Finger Thickening during Extra-Heavy Oil Waterflooding: Simulation and Interpretation Using Pore-Scale Modelling

Area of Science:

• Petroleum Engineering
• Enhanced Oil Recovery
• Fluid Dynamics

Background:

• Thermal methods for heavy oil recovery are often uneconomic.
• Alternative methods like water injection and polymer flooding are being explored.
• Laboratory studies revealed dendritic water fingers thickening and braiding post-breakthrough, improving sweep efficiency.

Purpose of the Study:

• To investigate and understand the phenomenon of finger thickening during water flooding of extra-heavy oils.
• To develop and validate a dynamic network model for simulating pore-scale displacement physics.
• To provide insights for optimizing water flooding processes for field applications.

Main Methods:

• Developed a fully dynamic network model simulating pore-scale displacement physics.
• Benchmarked numerical simulations against historical micromodel experiments.
• Conducted slab-scale simulations and compared results with experimental observations.

Main Results:

• The model successfully replicated observed finger architectures.
• Demonstrated and interpreted finger thickening post-water breakthrough in homogeneous media.
• Examined the impact of core length, wettability, and injection rate on finger swelling.

Conclusions:

• The developed model accurately reproduces finger thickening phenomena observed in experiments.
• Finger thickening and braiding are key mechanisms for improved sweep efficiency in water flooding.
• Further research is needed to understand the impact of fractures and optimize parameters for field application.