow behavior, and the simulator is used to generate indications of the state of the reservoir and/or the state of production of hydrocarbon fluid from the reservoir. The modified Darcy's law equations are particularly useful in analyzing any type of formation containing any type of hydrocarbon fluid including shale formations containing hydrocarbon gases. According to one embodiment, a dual-porosity shape factor useful in a formation simulator is also provided.

Abstract: Downhole fluid volumes of a geological formation may be estimated using nuclear magnetic resonance (NMR) measurements, even in organic shale reservoirs. Multi-dimensional NMR measurements, such as two-dimensional NMR measurements and/or, in some cases, one or more well-logging measurements relating to total organic carbon may be used to estimate downhole fluid volumes of hydrocarbons such as bitumen, light hydrocarbon, kerogen, and/or water. Having identified the fluid volumes in this manner or any other suitable manner from the NMR measurements, a reservoir producibility index (RPI) may be generated. The downhole fluid volumes and/or the RPI may be output on a well log to enable an operator to make operational and strategic decisions for well production.

Abstract: Systems and methods for generating a multi-dimensional distribution function. First data and second data may be received in response to one or more radiofrequency pulses that are transmitted into a subterranean formation. The first data may include Carr-Purcell-Meiboom-Gill data, and the second data may include diffusion editing data with initial echo spacings longer than subsequent echo spacings. The second data may be inverted. A multi-dimensional distribution function may be determined using the inverted second data.

Abstract: Nuclear magnetic resonance (NMR) methods and apparatus are provided for investigating a sample utilizing NMR pulse sequences. In various embodiments, the NMR pulse sequences have a solid state portion and a line-narrowing portion. In other embodiments, the NMR pulse sequences have a first line-narrowing portion and a second line-narrowing portion where the sequences of the different portions are different. In yet other embodiments, the NMR pulse sequences have a T1 portion and a line-narrowing portion. Processing of detected signals permits determination of characteristics of the sample including, in some cases, a differentiation of multiple components of the sample.

Abstract: Nuclear magnetic resonance (NMR) methods and apparatus are provided for investigating a sample utilizing NMR pulse sequences having solid state and CPMG pulse sequence portions. Various embodiments of solid state pulse sequences may be utilized including two-dimensional (repetitive) line-narrowing sequences. The hydrogen content of a solid portion of the sample may be determined by using one or more echoes resulting from the solid state sequence portion of the pulse sequence to establish a total organic hydrogen content of the sample, and by using a CPMG echo train to establish a fluid organic hydrogen content, and by subtracting one from the other to obtain the hydrogen content of the sample's solid portion. Additionally, or alternatively, the T2 values obtained from the line-narrowing and CPMG pulse sequences can be compared by plotting to obtain information regarding a characteristic of the sample. The NMR pulse sequence may also include a T1 portion.

Abstract: Levels of kerogen and bitumen are computed in a sample of rock from DRIFTS measurements on the sample. The DRIFTS spectrum of a rock sample is measured, resulting in an estimate of bitumen and kerogen. Bitumen is then washed from the rock and DRIFTS is re-measured, resulting in an estimate of kerogen. Bitumen quantity is calculated by subtracting the washed sampled results from first DRIFTS measurements.

Abstract: Methods for analyzing a formation samples using nuclear magnetic resonance (NMR) are described herein. One method includes performing an NMR measurement of the formation sample to obtain NMR data. The NMR measurement detects NMR signals with echo times of less than or equal to 100 microseconds. The NMR data is analyzed to determine a measure of organic hydrogen content of the formation sample, such as (i) total organic hydrogen content, (ii) kerogen content, (iii) bitumen content, and/or (iv) oil content.

Abstract: Methods for improved interpretation of NMR data acquired from industrial samples by simultaneously detecting more than one resonant nucleus without removing the sample from the sensitive volume of the NMR magnet or radio frequency probe are disclosed. In other aspects, the present disclosure provides methods for robust imaging/analysis of spatial distribution of different fluids (e.g., 1H, 23Na, 19F) within a core or reservoir rock. NMR data may be interpreted in real-time during dynamic processes to enable rapid screening, e.g. of enhanced oil recovery techniques and products and/or to provide improved interpretation of well-logs. Measurements of resonant nuclei other than 1H may be performed in the laboratory or downhole with a NMR logging tool. In other aspects, the present disclosure describes a novel kernel function to extract values for underlying parameters that define relaxation time behavior of a quadrupolar nucleus.

Abstract: Techniques for calculating metrics for reservoir quality based on light oil and total organic carbon in tight oil reservoirs are described. The techniques include calculating quantities of light oil and total organic carbon from logging data and generating therefrom a continuous log for reservoir quality metric. Additionally new reservoir quality indices are presented that more accurately predict reservoir quality in tight oil plays.

Abstract: Downhole fluid volumes of a geological formation may be estimated using nuclear magnetic resonance (NMR) measurements, even in organic shale reservoirs. Multi-dimensional NMR measurements, such as two-dimensional NMR measurements and/or, in some cases, one or more well-logging measurements relating to total organic carbon may be used to estimate downhole fluid volumes of hydrocarbons such as bitumen, light hydrocarbon, kerogen, and/or water. Having identified the fluid volumes in this manner or any other suitable manner from the NMR measurements, a reservoir producibility index (RPI) may be generated. The downhole fluid volumes and/or the RPI may be output on a well log to enable an operator to make operational and strategic decisions for well production.

Abstract: Methods for analyzing a reservoir in a formation containing hydrocarbon fluid are described. Information characterizing the formation is collected and applied to a formation simulator that is provided with a modified Darcy's law equation that ac counts for at least one of gas adsorption/desorption, various modes of diffusive transport, and non-Darcy flow behavior, and the simulator is used to generate indications of the state of the reservoir and/or the state of production of hydrocarbon fluid from the reservoir. The modified Darcy's law equations are particularly useful in analyzing any type of formation containing any type of hydrocarbon fluid including shale formations containing hydrocarbon gases. According to one embodiment, a dual-porosity shape factor useful in a formation simulator is also provided.

Abstract: An NMR method and apparatus for analyzing a sample of interest applies a static magnetic field together with RF pulses of oscillating magnetic field across a sample volume that encompasses the sample of interest. The RF pulses are defined by a pulse sequence that includes a plurality of measurement segments configured to characterize a plurality of relaxation parameters related to relaxation of nuclear magnetization of the sample of interest. Signals induced by the RF pulses are detected in order to derive the relaxation parameters. The measurement segments of the pulse sequence include at least one first-type measurement segment configured to characterize relaxation of spin-lattice interaction between nuclei of the sample of interest in a rotating frame (T1?) at a predefined frequency. The T1? parameter can be measured in conjunction with the measurement of other relaxation and/or diffusion parameters as part of multidimensional NMR experiments.

Abstract: Apparatus and methods for characterizing hydrocarbons in a subterranean formation include obtaining a sample of the subterranean formation; measuring, uphole, the porosity of the sample; using a nuclear magnetic resonance (NMR) tool downhole in the borehole, sending NMR pulse sequences configured for formation pore size and measuring NMR signals that characterize the formation at a location in the formation; analyzing the signals to find a gas porosity of the formation at the location; and determining a hydrogen index (HIg) of the subterranean formation from the gas porosity and from the porosity of the sample. The obtained HIg may then be used in conjunction with downhole NMR measurements to find corrected gas porosities at locations of the formation.

Abstract: A method for testing an unconventional core sample is provided. The method involves loading the unconventional core sample into a sample holder and introducing fluid into the sample holder at an elevated pressure such that fluid is injected into the internal pore space of the unconventional core sample in order to resaturate the unconventional core sample with the fluid, wherein the fluid is selected from the group including a hydrocarbon fluid and a water-based formation fluid. An apparatus and a system used in combination with the method are also provided.

Abstract: Methods for the determination of the Total Gas in Place (TGiP) in gas-bearing formations are provided. Aspects of the subject disclosure also relate to the determination of the TGiP from nuclear magnetic resonance (NMR) logs alone or in combination other well logs.

Abstract: Levels of kerogen and bitumen are computed in a sample of rock from DRIFTS measurements on the sample. the DRIFTS spectrum of a rock sample is measured, resulting in an estimate of bitumen and kerogen. Bitumen is then washed from the rock and DRIFTS is re-measured, resulting in an estimate of kerogen. Bitumen quantity is calculated by subtracting the washed sampled results from first DRIFTS measurements.

Abstract: Systems and methods for generating a multi-dimensional distribution function. First data and second data may be received in response to one or more radiofrequency pulses that are transmitted into a subterranean formation. The first data may include Carr-Purcell-Meiboom-Gill data, and the second data may include diffusion editing data with initial echo spacings longer than subsequent echo spacings. The second data may be inverted. A multi-dimensional distribution function may be determined using the inverted second data.

Abstract: Systems and methods for magic angle spinning nuclear magnetic resonance analysis of samples from unconventional reservoirs are described. Fast and inexpensive methods are described that can provide reliable information on TOC content, type, and maturity (via the relative abundances of different hydrocarbons, for example) without the need for more extensive sample preparation or destruction. If care is taken during sample recovery and storage, NMR can also yield an estimate of gas-in-place, including detailed typing (e.g. methane vs. ethane). The described MAS NMR analysis is used to determine various properties of unconventional reservoirs, including gas and oil shales, which are useful in evaluating their worth and producibility.

Abstract: Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the sending comprises pulse sequences configured for a formation pore size, and wherein the computing comprises porosity. Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the formation comprises a distribution of pore sizes of about 10 nm or more, and wherein the computing comprises natural gas composition.

Abstract: A computer-implemented method for reservoir volumetric estimation, a non-transitory computer-readable medium, and a computing system. The method may include running a molecular dynamics simulation of a fluid-rock model of a first reservoir system at a plurality of pressures. The fluid-rock model includes a fluid that is at least partially adsorbed in the first reservoir system at one or more pressures of the plurality of pressures. The method may also include calculating a plurality of isothermal density profiles of the fluid in the first reservoir system, in association with the plurality of pressures using a result of the molecular dynamics simulation. The method may further include determining a first gas accumulation of the fluid in the first reservoir system for the plurality of isothermal density profiles. The first gas accumulation is at least partially a function of a pore surface area of a sample of the first reservoir system.