Page 313 - Handbook Of Multiphase Flow Assurance

312 10. Research methods in flow assurance

FIG. 10.70 Needle-like growth of THF hydrate crystals.

THF + water + inhibitors solution with NaCl salt

A set of experiments was performed with 3.5 wt% of NaCl and kinetic inhibitors in the
solution at 1 °C. In 7 out of 12 tests the kinetic inhibitors (PVP, PVCap, VC-713) with 3.5 wt%
NaCl in the tested solution inhibited hydrate growth completely for at least 30 min after the
hydrate nucleation. In the remaining 5 cases the hydrate growth was planar.

Growth rate measurements
Measurements of hydrate growth rate through a capillary were not reproducible. It is rec-
ommended not to use narrow conduits for hydrate growth rate experiments.

Computer modeling of interaction between a hydrate surface
and an inhibitor

Organization of this section

This section deals with computer simulation of hydrate inhibition. Within we attempt to
determine the mechanism of kinetic inhibition and to explain why some inhibitors are better
than others. The section contains five main subsections:
1. Early modeling of clathrate hydrates at CSM.
2
2. Studies of inhibitor adsorption on hydrate using commercial software Cerius .
3. Using hand-written software for studying interaction of monomers with water and with
hydrate.
4. Adsorption of inhibitor polymers on hydrate.
5. Using the computer to design new inhibitors.