Fig. 4-Flow Curve of Hydrate Slurry with and without Antipolymer
in Pure Water
The experiments were carried out at the initial flow rate of 230 L / h
under different moisture content. It can be seen from the curve that
although the new Anti-agglomerants agent can effectively improve the
fluidity of hydrate slurry under different moisture content and
alleviate the trend of plugging, the flow change trend of the system
with Anti-agglomerants agent is usually disordered. Under the conditions
of 50 % and 70 % moisture content, many times of the flow rate of the
system temporarily dropped to zero before the hydrate slurry completely
stopped flowing. We suspect that when hydrate blockage occurs in the
system with Anti-agglomerants agent. The anti-agglomeration agent can
decompose the hydrates that have been generated, aggregated or deposited
on the wall of the pipe to restore the flow of the system, and the
change of the hydrate aggregation state will also make the flow of the
system change irregularly. Therefore, the flow change trend shown in the
following figure will appear.
Through previous studies, it can be known that the polymer inhibitor can
change the dispersion state of water molecules in oil-water emulsion to
make the emulsion more stable, resulting in water dispersed in the oil
phase in the form of water droplets. Gas hydrates formed on the surface
of water droplets will be solubilized in the microemulsion and thus
difficult to aggregate. Therefore, the polymer inhibitor can play an
anti-coagulation role of hydrate particles in oil-water emulsion system.
In pure water system, the mechanism of anti-agglomeration effect of
anti-agglomeration agent may be different from that of oil-water
emulsion. We believe that the aggregation behavior of hydrate crystals
is closely related to the cohesion between hydrate particles. Coconut
amide has a long alkyl chain, which can provide a more dense barrier,
thereby effectively reducing the cohesion between particles. These
molecules can reduce the interfacial tension and increase the contact
angle between natural gas hydrate and water, so as to minimize the
interaction between natural gas hydrate particles. In addition, AA also
affects the liquid bridge between gas hydrate particles by breaking
water molecules, thereby destabilizing the cohesion between hydrate
particles. Fig. 5 shows the mechanism of hydrate
Anti-agglomerants caused by Anti-agglomerants in self-made pure water
system.