Sand production model in gas hydrate-bearing sediments

• First work to incorporate the effect of sand migration into THM formulation for gas hydrate-bearing sediments.
• Sediment deformation, grain detachment, sand migration pressure change and temperature change are all coupled.
• The effect of hydrate dissociation on sand production is investigated.
• Sensitivity analyses are conducted to describe the effect of each parameter.
• Possibility of sand production management through various gas production methods is presented.

This paper provides a comprehensive analytical formulation that entails the features of sand production in gas hydrate-bearing sediments, including grain detachment, migration, sediment deformation and hydrate dissociation. The formulation is thermo-hydro-mechanically coupled such that grain detachment causes stress reduction, sediment shear deformation induces grain detachment and grain flow alters multiphase fluid pressure and temperature profiles. Through a series of analyses, the sensitivity of sand production related parameters on resulting solid volume changes is evaluated. Furthermore, the effect of various operational methods on mitigating sand production in hydrate-bearing sediments during gas production is numerically investigated. It is found that, out of the different operational methods investigated, lowering depressurization rate was the most effective in reducing sand production for a given gas production.