Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present
When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent Horizontal Transverse Isotropic (HTI) medium. However, geophysical data acquired over naturally fractured reservoirs often reveal the presence of m...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Technical Report |
| Language: | en_US |
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Massachusetts Institute of Technology. Earth Resources Laboratory
2014
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| Online Access: | http://hdl.handle.net/1721.1/90518 |
| _version_ | 1826188241831723008 |
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| author | Liu, Yuwei Fehler, Michael Fang, Xinding Liu, Cai |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Liu, Yuwei Fehler, Michael Fang, Xinding Liu, Cai |
| author_sort | Liu, Yuwei |
| collection | MIT |
| description | When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent Horizontal Transverse Isotropic (HTI) medium. However, geophysical data acquired over naturally fractured reservoirs often reveal the presence of multiple fracture sets. We investigate a case where there are two vertical sets of fractures having differing length scales. One fracture set has length scale that is much smaller than the seismic wavelength but the other has length scale that is similar to the seismic wavelength. We use synthetic data to investigate the ability to infer the properties of the small-scale fractures in the presence of the large-scale fracture set. We invert for the Thomsen-type anisotropic coefficients of the small-scale fracture set by using the difference of the P-wave amplitudes at two azimuths, which makes the inversion convex. Then we investigate the influence of the presence of the large-scale fractures on our ability to infer the properties of the small-scale fracture set. Surprisingly, we find that we can reliably infer the fracture density of the small scale fractures even in the presence of large scale fractures having significant compliance values. |
| first_indexed | 2024-09-23T07:56:41Z |
| format | Technical Report |
| id | mit-1721.1/90518 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T07:56:41Z |
| publishDate | 2014 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/905182019-04-09T15:40:24Z Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present Liu, Yuwei Fehler, Michael Fang, Xinding Liu, Cai Massachusetts Institute of Technology. Earth Resources Laboratory Fractures Inversion When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent Horizontal Transverse Isotropic (HTI) medium. However, geophysical data acquired over naturally fractured reservoirs often reveal the presence of multiple fracture sets. We investigate a case where there are two vertical sets of fractures having differing length scales. One fracture set has length scale that is much smaller than the seismic wavelength but the other has length scale that is similar to the seismic wavelength. We use synthetic data to investigate the ability to infer the properties of the small-scale fractures in the presence of the large-scale fracture set. We invert for the Thomsen-type anisotropic coefficients of the small-scale fracture set by using the difference of the P-wave amplitudes at two azimuths, which makes the inversion convex. Then we investigate the influence of the presence of the large-scale fractures on our ability to infer the properties of the small-scale fracture set. Surprisingly, we find that we can reliably infer the fracture density of the small scale fractures even in the presence of large scale fractures having significant compliance values. Massachusetts Institute of Technology. Earth Resources Laboratory (Founding Members Program) 2014-10-02T13:46:18Z 2014-10-02T13:46:18Z 2013 Technical Report http://hdl.handle.net/1721.1/90518 en_US Earth Resources Laboratory Industry Consortia Annual Report;2013-07 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Fractures Inversion Liu, Yuwei Fehler, Michael Fang, Xinding Liu, Cai Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title | Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title_full | Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title_fullStr | Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title_full_unstemmed | Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title_short | Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present |
| title_sort | estimating the fracture density of small scale vertical fractures when large scale vertical fractures are present |
| topic | Fractures Inversion |
| url | http://hdl.handle.net/1721.1/90518 |
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