Page 265 - Handbook Of Multiphase Flow Assurance

264 10. Research methods in flow assurance

FIG. 10.34 Oxygen-hydrogen radial distribution function for SPC water model simulation (this work)—solid
line, and experiment (Soper and Phillips, 1986)—line with circles.

and a prospective chemical polyvinyl cyanuric acid (PVCA). The structure of the new chem-
ical is presented in Fig. 10.36. The last three inhibitors were simulated as single monomers
in order to match the <1.0% weight concentration used in real experiments, and to use ef-
fectively the computer resources. The number of 5- and 6-membered rings in the pure water
simulation were compared with those of aqueous polymer/monomer solutions. For the poly-
mer/monomer solutions there was a dramatic decrease of the number of hydrogen bonded
rings in the water structure. It was hypothesized that this disappearance of hydrogen bonded
rings changes the water so that it cannot form gas hydrate without rearrangement of hydro-
gen bonds, which will require both energy and time. This is in a qualitative agreement with
the time dependent performance of kinetic inhibitors. There has been an experimental study
of the effectiveness of kinetic inhibitors monomers. This study indicated that monomers need
to be about 10 times more concentrated in water to inhibit hydrate growth as the polymer.