Experimental Research on Gradient Sand Control in the Exploitation of a Natural Gas Hydrate Reservoir

Short-term trials of natural gas hydrate (NGH) have demonstrated that the efficient and safe exploitation of NGH is impeded by sand production. Considering the highly argillaceous characteristics of NGH reservoirs, a refined sand control method has been proposed. The study investigates how to reduce the impact of mudcake plugging on the permeability of the sand control screens. The proposed gradient sand control method has been experimentally validated for its feasibility in reducing mudcake plugging. The optimal combination involves gradient sand control elements with sand control accuracies of 60 and 40 μm. By implementing this optimized approach, the sand production rate can be reduced by 78.1% while only causing a minor decrease of 9.1% in fluid production. This signifies a significant improvement in the sand control efficiency for NGH reservoirs.