Dynamic elastic properties of the Wufeng–Longmaxi formation shale in the southeast margin of the Sichuan Basin

Deng, Jixin; Shen, Hong; Xu, Zehao; Ma, Zhiming; Zhao, Qun; Li, Chengcheng

doi:10.1088/1742-2132/11/3/035004

Cited by 20 publications

(12 citation statements)

References 15 publications

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“…While all the velocities increase with increasing confining pressure, their dependence on the water saturation is rather complex. The increasing velocity with confining pressure is consistent with the experimental results on a range of porous reservoir rocks (e.g., Deng et al, 2014;Li et al, 2017;Szewczyk et al, 2018) and is attributed to the closure of low aspect ratio compliant pores or microcracks that leads to a stiffer rock frame (e.g., Shapiro, 2003;Zimmerman, 1991).…”

Section: Anisotropic Velocities Of the Intact Samplesupporting

confidence: 85%

“…With increasing confining pressure, the compressional wave anisotropy ε decreases in both the intact and fractured samples, and the rate of decrease appears to be gentler as the confining pressure becomes higher. This is consistent with the experimental observations of Song et al () on anisotropic tight sandstone and Deng et al () one on the most important shale plays in China. The reducing ε with increasing confining pressure is also related to the closure of compliant pores and part of the fractures that makes the rock less anisotropic.…”

Section: Resultsmentioning

confidence: 99%

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Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Han

Gurevich

et al. 2020

JGR Solid Earth

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Fractures are commonly existing in the subsurface rocks, and understanding the seismic anisotropy in fractured rocks is of great importance in a range of geophysical applications. However, although all the fractured rocks are suffering from geological stresses and most of them are experiencing partial water saturation, the combined effects of confining pressure and water saturation on the seismic anisotropy in fractured rocks remain poorly understood. To obtain such knowledge, we measured and compared the anisotropic velocities and corresponding seismic anisotropy in two artificial porous sandstone samples with and without aligned fractures, respectively, as functions of varying confining pressure and degree of water saturation. We showed that the existence of aligned fractures significantly reduced the five measured velocities but dramatically enhanced the seismic anisotropy in the fractured sample. We also showed that confining pressure and water saturation had an interdependent complex effect on the seismic anisotropy of the fractured sample. The seismic anisotropy of the dry sample showed the highest-pressure sensitivity, and the saturation effect was most significant at low confining pressure. Integrated interpretation of the experimental data indicated that wave-induced fluid flow due to pore-scale and mesoscale fluid distribution in the rocks is responsible for most of the observed pressure and saturation-dependent anisotropic behaviors in the rocks. The results have helped to gain new knowledge on the seismic anisotropy in partially saturated fractured rocks subject to varying pressures and suggest the requirement for advanced theoretical models to fully understand the acquired data.

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Section: Anisotropic Velocities Of the Intact Samplesupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Han

Gurevich

et al. 2020

JGR Solid Earth

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“…Recently, the research of semiconductor catalysts as efficient photocatalytic activity have become hot spot topics . However, most of the photocatalysts have two key technology problems: (1) The catalysts have low rate of utilization of solar energy which only 5% of the UV light to the sun light can be used; (2) The catalysts always suffer from the fast recombination of photo‐induced electron‐hole pairs, which severely limit its photocatalytic performance .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of BN/g‐C₃N₄ as Visible‐light‐driven Photocatalysts for Degradation of Different Organic Pollutants

Liao

Deng

2018

ChemistrySelect

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In this work, BN/g‐C3N4 composites were prepared by hydrothermal reaction. The BN/g‐C3N4 composites were successfully characterized by FTIR spectra, XRD, SEM, HRTEM, UV/Vis DRS, N2 adsorption–desorption isotherms and BET. The photocatalytic activities of the as‐prepared catalysts were evaluated by the degradation of different organic pollutants, such as Acid Red (AR), Rhodamine B (RhB), Congo Red (CR), Methyl Orange (MO), Methyl Red (MR), and Phenol. The best result showed that the 40 wt% BN was added to g‐C3N4 (BN/g‐C3N4‐4) achieved up to 99% decomposition of AR within 90 min under visible‐light irradiation. The kinetics of BN/g‐C3N4 ‐4 for degradation of AR was almost six times than that of pure g‐C3N4. Finally, the degradation processes of different pollutants and the photocatalytic mechanism had been explained concretely.

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“…Utilizing several advanced approaches (field emission scanning electron microscopy (FE-SEM) (JSM-6700F, JEOL USA, Inc., CA, USA), gas adsorption, and helium pycnometry), the complexity of pores structures and the properties of nanoscale pores in Longmaxi shale are identified clearly [38,39]. Also, the relationship between mineral components and dynamic elastic properties of shale rock has been measured using an ultrasonic transmission technique [40]. These research works have enhanced the understanding of Longmaxi shale and improved shale-gas exploitation remarkably in China.…”

Section: Introductionmentioning

confidence: 99%

“…Only a few researchers have investigated the velocity of P-and S-waves using a traditional uniaxial/triaxial compression experiment [40,41]. According to previous research, the clay content, fracture azimuth and volume density of cracks are the key factors affecting the velocity value.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity Analysis of Seismic Velocity and Attenuation Variations for Longmaxi Shale during Hydraulic Fracturing Testing in Laboratory

et al. 2017

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During the hydraulic fracturing procedure in shale-gas exploitation, the poroelastic properties of shale formation can be altered significantly. However, it is difficult to evaluate these variations using microseismic field data. In this study, we conduct a hydro-fracturing experiment using Longmaxi shale, which is a major formation for shale-gas production in China, to simulate the water injection and rock fracturing procedure. The variation of the velocity and attenuation for primary/secondary (P/S) ultrasonic waves was investigated throughout the entire experimental procedure. The results show that the attenuation is more sensitive to sample rupture than the velocity. However, P-wave attenuation loses sensitivity to the water injection after the fractures are saturated with water. In that case, it is preferable to use S-wave attenuation to identify the opening/closing of the fractures. Based on the experimental results, we can conclude that the variation of the attenuation must be considered during microseismic data processing and interpretation.

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Dynamic elastic properties of the Wufeng–Longmaxi formation shale in the southeast margin of the Sichuan Basin

Cited by 20 publications

References 15 publications

Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Synthesis of BN/g‐C₃N₄ as Visible‐light‐driven Photocatalysts for Degradation of Different Organic Pollutants

Sensitivity Analysis of Seismic Velocity and Attenuation Variations for Longmaxi Shale during Hydraulic Fracturing Testing in Laboratory

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Dynamic elastic properties of the Wufeng–Longmaxi formation shale in the southeast margin of the Sichuan Basin

Cited by 20 publications

References 15 publications

Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Combined Effects of Pressure and Water Saturation on the Seismic Anisotropy in Artificial Porous Sandstone With Aligned Fractures

Synthesis of BN/g‐C3N4 as Visible‐light‐driven Photocatalysts for Degradation of Different Organic Pollutants

Sensitivity Analysis of Seismic Velocity and Attenuation Variations for Longmaxi Shale during Hydraulic Fracturing Testing in Laboratory

Contact Info

Product

Resources

About

Synthesis of BN/g‐C₃N₄ as Visible‐light‐driven Photocatalysts for Degradation of Different Organic Pollutants