A creep model for weakly consolidated porous sandstone including volumetric creep

• Porous sandstone exhibited viscous volumetric behaviour.
• Burgers model was modified to describe the time-dependant volumetric deformation.
• Volumetric viscosity parameters KKKK, ηmM, and ηmK were added.
• The finite difference method was used to simulate the creep test results of porous sandstone.
• Provide a theoretical model for the time-dependant deformation of reservoir stratum.