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Elastic wave tools

Elastic wave tools operate by sending ultrasoimds in two directions along the pipeline to locate and size longitudinally oriented crack and manufacturing defects. [Pg.522]

Generally, the borehole tool is applicable in all rocks which show spontaneous and fast crack formation. Difficulties will occur in layered or multiply jointed rocks, because such rock types show a high attenuation and strong absorption of the elastic waves. The borehole tool was developed... [Pg.276]

Rock drillability is also controlled by strength properties. Therefore, correlations between elastic wave velocities and parameters of rock drillability have also been investigated. For example, Somerton et al. (1969) reported that sonic velocity is a good indicator of rock drillability for hme- and sandstones, and the type of drilling tool. [Pg.292]

The shear and compressional acoustic wave velocities for the inner core are the direct output parameters from seismological observations. In order to make a direct comparison between the seismic data and measured physical properties, measurements of the acoustic velocities for iron at core pressures are required. Only very recently has it become possible to measure the elastic constants of s-Fe at high pressures and room temperature (Mao etal., 1999 Lubbers etal., 2000 Fiquet et al., 2001 Anderson et at, 2001). Recent advances in theory and computational methods have also provided new tools for computing the elastic constants of s-Fe at core pressures (Stixrude and Cohen, 1995 Soderhnd et al., 1996 Cohen et al., 1997 Steinle-Neumann and Stixrude, 1999) and core conditions (Laio et al., 2000 Steinle-Neumann et al, 2001 Alfe et al., 2001). There is considerable disagreement on the elastic constants of s-Fe between experimental results and theoretical calculations. The dilferences in the aggregate shear (FJ and compressional (Vp) wave velocities are smaller (Hemley and Mao, 2001 Steinle-Neumann et ai, 2001). Further improvement of theory and experiment is required to resolve the discrepancies. [Pg.1225]

In what follows the theoretical background of the most common physical properties and their measuring tools are described. Examples for the wet bulk density and porosity can be found in Section 2.2. For the acoustic and elastic parameters first the main aspects of Biot-Stoll s viscoelastic model which computes P- and S-wave velocities and attenuations for given sediment parameters (Biot 1956a, b, Stoll 1974, 1977, 1989) are summarized. Subsequently, analysis methods are described to derive these parameters from transmission seismograms recorded on sediment cores, to compute additional properties like elastic moduli and to derive the permeability as a related parameter by an inversion scheme (Sect. 2.4). [Pg.29]

Direct measurements of permeabilities in unconsolidated marine sediments are difficult, and only few examples are published. They confine to measurements on discrete samples with a specially developed tool (Lovell 1985), to indirect estimations by resistivity measurements (Lovell 1985), and to consolidation tests on ODP cores using a modified medical tool (Olsen et al. 1985). These measurements are necessary to correct for the elastic rebound (MacKillop et al. 1995) and to determine intrinsic permeabilities at the end of each consolidation step (Fisher et al. 1994). In Section 2.4.2 a numerical modeling and inversion scheme is described which estimates permeabilities from P-wave attenuation and dispersion curves (c.f. also section 3.6). [Pg.42]

Quasi-elastic Laser Scattering (QELS) provides a versatile tool for monitoring in situ the frequency of thermally induced capillary waves at the Uquid/hquid junction [26, 27]. Unlike the previous techniques based on an absorption/fluores-cence signal arising from molecular probes at the interface, QELS is not sensitive to specific molecules but to the interfacial tension of the molecular junc-... [Pg.139]


See other pages where Elastic wave tools is mentioned: [Pg.365]    [Pg.239]    [Pg.81]    [Pg.499]    [Pg.412]    [Pg.44]    [Pg.59]    [Pg.59]    [Pg.31]    [Pg.329]    [Pg.229]    [Pg.160]    [Pg.164]    [Pg.264]    [Pg.2948]    [Pg.39]    [Pg.128]    [Pg.2694]    [Pg.2705]    [Pg.2808]    [Pg.104]    [Pg.21]    [Pg.282]    [Pg.514]   
See also in sourсe #XX -- [ Pg.522 ]




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