US 11,891,861 B2
Multi-mode pumped riser arrangement and methods
Per Christian Stenshorne, Oslo (NO); David Edward Smith, Katy, TX (US); and Gustav Olov Skärgård, Oslo (NO)
Assigned to Enhanced Drilling AS, Straume (NO)
Appl. No. 17/770,510
Filed by Enhanced Drilling AS, Straume (NO)
PCT Filed Oct. 30, 2020, PCT No. PCT/NO2020/050266
§ 371(c)(1), (2) Date Apr. 20, 2022,
PCT Pub. No. WO2021/086200, PCT Pub. Date May 6, 2021.
Claims priority of application No. 20191299 (NO), filed on Oct. 30, 2019.
Prior Publication US 2022/0389770 A1, Dec. 8, 2022
Int. Cl. E21B 17/01 (2006.01); E21B 21/00 (2006.01); E21B 21/08 (2006.01)
CPC E21B 17/01 (2013.01) [E21B 21/001 (2013.01); E21B 21/082 (2020.05)] 9 Claims
OG exemplary drawing
 
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.