Investigation of pore structure and fractal characteristics of marine-continental transitional shales from Longtan Formation using MICP, gas adsorption, and NMR (Guizhou, China)

Ma, Xiao; Guo, Shaohui; Shi, Dishi; Zhou, Zhi; Liu, Guoheng

doi:10.1016/j.marpetgeo.2019.05.018

Cited by 51 publications

(49 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The average pore diameter was calculated by equation: (4 V p / A s ) × 2, where V p = total PV of shale, and A s = total SSA 67 . Incremental PV distribution curves were used to investigate the characteristics of PSD, and each peak in the PSD curve represents the development of a specific pore size 56 …”

Section: Resultsmentioning

confidence: 99%

“…The R o test was carried out by a Leitz MPV‐SP photometer microscope, following China National Standards (GB/T6948‐1998), with temperature of 22°C and humidity of 30% 56 . The TOC test was performed by using a Leco CS‐200 carbon‐sulfur analyzer, according to China National Standards (GB/T19145‐2003) with temperature of 27°C 56 . Samples should be put in 5% HCL for 2 hours to take off carbonates and impurities before use.…”

Section: Samples and Methodsmentioning

confidence: 99%

“…Samples should be put in 5% HCL for 2 hours to take off carbonates and impurities before use. The kerogen type was determined by a FM‐252 gas isotope mass spectrometer, following Oil and Gas Industry Standards (SY/T5238‐2008) 56 . Samples were leached in 5% HCL and HF for 12 hours in turn to remove carbonates and silicates.…”

Section: Samples and Methodsmentioning

confidence: 99%

“…According to Oil and Gas Industry Standards (SY/T5463‐2010), the XRD mineral content was obtained by using a D8 Discover X‐ray diffractometer (Bruker) 56 . Firstly, the shale samples were crushed to <300 meshes and mixed with ethanol,then, they were grinded in a mortar and smear‐mounted on glass slides for XRD analysis.…”

Section: Samples and Methodsmentioning

confidence: 99%

“…Fractal dimension ( D ) can be calculated using the Frenkel‐Halsey‐Hill (FHH) model and equation: ln( V ) = C + ( D − 3) × ln(ln( P 0 / P )) 19 if shale pore structure has fractal characteristic 56 . In this equation, P (MPa) is equilibrium pressure, P 0 (MPa) is the gas saturation pressure, V (cm 3 /g) is adsorbed N 2 volume at P , and C is a constant.…”

Section: Samples and Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Study on pore evolution and diagenesis division of a Permian Longtan transitional shale in Southwest Guizhou, China

Guo

2020

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

Organic‐rich shales, deposited in marine‐continental transitional environments, are widely distributed in southern China. The pore evolution of the Late Permian Longtan Formation shale (Guizhou Province) during its diagenesis and organic matter (OM) evolution was quantitatively and qualitatively investigated through thermal simulation, mercury intrusion capillary pressure, gas adsorption, fractal dimension, and field emission‐scanning electron microscopy observation. Diagenesis and OM evolution stage were subdivided on the basis of X‐ray diffraction, rock pyrolysis, and vitrinite reflectance test; moreover, the main controlling factors of pore structure during evolution were also discussed. Shales were heated to different temperatures with their vitrinite reflectance ranged between 1.23% and 3.12%, indicating that organic matter had evolved from a low‐ to a post‐mature stage. According to the changes in clay mineral composition, hydrocarbon generation, and Tmax, we subdivided diagenesis into four parts, each of which has a good correspondence with OM evolution. Pore volume (PV) varied between 0.012162 and 0.033482 cm3/g, while the specific surface area (SSA) varied between 13.3693 and 23.0094 m2/g. Mesopores were the main contributors to the total pore volume, while mesopores and micropores were the main contributors to the total specific surface area. In this study, the evolution of pore structure was not monotonous, but intermittent: The PV and SSA of shale samples first decreased and then increased. Maturity was the most important factor affecting the evolution of pore structure. The abundance of pores in OM, associated with hydrocarbon generation, resulted in large micro‐PV and micro‐SSA; moreover, the composition of clay minerals also influenced the pore structure evolution. The transformation of kaolinite into illite increased the content of illite and illite/smectite mixed layer, hence affecting the overall meso‐PV and meso‐SSA.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Samples and Methodsmentioning

confidence: 99%

Section: Samples and Methodsmentioning

confidence: 99%

Section: Samples and Methodsmentioning

confidence: 99%

Section: Samples and Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Study on pore evolution and diagenesis division of a Permian Longtan transitional shale in Southwest Guizhou, China

Guo

2020

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

A 3D FIB‐SEM technique for quantitative characterization of oil shale's microstructure: A case study from the Shahejie Formation in Dongying Depression, China

Zhao

Dong

Zhang

et al. 2020

Energy Science & Engineering

View full text Add to dashboard Cite

Investigating the pore structure of shale rocks plays an important role in understanding the mechanism of shale oil accumulation and migration; thus, it has a notable influence on the exploration and development of shale oil resources. In the present study, the microstructure of oil shale samples extracted from the Shahejie Formation in the Dongying Depression was investigated through the joint usage of focused ion beam (FIB) and scanning electron microscopy (SEM). Herein, we selected four representative samples. The SEM images of the sample surfaces milled by FIB indicated that pores were found in both the organic and inorganic matter. Organic pores were less developed in the samples because of the low thermal maturity of the organic matter. Continuous 3D digital rock images of shale samples were generated by FIB grinding and SEM in situ imaging. Based on multithreshold segmentation, the shale rocks were separated into different parts including kerogen, inorganic matter, and pores. The pore connectivity and pore size distributions were analyzed via Avizo software and in‐house developed MATLAB scripts. The pore size and corresponding volume distributions suggested that mesoscale pores (2‐50 nm) were abundant in the samples but they contributed limitedly to the total pore volume. Macropores (>50 nm) accounted for a small proportion but they had a greater contribution to the overall pore space volume. The coordination numbers of the subject four samples were mainly 0 and 1, which means that isolated pores accounted for the vast majority of the pores. These observations are critical to conduct reliable petrophysical simulations in the oil shales and understand their intrinsic properties accurately.

show abstract

Pore Structure Characterization Using Fractal Theory and 3D Digital Core

Zhao

Chen²,

Li³

2021

Springer Series in Geomechanics and Geoengineering

View full text Add to dashboard Cite

Investigation of pore structure and fractal characteristics of marine-continental transitional shales from Longtan Formation using MICP, gas adsorption, and NMR (Guizhou, China)

Cited by 51 publications

References 35 publications

Study on pore evolution and diagenesis division of a Permian Longtan transitional shale in Southwest Guizhou, China

Study on pore evolution and diagenesis division of a Permian Longtan transitional shale in Southwest Guizhou, China

A 3D FIB‐SEM technique for quantitative characterization of oil shale's microstructure: A case study from the Shahejie Formation in Dongying Depression, China

Pore Structure Characterization Using Fractal Theory and 3D Digital Core

Contact Info

Product

Resources

About