Some Oil and Gas fields in Indonesia, particularly in offshore have not been explored due to field economics. The absence of a thorough study of a potential development in the entire reservoir at a Production Working Area contributes the high cost of the development. The O-field would be the object of study with emphasis on the development of conceptual study for surface facilities. Some challenges that must be overcome for the development of this field, including the O-field is comprised of several small reservoirs and scattered. It is located in shallow waters and is in the area of export tankers for shipment of oil and other chemicals. The development of this field also becomes complex because its dependency to an existing facility.