Gas Hydrates

 

Current industry trends, including deepwater exploration, increasing exploitation of marginal fields, long tie-backs, and production from ageing reservoirs with high water-cuts all present major hydrate flow assurance challenges.

Conventional thermodynamic hydrate inhibition approaches (e.g. methanol, glycols) are starting to be superseded by more cost-effective emerging technologies such as LDHIs (Low Dosage Hydrate Inhibitors) and cold flow/Hydraflow. Highly tailored, field specific solutions are now the industry norm for economic and safe production.

Combining the facilities of the Centre for Gas Hydrate Research (CGHR) and Centre for Flow Assurance Research (C-FAR) with our own, at Hydrafact we have access to some of the most advanced laboratory equipment for hydrate and flow assurance studies in the world. The majority of our set-ups were custom built in-house based on designs developed through many years R&D experience in the petroleum industry.

Gas Hydrate Plug

Gas hydrates removed from a subsea transfer line (courtesy of Petrobras, Brazil).

Gas hydrate technical studies we offer include:

Hydrate measurements for multicomponent systems containing

  • Gas (natural gas, CO2...) and liquid hydrocarbons (oil, gas condensate...)
  • Condensed water and formation brines
  • Organic inhibitors (alcohols, glycols...)
  • Drilling muds and completion fluids
  • Wax (e.g. solids co-precipitation studies) and inhibitors
  • Corrosion inhibitors
  • Hydraulic fluids
  • Process/product gases/liquids and chemicals

heavy oil seperation data and predictions
Hydrate experimental data and model predictions for a heavy oil + synthetic formation brine pre- and post subsea separation.

Phase compositional analyses

  • Amount and composition of hydrates
  • Aqueous and hydrocarbon phase compositions
  • Inhibitor (e.g. methanol) loss to the vapour phase
  • Water content of natural gases
  • Simulation of various production scenarios (e.g. subsea separation)

 

Low Dosage Hydrate Inhibitor (LDHI) performance and screening

  • Kinetic inhibitor (KHI) induction times
  • Hydrate formation and dissociation rates
  • Simulation of various operating scenarios (e.g. shut-in, start-up)
  • Compatibility of other production chemicals (e.g. corrosion inhibitors)

 

Anti-Agglomerant performance and Cold Flow/Hydraflow studies

  • Viscosity of hydrate/water/oil slurries
  • Effect of water cut, salt, natural inhibitors
  • Simulation of various operating scenarios

Gas Hydrate Prediction
Hydrate/water/oil slurry viscosities for increasing volume fractions of hydrate (H)

Flow loop studies

  • LDHI assessment
  • AA performance
  • Cold Flow/Hydraflow development
  • Hydrate monitoring and early warning systems

 

Hydrate blockage removal and other studies

  • Removal of hydrate blockages in wells and flowlines
  • Hydrate formation, prevention and plug removal during shut-down and start-up
  • Hydrate formation/prevention in chokes and control valves
  • Hydrate formation risks in HIPPS impulse lines
Heriot Watt University Centre for Gas Hydrate Research