Hydraulic Fracturing Design Optimization in Shale Gas Reservoirs

Abstract

Hydraulic fracturing is a key technique for enabling economically viable production from shale gas reservoirs, as shale formation typically exhibit very low permeability and complex mechanisms of shale gas storage. However, the effectiveness of hydraulic fracturing is based on fracture design, and uncertainty remains regarding which parameters that significant impact on gas recovery. This study aims to evaluate and optimize hydraulic fracturing parameters using a dual-porosity numerical reservoir model representative of Marcellus shale formation. A base-simulation resulted in a cumulative gas production of 0.88 Bscf with a recovery factor of 9.72% from an Original Gas In Place (OGIP) of 9.05 Bscf. Sensitivity analysis was performed using Latin Hypercube Sampling and Assisted History Matching, generating with 100 variant case scenarios. The results indicate that stimulated reservoir length, half-length, and number of fractures are dominantly parameters which influence cumulative gas production, with stimulated reservoir length showing a strong positive correlation (R = 0.71) to total gas output. Optimization based on probabilistic analysis resulted a P50 case with cumulative gas production of 2.90 Bscf and a recovery factor of 32.03% resulting in a recovery factor more than three times higher than the base case scenario, while free gas still become the major dominant contributor to total production, accounting for approximately 88% of total produced gas, whole the contribution of adsorbed gas increased from 0.10 Bscf to 0.34 Bscf under optimized conditions. The results of this study may serve as a strategic reference for optimizing fracture geometry and stimulated reservoir volume to enhance shale gas recovery, while also offering a robust quantitative basis for improving hydraulic fracturing design in unconventional gas reservoirs.