HPHT drilling riser systems
Our award-winning 10,000psi riser system uses a shrink-fit flange to negate many of the issues inherent in working with HPHT-grade riser materials. Subsequently, this new drilling riser technology enables the drilling of HPHT wells from a standard jack up – at a stroke enhancing the economics of HPHT projects.
The advent of a reliable process to negate the issues inherent in welding high-grade steels has enabled HPHT drilling from jack ups for the first time – it is now possible to create API NACE compliant systems that operate in excess of 10,000psi.
The riser negates welding through the use of flange technology developed in-conjunction with our sister company, Subsea Riser Products. Instead of welding, the flange is heated until it expands and can be fitted over the riser joint pipe – once cooled and ‘shrunk’ this process, along with a profile inside the flange, creates a join that is stronger than the yield strength of the riser joint – the pipe would fail before the seal itself. Even greater back up is afforded due to the bore pressure actually energising the seal – the higher the internal bore pressure, the greater the union between the flange and joint.
Thus, our award-winning shrink-fit flange negates many of the issues inherent in working with HPHT-grade riser materials by replacing weld completely.
- The world’s first API NACE compliant full-bore (18 ¾”) access riser capable of working at pressures in excess of 12,000psi (operating pressure 10,000psi)
- The world’s first attachment of flanges to a riser by shrink fit process
- Allows high pressure wells to be drilled by a standard jack-up rig with a surface BOP, avoiding the need for a floating vessel with subsea BOP
Shrink Fit Flange:
- Based on well established physical principles.
- Contact friction and machined profile give load capacity.
- Mechanical back-up with capacity greater than pipe sections.
- The seal mechanism is enhanced as the riser internal pressure increases.
- Shrink fit gives excellent fatigue performance – no weld and low stress concentration.
- Induction coils are wrapped around the flange which is then insulated.
- Flange heated up using induction coils.
- Cold pipe is then inserted in the flange in a carefully controlled operation
- Once the flange cools a super-strong connection with the pipe is created – negating the need to well HPHT-grade materials.