Permeability Evaluation in Hydrate-Bearing Sand Using Tubular Cell Setup

Abstract

Production of natural gas from hydrate-bearing sediments is significantly influenced by permeability variations in the presence of gas hydrate. The quantification on how absolute permeability and relative permeability affect natural gas production from hydrate-bearing sediments is one of the key interests for reservoir engineering studies. This study focuses on the relationship between water saturation, permeability, and porosity in unconsolidated quartz sand. Methane hydrate was formed in quartz sand in high-pressure stainless steel cell using deionized water at 276 K and 8 MPa. The sand pack with porosity of 40% was saturated with 35% water. This study found that porosity of the sample reduced significantly as the sand pack saturated with 35% of water. Porosity reduced from 40 to 37.4% due to the increase of hydrate saturation. Absolute permeability is 108.72 mD, and it was measured before gas hydrate formation. Relative permeability was measured after gas hydrate formation, and results show that relative permeability is 0.49. Formation of hydrate in pores significantly reduces the relative permeability and porosity. Relative permeability from this work is compared with a theoretical model, and the value shows that the relative permeability from this work is close to the value from Masuda model with N = 10.