Abstract

Complex geological-settings are generally characterized with the presence of highly undulating topography, steep dips, faults etc., posing striking challenges to seismic imaging of data acquired in such areas. The Assam-Arakan Basin and adjacent fold belts exhibit multiple imbricated thrust systems, tight anticlinal structures, steeply dipping sedimentary sequences, velocity inversion zones and rapid velocity variations etc. which complicate the seismic wave propagation, leading to distortions in statics, low signal-to-noise ratio, mispositioning of fault and reflectors, making it very difficult to analyze reflection events. Traditional seismic processing techniques often fall flat in such scenarios, resulting into poor/inaccurate imaging and interpretation. Furthermore, the anisotropic behavior of seismic waves, caused by variations in rock properties, necessitates advanced processing techniques to correct such anomalies. The need for specific processing methodology is required to untangle these complex subsurface images. This work explores the implementation of a customized workflow for Seismic Data Processing as an effective tool for such tricky areas. This work introduces a methodology that not only computes floating datum static corrections but also includes several steps like velocity analysis at floating datum, careful noise removal, surface consistent residual statics correction, running pre-stack Kirchhoff’s migration using both RMS velocity as well as Eta (η) volume, preserving reflected energy from anticline at far offset traces and careful selection of mute for preserving far offset traces etc. significantly enhanced imaging, particularly at the anticlinal part. The area of study comprises of the Khowai-Kalyanpur area, within the Tripura Fold belt. The one Baramura anticline mapped using customised workflow of processing is the second largest structure mapped in the Western Tripura and is one of the important structures for the accumulation of hydrocarbons. Conventional processing yielded poor reflector continuity, time sag, and mis-positioned anticlinal structures and faults. The use of customised processing flow in the fold-belt of Tripura region have led to enhanced imaging of subsurface anticlinal structures and faults which have hydrocarbon potential.