What Does Hydrate Inhibitor Mean?
Hydrate inhibitors are the devices or chemical substances designed to control the formation of hydrates during natural gas production at an oil or gas condensate well. Hydrate inhibitors help avoid problems due to hydrate formation such as hydrate plugs and line blockages. Hydrate formation can also occur in a shut-in oil well, leading to solid slurry that is capable of accumulating and plugging the pipe.
Corrosionpedia Explains Hydrate Inhibitor
Gas hydrates are formed during natural gas production at an oil or gas condensate well when free water and natural gas come in contact with each other at low temperature and high pressure. These hydrates look similar to pieces of ice and can clog the flow lines. The location and quantity of the hydrates that form in a well depends on:
- Operating regime
- Well design
- Geothermal gradient in the well
- Fluid composition
- Other factors
Hydrate formation is a big problem in the oil and gas industry. Hydrate inhibitors are used to control hydrate formation. Three types of hydrate inhibitors are used:
- Environmental inhibitor – This is the simplest method adopted by natural gas producers. Here, moisture is removed from the gas before it is cooled. This ensures the absence of water and therefore no hydrate formation occurs.
- Thermodynamic inhibitor – This is one of the most common hydrate inhibition methods adopted. It is done either by:
- Heating the gas
- Decreasing pressure in the system
- Injecting a salt solution
- Injecting alcohol (methanol) or ethylene glycol
- Kinetic inhibitor – Also known as a low dose hydrate inhibitor, it offers advantages over the other two methods. These inhibitors substantially reduce chemical consumption, they are environmentally friendly and they are suitable for challenging production conditions such as deep-water pipelines and subsea tie backs.