Hydrate reservoirs often experience phase transitions such as decomposition and reformation during production process, which can significant fluid flow and reduce gas recovery efficiency. To reveal the mechanism between hydrate phase transition and gas–water two-phase flow behaviors, a visualized experimental setup was developed to monitor hydrate phase transition characteristics under different initial pressure and saturation conditions during the multiphase flow process. The experimental results indicated that initial conditions played a critical role in the onset timing of hydrate decomposition and flow continuity. The high hydrate saturation and pressure were more likely to induce flow blockage and delayed decomposition of methane hydrate. Intermittent “flow–blockage–recovery” dynamics were observed, suggested the repetitive hydrate decomposition–reformation cycles. Moreover, gas–water flow was not only a consequence of phase change but also a driver that promoted local decomposition and flow path reconstruction through thermal and pressure disturbances. This study provided experimental insights into the non-equilibrium interactions between flow and phase transition in hydrate reservoirs and contributed to developing flow-control strategies for efficient hydrate exploitation.
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Funding
This research was no funding provided.
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