Wellhead Control panels at wells op

Asghar,

Installing a Filter Separator with charcoal filter and silca gel bed is an expensive idea and you will need it at each wellsite. This equipment does not actually solve the root problem, which is the fuel gas itself. Most often the fuel gas separators do not knockout sufficient HC liquids. Typical fuel gas separators supply fuel gas based on hydrocarbon dewpoint of -12 to -10°C. This is insufficient when insulated fuel gas lines run above ground at ambient temperatures lower than -12°C. Hydrocarbon liquid and water if the fuel gas was wet, drop out in the fuel line. The liquid drop out is in case too much for the fuel gas scrubbers to handle and carries over into the instrument lines. Preheating the fuel gas works if the sources are close by. On long lines the fuel gas cools of quickly and you experience the same problems again as fuel gas lines are typical uninsulated.

Possible Solutions:
1. Reduce HC dewpoint of the source fuel gas lines to -35°
(best solution)
2. Preheat fuel gas if sources are close by
3. Install small coalescing filters instead of standard
fuel gas scrubbers with autodumps liquid.
4. Inject methanol (does not solve liquid problem)

Some companies make insulated shacks with fuel gas scrubber and preheat coils mounted in front of a catalytic heater. These shacks are specially designed for wellsite locations and are relative cheap

Krossview

Thanks Krossview for the response. your point is valid in areas where there is low temper but in areas where these field are located the temperature does not go below Zero degree C and there is no means to reduce the Dew point except passing through filter separators or any such stationary equipment.
There are filter separator and seemed like they are not providing the desired results. The only option I can think of is # 3, which you are proposing.

But to be extra cautious I have put an activated charcoal and a desicator bed. As far as I know the activated charcoal has a tendency to absorb the heavy hydrocarbons (unless someone has different experience, which I sure would like to know).

The only things worries me is that the silica gel/Alumina will be coated with charcoal particles and may have to be changed frequently, which will create probelum. Similarly the filter cartridge may get plugged with charcoal particles very often.

Any one has better idea than we two have discussed?

Possible Solutions:
1. Reduce HC dewpoint of the source fuel gas lines to -35°
(best solution)
2. Preheat fuel gas if sources are close by
3. Install small coalescing filters instead of standard
fuel gas scrubbers with autodumps liquid.
4. Inject methanol (does not solve liquid problem)