Inhibex™ gas hydrate inhibitors
Low Dose Hydrate Inhibitors (LDHIs), technology developed in the 1990s, significantly improved the options available to offshore operators in preventing type I, II and H gas hydrates, the ice-like crystals that left untreated will damage or rupture pipelines, valves and well heads located under water. These LDHIs, based on Poly VCap polymers, require less than 1 percent (wt.%) to prevent gas hydrates from forming in fields with high water cut.
Inhibex 301 gas hydrate inhibitors, one of the first commercially available low-dose kinetic hydrate inhibitors from Ashland, remains as an alternative to thermodynamic hydrate inhibitors (THI) in some cases, and a booster to THI methods in other scenarios.
Today, however, offshore oil and gas operators work within a larger spectrum of temperature and pressure conditions. Ashland has responded to requests from oilfield chemical formulators for new polymeric gas hydrate inhibitors that address more challenging operational conditions offshore (and changing regulatory requirements). The chemistry of Inhibex gas hydrate inhibitors continues to expand in support of higher cloud points, higher sub-cooling conditions and regulatory schemes that require the use of biodegradable chemicals.
LDHIs based on Poly Vinyl Pyrrolidone (PVP) and Poly Vinyl Caprolactam (VCap) retard gas hydrates by functioning as “anti-nucleates.” Specifically, as KHIs, these technologies interact with crystal growth sites to delay hydrate nucleation.
- Lower dose rate vs. standard THIs
- Subcooling performance up to 11.5°C in lab tests
- Salt and temperature tolerance at certain conditions
- Moderate viscosity for consistent formulation
- Comparable subcooling vs. 25 percent dose rate methanol
- Methanol compatible
- Lower environmental impact than methanol
Formulations and Solution Properties
Inhibex gas hydrate inhibitors are available in three distinct formulas:
• Inhibex 301
• Inhibex 501
• Inhibex 713