An unexpected technical issue arising during a test run of an oil refinery in northern Vietnam has prevented the multibillion-dollar facility from beginning operations as scheduled.

The Nghi Son Oil Refinery, a US$9 billion facility developed by national oil and gas giant PetroVietnam, has reached 96.6 percent completion and was testing its technology and supporting units when a technical fault was detected.

With the affected units now pending repairs, the trial run is likely to be extended by three to six months from the planned completion this March.

PetroVietnam and the refinery operator have closed an agreement whereby the the oil and gas giant will purchase all of the output of the facility. The late commission of the refinery will therefore affect PetroVietnam’s fuel import and business plans.

Located in the northern province of Thanh Hoa, 160km south of Hanoi, the Nghi Son refinery consumes a total investment of $9 billion, with more than $8 billion already disbursed.

The project has so far received $5.5 billion worth of bank loans and $2.4 billion capital contributed by its stakeholders. PetroVietnam alone provided $602.4 million in capital contribution, and $333.83 million in loan for the massive project.