InterPore2026

Hysteresis Mechanisms and Numerical Simulation of Hydro-Mechanical Coupling during Cyclic Injection–Production in Karst Aquifer Gas Storage Reservoirs

19 May 2026, 14:50

15m

Oral Presentation (MS16) Complex fluid and Fluid-Solid-Thermal coupled process in porous media: Modeling and Experiment MS16

Speaker

Yuchun Du

Description

Karst aquifer gas storage reservoirs operated for peak shaving undergo long-term cyclic injection and production. The pore pressure oscillates between upper and lower bounds, driving a looped evolution of effective stress paths and consequently inducing hysteretic changes in porosity and permeability as well as irreversible accumulated damage. These effects manifest as deliverability degradation, amplified deformation responses, and elevated integrity risks. To elucidate the key controlling mechanisms and engineering constraints under cyclic operation, this study develops a hydro-mechanical (HM) coupled numerical model for cyclic injection–production in an aquifer gas storage reservoir. The model couples fluid flow with rock mechanical equilibrium, adopts a Biot poroelastic framework, and incorporates an elastoplastic constitutive law to capture plastic accumulation under cyclic loading. Stress-dependent permeability and porosity evolution are further considered to realize a closed-loop feedback among pore pressure, effective stress, and flow properties. A series of cases with varying injection–production amplitude, cycle period, and number of cycles is designed, and the following outputs are analyzed comparatively: (1) hysteresis loops of porosity/permeability and the evolution of the injection index with cycle number; (2) effective stress paths at representative locations and the spatiotemporal development of plastic zones/damage indicators; and (3) the maximum allowable injection pressure derived from shear-yield and tensile-failure criteria, together with its coupled constraints on working gas capacity. The proposed workflow and evaluation metrics provide a reproducible numerical basis for optimizing cyclic operation schemes and defining safe operating windows for aquifer gas storage reservoirs, and also lay the groundwork for future extensions to gas–water two-phase hysteresis and thermo–hydro–mechanical coupling.