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f Acoustic anisotropy of synthetics with controlled crack geometries
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 53rd EAEG Meeting, May 1991, cp-42-00267
- ISBN: 978-90-73781-03-0
Abstract
The knowledge of crack distributions is of vital importance for the withdrawal of fluids from reservoirs in which cracks exist as penetrating fractures, serving as primary channels for fluid flow. The presence rif cracks affects the acoustic wave velocities giving rise to anisotropy. It is to be able to predict theoretically whether the observed anisotropy is caused by a large number of small, isolated microcracks, or by a few similarly oriented, larger and possibly connected fractures. Several theoretical models for the acoustic behaviour in cracked and jointed media exist (Hudson, 1981, Thomsen, 1986), yet none of them have been confirmed in a controlled experiment, one in which sizes, shapes, amounts and orientational distributions of cracks are known. In geomaterials these are generally unknown parameters. Hence we have undertaken the task of producing a synthetic material in which the above crack parameters are known.