The Marjan Complex is comprised of four offshore fields - Marjan, Lawhah, Maharah and Hamur. Marjan is the largest of the four and is partially shared with Iran. The bigger portion of oil reserves lie within Saudi Arabia but Iranian Foroozan also holds significant part of the reserve.
The Marjan expansion project was launched in 2017 with an estimated total cost of up to US$15 billion. The offshore facilities are expected to be designed to handle around 300,000 bpd of oil and will involve more than 100 development wells. The expansion plan also involves the installation of a new 79 mcm per day onshore gas-processing plant, tie-in, accommodation and auxiliary platforms, a 100-km 36-inch (914 mm) trunkline, and two subsea cables linking a gas/oil separation plant (GOSP) to onshore facilities. Marjan will be tied-back to Tanajib onshore gas processing hub, 200km north of Damman. 
EPCI packages (total value of US$5 billion)
The larger of the packages covers a gas/oil separation plant (GOSP) – GOSP-4 – to handle 475,000 bpd of crude, 21 mcm per day of gas and just over 800,000 bpd of liquids.
The second package covers a cap gas production (CGP) network, including two wellhead platforms, a tie-in platform, and five subsea gas and mono-ethylene glycol (MEG) trunklines to existing Tanajib.
Operators:
Saudi Aramco: Operator with 100% interest
Contractors:
Baker Hughes: Drilling, coiled tubing and drilling fluids engineering services
Wood Group: engineering and project management services (February, 2018))
WorleyParsons: project management and front end engineering and design (FEED) fpr for offshore work and onshore pipelines (July, 2017)
Amec Foster Wheeler: Integrated oil and gas expansion of the Marjan complex (June, 2017)
Saipem S.p.A.: Fabrication, transportation and installation of offshore structures
- EPIC work for the development of Marjan, Zuluf and Safaniya (November, 2016), EPCI contract (January 2019)
McDermott (Dubai): Initial work for a power supply system replacement contract. The overall brownfield project comprises EPCI and replacement of the decks of two existing tie-in platforms, as well as the removal and salvage of existing gas turbine generators, and the installation of two new 115kV subsea power and communication cables. (2016), EPCI Contract (February 2019)