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Summary The Damodar Valley Basin (DVB), host to Asia’s first shale-gas well, presents significant hydrocarbon and storage potential, yet remains a frontier for energy studies due to uncertainties in shale characterization. In this study, we implement a comprehensive multiphysics approach, where benchtop ultrasonic tests are used to gauge dynamic elastic parameters, complemented by petrophysical and petrographic analyses. The techniques used are low-pressure nitrogen adsorption, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and porosity-permeability calculations on 27 distinct and representative core samples. These core samples cover four wells spanning the Barren Measures Formation (BMF) and the Raniganj Formation (RF) of the Raniganj sub-basin (RSB) and Jharia sub-basin (JSB) within the basin. We correlate dynamic elastic properties with petrophysical characteristics and compare them with static elastic parameters reported in shale literature. Our tests reveal that porosity ranges between 1.31% and 6.25%, while permeability varies between 0.00006 m and 0.0112 m in the sub-basins. The tests also indicate post-depositional carbonate cementation and hydrothermal activity related to igneous activities in the sub-basins. A mineralogical control on velocities is also observed, with carbonates positively affecting the velocity of both primary and secondary waves, indicating their role in the rock’s load-bearing framework. We observed different mechanical behaviors, such as higher stiffness in the case of the BMF, due to post-depositional carbonate-rich cementation, and the presence of minerals such as pyrite and iron oxides. We observed a higher shear failure and lower shear modulus in the RF related to mixed lithology and muscovite-rich laminations. We estimated average dynamic bulk moduli of approximately 22.45 GPa vs. 15.09 GPa, dynamic shear moduli of about 16.08 GPa vs. 10.21 GPa, and Poisson’s ratios of about 0.21 and 0.22 for the BMF and RF, respectively. We report the first data set of dynamic elastic moduli for the sub-basins, which so far have remained poorly studied. We present a strong and statistically significant correlation between shear and compressive waves for the sub-basins, which would be helpful in cases where shear data are absent or not acquired. The findings provide critical insights into the basin and give a foundational data set for future rock physics modeling and feasibility assessments, supporting future energy exploration and underground storage initiatives in this region.
Jamwal et al. (Fri,) studied this question.