Nam Du and U Minh gas fields are located offshore Vietnam. Credit: Jadestone Energy.
The fields are operated by Jadestone Energy. Credit: curraheeshutter on Shutterstock.
The Nam Du field is expected to come onstream in late 2021. Credit: Jadestone Energy.

Nam Du and U Minh gas fields are located in blocks 46 / 07 and 51 respectively, offshore Vietnam.

The fields are collectively estimated to contain gross 2C gas resources of 171.3 billion cubic feet (Bcf) and gross 2C liquid resources of 1.6 million barrels of oil (MMbbl).

Jadestone Energy holds a 100% operated working interest in block 46 / 07 and block 51. The company received modified investment licences for the production sharing contracts (PSCs) of the two blocks in 2019, confirming the formal registration of the increase in the interests to 100%.

PetroVietnam Exploration Production (PVEP), a subsidiary of Petrovietnam, relinquished its 30% interest in both the blocks with effect from May 2017.

The field development plan (FDP) for the two fields was submitted to Vietnam Oil and Gas Group (Petrovietnam) for approval, in October 2019. The detailed engineering and procurement activities for the project are currently underway. The first gas production from Nam Du and U Minh fields is anticipated in late 2021 and 2023, respectively.

Jadestone reached a heads of agreement with Petrovietnam for the sale of all discovered resources from the two fields, in April 2019.

Upon approval of the FDP, the company expects to execute contracts related to FPSO lease, engineering, procurement and construction (EPC) and operation and maintenance (O&M).

Nam Du and U Minh gas fields location

Nam Du and U Minh fields are located in the Malay-Tho Chu Basin, offshore southwestern Vietnam.

Nam Du is situated on the north-eastern margin of the basin while U Minh field is located within the boundaries of the block 51 PSC.

The Nam Du discovery is situated in a water depth of 47.9m while U Minh lies at a depth of 64m. Both the fields are located approximately 200km off the coast of Vietnam.

Discovery and exploration of Nam Du and U Minh gas fields

An exploration well, 46/07-ND-1X, drilled by Mitra Energy resulted in the Nam Du field discovery, in 2013. Drilled to a total depth of 2,297 metres measured depth (mMD), the well discovered gas in two main Miocene fluvial channel reservoirs.

The well encountered 20m net sand with a porosity of 29% and ten additional gas-bearing reservoir sandstone intervals.

“The appraisal / development well ND-2X is planned to be drilled into the southern fault block.”

U Minh was discovered in 1997 by exploration well 51-UM-1X. The well was drilled by FINA Exploration Minh Hai and is the sole well on the field.

The well underwent two drill stem tests with one of them being carried out over the H-100 reservoir. It indicated a high permeability reservoir of approximately 770 millidarcy (Md) with high flow at small pressure drawdowns.

The gas in U Minh’s H-100 reservoir is fairly lean. It is richer in condensate than the Nam Du reservoir, with an initial condensate yield estimated to be between 22 stock tank barrels (stb) / million standard cubic feet (MMscf) and 32stb / MMscf.

Development plan for Nam Du and U Minh gas fields

The Nam du and U Minh fields will be developed in a phased manner with the development plan, including two unmanned well head platforms (WHP), two wells per field and a leased floating production storage and offloading (FPSO) to be located at Nam Du.

The FPSO will serve as the central processing facility and will be equipped to carry out separation, dehydration and compression. The WHP over the U Minh field will have a multi-phase tie-in pipeline to Nam Du. The unmanned WHPs will be installed by a jack-up drilling rig.

A 12in, 24km-long inter-field pipeline will be installed from the U Minh WHP to the FPSO while a  12in, 1.5km-long inter-field pipeline will connect the Nam Du WHP to the FPSO.

A 14in, 34km-long export pipeline will originate from the FPSO to be hot-tapped into the existing 18in PM3 / Ca Mau pipeline to back-fill as ullage increases.

The gas will be transported via the Ca Mau pipeline to feed the onshore Ca Mau power complex and an adjacent fertiliser plant in Southern Vietnam, whereas liquid hydrocarbons are planned to be exported via tankers.

The PM3 / Ca Mau pipeline has a capacity of 215MMscf/d and is owned by PetroVietnam. It currently carries gas from PM-03 commercial arrangement area (CAA) block lying south of block 46 / 07. Jadestone intends to tap sufficient ullage expected within the pipeline due to declining production from the PM-03 CAA block.