E-Book, Englisch, 729 Seiten
Barton Rock Quality, Seismic Velocity, Attenuation and Anisotropy
1. Auflage 2007
ISBN: 978-1-134-16013-6
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
E-Book, Englisch, 729 Seiten
ISBN: 978-1-134-16013-6
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
Seismic measurements take many forms, and appear to have a universal role in the Earth Sciences. They are the means for most easily and economically interpreting what lies beneath the visible surface. There are huge economic rewards and losses to be made when interpreting the shallow crust or subsurface more, or less accurately, as the case may be.
This book describes seismic behaviour at many scales and from numerous fields in geophysics, tectonophysics and rock physics, and from civil, mining and petroleum engineering. Addressing key items for improved understanding of seismic behaviour, it often interprets seismic measurements in rock mechanics terms, with particular attention to the cause of attenuation, its inverse seismic quality, and the anisotropy of fracture compliances and stiffnesses.
Reviewed behaviour stretches over ten orders of magnitude, from micro-crack compliance in laboratory tests to cross-continent attenuation. Between these extremes lie seismic investigation of rock joints, boreholes, block tests, dam and bridge foundations, quarry blasting, canal excavations, hydropower and transportation tunnels, machine bored TBM tunnels, sub-sea sediment and mid-ocean ridge measurements, where the emphasis is on velocity-depth-age models. Attenuation of earthquake coda-waves is also treated, including in-well measurements.
In the later chapters, there is a general emphasis on deeper, higher stress, larger scale applications of seismic, such as shear-wave splitting for interpreting the attenuation, anisotropy and orientation of permeable 'open' fracture sets in petroleum reservoirs, and the 4D seismic effects of water-flood, oil production and compaction. The dispersive or frequency dependence of most seismic measurements and their dependence on fracture dimensions and fracture density is emphasized. The possibility that shear displacement may be required to explain permeability at depth is quantified.
This book is cross-disciplinary, non-mathematical and phenomenological in nature, containing a wealth of figures and a wide review of the literature from many fields in the Earth Sciences. Including a chapter of conclusions and an extensive subject index, it is a unique reference work for professionals, researchers, university teachers and students working in the fields of geophysics, civil, mining and petroleum engineering. It will be particularly relevant to geophysicists, engineering geologists and geologists who are engaged in the interpretation of seismic measurements in rock and petroleum engineering.
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
Preface
Introduction
The multi-disciplinary scope of seismic and rock quality
Revealing hidden rock conditions
Some basic principles of P, S and Q
Q and Q
Limitations of refraction seismic bring tomographic solutions
Nomenclature
PART I
1 Shallow seismic refraction, some basic theory, and the importance of rock type
- 1.1 The challenge of the near-surface in civil engineering
- 1.2 Some basic aspects concerning elastic body waves
- 1.2.1 Some sources of reduced elastic moduli
- 1.3 Relationships between Vp and Vs and their meaning in field work
- 1.4 Some advantages of shear waves
- 1.5 Basic estimation of rock-type and rock mass condition, from shallow seismic P-wave velocity
- 1.6 Some preliminary conversions from velocity to rock quality
- 1.7 Some limitations of the refraction seismic velocity interpretations
- 1.8 Assumed limitations may hide the strengths of the method
- 1.9 Seismic quality Q and apparent similarities to Q-rock
2 Environmental effects on velocity
- 2.1 Density and Vp
- 2.2 Porosity and Vp
- 2.3 Uniaxial compressive strength and Vp
- 2.4 Weathering and moisture content
- 2.5 Combined effects of moisture and pressure
- 2.6 Combined effects of moisture and low temperature
3 Effects of anisotropy on Vp
- 3.1 An introduction to velocity anisotropy caused by micro-cracks and jointing
- 3.2 Velocity anisotropy caused by fabric
- 3.3 Velocity anisotropy caused by rock joints
- 3.4 Velocity anisotropy caused by interbedding
- 3.5 Velocity anisotropy caused by faults
4 Cross-hole velocity and cross-hole velocity tomography
- 4.1 Cross-hole seismic for extrapolation of properties
- 4.2 Cross-hole seismic tomography in tunnelling
- 4.3 Cross-hole tomography in mining
- 4.4 Using tomography to monitor blasting effects
- 4.5 Alternative tomograms
- 4.6 Cross-hole or cross-well reflection measurement and time-lapse tomography
5 Relationships between rock quality, depth and seismic velocity
- 5.1 Some preliminary relationships between RQD, F, and Vp
- 5.2 Relationship between rock quality Q and Vp for hard jointed, near-surface rock masses
- 5.3 Effects of depth or stress on acoustic joint closure, velocities and amplitudes
- 5.3.1 Compression wave amplitude sensitivities to jointing
- 5.3.2 Stress and velocity coupling at the Gjøvik cavern site
- 5.4 Observations of effective stress effects on velocities
- 5.5 Integration of velocity, rock mass quality, porosity, stress, strength, deformability
6 Deformation moduli and seismic velocities
- 6.1 Correlating Vp with the ‘static’ moduli from deformation tests
- 6.2 Dynamic moduli and their relationship to static moduli
- 6.3 Some examples of the three dynamic moduli
- 6.4 Use of shear wave amplitude, frequency and petite-sismique
- 6.5 Correlation of deformation moduli with RMR and Q
7 Excavation disturbed zones and their seismic properties
- 7.1 Some effects of the free-surface on velocities and attenuation
- 7.2 EDZ phenomena around tunnels based on seismic monitoring
- 7.3 EDZ investigations in selected nuclear waste isolation studies
- 7.3.1 BWIP – EDZ studies
- 7.3.2 URL – EDZ studies
- 7.3.3 Äspö – EDZ studies
- 7.3.4 Stripa – effects of heating in the EDZ of a rock mass
- 7.4 Acoustic detection of stress effects around boreholes
8 Seismic measurements for tunnelling
- 8.1 Examples of seismic applications in tunnels
- 8.2 Examples of the use of seismic data in TBM excavations
- 8.3 Implications of inverse correlation between TBM advance rate and Vp
- 8.4 Use of probe drilling and seismic or sonic logging ahead of TBM tunnels
- 8.5 In-tunnel seismic measurements for looking ahead of the face
- 8.6 The possible consequences of insufficient seismic investigation due to depth limitations
9 Relationships between Vp, Lugeon value, permeability and grouting in jointed rock
- 9.1 Correlation between Vp and Lugeon value
- 9.2 Rock mass deformability and the Vp-L-Q correlation
- 9.3 Velocity and permeability measurements at in situ block tests
- 9.4 Detection of permeable zones using other geophysical methods
- 9.5 Monitoring the effects of grouting with seismic velocity
- 9.6 Interpreting grouting effects in relation to improved rock mass Q-parameters
PART II
10 Seismic quality Q and attenuation at many scales
- 10.1 Some basic aspects concerning attenuation and Qseismic
- 10.1.1 A preliminary discussion of the importance of strain levels
- 10.1.2 A preliminary look at the attenuating effect of cracks of larger scale
- 10.2 Attenuation and seismic Q from laboratory measurement
- 10.2.1 A more detailed discussion of friction as an attenuation mechanism
- 10.2.2 Effects of partial saturation on seismic Q
- 10.3 Effect of confining pressure on seismic Q
- 10.3.1 The four components of elastic attenuation
- 10.3.2 Effect on Qp and Qs of loading rock samples towards failure
- 10.4 The effects of single rock joints on seismic Q
- 10.5 Attenuation and seismic Q from near-surface measurements
- 10.5.1 Potential links to rock mass quality parameters in jointed rock
- 10.5.2 Effects of unconsolidated sediments on seismic Q
- 10.5.3 Influence of frequency variations on attenuation in jointed and bedded rock
- 10.6 Attenuation in the crust as interpreted from earthquake coda
- 10.6.1 Coda Qc from earthquake sources and its relation to rock quality Qc
- 10.6.2 Frequency dependence of coda Qc due to depth effects
- 10.6.3 Temporal changes of coda Qc prior to earthquakes
- 10.6.4 Possible separation of attenuation into scattering and intrinsic mechanisms
- 10.6.5 Changed coda Q during seismic events
- 10.6.6 Attenuation of damage due to acceleration
- 10.6.7 Do microcracks or tectonic structure cause attenuation
- 10.6.8 Down-the-well seismometers to minimise site effects
- 10.6.9 Rock mass quality parallels
- 10.7 Attenuation across continents
- 10.7.1 Plate tectonics, sub-duction zones and seismic Q
- 10.7.2 Young and old oceanic lithosphere
- 10.7.3 Lateral and depth variation of seismic Q and seismic velocity
- 10.7.4 Cross-continent Lg coda Q variations and their explanation
- 10.7.5 Effect of thick sediments on continental Lg coda
- 10.8 Some recent attenuation measurements in petroleum reservoir environments
- 10.8.1 Anomalous values of seismic Q in reservoirs due to major structures
- 10.8.2 Evidence for fracturing effects in reservoirs on seismic Q
- 10.8.3 Different methods of analysis give different seismic Q
11 Velocity structure of the earth’s crust
- 11.1 An introduction to crustal velocity structures
- 11.2 The continental velocity structures
- 11.3 The continental margin velocity structures
- 11.3.1 Explaining a velocity anomaly
- 11.4 The mid-Atlantic ridge velocity structures
- 11.4.1 A possible effective stress discrepancy in early testing
- 11.4.2 Smoother depth velocity models
- 11.4.3 Recognition of lower effective stress levels beneath the oceans
- 11.4.4 Direct observation of sub-ocean floor velocities
- 11.4.5 Sub-ocean floor attenuation measurements
- 11.4.6 A question of porosities, aspect ratios and sealing
- 11.4.7 A velocity-depth discussion
- 11.4.8 Fracture zones
- 11.5 The East Pacific Rise velocity structures
- 11.5.1 More porosity and fracture aspect ratio theories
- 11.5.2 First sub-Pacific ocean core with sonic logs and permeability tests
- 11.5.3 Attenuation and seismic Q due to fracturing and alteration
- 11.5.4 Seismic attenuation tomography across the East Pacific Rise
- 11.5.5 Continuous sub-ocean floor seismic profiles
- 11.6 Age effects summary for Atlantic Ridge and Pacific Rise
- 11.6.1 Decline of hydrothermal circulation with age and sediment cover
- 11.6.2 The analogy of pre-grouting as a form of mineralization
12 Rock stress, pore pressure, borehole stability and sonic logging
- 12.1 Pore pressure, over-pressure, and minimum stress
- 12.1.1 Pore pressure and over-pressure and cross-discipline terms
- 12.1.2 Minimum stress and mud-weight
- 12.2 Stress anisotropy and its intolerance by weak rock
- 12.2.1 Reversal of Ko trends nearer the surface
- 12.3 Relevance to logging of borehole disturbed zone
- 12.4 Borehole in continuum becomes borehole in local discontinuum
- 12.5 The EDZ caused by joints, fractures and bedding-planes
- 12.6 Loss of porosity due to extreme depth
- 12.7 Dipole shear-wave logging of boreholes
- 12.7.1 Some further development of logging tools
- 12.8 Mud filtrate invasion
- 12.9 Challenges from ultra HPHT
13 Rock physics at laboratory scale
- 13.1 Compressional velocity and porosity
- 13.2 Density, Vs and Vp
- 13.3 Velocity, aspect ratio, pressure, brine and gas
- 13.4 Velocity, temperature and influence of fluid
- 13.5 Velocity, clay content and permeability
- 13.6 Stratigraphy based velocity to permeability estimation
- 13.6.1 Correlation to field processes
- 13.7 Velocity with patchy saturation effects in mixed units
- 13.8 Dynamic Poisson’s ratio, effective stress and pore fluid
- 13.9 Dynamic moduli for estimating static deformation moduli
- 13.10 Attenuation due to fluid type, frequency, clay, over-pressure, compliant minerals, dual porosity
- 13.10.1 Comparison of velocity and attenuation in the presence of gas or brine
- 13.10.2 Attenuation when dry or gas or brine saturated
- 13.10.3 Effect of frequency on velocity and attenuation, dry or with brine
- 13.10.4 Attenuation for distinguishing gas condensate from oil and water
- 13.10.5 Attenuation in the presence of clay content
- 13.10.6 Attenuation due to compliant minerals and microcracks
- 13.10.7 Attenuation with dual porosity samples of limestones
- 13.10.8 Attenuation in the presence of over-pressure
- 13.11 Attenuation in the presence of anisotropy
- 13.11.1 Attenuation for fluid front monitoring
- 13.12 Anisotropic velocity and attenuation in shales
- 13.12.1 Attenuation anisotropy expressions e, g and d
- 13.13 Permeability and velocity anisotropy due to fabric, joints and fractures
- 13.13.1 Seismic monitoring of fracture development and permeability
- 13.14 Rock mass quality, attenuation and modulus
14 P-waves for characterising fractured reservoirs
- 14.1 Some classic relationships between age, depth and velocity
- 14.2 Anisotropy and heterogeneity caused by inter-bedded strata and jointing
- 14.2.1 Some basic anisotropy theory
- 14.3 Shallow cross-well seismic tomography
- 14.3.1 Shallow cross-well seismic in fractured rock
- 14.3.2 Cross-well seismic tomography with permeability measurement
- 14.3.3 Cross-well seismic in deeper reservoir characterization
- 14.4 Detecting finely inter-layered sequences
- 14.4.1 Larger scale differentiation of facies
- 14.5 Detecting anisotropy caused by fractures with multi-azimuth VSP
- 14.5.1 Fracture azimuth and stress azimuth from P-wave surveys
- 14.5.2 Sonic log and VSP dispersion effects and erratic seismic Q
- 14.6 Dispersion as an alternative method of characterization
- 14.7 AVO and AVOA using P-waves for fracture detection
- 14.7.1 Model dependence of AVOA fracture orientation
- 14.7.2 Conjugate joint or fracture sets also cause anisotropy
- 14.7.3 Vp anisotropy caused by faulting
- 14.7.4 Poisson’s ratio anisotropy caused by fracturing
- 14.8 4C four-component acquisition of seismic including C-waves
- 14.9 4D seismic monitoring of reservoirs
- 14.9.1 Possible limitations of some rock physics data
- 14.9.2 Oil saturation mapping with 4D seismic
- 14.10 4D monitoring of compaction and porosity at Ekofisk
- 14.10.1 Seismic detection of subsidence in the overburden
- 14.10.2 The periodically neglected joint behaviour at Ekofisk
- 14.11 Water flood causes joint opening and potential shearing
- 14.12 Low frequencies for sub-basalt imaging
- 14.13 Recent reservoir anisotropy investigations involving P-waves and attenuation
15 Shear wave splitting in fractured reservoirs and resulting from earthquakes
- 15.1 Introduction
- 15.2 Shear wave splitting and its many implications
- 15.2.1 Some sources of shear-wave splitting
- 15.3 Crack density and EDA
- 15.3.1 A discussion of ‘criticality’ due to microcracks
- 15.3.2 Temporal changes in polarization in Cornwall HDR
- 15.3.3 A critique of Crampin’s microcrack model
- 15.3.4 90°-flips in polarization
- 15.4 Theory relating joint compliances with shear wave splitting
- 15.4.1 An unrealistic rock simulant suggests equality between ZN and ZT
- 15.4.2 Subsequent inequality of ZN and ZT
- 15.4.3 Off-vertical fracture dip or incidence angle, and normal compliance
- 15.4.4 Discussion of scale effects and stiffness
- 15.5 Dynamic and static stiffness tests on joints by Pyrak-Nolte
- 15.5.1 Discussion of stiffness data gaps and discipline bridging needs
- 15.5.2 Fracture stiffness and permeability
- 15.6 Normal and shear compliance theories for resolving fluid type
- 15.6.1 In situ compliances in a fault zone inferred from seismic Q
- 15.7 Shear wave splitting from earthquakes
- 15.7.1 Shear-wave splitting in the New Madrid seismic zone
- 15.7.2 Shear-wave splitting at Parkfield seismic monitoring array
- 15.7.3 Shear-wave splitting recorded at depth in Cajon Pass borehole
- 15.7.4 Stress-monitoring site (SMS) anomalies from Iceland
- 15.7.5 SW-Iceland, Station BJA shear wave anomalies
- 15.7.6 Effects of shearing on stiffness and shear wave amplitude
- 15.7.7 Shear-wave splitting at a geothermal field
- 15.7.8 Shear wave splitting during after-shocks of the Chi-Chi earthquake in Taiwan
- 15.7.9 Shear-wave splitting under the Mid-Atlantic Ridge
- 15.8 Recent cases of shear wave splitting in petroleum reservoirs
- 15.8.1 Some examples of S-wave and PS-wave acquisition methods
- 15.8.2 Classification of fractured reservoirs
- 15.8.3 Crack density and shearing of conjugate sets at Ekofisk might enhance splitting
- 15.8.4 Links between shear wave anisotropy and permeability
- 15.8.5 Polarization-stress alignment from shallow shear-wave splitting
- 15.8.6 Shear-wave splitting in argillaceous rocks
- 15.8.7 Time-lapse application of shear-wave splitting over reservoirs
- 15.8.8 Temporal shear-wave splitting using AE from the Valhall cap-rock
- 15.8.9 Shear-wave splitting and fluid identification at the Natih field
- 15.9 Dual-porosity poro-elastic modelling of dispersion and fracture size effects
- 15.9.1 A brief survey of rock mechanics pseudo-static models of jointed rock
- 15.9.2 A very brief review of slip-interface, fracture network and poro-elastic crack models
- 15.9.3 Applications of Chapman model to Bluebell Altamont fractured gas reservoir
- 15.9.4 The SeisRox model
- 15.9.5 Numerical modelling of dynamic joint stiffness effects
- 15.9.6 A ‘sugar cube’ model representation
- 15.10 A porous and fractured physical model as a numerical model validation
16 Joint stiffness and compliance and the joint shearing mechanism
- 16.1 Some important non-linear joint and fracture behaviour modes
- 16.2 Aspects of fluid flow in deforming rock joints
- 16.2.1 Coupled stress-flow behaviour under normal closure
- 16.2.2 Coupled stress-flow behaviour under shear deformation
- 16.3 Some important details concerning rock joint stiffnesses Kn and Ks
- 16.3.1 Initial normal stiffness measured at low stress
- 16.3.2 Normal stiffness at elevated normal stress levels
- 16.4 Ratios of Kn over Ks under static and dynamic conditions
- 16.4.1 Frequency dependence of fracture normal stiffness
- 16.4.2 Ratios of static Kn to static Ks for different block sizes
- 16.4.3 Field measurements of compliance ZN
- 16.4.4 Investigation of normal and shear compliances on artificial surfaces in limestones
- 16.4.5 The Worthington-Lubbe-Hudson range of compliances
- 16.4.6 Pseudo-static stiffness data for clay filled discontinuities and major shear zones
- 16.4.7 Shear stress application may apparently affect compliance
- 16.5 Effect of dry or saturated conditions on shear and normal stiffnesses
- 16.5.1 Joint roughness coefficient (JRC)
- 16.5.2 Joint wall compression strength (JCS)
- 16.5.3 Basic friction angle f b and residual friction angle f r
- 16.5.4 Empirical equations for the shear behaviour of rock joints
- 16.6 Mechanical over-closure, thermal-closure, and joint stiffness modification
- 16.6.1 Normal stiffness estimation
- 16.6.2 Thermal over-closure of joints and some implications
- 16.6.3 Mechanical over-closure
- 16.7 Consequences of shear stress on polarization and permeability
- 16.7.1 Stress distribution caused by shearing joints, and possible consequences for shear wave splitting
- 16.7.2 The strength-deformation components of jointed rock masses
- 16.7.3 Permeability linked to joint shearing
- 16.7.4 Reservoir seismic case records with possible shearing
- 16.7.5 The apertures expected of highly stressed ‘open’ joints
- 16.7.6 Modelling apertures with the BB model
- 16.7.7 Open joints caused by anisotropic stress, low shear strength, dilation
- 16.8 Non-linear shear strength and the critical shearing crust
- 16.8.1 Non-linear strength envelopes and scale effects
- 16.9 Critically stressed open fractures that indicate conductivity
- 16.9.1 The JRC contribution at different scales and deformations
- 16.9.2 Does pre-peak or post-peak strength resist the assumed crustal shear stress?
- 16.10 Rotation of joint attributes and unequal conjugate jointing may explain azimuthal deviation of S-wave polarization
- 16.11 Classic stress transformation equations ignore the non-coaxiality of stress and displacement
- 16.12 Estimating shallow crustal permeability from a modified rock quality Q-water
- 16.12.1 The problem of clay-sealed discontinuities
17 Conclusions
Appendix A – The Qrock parameter ratings
- The six parameters defined
- Combination in pairs
- Definitions of characterization and classification as used in rock engineering
- Notes on Q-method of rock mass classification
Appendix B – A worked example
References
Index
Colour Plates
