Behavior of organic matter-hosted pores within shale gas reservoirs in response to differential tectonic deformation: Potential mechanisms and innovative conceptual models

Yang, Wei; Wang, Yaohua; Du, Wei; Yan, Song; Jiang, Zhenxue; Wang, Qianyou; Xu, Liang; Zhao, Fanfan; Chen, Yi; Shi, Fulun; Yao, Shuanghong; Hou, Haodong; Xiong, Shuling

doi:10.1016/j.jngse.2022.104571

Cited by 11 publications

(16 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The adsorption–desorption isotherm curves were obtained at relative pressures ( P / P 0 ) ranging from 0.01 to 0.995. In this study, the quenched solid density functional theory (QSDFT) model was used to provide information on pore size ranging from approximately 0.9 to 30 nm …”

Section: Methodsmentioning

confidence: 99%

“…In this study, the quenched solid density functional theory (QSDFT) model was used to provide information on pore size ranging from approximately 0.9 to 30 nm. 26 …”

Section: Methodsmentioning

confidence: 99%

“…It is noted that the resolution of SEM images is about 5 nm; thus the pores less than 5 nm are not seen. The related definition and explanation of geometric parameters in PCAS have been given by Liu et al and Jiao et al , Among these parameters, the form factor can indicate the regularity of pores, a form factor of 1.0 represents a perfect circle, whereas a form factor of 0.75 represents a square in 2D images. An increase in the form factor can decrease the complexity of the pore boundary .…”

Section: Samples and Experimentsmentioning

confidence: 99%

“…In this study, the quenched solid density functional theory (QSDFT) model was used to provide information on pore size ranging from approximately 0.9 to 30 nm. 26 CO 2 adsorption was conducted at relative pressures (P/P 0 ) ranging from 0.0004 to 0.032 at 273 K using an ASAP 2000 HD88 Analyzer at the Beijing Center for Physical & Chemical Analysis. The DFT model was applied to provide the information on pore sizes ranging from 0.3 to 1.4 nm.…”

Section: Field Emission Scanning Electron Microscopy (Fe-sem)mentioning

confidence: 99%

“…The shale gas production in the Sichuan Basin was already above 230 × 10 8 m 3 by the end of 2021. Numerous studies have been conducted on the Wufeng–Longmaxi shales from the aspects of depositional conditions, , physical properties, , shale gas accumulation, − and pore structure characteristics. − In terms of OM pore structure, great attention have been given; − however, some key issues remain unresolved. ,, …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Identifying Organic Matter (OM) Types and Characterizing OM Pores in the Wufeng–Longmaxi Shales

Guoliang

Hao

2022

ACS Omega

View full text Add to dashboard Cite

Organic matter (OM) pores are considered to be an important pore type in the Ordovician Wufeng–Silurian Longmaxi Formation shales in the Sichuan Basin, China, because they have a high capacity to store natural gas. However, to the best of our knowledge, research on the characterization and quantitation of different OM pore characteristics is insufficient. In this study, detailed optical microscope and scanning electron microscope (SEM) observations and the pores/particles and cracks analysis system (PCAS) were applied to identify the OM pores and obtain quantitative information on pores such as pore size, surface porosity, form factor, and probability entropy. Moreover, CO2 and N2 adsorption experiments were performed to study the properties of pores for samples with different TOC and mineral compositions. The results show the following. (1) Pyrobitumen and kerogen can be distinguished under an optical microscope and SEM; the former can be further divided into pyrobitumen without a fixed shape and pyrobitumen with a certain shape, and the latter contains algal fragments, bacteria-like aggregates, graptolite, and micrinite. The overwhelming number of SEM-visible OM pores are mainly observed in pyrobitumen without a fixed shape, whereas pores in other OM types are complex. A PCAS analysis showed that meso-macropores are developed in pyrobitumen without a fixed shape, whereas pores in algal fragments and bacterial-like aggregates are mainly mesopores. (2) Quartz-rich brittle shale will provide more visible SEM pores compared to clay-rich ductile shale, and carbonates are unfavorable for pore development because they can block the pore as cements. Moreover, the rigid mineral framework, including that constructed by quartz recrystallization and pyrite cementation, and the pore-fluid pressure are favorable for the development of OM pores. (3) Adsorption experiments showed that pyrobitumen makes a great contribution to pore development, including micropores and meso-/macropores. Finally, we propose that the pore parameters (e.g., pore diameter, pore form factor, and deformation) of pyrobitumen without a fixed shape may characterize the enrichment condition of shale gas.

show abstract

Section: Methodsmentioning

confidence: 99%

“…In this study, the quenched solid density functional theory (QSDFT) model was used to provide information on pore size ranging from approximately 0.9 to 30 nm. 26 …”

Section: Methodsmentioning

confidence: 99%