Publications

A spectral decomposition of full stack seismic data followed by an RGB (red, green, blue) blending has been used in an attempt to identify the thin Ubadari sandstone reservoirs in Kasuri block. This study was done first by analysing the geological events at two wells where the Ubadari sandstone reservoirs have different appearance, both in seismic and spectra. Several different reservoir models were built and the synthetic seismic and its spectrum were generated to review the difference in order to distinguish the response of the reservoir in the RGB domain. Following this, a synthetic 3D seismic data containing various models were created and the spectral decomposition volumes of different frequencies were calculated. Various RGB blending of different sets of three frequency components were tested to evaluate the ability of the method to map the distribution of the Ubadari sandstone models. The modelling included the models where the Ubadari sandstone were removed to evaluate the sensitivity of the RGB blending of the spectral decomposition components in resolving thin Ubadari sandstone reservoirs sitting very close below a thick Roabiba sandstone reservoir in which the seismic reflection from the base of the Roabiba sandstone reservoir dominates. The results indicate that Ubadari sandstone can be qualitatively mapped by using RGB blending method to show the distribution of the Ubadari sandstone reservoir to some extents with careful analysis on the spectrum amplitude after calibration to the wells response.