| dc.description.abstract | The AVO modelling data is compared with the real seismic data. The data is acquired and seismic cubes are processed on Near, Mid, Far, Ultra and Full Stacks by Schlumberger as part of Statoil's order. Then the stratigraphy of Eastern Barents Sea is studied in a lot of details.
This seismic data had to be prepared for the careful AVO and attribute analysis, which is done by preconditioning. Than detailed attribute analysis is performed and following attributes are derived: Fluid Index, Lithology Index, II class, Intercept x Gradient, Instantaneous Frequency, Instantaneous Phase and Instantaneous Amplitude and interpreted. Several flat spots are detected and investigated. It is proven that flat-spots in the outer-dome structure are unresolved multiples, but the nature of the flat-spot within the inner-dome structure has been studied in detail. Fluid Index attribute shows a weak anomaly most likely related to the fluid content, Lithology Index cannot be interpreted properly since it is affected by the multiple, and no clear anomaly in the inner-dome is observed. II class attribute shows the presence of II class anomaly in the inner-dome area, which can be interpreted as a sign for a fluid content. The study of Intercept x Gradient, Instantaneous Frequency and Instantaneous Phase shows no interpretable anomalies, but there is a prominent amplitude anomaly in the inner-dome structure on the Instantaneous Amplitude attribute, well-correlated with the flat-spot, and most likely caused by fluid saturation.
The AVO cross-plotting is also done. The Intercept-Gradient and Intercept-Curvature cross-plots show that Hekkingen formation is actually not a single formation, but 3 similar, but well separated formations. Some anomalies related to the porosity and fluid saturation are observed in the Base Hekkignen - Top Fruholmen, Base Snadd - Top Intrasnadd and Top Intrasnadd +100 ms intervals. This formations become a target for a forward modelling, which shows that either Nordmella or Sto fluid bearing sands should underlie the surface of Base Hekkingen formation.
Therefore the conclusion can be drawn that in the interval of Base Hekkingen - Top Fruholmen formations in the inner-dome structure of the North-West slope of the Fedynsky High the fluid saturation is very likely according to the research that was done. | en |
