Frequency-dependent AVO (FAVO) attribute extraction

Project description
The oil and gas industry has traditionally been highly focused on seismic amplitude interpretation for fluid type and fluid saturation. It is well known that small gas saturations can trigger a major elastic response which remains largely invariant when increasing gas saturation. But is the frequency content of the seismic signal equally insensitive to saturation?

The FAVO technique exploits the link between fluid saturation (particularly in gas reservoirs) and seismic dispersion & attenuation, which affect the frequency content. Research Institutions and Energy Companies have investigated and published that fluid saturation and reservoir heterogeneity may be the main factors controlling the frequency response in sandstone reservoirs, but detailed information has not been revealed.

Thids thesis will include building a code to Extract the “FAVO wave” from spectral decomposition cubes. That is, given a SEGY file, extract amplitude values at different offsets and different frequencies for the same point defined by X,Y,Z coordinates. The code will be tested on the Blasto and Blasto Vest structures in the North Sea to investigate if the FAVO waves can separate between the different hydrocarbon saturations in the two structures. The ability of identifying gas saturations in general will be addressed based on the results of these investigations.

Photo:

Foster et al., 2020, Close et al., 2010

Proposed course plan during the master's degree (60 ECTS):
GEOV 274 (10), GEOG 277 (10), GEOV 218 (10), GEOV 276 (10), GEOV 375 (10), GEOV 272 (10)

Felt- lab- og analysearbeid
Analyses of seismic data provided by Equinor