Exploiting P-S converted waves. Part 1: Modeling the effects of anisotropy and heterogeneities
- Intevep S.A., Caracas (Venezuela)
The authors performed extensive modeling studies to evaluate P-S converted waves effectiveness and limitations in the estimation of both cracks orientation and density. The target area is a fractured, carbonate reservoir located in south-west Venezuela. The reservoir depth is on the order of 3000 m, which implies that high quality P-S data are needed to obtain detectable information about the anisotropy at this depth. They focused their analysis on P-S converted waves because only explosives charges were available as energy sources. The modeling was performed prior to and after the data acquisition to help both design of the experiment and interpretation of the data. Synthetic seismograms were generated using 2D, elastic finite difference, along with a 3D-3C, paraxial ray tracing codes. They conducted also a noise-spread test to complement this study and determine the acquisition parameters. A 3D velocity model of the subsurface was built based on previous P-wave seismic sections, well logs (dual-sonic, density, check-shots and FMS), geological maps, and production information. This model was perturbed in a layer stripping fashion until an acceptable match was obtained around the depth of interest between synthetic and multicomponent field data. The anisotropy produced measurable differences in traveltimes and amplitudes between in-line and cross-line components. These differences (which are comparable to those observed on the field data) suggest that it is feasible to map fractures at depths around the reservoir area by using P-S converted waves.
- OSTI ID:
- 80198
- Report Number(s):
- CONF-941015-; TRN: IM9532%%325
- Resource Relation:
- Conference: 64. annual meeting of the Society of Exploration Geophysicists and international exposition, Los Angeles, CA (United States), 23-27 Oct 1994; Other Information: PBD: 1994; Related Information: Is Part Of SEG international exposition and sixty-fourth annual meeting -- 1994 Technical program: Expanded abstracts with authors` biographies; PB: 1736 p.
- Country of Publication:
- United States
- Language:
- English
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