During the process of natural gas hydrate exploitation, the cementation state of the stratum changes due to the decomposition of skeleton hydrate. Fine sand in the reservoir will migrate to the wellbore with the fluid, which is the so-called sand production phenomenon. Sand production will bring great harm to hydrate exploitation. In this paper, a set of macroscopic visualized sand production vessel is designed, which can observe the migration of sand in the sediment layer under different working conditions, and the factors influencing the sand production characteristics are obtained by measuring the amount and the size of sand production. It is found that fine sand will invade and block the gravel layer driven by water and it is accompanied by the collapse and subsidence of the sand layer. Fluid velocity and initial hydrate saturation are important factors affecting the characteristics of sand production. In addition, it is of certain guiding significance to select the appropriate median diameter ratio of sand to gravel for sand control in the actual exploitation process.
Keywords Hydrate, Sand production characteristic, Fine sand migration, Gravel pack