Speaker
Description
Acid fracturing is a pivotal stimulation technique for enhancing recovery in carbonate reservoirs. However, accurately predicting fracture propagation is challenging due to the intricate interplay of acid-rock reactions, fluid dynamics, and rock mechanics, further complicated by reservoir heterogeneity and natural fractures. This study presents a comprehensive Hydro-Mechano-Chemical (HMC) coupled simulation framework based on the phase field method to systematically investigate acid fracture propagation mechanisms under varying geological conditions and treatment parameters.
The proposed model incorporates a dual-scale continuum approach for reactive flow and a two-stage homogenization scheme to rigorous account for rock heterogeneity from micro to meso scales. Utilizing this unified framework, we investigate three critical scenarios: (1) Effect of Acid Pre-treatment: The simulation demonstrates that acid pre-treatment significantly reduces breakdown pressure through the formation of wormholes. We identify optimal acid concentrations and treatment durations to maximize stimulation efficiency while minimizing resource consumption. (2) Interaction with natural fractures: We clarify how stress differences, approaching angles, and fluid viscosity dictate the crossing or diverting behaviors of acid fractures. The results highlight how acid dissolution alters fracture surface morphology and mechanical properties, thereby influencing propagation paths. (3) Propagation in layered formations: The study analyzes the impact of acid concentration and injection rates on fracture containment and height growth within geologically layered heterogeneous reservoirs.
Our findings indicate that the evolution of porosity and mechanical properties induced by acid dissolution is critical in determining fracture geometry. This integrated modeling approach provides valuable theoretical insights and quantitative guidance for optimizing fracturing designs, including acid concentration, injection rates, and pre-treatment strategies in complex reservoirs.
| Country | China |
|---|---|
| Acceptance of the Terms & Conditions | Click here to agree |
