Abstract

The hydrocarbon potential of the Kalol Formation in the Ahmedabad Field, located in the central part of the Cambay Basin, is well established. Although seismic data in this area have been acquired and processed multiple times, the interpretability of processed seismic sections for the thin sands of the Kalol Formation still required enhancement. Additionally, the presence of coal seams within the overlying reservoir formation poses an added challenge in accurately imaging deeper geological events. The quality of the Time migration results depends a lot on the accuracy of the velocity model, which serves the dual purpose of imaging and providing time. For improved subsurface imaging, previously processed seismic data were reprocessed with the consideration of seismic anisotropy. Seismic anisotropy indicates that seismic wave velocity, amplitude, and other physical properties vary with direction. It is a critical aspect of petroleum geophysics, providing valuable insights into subsurface structures and reservoir properties. Building a geologically and structurally consistent velocity model that incorporates anisotropy is of paramount importance for improving the imaging of geological events. This paper presents the methodology and results of reprocessing a 3D seismic volume of the Ahmedabad field to improve reservoir mapping. An anisotropic pre-stack time migration approach was employed for imaging the field data. The results demonstrated that anisotropic pre-stack time migration processing significantly improves the accuracy of seismic images, enhances lateral resolution, and increases the signal-to-noise ratio. With advance seismic data processing, integration of interpreted seismic attributes has proven effective for advanced reservoir characterization.