Conclusion
In this work, the effect of new anti-agglomeration agent ( coconut oil amide propyl betaine ) on the flow stability of oil-water emulsion system under different water contents and flow rates was explored, and it was confirmed that the new anti-agglomeration agent under high water content or even pure water conditions can still play an anti-agglomeration role, so that hydrates can form stable and mobile mud. In addition, in order to explore the parameter changes in the system caused by the transient changes ( shutdown and start ) in the flow system and the flow characteristics of hydrate in the non-flat pipeline, the flow characteristics of hydrate slurry with inclined pipe section are explored, and the changes in the flow characteristics of hydrate with shutdown and restart in the actual production process are explored by stopping and restarting the equipment. The specific research results are as follows :
Coconut oil amide propyl betaine can be used as an excellent anticoagulant to prolong the plugging time of hydrate under pure water conditions. However, when it plays a role, it will generally make the flow in the system fluctuate significantly and irregularly. This may be caused by the change of hydrate aggregation state by the inhibitor. The specific mechanism still needs further study to supplement the insufficient understanding of the anti-aggregation process mechanism of the inhibitor. The water content can affect the liquid bearing capacity and the unit solubility of the hydrate formation region. The initial flow rate will change the gas-water mass transfer efficiency during hydrate formation and the shear force on the hydrate layer on the wall. The increase of water content and initial flow rate will prolong the plugging time of hydrate. The conclusion can be used as a theoretical support for mobility support technology. The plugging time of inclined pipe is usually shorter than that of the straight pipe with the same inclination condition, which may be due to the existence of dead angle in inclined pipe and the accumulation of exfoliated hydrate sediments, leading to a sharp increase in pressure drop. It is necessary to further develop the flow support technology for inclined pipes to ensure the stable operation of energy transmission in unconventional pipe sections. Adding polymer inhibitor can prolong the plugging time after shutdown and restart, and the plugging mechanism of hydrate from formation to plugging in the system of shutdown and restart is drawn.