Water flowing together with oil and gas in the wellhead stream to production facility is removed by the surface separators. However, the separated gas contains saturated water that must be further removed, in a process called dehydration. If the water saturated in the gas stream is not removed, there is a high possibility for that water to condense out at different pressure and temperature conditions, form hydrates and cause corrosion to pipelines and other system components. In general, the methods available for gas dehydration include refrigeration, adsorption, membrane separation and glycol dehydration.
The gas dehydration methods of Generon on offer include:
- TEG Dehydration
- Membrane separation
- Low temperature separation unit / hydrate inhibitor unit
- PSA / TSA dehydration
The most common and widely used method is using Tri-Ethylene Glycol (TEG) for absorbing water from the gas stream. This method requires the lower OPEX and CAPEX than any other dehydration method. PSA/TSA dehydration system is used for gas streams with high H2S content and oxygen content, where very low water dew points are required, and when both water and hydrocarbon dew points of gas must be simultaneously controlled. In terms of CAPEX and OPEX, PSA/TSA systems are more expensive than glycol systems.
|TEG dehydration||Membrane Separation||Low Temperature separation unit / hydrate inhibitor unit||PSA/TSA dehydration|
|Flow Rate||Up to 100 MMscf/d||Up to 500 MMscf/d||Up to 100 MMscf/d||< 20 MMscf/d|
|Pressure||150 – 200 psi||Up to 2000 psi||>100 – 400 psi||100 – 400 psi|