Since 2002, CEESI has performed experimental studies in a specially built Hydrate Test Facility (HTF).
Hydrates are an ice-like crystalline formation that can form whenever water and natural gas are in contact with each other.
Given sufficient time, and the proper pressure and temperature conditions, the hydrate formation can grow to a size that will completely block a pipeline.
Although hydrates resemble freezing water, they will form above the ice-point (0°C, 32°F).
For example if water is present in a pipeline that is operating at a pressure of 800 psi, hydrates can form at temperatures as high as 60°F.
The natural gas producers and storage well operators are continually confronting the problems associated with the formation of hydrates.
The Hydrate Test Facility is capable of duplicating field conditions where hydrate formation causes problems for the pipeline operators.
Common field conditions such as shut-in piping, problematic piping configurations, and low pipeline gas velocity can be simulated.
Experiments at these conditions can be performed to identify mechanisms of hydrate growth and identify the effects of hydrate flows on equipment.
The experiments may lead to actions which could control, remove, or prevent the formation of hydrates at an operator's site.
At present, the natural gas industry use expensive inhibitors such as methanol to help control the hydrate problem.
One of the goals of the initial hydrate test program was to find a way to reduce or eliminate the amount inhibitor required for storage field operations.
The Hydrate Test Facility can perform experimental tests over a pressure range of 100 to 1200 psi in pipe sizes from 1" to 8".
Gas velocities from 0.1 to 20 feet/second in a 4 inch pipe can be obtained.
Also, at high pressures up to 4500 psi, velocities from 0 to 1 ft/sec can be obtained in 4" schedule 160 pipe.
Water content and inhibitor injection can be varied to a client's needs.
Typically, the Hydrate Test Facility uses lean natural gas with an energy content of 1000 to 1100 BTU/cubic-foot as the gaseous flowing media.
However, since the HTF is a closed-loop system, a specific mixture of natural gas components can be made for special testing. |
Snapshots of hydrate transport in piping section with gas velocity of about 2 ft/sec.
The only components in the pipeline are natural gas and pure water.
The gas temperature is about 10 degrees below hydration formation temperature.
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