Borehole Seismic Source Radiation In Layered Isotropic And Anisotropic Media: Boundary Element Modeling
Author(s)
Dong, Wenjie; Bouchon, Michel; Toksoz, M. N.
Download1994.13 Dong et al.pdf (986.8Kb)
Other Contributors
Massachusetts Institute of Technology. Earth Resources Laboratory
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Show full item recordAbstract
An algorithm based on the boundary element method is established for modeling seismic
source radiation from open or cased boreholes in layered transversely isotropic (TI)
media. The axis of symmetry of TI layers is assumed to be parallel to the borehole
axis. Under this assumption, the problem is significantly simplified because the element
discretization of the borehole remains one dimensional. For fluid-filled open boreholes,
three equivalent sources on each element are required to represent the boundary effects
on the inner fluid and the outer solid. The three boundary conditions for a f1uidsolid
interface set up a system of equations for the equivalent sources on all elements.
Once the sources are known, displacements in the solid and pressure in the fluid are
obtained. For fluid-filled and cased boreholes, the method treats borehole fluid, casing,
and cement as a cylindricaliy layered isotropic medium. In this case, the boundary
conditions to be satisfied at the borehole wall are four (continuity of the normal and
tangential displacements and stresses). The implementation of the method is illustrated
through a few examples.
Date issued
1994Publisher
Massachusetts Institute of Technology. Earth Resources Laboratory
Series/Report no.
Earth Resources Laboratory Industry Consortia Annual Report;1994-13