The riser joints currently used aboard D/V Chikyu are made of steel, but it’s very difficult to adapt steel riser joints to ultra-deep water (>4,000 meters) operations. At these depths, lighter and stronger materials need to be considered, such as carbon-fiber reinforced plastic (CFRP) riser joints.
- New riser joints must be suitable for drilling operations in >4,000 meter water depths.
- New materials must be stronger, but lighter, than the currently used steel riser joints.
- New riser joints must have high reliability for long-term use.
- New inspection and certification standards need to be established.