Haiyang Shiyou 981
semi-submersible MODU · CNOOC / COSL
- Type
- semi-submersible MODU
- Operator
- CNOOC / COSL
- Water depth
- 3000 m
- Region
- South China Sea
- Country
- China
- Commissioned
- 2012
- Status
- active
About this platform type
Semi-submersible MODUs (Mobile Offshore Drilling Units) drill new wells from a partially-submerged buoyant hull. Older deep-water rigs are typically semi-sub MODUs; new builds favour drillships.
For seafarers
Offshore-fleet roles command significantly higher pay than equivalent deep-sea cargo ranks (see /career-maps/offshore-vs-deep-sea-pay-tradeoff) but require sector-specific certification — DP-2/3 for marine officers on dynamically-positioned units, process-safety and operator-specific training for production-platform crews, and the offshore-specific rotation patterns (28/28 or 35/35 day). Entry requires either a maritime-academy background plus offshore conversion or transition from a related onboard-engineering background.
Sources: operator websites, classification-society publications, and offshore-industry news for the public data above. The platforms' status changes — confirm currency before relying on it for crew-scheduling decisions. Cross-references: /career-maps/highest-paying-niches-2026, /shipyards.