Offshore processing method and system

摘要

A method for removal of a compound from a crude hydrocarbon gas stream to be obtained from a sub-sea well is disclosed. The method comprises bringing the crude hydrocarbon gas stream in contact with a treatment solution comprising an absorbent at least partly selective to the compound to be removed, thereby obtaining a rich treatment solution and a compound depleted gas stream, regenerating the treatment solution comprising the absorbent by desorbing the compound from the rich treatment solution, thereby obtaining a compound stream. The crude hydrocarbon gas stream is brought in contact with the treatment solution comprising the absorbent subsea, the compound depleted gas stream is obtained subsea, where as the regenerating of the rich treatment solution and obtaining the compound stream is performed topside Further a system for transporting a treatment fluid from a subsea treatment unit to a topside regeneration involving adding pressurized hot natural gas to the treatment fluid subsea as a lift gas and separating the natural gas from the treatment fluid topside before the treatment fluid enters the treatment unit is described.

主权项

1. A crude natural gas treatment system for removal of a compound from a crude natural gas stream, the system comprising:
an absorption unit which includes a natural gas inlet, a treatment solution inlet, a compound depleted gas outlet and a rich treatment solution outlet; a desorption unit which includes a rich treatment solution inlet, a compound outlet and a depleted treatment solution outlet; wherein the rich treatment solution outlet is in fluid communication with the rich treatment solution inlet and the depleted treatment solution outlet is in fluid communication with the treatment solution inlet; wherein the absorption unit is located subsea and the desorption unit is located topside; and a heat exchanger for heat exchanging the rich treatment solution with the depleted treatment solution; wherein the heat exchanger is a pipe-in-pipe riser through which the rich treatment solution and the depleted treatment solution are conveyed.