Authors(s): Manoj Kumar Bhartee1*, Uma Shankar2, Yadunath Jha1 and Nani Madhab Dutta3
Date of Publication: March, 2025
Publication reference: J. Ind. Geophys. Union, 29(2) (2025), 101-114
Abstract:
Even though there have been substantial advancements in seismic data acquisition and processing, imaging in structurally complex regions like fold belts has seen only marginal improvement. In such geologically intricate areas, the conventional imaging approach may not yield satisfactory results. While 3D surface seismic surveys are preferred, acquiring 3D seismic data can be challenging due to logistical constraints. Moreover, the rugged terrain and difficult accessibility in these areas make 3D land seismic data acquisition prohibitively expensive. Conventional 2D land seismic data also has limitations, particularly in accurately imaging anticlinal features. An alternative to traditional 2D surveys in such contexts is the swath-line recording geometry. Swath line recording offers significantly higher fold (720-fold in the present case), compared to typical 2D land surveys, resulting in data with an improved signal to-noise ratio. However, several issues adversely impact imaging quality in thrust fold belts. Key factors affecting the quality of processed outputs include geometry, statics, and poor signal-to-noise ratio. Survey objectives may remain unmet unless these factors are addressed or minimized. We utilized a hybrid approach, combining multiple techniques including geometry corrections, nonlinear tomography-based statics solutions, velocity estimation using the CVS method, and leveraging different software suites and algorithms to address these inherent challenges.
Keywords: Tripura Fold belt, Swath-line, CMP line, S/N ratios, Semblance, Constant velocity stack method (CVS), PSTM