Compaction trend versus seismic anisotropy in shaly formations
Shales comprise more than 60% of sedimentary rocks and form natural seals above hydrocarbon reservoirs. Their sealing capacity is also used for storage of nuclear wastes. The world's most important conventional oil and gas reservoirs have their corresponding source rocks in shale. Furthermore,...
| Main Authors: | , |
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| Format: | Journal Article |
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Wiley-Blackwell
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/53277 |
| _version_ | 1848759106616164352 |
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| author | Pervukhina, Marina Rasolofosaon, P. |
| author_facet | Pervukhina, Marina Rasolofosaon, P. |
| author_sort | Pervukhina, Marina |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Shales comprise more than 60% of sedimentary rocks and form natural seals above hydrocarbon reservoirs. Their sealing capacity is also used for storage of nuclear wastes. The world's most important conventional oil and gas reservoirs have their corresponding source rocks in shale. Furthermore, shale oil and shale gas are the most rapidly expanding trends in unconventional oil and gas. Shales are notorious for their strong elastic anisotropy, i.e., so-called vertical transverse isotropy. This vertical transverse isotropy, characterised by a vertical axis of invariance, is of practical importance as it is required for correct surface seismic data interpretation, seismic to well tie, and amplitude versus offset analysis. A rather classical paradigm makes a clear link between compaction in shales and the alignment of the clay platelets (main constituent of shales). This would imply increasing anisotropy strength with increasing compaction. Our main purpose is to check this prediction on two large databases in shaly formations (more than 800 samples from depths of 0-6 km) by extracting the major trends in the relation between seismic anisotropy and compaction. The statistical analysis of the database shows that the simultaneous increase in density and velocity, a classical compaction signature, is quite weakly correlated with the anisotropy strength. As a consequence, compaction can be excluded as a major cause of seismic anisotropy, at least in shaly formations. Also, the alignment of the clay platelets can explain most of the anisotropy measurements of both databases. Finally, a method for estimating the orientation distribution function of the clay platelets from the measurement of the anisotropy parameters is suggested. |
| first_indexed | 2025-11-14T09:54:37Z |
| format | Journal Article |
| id | curtin-20.500.11937-53277 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:54:37Z |
| publishDate | 2017 |
| publisher | Wiley-Blackwell |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-532772017-10-13T04:12:43Z Compaction trend versus seismic anisotropy in shaly formations Pervukhina, Marina Rasolofosaon, P. Shales comprise more than 60% of sedimentary rocks and form natural seals above hydrocarbon reservoirs. Their sealing capacity is also used for storage of nuclear wastes. The world's most important conventional oil and gas reservoirs have their corresponding source rocks in shale. Furthermore, shale oil and shale gas are the most rapidly expanding trends in unconventional oil and gas. Shales are notorious for their strong elastic anisotropy, i.e., so-called vertical transverse isotropy. This vertical transverse isotropy, characterised by a vertical axis of invariance, is of practical importance as it is required for correct surface seismic data interpretation, seismic to well tie, and amplitude versus offset analysis. A rather classical paradigm makes a clear link between compaction in shales and the alignment of the clay platelets (main constituent of shales). This would imply increasing anisotropy strength with increasing compaction. Our main purpose is to check this prediction on two large databases in shaly formations (more than 800 samples from depths of 0-6 km) by extracting the major trends in the relation between seismic anisotropy and compaction. The statistical analysis of the database shows that the simultaneous increase in density and velocity, a classical compaction signature, is quite weakly correlated with the anisotropy strength. As a consequence, compaction can be excluded as a major cause of seismic anisotropy, at least in shaly formations. Also, the alignment of the clay platelets can explain most of the anisotropy measurements of both databases. Finally, a method for estimating the orientation distribution function of the clay platelets from the measurement of the anisotropy parameters is suggested. 2017 Journal Article http://hdl.handle.net/20.500.11937/53277 10.1111/1365-2478.12486 Wiley-Blackwell restricted |
| spellingShingle | Pervukhina, Marina Rasolofosaon, P. Compaction trend versus seismic anisotropy in shaly formations |
| title | Compaction trend versus seismic anisotropy in shaly formations |
| title_full | Compaction trend versus seismic anisotropy in shaly formations |
| title_fullStr | Compaction trend versus seismic anisotropy in shaly formations |
| title_full_unstemmed | Compaction trend versus seismic anisotropy in shaly formations |
| title_short | Compaction trend versus seismic anisotropy in shaly formations |
| title_sort | compaction trend versus seismic anisotropy in shaly formations |
| url | http://hdl.handle.net/20.500.11937/53277 |