Patent ID: 11891861
Assignee: ENHANCED DRILLING AS
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 0:
1. A riser arrangement for performing operations, in a well extending from a bottom of a body of water, the riser arrangement comprising:
a riser;
a choke line coupled to the riser at a blowout preventer (“BOP”) in the riser;
the riser having a return outlet to a subsea return pump at a location substantially below a surface of the body of water, the subsea return pump being coupled to a return line to pump fluids from the riser to above the surface of the body of water;
the return line being a separate line, at least one sealing element being arranged within the riser at a location above the return outlet;
wherein a bypass is arranged to bypass the sealing element, the bypass extending from a port at the riser below the sealing element to a port at the riser above the sealing element, the bypass being equipped with at least one isolation valve that is selectively controllable;
the return line being coupled to a choke downstream of the subsea return pump; and
wherein a riser insert, with a substantially smaller flow capacity than the riser, is arranged above the sealing element.