Page 339 - Handbook Of Multiphase Flow Assurance

338 10. Research methods in flow assurance

1.00
no polymer
PVCap
Fraction of simulation CH4 spent in cavities
0.80 PVP
new-3-PVP
new-2-PVP
new-2-PVCap
0.60

0.40

0.20

0.00
100.00 200.00 300.00 400.00
Temperature, K

FIG. 10.87 Methane blocking performance of commercially available or feasible chemicals.

Poly(1-acryloyl-azepan-2-one) (also named new-2-pvcap) and poly(4,4-dimethyl-3-
vinyloxy-dihydro-furan-2-one) (new-2-pvp) are potentially good inhibitors and their synthe-
sis is under way.

Summary of simulations

The following conclusions can be made from the Monte Carlo simulation results:
(1) All studied chemicals (both inhibitors and non-inhibitors) adsorbed on hydrate surface
with favorable energies. More polar chemicals adsorbed stronger. Adsorption strength
increased with the number of hydrogen bonds from polymer to surface. Comparison
of adsorption between monomers and polymers (Table 10.23) shows that both groups
have inhibitors adsorbing stronger to hydrate. However, the adsorption strengths of
PVCap and PVA polymers are very close, but their inhibition performances are different.
Adsorption strength should not be used as the only criterion for finding good inhibitors.
(2) Simulation performance of chemicals in blocking methane adsorption on the hydrate
is strongly related to the gas consumption performance of chemicals. Chemicals with