Steel properties
- High toughness to improve impact resistance depend on the oil drilling environment deterioration (deep sea, low temperature)
- High strength to withstand external pressure when fragmentize 2-4 km underground
- Reduce difference between longitudinal and transverse properties, through anisotropic improvement
Applied parts
- Drill collar: delivers torque to Bit and weighing to fragmentize the ground
- Drill pipe: delivers torque to Bit and circulate mud
- Too joint, valve, subs: links each parts
Type of steel used
- AISI4130, AISI4140(L80, P110Grade), AISI4145M, AISI4330V
Technology development
- Alloy design and process design optimization to secure high toughness and high strength of mechanical property
- Add alloy elements to improve hardenability to secure high strength characteristics of mechanical property
- - Conduct extremely low P,H work to secure toughness against low temperature impacty
- Continuous casting process and rolling process condition optimization for segregation reduction
- - QT process optimization for stable quality assurance
