Search

In the exploitation of unconsolidated argillaceous reservoirs containing natural gas hydrate (NGH), challenges related to sand production and reservoir instability are widespread. To comprehensively understand this complex phenomenon, a three-dimensional thermal–hydrologic–mechanical–chemical (THMC) coupling model was established in this study. Within this model, the thermal, hydrologic, and chemical (THC) fields are fully coupled and the mechanical field demonstrates bidirectional coupling. The model incorporates a sand control standard, with Dpvalues of 2, 4, 6, 8, and 10 μm representing different grades of sand control ranging from high to low. This study delves into the production capacity, sand production, reservoir subsidence, and hydrate reformation across various sand control standards and production pressure differentials. The results show that increasing sand control standards or reducing production pressure differentials leads to a decrease in gas production. However, these changes prove effective in curbing sand production and hydrate reformation, with no significant impact on the geomechanical response. It is worth noting that the sand control strategy with a Dpof 8 μm has achieved the best results. This method achieved a production level equivalent to a Dpof 10 μm and ensured stable sand control.