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.