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oa Broadband Seismic Processing enhances illumination of deeper targets on shallow-waters off India
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE Workshop on Broadband Marine Seismic Data, May 2015, Volume 2015, p.1 - 2
Abstract
In a shallow water block in the vicinity of the Krishna River, east coast off India, new geophysics data from a 2013/2014 3D survey long offset data was broadband processed pre-stack time and depth. Broadband increased the lower and higher frequency amplitude spectra providing for high precision seismic resolution to several of the deep seated features of pre-rift and syn-rift that were essentially invisible (or not properly imaged) with vintage seismic.
The Ghost Wavefield Elimination (GWE) with Frequency-P (Slowness) domain bootstrap pre-mig deghosting method was employed for this data. The extra low frequency from de-ghosting successfully imaged the deeper targets, such as steep flanks around 2s to 4s.
With the clearer images, the velocity analysis and modeling were much reliable. Comprehensive demultiples flow was applied for this data too: SWD + SRME + Tau-P decon, to address the severe multiples issue due to shallow water bottom. The enhanced low frequency spectra are also paramount for the improved depth migration derived from velocity models.