A Novel Relative Permeability Model for Gas and Water Flow in Hydrate-Bearing Sediments With Laboratory and...

Area of Science:

• Geosciences
• Petroleum Engineering
• Chemical Engineering

Background:

• Producing gas hydrate reservoirs exhibit dynamic effective porosity due to hydrate dissociation.
• Legacy relative permeability models require extensive calibration for hydrate-bearing media, often hindered by data scarcity.

Purpose of the Study:

• To develop a novel relative permeability model for gas hydrate-bearing sediments.
• To address the limitations of existing models in capturing the impact of evolving hydrate saturation on fluid flow.

Main Methods:

• Proposed a new relative permeability model incorporating capillary pressure, pore size distribution, and residual saturations.
• The model requires fitting six empirical parameters only once, applicable across all hydrate saturations (S_h).
• Implemented the model in a numerical simulator and compared computational efficiency with the Brooks-Corey model.

Main Results:

• The proposed model successfully predicts relative permeability across a range of hydrate saturations using a single parameter set.
• The model's computational time is comparable to the established Brooks-Corey model.
• The model effectively accounts for capillarity and pore-size distribution effects.

Conclusions:

• The developed relative permeability model offers a significant advancement for simulating multiphase flow in gas hydrate systems.
• It provides a physically accurate approach to modeling fluid flow dynamics influenced by changing gas hydrate saturations.
• The model's simplified calibration and broad applicability enhance its practical utility in reservoir simulation.