Modeling and simulation study of CO2 fracturing technique for shale gas productivity: a case study (India).

Carbon dioxide (CO₂) fracturing as an alternative to hydrofracturing is one of the most effective fracking techniques for shale gas extraction. As the water-based fracturing fluid can cause formation damage, clay swelling, and water blocking in shale, it is essential to replace it with CO₂ fracturing fluids. The CO₂ fracturing technique utilizes comparatively fewer chemicals and water, and has a high capacity for adsorbing CO₂ with CH₄. The CO₂ fracturing technique is an appropriate fracturing technique as compared to other fracturing fluids. As the shale reservoirs are heterogenous, fracturing techniques are controlled by several parameters. Therefore, the shale reservoirs need to analyze adequately at a different scale. 3D modeling is essential to understand the efficacy of fracturing in unconventional reservoirs. The present study demonstrates the 3D geo-mechanical model through reservoir simulation techniques, and we estimate the gas recovery for a shale reservoir. The multi-stage fracturing tests were conducted on the unconventional reservoir using the fracture model to assess the heterogeneity, and change in the distance between the fractures. This study also analyzes the effects due to the space distance and fracture conductivities. The simulation study is conducted under different conditions by using CO₂ as a fracturing fluid. The results suggest that the shale gas recovery rate increased by approximately 3 to 7% with the changes in fracture half-length, spacing, and fracture numbers. [ABSTRACT FROM AUTHOR]