Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)

Yao, Yanbin; Liu, Dameng; Yao, Che; Tang, Dazhen; Tang, Shuheng; Huang, Wenhui

doi:10.1016/j.fuel.2009.11.005

Cited by 755 publications

(479 citation statements)

References 22 publications

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“…The TC model has been modified by many scholars to adapt to various conventional reservoirs under different geologic backgrounds [30,31]. Yao has also modified this model and applied it to the permeability calculation of coal samples [11].…”

Section: Nmr Permeabilitymentioning

confidence: 99%

“…Based on the NMR porosity of movable water, Yao et al [11] proposed a PP model to calculate the permeability of coal reservoir.…”

Section: Nmr Permeabilitymentioning

confidence: 99%

“…NMR usually uses the transverse relaxation time (T 2 ) to analyze the pore size distribution (PSD). The pores corresponding to the T 2 peaks are divided into adsorption pores, seepage pores, and fissures by Yao et al [11] and Cai et al [12]. They think that the patterns of unimodal, bimodal, and multi-peak in the T 2 spectra represent different pore types and PSD, and the pore characteristics of NMR were compared with those of MIP and CT scanning [13,14].…”

Section: Introductionmentioning

confidence: 99%

“…In general, it is necessary to determine the value of T 2C by a centrifugal experiment and then calculate the fluid porosity, which requires drilling cores and a series of laboratory work. Some scholars have established many models of permeability and porosity, and the scope of application of these models is very limited, so it is very important to establish a widely and easily calculated equation [11,15,16].…”

Section: Introductionmentioning

confidence: 99%

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Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Song

Zhao

et al. 2018

Applied Sciences

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Abstract:On the basis of the complexity of the pore structure characteristics of a coal reservoir, coal samples with different ranks were selected to study the difference in pore structures and permeability using nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and permeability measurement. Porosity and pore size distribution (PSD) above 20 nm can be analyzed by the improved NMR equation, and the results were basically consistent with that of SEM and MIP. The NMR spectra of the coal samples from the same location were close, but the difference between the coal samples from different locations was quite large, which indicated that the heterogeneity of a coal reservoir was strong. An empirical equation of movable fluid porosity was proposed, which can be used to evaluate the fluid migration characteristics of the coal reservoir, and the porosity of movable fluid mainly came from the contribution of fissures and micro-fissures. The average movable fluid porosity of the coal samples from the Chengzhuang (CZ) coal mine, Wuyang (WY) coal mine, and Yujialiang (YJL) coal mine was 1.37%, 0.67%, and 4.26%, respectively. Although the permeability is related to the NMR porosity and movable fluid porosity, it was difficult to establish a widely used mathematical equation correlating permeability and porosity based on the experimental data.

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Section: Nmr Permeabilitymentioning

confidence: 99%

“…Based on the NMR porosity of movable water, Yao et al [11] proposed a PP model to calculate the permeability of coal reservoir.…”

Section: Nmr Permeabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Song

Zhao

et al. 2018

Applied Sciences

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“…These include low-pressure gas (N 2 /CO 2 ) adsorption/desorption techniques [9][10][11][12], high-pressure mercury intrusion porosimetery (MIP) [12][13][14], ultra/small-angle neutron scattering (SANS) [15,16], focused ion beam scanning electron microscopy [17], field emission scanning electron microscopy/transmission electron microscopy [18], nuclear magnetic resonance [19,20], and X-ray computed tomography [17,19,20]. There are several types of pore classification systems employed for various pore scales in CBM research, including Hodot classification, the classification of International Union of Pure and Applied Chemistry (IUPAC), and Gan classification [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Changes in Pore Structure of Coal Caused by CS₂ Treatment and Its Methane Adsorption Response

et al. 2018

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The pore structure and gas adsorption are two key issues that affect the coal bed methane recovery process significantly. To change pore structure and gas adsorption, 5 coals with different ranks were treated by CS 2 for 3 h using a Soxhlet extractor under ultrasonic oscillation conditions; the evolutions of pore structure and methane adsorption were examined using a highpressure mercury intrusion porosimeter (MIP) with an AutoPore IV 9310 series mercury instrument. The results show that the cumulative pore volume and specific surface area (SSA) were increased after CS 2 treatment, and the incremental micropore volume and SSA were increased and decreased before and after R o,max = 1 3%, respectively; the incremental big pore (greater than 10 nm in diameter) volumes were increased and SSA was decreased for all coals, and pore connectivity was improved. Methane adsorption capacity on coal before and after R o,max = 1 3% also was increased and decreased, respectively. There is a positive correlation between the changes in the micropore SSA and the Langmuir volume. It confirms that the changes in pore structure and methane adsorption capacity due to CS 2 treatment are controlled by the rank, and the change in methane adsorption is impacted by the change of micropore SSA and suggests that the changes in pore structure are better for gas migration; the alteration in methane adsorption capacity is worse and better for methane recovery before and after R o,max = 1 3%. A conceptual mechanism of pore structure is proposed to explain methane adsorption capacity on CS 2 treated coal around the R o,max = 1 3%.

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Experimental Understanding of Pore Structure and Wettability of the Unconventional Reservoir

Kibria¹,

Hu²

2022

Handbook of Petroleum Geoscience

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Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)

Cited by 755 publications

References 22 publications

Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Changes in Pore Structure of Coal Caused by CS₂ Treatment and Its Methane Adsorption Response

Experimental Understanding of Pore Structure and Wettability of the Unconventional Reservoir

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Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)

Cited by 755 publications

References 22 publications

Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Experimental Analysis of Pore and Permeability Characteristics of Coal by Low-Field NMR

Changes in Pore Structure of Coal Caused by CS2 Treatment and Its Methane Adsorption Response

Experimental Understanding of Pore Structure and Wettability of the Unconventional Reservoir

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Product

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Changes in Pore Structure of Coal Caused by CS₂ Treatment and Its Methane Adsorption Response