The Sao Vang and Dai Nguyet gas and condensate field commenced production in November 2020. Image courtesy of PTSC Production Services JSC.
A gas pipeline from the field is connected to the Nam Con Son 2 pipeline for transporting gas onshore. Image courtesy of PTSC M&C.
The condensate produced in the field is transported to the Golden Star FSO. Image courtesy of Mammoet.

The Sao Vang and Dai Nguyet gas and condensate field, located off the coast of Vietnam, commenced production in November 2020.

Idemitsu Gas Production is the operator and holds a 43.08% stake in the field, while the other development partners are Teikoku Oil, a subsidiary of Japan-based Inpex (36.92%) and Vietnam Oil and Gas Group ( PetroVietnam, 20%).

Sao Vang and Dai Nguyet is the first gas field development by Idemitsu in Vietnam. The offshore field was discovered in 2004 and Idemitsu entered into a production sharing contract with PetroVietnam in the same year.

The field development plan was approved by the Vietnamese authorities in 2017, and Petrovietnam Gas announced the first gas flow from Sao Vang to the Nam Con Son 2 pipeline in November 2020. The floating storage and offloading (FSO) unit Golden Star also received the first condensate from the field in the same month.

The annual production from the Sao Vang-Dai Nguyet field is expected to be approximately 1.5 billion cubic metres (bcm) of gas and 2.8 million barrels (Mbl) of crude oil and condensate.


The Sao Vang and Dai Nguyet offshore field is located in Blocks 05-1b and 05-1c in Nam Con Son Basin, in southern Vietnam. The field lies approximately 350km southeast of Ho Chi Minh City and the water depth in the project area is approximately 120m.

Field development plan

The Sao Vang and Dai Nguyet field development includes the Sao Vang central processing platform (Sao Vang CPP), Dai Nguyet wellhead platform, and infield pipeline system.

The topside of the Sao Vang CPP weighs approximately 15,500 tonnes (t), while the jacket and piles weigh approximately 16,500t. The topside of the Dai Nguyet wellhead platform weighs approximately 1,500Tt with the jacket and piles weighing approximately 8,700t.

The condensate produced in the field is pumped to a floating storage and offloading (FSO) facility named Golden Star.

A gas pipeline was laid to export up to 3bcm of gas from the Sao Vang and Dai Nguyet, as well as  the Thein Ung and Dai Hung fields to the Nam Con Son 2 pipeline at the BK Thien Ung area.

FSO Golden Star

The Golden Star FSO is 298.74m-long, 43.8m-wide, and 21m-deep. The storage capacity of the FSO is 800,000 barrels and it has a design life of 15 years.

Malaysia Vietnam Offshore Terminal (MVOT), a joint venture between PetroVietnam Technical Services Corporation (PTSC) and Malaysia-based MISC, is the owner of the FSO.

YASA Golden Horn was converted to FSO Golden Star at the Malaysia Marine and Heavy Engineering’s (MMHE) shipyard in Malaysia. The FSO sailed away to the Sao Vang and Dai Nguyet field in September 2020.

Contractors involved

PTSC Mechanical & Construction was awarded the main engineering, procurement, construction, installation, and commissioning (EPCIC) contract for the platforms and the infield pipeline system for the Sao Vang and Dai Nguyet field in February 2018.

The scope of the contract included the project management, detail engineering, procurement, construction, as well as the transportation and installation, hook-up, and commissioning services. The entire project is expected to be completed by October 2021.

The construction of the platforms for the Sao Vang Dai Nguyet project was started at PTSC Mechanical & Construction fabrication yard in Vungtau city, south Vietnam in March 2018.

PTSC Mechanical & Construction Company awarded a contract to Mammoet for load-out of the Sao Vang jacket, flare tip installation, installation of the living quarters module and topsides integration with a deck support frame.

McDermott International was awarded a transportation and installation subcontract by PetroVietnam Technical Services Corporation (PTSC) Offshore Services in May 2018. The contract scope included the transportation and installation services for the central processing platform jacket, topside float-over, wellhead platform, flexible pipelines, subsea power cables, and auxiliary services.

MAN Diesel & Turbo received a contract from PTSC Mechanical & Construction to supply two booster and export gas compressor trains in March 2018. Each gas compressor train consists of two RB35 barrel-type compressors powered by a 13MW gas turbine.

Wasco Engineering Indonesia was awarded an EPC contract for the LP-MP compressor package by PTSC.

Aker Solutions was engaged as the front-end engineering design (FEED) contractor for the Sao Vang and Dai Nguyet field in July 2016.

FSO contracts awarded

Malaysia Vietnam Offshore Terminal (MVOT) was awarded a £137m ($176m) contract to provide the engineering, procurement, construction, installation, commissioning as well as the charter services for the Golden Star FSO  for the field by in October 2018.

Malaysia Marine and Heavy Engineering (MMHE) was awarded the conversion contract for the FSO facility by Malaysia Vietnam Offshore Terminal (MVOT) in 2019.

Separately, MMHE was awarded a contract for the construction and commissioning of the external turret for the FSO by Promor.