Detection of open fractures with vertical seismic profiling

Beydoun, Wafik; Cheng, C. H.; Toksöz, M. Nafi

doi:10.1029/jb090ib06p04557

Cited by 53 publications

(50 citation statements)

References 8 publications

(3 reference statements)

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“…Therefore, characterizing their hydraulic properties is significant in oil/gas exploration and in seismology. In VSP experiments using a fluid-filled borehole, it is well known that low-frequency Stoneley waves (tube waves) are generated at fractures intersecting the borehole (e.g., Beydoun et al, 1985). This is caused by fluid exchange between the borehole and the fracture due to the deformation of the fracture by an incident P wave, which gives a direct measure of the hydraulic properties of the fracture.…”

Section: Introductionmentioning

confidence: 99%

“…All the theories so far consider the cylindrical coordinate system, i.e., horizontal structures. A few studies consider a modification of the horizontal structure model due to the small dip angles (Beydoun et al, 1985;Li et al, 1994). The tube-wave reflection and transmission problem in acoustic logging (e.g., Hornby et al, 1989;Tang and Cheng, 1993) propose approximate solutions for dipping structures.…”

Section: Introductionmentioning

confidence: 99%

“…This is caused by fluid exchange between the borehole and the fracture due to the deformation of the fracture by an incident P wave, which gives a direct measure of the hydraulic properties of the fracture. The tube waves have extensively been studied in the past in order to characterize fractures intersecting a borehole (e.g., Beydoun et al, 1985;Hornby et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

“…Conventionally, the models of tube-wave generation have considered the fluid flow due to the deformation of (1) a parallel-wall open fracture (Beydoun et al, 1985;Hardin et al, 1987;Ionov, 2007;Bakku et al, 2013) or (2) a permeable layer (Li et al, 1994). The former is found to be useful to estimate the permeability corresponding to µm-to-mm scale fractures (e.g., Hardin et al, 1987;Hornby et al, 1989), whereas the latter is useful for larger-scale (cm-to-m) geological faults (e.g., Li et al, 1994;Kiguchi et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Beydoun et al (1985) first considered the tube-wave generation using the Darcy's law (low-frequency approximation). They assume that the deformation of the fracture aperture is equivalent to the displacement amplitude of the incident P wave and it is uniform everywhere along the fracture.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Tube-wave Generation Due to Permeable Layers in a VSP Experiment - A New Model Elucidating the Effect of Dip Angles

Minato

Ghose

2017

Proceedings

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The hydraulic properties of subsurface fractures are critically important in the exploration of geothermal and hydrocarbon reservoirs. The analysis of tube waves (low-frequency Stoneley waves propagating along a fluid-filled borehole) is a promising approach to estimate the hydraulic properties of fractures intersecting a borehole. We present a new model for tube-wave generation in a borehole (VSP) by a permeable structure characterized by certain values of porosity and permeability. Contrary to the conventional theory, the new model accounts for the layer stiffness in the deformation process and it is valid for the large tube-wave amplitude. For the first time, it was possible to show a clear connection between the permeable-layer model and the parallel-wall open fracture model developed earlier. The generated tube-wave amplitudes well correspond to those of the multiple open fractures. Furthermore, the effect of large dip angles is extensively discussed. The approximate solution (the Mathieu functions) and the numerical modeling results (FEM) reveal that the effect of the dip angle is significant for a thick structure and large dip angles. The developed theory is important to evaluate field data which contain the effects of tube waves due to dipping, permeable layers, e.g., cataclasite layers and fault gouges.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Tube-wave Generation Due to Permeable Layers in a VSP Experiment - A New Model Elucidating the Effect of Dip Angles

Minato

Ghose

2017

Proceedings

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Hydraulic Properties of Closely Spaced Dipping Open Fractures Intersecting a Fluid‐Filled Borehole Derived From Tube Wave Generation and Scattering

et al. 2017

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Fluid‐filled fractures and fissures often determine the pathways and volume of fluid movement. They are critically important in crustal seismology and in the exploration of geothermal and hydrocarbon reservoirs. We introduce a model for tube wave scattering and generation at dipping, parallel‐wall fractures intersecting a fluid‐filled borehole. A new equation reveals the interaction of tube wavefield with multiple, closely spaced fractures, showing that the fracture dip significantly affects the tube waves. Numerical modeling demonstrates the possibility of imaging these fractures using a focusing analysis. The focused traces correspond well with the known fracture density, aperture, and dip angles. Testing the method on a VSP data set obtained at a fault‐damaged zone in the Median Tectonic Line, Japan, presents evidences of tube waves being generated and scattered at open fractures and thin cataclasite layers. This finding leads to a new possibility for imaging, characterizing, and monitoring in situ hydraulic properties of dipping fractures using the tube wavefield.

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Flow and Transport in Fractured Rocks

Wang

1991

Reviews of Geophysics

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Laboratory‐scale studies of discrete fractures lead to better understanding of the relationship between flow properties and pore geometry. Field‐scale studies of fracture networks test the validity of classical continuum approaches for transport processes in heterogeneous media. During 1987 to 1990, earth scientists have made significant advances in quantifying flow channeling and solute breakthrough in rough‐walled fractures, analyzing transitions between fracture and matrix flows under multiphase conditions, and characterizing fracture networks with hydrological and geophysical studies. In this review, the effect of heterogeneity and the issue of scaling are discussed. Many common features and similiar approaches can be identified in microcracks, discrete fractures, soil macropores, fractured rock masses, and heterogeneous reservoirs at different scales.

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Detection of open fractures with vertical seismic profiling

Cited by 53 publications

References 8 publications

Tube-wave Generation Due to Permeable Layers in a VSP Experiment - A New Model Elucidating the Effect of Dip Angles

Tube-wave Generation Due to Permeable Layers in a VSP Experiment - A New Model Elucidating the Effect of Dip Angles

Hydraulic Properties of Closely Spaced Dipping Open Fractures Intersecting a Fluid‐Filled Borehole Derived From Tube Wave Generation and Scattering

Flow and Transport in Fractured Rocks

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