transfer of condensate from platform to onshore

[ehsank1358]

Dear Friends
My question is regarding transfer of condensate from a gas field platform to onshore.
In all projects that i have seen ever , after separation of gas and condensate and water in free water knock out drum and coalecer the gas and condensate are mixed together and sent to onshore via a common pipeline along with a piggy back line(meg injection).(e.g.gas+condensate line size is 32", and meg line size is 4")
but recently i saw a project that transfer gas and condensate separately to offshore and piggy back line(meg injection) is installed on condensate line.(gas line size is 26",condensate size is 12" and meg line size is 4")
i want to know the reason and criteria for selecting unique or divided pipeline system for transfer of gas and condensate.
any help is highly appreciated

 

[JLSeagull]

Some platforms process gas offshore including sweetening to remove hydrogen sulfide and dehydrating to remove produced water. Perhaps where sufficient processing is performed it makes sense to pump the condensate onshore instead of spike the processed gas.