Rock quality assessment for hydraulic fracturing: A rock physics perspective

Cho, David; Perez, Marco

doi:10.1190/segam2014-1624.1

Cited by 5 publications

(5 citation statements)

References 8 publications

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“…The theory of the Griffith energy balance indicates that a high Poisson's ratio and a low Young's modulus mean more favorable conditions for rock failure (Kartashov, 1978;Wang et al, 2015). The decrease in Young's modulus would reduce the critical tensile stress required to generate crack growth (Kartashov, 1978;Cho and Perez, 2014). Therefore, the BI of shale under hydraulic fracturing cannot be accurately reflected only by the Young's modulus and Poisson's ratio.…”

Section: Full-angle Anisotropic Bi With Failure Criteria Stress (Biac)mentioning

confidence: 99%

“…Then, T C ðθÞ is normalized as The greater the Young's modulus, the stronger the brittleness. However, a greater Young's modulus would increase the critical tensile stress, which leads to the need for greater force to create crack growth (Kartashov, 1978;Cho and Perez 2014;Yin et al, 2017). To balance this deficiency in equations 7 and 8, we have now combined it with stress failure criteria:…”

Section: Full-angle Anisotropic Bi With Failure Criteria Stress (Biac)mentioning

confidence: 99%

“…Another shortfall of current popular BI estimation is that those methods ignore the rock physics behavior of shale formations. The failure criterion of rock is one of the original concepts used to determine the stress conditions of fracture and fail for brittle rocks (Cho and Perez 2014). Wang et al (2015) propose a method using an anisotropic brittleness criterion index that takes into account parameters of anisotropy, failure criteria, and the angle between the axis of symmetry and the propagating direction (Cho and Perez, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…The failure criterion of rock is one of the original concepts used to determine the stress conditions of fracture and fail for brittle rocks (Cho and Perez 2014). Wang et al (2015) propose a method using an anisotropic brittleness criterion index that takes into account parameters of anisotropy, failure criteria, and the angle between the axis of symmetry and the propagating direction (Cho and Perez, 2014). However, this method does not consider the S-wave splitting of vertically transversely isotropic (VTI) media that result from changes in the incidence angles of seismic waves.…”

Section: Introductionmentioning

confidence: 99%

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Effect of anisotropy, angle, and critical tensile stress and confining pressures on evaluation of shale brittleness index — Part 1: Methodology and laboratory study

et al. 2019

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Brittleness is an important evaluation parameter in shale fracturing. Current methods of brittleness evaluation can be classified into two categories: elastic parameter-based and mineral content-based methods. However, both categories neglect the effect of anisotropy on the brittleness index (BI) computation of shale resources. We have redefined a new BI by integrating failure criteria stress and anisotropy parameters estimated (BIac) from seismic waves. According to the new definition, the BI at one analysis point varies with the incident angle of the seismic wave and confining pressures. We applied the BIac method to laboratory-measured shale samples acquired from the Monterey Formation, Santa Maria Basin. We found that the delta parameter [Formula: see text] is more responsive to the BIac than the gamma [Formula: see text] and epsilon [Formula: see text] anisotropic parameters, and it indicates a good linear fit relationship with the BIac at different angles. The slope of the linear is variable with the angles, thus delta can be used to predict the BIac in the Monterey Formation, Santa Maria Basin.

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Section: Full-angle Anisotropic Bi With Failure Criteria Stress (Biac)mentioning

confidence: 99%

Section: Full-angle Anisotropic Bi With Failure Criteria Stress (Biac)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of anisotropy, angle, and critical tensile stress and confining pressures on evaluation of shale brittleness index — Part 1: Methodology and laboratory study

et al. 2019

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“…Meanwhile, Heidari et al (2014) pointed out that there was no correlation between the brittleness index values and the porosity values. Sometimes, this method may lead to contradictory results in field applications (Cho and Perez, 2014).…”

Section: Introductionmentioning

confidence: 99%

A method to evaluation rock brittleness based on statistical damage constitutive parameters

Gao

Li²,

Gao³

et al. 2023

Front. Earth Sci.

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Brittleness is an important parameter to evaluate the performance of rock engineering. A scientific and reasonable brittleness evaluation method is of great significance to theoretical research and the engineering practice of rock mechanics. In view of the existing statistical constitutive models of rock based on the Weibull distribution being able to express various constitutive behaviors well, such as brittleness, plasticity, strain softening, this paper wants to determine rock brittleness from constitutive models. First, the parameter m, which can effectively reflect the overall characteristics of the rock stress-strain curve, and the parameter δ, which can reflect the post-peak characteristics, are selected. Then, a brittle evaluation method based on rock statistical damage constitutive parameters is proposed, and the brittleness index Bm (Bm = m·δ) is established. The feasibility is verified by the testing data of granite, sandstone and marble under different conditions. The results show that the brittleness of those hard rocks decrease with the increasing of confining pressure. For confining pressures of 5 MPa and 15 MPa, the brittleness of granite under triaxial unloading test is greater than that under triaxial compression test. The calculation results quantitatively reflect the brittle characteristics of sandstone, marble and granite in the test. Compared with the existing representative brittleness indexes, it is found that the brittleness index Bm can effectively reflect the characteristics of rock brittleness decreasing with increasing confining pressure and enhancement under unloading stress path. This paper provides a way to evaluate rock brittleness from the perspective of a constitutive model, which is helpful to enrich our understanding of rock brittleness.

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Optimizing Oil and Gas Reservoir Performance and Management Through Petrophysics/Rock Physics Integration – A Workflow

Habib

Yao

Xie

2020

Springer Series in Geomechanics and Geoengineering

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Rock quality assessment for hydraulic fracturing: A rock physics perspective

Cited by 5 publications

References 8 publications

Effect of anisotropy, angle, and critical tensile stress and confining pressures on evaluation of shale brittleness index — Part 1: Methodology and laboratory study

Effect of anisotropy, angle, and critical tensile stress and confining pressures on evaluation of shale brittleness index — Part 1: Methodology and laboratory study

A method to evaluation rock brittleness based on statistical damage constitutive parameters

Optimizing Oil and Gas Reservoir Performance and Management Through Petrophysics/Rock Physics Integration – A Workflow

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