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The importance of seismic anisotropy has been recognized by the oil industry since its first observation in hydrocarbon reservoirs in 1986, and the application of seismic anisotropy to solve geophysical problems has been keenly pursued since then. However, a lot of problems remain, which have limited the applications of the technology. Nowadays, more and more 3D multi-component seismic data with wide-azimuth are becoming available. These have provided more opportunities for the study of seismic anisotropy. My thesis has focused on the study of using seismic anisotropy in 3D multi-component seismic data to characterize subsurface fractures, improve converted wave imaging and detect fluid content in fractured reservoirs, all of which are important for fractured reservoir exploration and monitoring. For the use of seismic anisotropy to characterize subsurface fracture systems, equivalent medium theories have established the link between seismic anisotropy and fracture properties. The numerical modelling in the thesis reveals that the amplitudes and interval travel-time of the radial component of PS converted waves can be used to derive fracture properties through elliptical fitting similar to P-waves. However, sufficient offset coverage is required for either the P- or PS-wave to reveal the features of elliptical variation with azimuth. Compared with numerical modelling, seismic physical modelling provides additional insights into the azimuthal variation of P and PS-wave attributes and their links with fracture properties. Analysis of the seismic physical model data in the thesis shows that the ratio of the offset to the depth of a target layer (offset-depth ratio), is a key parameter controlling the choice of suitable attributes and methods for fracture analysis. Data with a small offset-depth ratio from 0.7 to 1.0 may be more suitable for amplitude analysis; whilst the use of travel time or velocity analysis requires a large offset-depth ratio above 1.0, which can help in reducing the effect of the acquisition footprint and structural imprint on the results. Multi-component seismic data is often heavily contaminated with noise, which will limit its application potential in seismic anisotropy analysis. A new method to reduce noise in 3D multi-component seismic data has been developed and has proved to be very helpful in improving data quality. The method can automatically recognize and eliminate strong noise in 3D converted wave seismic data with little interference to useful reflection signals. Component rotation is normally a routine procedure in 3D multi-component seismic analysis. However, this study shows that incorrect rotations may occur for certain acquisition geometry and can lead to errors in shear-wave splitting analysis. A quality control method has been developed to ensure this procedure is correctly carried out. The presence of seismic anisotropy can affect the quality of seismic imaging, but the study has shown that the magnitude of the effects depends on the data type and target depth. The effects of VTI anisotropy (transverse isotropy with a vertical symmetry axis) on P-wave images are much weaker than those on PS-wave images. Anisotropic effects decrease with depth for the P- and PS-waves. The real data example shows that the overall image quality of PS-waves processed by pre-stack time migration has been improved when VTI anisotropy has been taken into account. The improvements are mainly in the upper part of the section. Monitoring fluid distribution is an important task in producing reservoirs. A synthetic study based on a multi-scale rock-physics model shows that it is possible to use seismic anisotropy to derive viscosity information in a HTI medium (transverse isotropy with a horizontal symmetry axis). The numerical modelling demonstrates the effects of fluid viscosity on medium elastic properties and seismic reflectivity, as well as the possibility of using them to discriminate between oil and water saturation. Analysis of real data reveals that it is hard to use the P-wave to discriminate oil-water saturation. However, characteristic shear-wave splitting behaviour due to pore pressure changes demonstrates the potential for discriminating between oil and water saturation in fractured reservoirs.

The anistropy of the orbital and spin properties of conduction electrons in InSb has been measured simultaneously using a cyclotron-resonance type experiment. This represents the first time that the anistropy of effective mass in InSb has been directly measured using an optical method.

Lo Chi-keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 69-72). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- What is an electrorheological fluid? --- p.1 / Chapter 1.2 --- Overview of recent theoretical studies on ER fluids --- p.2 / Chapter 1.3 --- Objectives of the thesis --- p.4 / Chapter 2 --- Review of some established macroscopic concepts --- p.8 / Chapter 2.1 --- Local field and depolarization tensor --- p.8 / Chapter 2.2 --- Clausius-Mossotti equation --- p.10 / Chapter 3 --- Ewald-Kornfeld formulation and effects of geometric anisotropy on local field distribution --- p.12 / Chapter 3.1 --- The development of the Ewald-Kornfeld method --- p.12 / Chapter 3.2 --- General Ewald-Kornfeld Formalism - point dipole approximation --- p.13 / Chapter 3.3 --- Ewald-Kornfeld Formalism - tetragonal lattice of point dipoles --- p.14 / Chapter 3.4 --- Numerical Results --- p.16 / Chapter 3.5 --- Contact with macroscopic concepts --- p.18 / Chapter 3.5.1 --- Generalized Clausius-Mossotti equation --- p.18 / Chapter 3.5.2 --- Onsager reaction field --- p.19 / Chapter 3.6 --- Figures --- p.22 / Chapter 4 --- Field-induced structure transformation in ER solid --- p.24 / Chapter 4.1 --- Ewald-Kornfeld Formalism - body-centered tetragonal lattice --- p.25 / Chapter 4.2 --- Effects of structure transformation on the local field --- p.27 / Chapter 4.3 --- Structure transformation via rotating electric fields --- p.28 / Chapter 4.4 --- Competitions between FCC and HCP --- p.30 / Chapter 4.5 --- Figures --- p.31 / Chapter 5 --- Geometric anisotropy from distortive lattices: ferrodistortive and antidistortive systems --- p.34 / Chapter 5.1 --- Ferrodistortive lattice --- p.35 / Chapter 5.1.1 --- Sublattice interaction tensors --- p.36 / Chapter 5.1.2 --- Effective polarizability and Clausius-Mossotti equation --- p.37 / Chapter 5.2 --- Antidistortive lattice --- p.39 / Chapter 5.2.1 --- Sublattice interaction tensors --- p.40 / Chapter 5.2.2 --- Sublattice dipole moments --- p.41 / Chapter 5.2.3 --- Effective polarizability and polarization catastrophe --- p.43 / Chapter 5.2.4 --- Depolarization field --- p.44 / Chapter 5.3 --- Experimental realization - colloidal self-assembly --- p.45 / Chapter 5.4 --- Figures --- p.46 / Chapter 6 --- Discussion and conclusion --- p.52 / Chapter 6.1 --- Discussion on our work and possible future extension --- p.52 / Chapter 6.2 --- Conclusion --- p.54 / Chapter A --- Piezoelectric coefficients by Ewald-Kornfeld formulation --- p.57 / Chapter B --- Alternative formulation for Ewald-Kornfeld formulation by di- rect calculations of the dipole interaction tensor --- p.59 / Chapter C --- Ewald-multipole formulation --- p.63 / Chapter C.1 --- Multipole fields --- p.64 / Chapter C.2 --- Coupled dipole-quadrupole lattice --- p.66 / Bibliography --- p.69

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Physical vapour deposition at oblique angles produces coatings that have oriented internal structure, a consequence of self-shadowing and limited diffusion. Structured media have a number of useful properties, including form birefringence which affects the polarization of light. Whilst oblique deposition technology is mature, there is room for further exploration to open up new applications and provide further insight. One door only recently opened is lithographic patterning, and this thesis seeks to map out part of that frontier. Lithography allows rapid replication of a pattern, and is being extended to the nano-scale, via two routes identified as "top-down" and "bottom-up". In this thesis bottom-up processing is pursued as a secondary theme, developing computer programs for investigation of the effect of substrate patterning on growth and subsequent birefringence. The primary focus is the application of top-down patterning to obliquely-deposited polarizing elements, for the production of pixellated polarizing arrays. The growth of obliquely deposited coatings is well understood, and the process has been developed using dynamic substrate rotation to produce several interesting morphologies. Standard results of computer simulations are replicated for illustration. The relationship between morphology and optical properties has been extensively studied from an empirical standpoint, resulting in production of polarizing elements such as retarders, linear- and circular- polarizers. Surprisingly little study has focussed on simulation of the optical anisotropy of arbitrary structures, and here programs are developed for initial prediction of the birefringence of coatings deposited over patterned substrates. Top-down patterning approaches are directly applied to obliquely-deposited dielectric coatings. Standard reactive ion etching protocols are tested, particularly for silicon films, measuring the effect of deposition parameters on etch-rate. Lift-off patterning at significantly oblique angles requires special attention, and an undercut tri-layer process is developed, resulting in patterning of chiral oxide films. Additionally a novel masking process is developed, that allows the production of pixellated arrays comprised of different polarizers in a single coating operation. One such array is used as the essential component in the production of a space-multiplexed array polarimeter.

The backlimb trishear velocity field is compared to that of mechanical models of fault-bend folds in an incompressible anisotropic viscous media to determine the relationship between the magnitude and orientation of mechanical anisotropy and the kinematic parameters of the trishear model. The trishear model can describe the velocity field of the mechanical model, at least to first order approximation for some cases. We find that the apical angle, asymmetry angle and overall geometry of the hanging-wall syncline above the ramp depend on the magnitude and orientation of the planar anisotropy inherent in stratigraphic sequences. The asymmetry of trishear zone in the backlimb region mimics that of the planar anisotropy. In general, as the magnitude and inclination of the anisotropy increase, the trishear apical angle decreases. The trishear parameters that describe physical models of fault-bend folds with different magnitudes of anisotropy also show a decrease in apical angle with an increase in magnitude of anisotropy. Yet the apical angles of the backlimb of physical models generally are less than these predicted by the mechanical model for the same magnitude of anisotropy. In addition, the physical models display significantly more negative asymmetry than predicted by the mechanical model. The results of this study may be used to determine the conditions under which the trishear model is an acceptable approximation to natural formation and help guide the selection of trishear parameters for subsurface structural interpretations in fault-fold terrains.

The problem of evaluating permeability anisotropy in the Tilje Formation, Heidrum field, offshore mid-Norway, has been investigated by the Statoil Research Centre by a detailed combination of the geological and petrophysical data. The large diversity and contrasting levels of heterogeneity within depositional facies observed in the Tilje Formation reflect complicated patterns of deposition along deltaic shorelines and the adjunct shelf of a tidally influenced, narrow seaway. Permeability anisotropy can alter the directionality of the fluid flow in the reservoir, and thereby affect the most important exploration procedures: perforation, water and gas injection, production, and estimation of the field resource. This thesis presents a simplified method of modeling permeability anisotropy in the Tilje Formation.