Hybrid riser pipeline

[zacharialamsyah]

Dear all, I find difficulties to find one terms of pipelines system , related to hybrid riser, it might be basic knowledge..hope your input will be enlightening me

1.What specifically Hybrid riser means? I searching by google, hybrid riser means the integration (in one bundle) consist of Rigid Riser and flexible riser, is that right?

2.In what circumstances, hybrid riser should applied? What the advantages/disadvantages?

3.If hybrid riser consist of rigid riser and flexible riser, how comes hydrotest will be applied, can it proceed simultaneously (in same time), or in different procedure respectively, because the MOP (maximum allowable pressure) of these riser (rigid and flexible) are different?

Thank you before for your answer and input

Regards,
Zachari Alamsyah

 

[LittleInch]

ON the basis that no one has tried this, here is my input.

1) I've not specifically come across the term, but I think you're correct - this is a mixture of rigid riser and flexible.

2) the rigid part can be securely attached to a structure during construction or even retrofit and is much stronger and more able to deal with the wave forces etc compared to a flexible riser. It might also be part of a floating structure going some depth below the surface. Some sort of connector can then be used to connect the flexible using ROV or divers.

3) Given the rigid riser is normally pre-installed, this would be pre-tested to some design pressure, probably equal to the maximum flange rating or some designated level (say 5,000 psi). If flexible is then retrofitted, the leak test of the flexible should be less than the test pressure of the rigid pre-tested section.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way