What are the typical applications?
The Hydrate Safety Margin
The hydrate safety margin can be calculated for systems using thermodynamic hydrate inhibitors. The hydrate phase boundary is first calculated by feeding the concentration of salt and inhibitor determined by HydraCHEK and the hydrocarbon fluid composition into a thermodynamic model (see our hydrate prediction software HydraFLASH).
The operating pipeline temperature and pressure can then be superimposed to give the hydrate safety margin of a system.
HydraCHEK can be used to continuously monitor the hydrate safety margin and provide a warning if operating conditions are inside the hydrate stability zone. This provides an extra level of protection for a system against pump malfunction or changes in process variables and helps increase the reliability of production.
Optimising Inhibitor Injection Rates
Hydrate remediation strategies often involve excessive dosing of inhibitor to minimise the risk of hydrate blockage. Inhibitor dosage is usually determined based on predicted/ measured hydrate phase boundary, water-cut, worst operating conditions and the estimated inhibitor loss to non-aqueous phases. A safety factor is also applied for numerous other variables (e.g. pump rate) with the overall result being large over inhibition for many systems.
The consequences of this are unnecessarily high CAPEX and OPEX relating to inhibitor transport and storage, regeneration and reclamation, water management and Health, Safety and Environmental (HSE) risks.
HydraCHEK can be used to optimise inhibitor injection rates by providing a rapid, accurate and highly repeatable way of quantitatively measuring the degree of inhibition of a system.
If a system is being over inhibited and is safely outside the hydrate stability zone, injection rates can be optimised and HydraCHEK can be used to continuously monitor the effect of lowering the dosage.
HydraCHEK gives the operator a clear picture about the hydrate inhibition characteristics of a system and the confidence to optimise inhibitor injection rates.
Low Dosage Hydrate Inhibitors (LDHIs)
Low dosage hydrate inhibitors: kinetic hydrate inhibitors (KHIs) and anti-agglomerants(AAs) can be used efficiently at much lower doses (0.5 - 4 wt. %) than thermodynamic inhibitors. The rate of hydrate formation and risk from under dosing is therefore much greater and monitoring of KHI and AA in a production system is essential to ensure efficient injection.
HydraCHEK can be used to accurately measure KHIs and AAs in produced water samples providing a fast and reliable method for operators to confirm inhibitor is present downstream from injection and ensure the prevention of hydrate formation.
HydraCHEK can also be used to:
- Monitor concentrations in lean and rich streams in methanol/glycol regeneration units or gas dehydration processing
- Monitor residual inhibitor concentrations during start-up before ramping up production