Application of time-frequency decomposition and seismic attributes for stratigraphic interpretation of thin reservoirs in “Jude Field”, Offshore Niger Delta

Abstract

Precise reservoir characterization has been challenging and demanding due to the in-homogeneity involving sand and shale distribution. The complexity of the subtle structures within thin reservoirs in the deep-water depositional system is another factor. The reservoirs of interest are trapped within an important area noted for exploration activities. Regardless, they can be bypassed considering the complexity that results in poor resolution of the seismic data. Fewer research activities have been carried out within the thinly bedded reservoirs. Spectral Decomposition (Time-Frequency Decomposition) was used for the characterization of the complicated reservoirs to delineate structural changes and stratigraphic information along interpreted horizons. Also, it gains insight into the stratigraphic setting and the complexity of the geology. The transformed results include tuning volumes and a variety of frequency slices. When the fast Fourier algorithm was applied to seismic reflection data, the seismic signal was broken down into its frequency components and allowed visualization of the data at specific frequencies. Stratigraphic and structural features that otherwise would have been overlooked in full bandwidth display were identified. The obtained result revealed concealed and complex geologic features such as multi-complex and meandering channels, subtle faults and lobes. Time-frequency decomposition of seismic data for thinly bedded reservoirs interpreted using high frequency has led to the precise delineation of geologic features of interest. This study will also help in the recovery of more hydrocarbon as bypassed zones and subtle structures are revealed.

Keywords

• in-homogeneity
• hydrocarbon accumulation
• reservoir characterization
• meandering channels
• fourier transform