Plugging Experiments for Ceramic Filling Layer with Different Grain Sizes Under Gas–Water Mixed Flow for Natural Gas Hydrate Development

The natural gas hydrate reservoir in the sea area is shallowly buried and mainly composed of silty silt. The reservoir sediment is weakly consolidated and has fine particles, which shows a higher sand production risk and needs sand control. However, the fine silt particles can easily cause blockages in the sand control medium, so the balance between sand control efficiency and gas production should be considered. At present, there is a lack of reasonable and effective measures to prevent pore blockage in the sand control medium. In this study, the influence of the formation of sand on the blockage in sand-retaining mediums under the condition of gas–water mixed flow is discussed, and the plugging process is analyzed. The results show that: (1) Although the ceramic particles have high sphericity and regular shape, they can form higher porosity and permeability, but the finer ceramic particles will also cause blockages in the muddy silt and reduce productivity. (2) The experimental results of different ceramide filling schemes show that Saucier’s empirical criteria are not suitable for hydrate reservoir development and cannot be directly used for reference. In order to balance the problem of sand control and productivity in the development of the hydrate reservoir, it is recommended to use a 40 × 70 mesh ceramide as the critical optimal condition. The experimental results of this paper have important guiding significance for the development of pre-filled sand control screens and the formulation and optimization of sand control schemes.