Contributions of Compaction And Aquathermal Pressuring to Geopressure and the Influence of Environmental Conditions: DISCUSSION
| Autor: | T. W. Miller, C. H. Luk |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
geography
geography.geographical_feature_category Mathematical model Compaction Energy Engineering and Power Technology Geology Sediment compaction Structural basin Sedimentary basin Thermal expansion Fuel Technology Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Fracture (geology) Geotechnical engineering Material properties |
| Zdroj: | AAPG Bulletin. 77 |
| ISSN: | 0149-1423 |
| DOI: | 10.1306/bdff8fa6-1718-11d7-8645000102c1865d |
| Popis: | Luo and Vasseur (1992) presented a useful methodology of simplifying the complex equations that describe basin compaction and thereby directly assessing the contribution of aquathermal effects in the development of abnormal pressures. Their methodology leads to the conclusion that aquathermal pressuring plays only a small role in the development of overpressures in sedimentary basins. Although this conclusion follows from the cases studied, it is possible to conclude otherwise using (1) a more general model of sediment compaction, and (2) material properties that are more representative of conditions at depth. The primary factor behind objection to the conclusion in Luo and Vasseur (1992) is that is fundamental equations, which formed the basis for the simplifying methodology, do not account fully for conditions in which a sediment's effective stresses are reduced. We emphasize here that we do not claim that thermal effects are the dominant cause of overpressures; rather, our calculations suggest that they are not negligible in all cases. There is a complex interplay of the various mechanisms that cause excess pore-water pressures; no one mechanism of overpressuring dominates all others for all situations. Because thermal effects not only cause higher excess pore pressures but also reduce effective stresses, thermal effectsmore » will be minimized by default in calculations that do not account for effective-stress reduction. The resulting reduced effective stresses also have important implications for geological questions such as acoustic velocities and fracture potential.« less |
| Databáze: | OpenAIRE |
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