The company spudded its first well on 8 January with the drillship Neptune Discoverer for VietGazprom, an operating company representing Russia's Gazprom and Zarubehneftegaz (85%) and PetroVietnam Exploration&Production (15%).
However, drilling stopped on 16 January due to problems with the drillstring motion compensator.
Neptune had estimated repairs would take eight to 13 days to complete, but it is taking longer.
A company spokesman was unwilling to comment on when the unit, which is not earning a dayrate, would be back working.
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