This project aimed to constrain the interpretation uncertainties associated with reflection seismic data of deep-water slope deposits. The basic premise of the project is that seismic data is affected by small-scale architectural elements and even conventional low-frequency data may contain clues of the sub-seismic geometries. These can be decoded by understanding the interaction between internal elements and the seismic wavelet. A series of outcrop-derived forward seismic models was created, representing different types of outcrop based slope deposits. The seismic interpretation of the forward models was based on amplitude analysis supplemented by instantaneous attributes and spectral decomposition. In order to create realistic synthetic seismograms, input models included geometries whose thickness was as low as 1% of the resolution limit. By revealing the influence of small-scale structures on synthetic seismic data at the high end of the spectrum (70Hz to 100Hz), the knowledge of tuning effects and the interaction between interfering reflections at lower frequencies (i.e. 20, 40 and 60Hz) could potentially be significantly improved. The gained experience was then applied to real seismic data. It was proven that small-scale geometries have an additional, highly significant effect on the composite reflection. Because of the inherent non-uniqueness in seismic reflection, the specific seismic forward models of particular outcrop analogues can only be used as guides to the seismic interpretation of the particular architectural elements of a subsurface deposit and not as definite models against which one can definitely pattern match real and modelled seismic data. as burial depth increases, so does the non-uniqueness of the seismic interpretation of seismic data from deposits whose internal geometries are around/below the tuning thickness.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:521244 |
| Date | January 2009 |
| Creators | Szuman, Magdalena Katarzyna |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=105419 |
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