| Abstract Submission No. | ABS-2.4-0087 |
| Title of Abstract | Fluid Substitution Modelling of Unconventional Shale Reservoir to identify shale resource potential in the Damodar River Valley Basin, India |
| Authors | Arpan Pan* |
| Organisation | IIT ISM Dhanbad |
| Address | Vill- RASKUNDU PO - RASKUNDU Midnapore, West Bengal, India Pincode: 721127 E-mail: arpanpan105@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Fluid Substitution Modelling is a powerful tool to assess the sensitivity of elastic properties to pore fluid variations and plays a vital role in evaluating unconventional shale reservoirs. The characterization of such reservoirs requires a robust understanding of rock¿fluid interactions, as their elastic responses are strongly influenced by pore structure, mineral heterogeneity, and fluid distribution. In this study, Fluid Substitution Modelling was applied to two wells containing prominent shale formation in the Damodar River Valley Basin of India to investigate the shale resource potential. Well log data were used to derive petrophysical properties, including porosity, volume of shale, and water saturation, which formed the input for subsequent rock physics analysis. Fluid substitution was performed using Gassmann, Mavko¿Gassmann, Soft Porosity Model (SPM) and Single Aspect Ratio (SAR) formulations to simulate elastic responses under varying fluid conditions. The results indicate a clear difference in the sensitivity of different models. SPM revealed the strongest gas effect on compressional velocity (Vp), SAR showed intermediate sensitivity, while Gassmann consistently produced the smallest fluid response.. Shear wave velocity (Vs) remains largely unaffected in all cases, but variations in acoustic impedance and Vp/Vs provide effective discrimination between gas- and brine-saturated zones. Comparative analysis shows that SPM captures fluid sensitivity more effectively and matches measured log responses more closely than SAR and Gassmann formulations, enabling more reliable elastic characterization of shale intervals. The improved consistency between modelled & measured responses further validates the applicability of SPM for unconventional shale settings. This study demonstrates that fluid substitution, when constrained by petrophysical analysis and calibrated rock physics models, can delineate potential gas-bearing zones in the prominent shale formation with improved confidence. |
| Keywords | Unconventional Shale; Fluid Substitution Modelling; Rock Physics Analysis; Damodar Basin |