US 12,286,876 B2
Drain apparatus for a subsea pipeline
Laura Liébana Yeste, Surrey (GB); and Lee Trevelyan Thomas, Surrey (GB)
Assigned to Trevelyan Trading Ltd, Surrey (GB)
Filed by Trevelyan Trading Ltd, Surrey (GB)
Filed on Aug. 17, 2023, as Appl. No. 18/451,401.
Application 18/451,401 is a continuation of application No. 16/326,500, granted, now 11,767,747, previously published as PCT/GB2017/052463, filed on Aug. 21, 2017.
Claims priority of application No. 1614196 (GB), filed on Aug. 19, 2016; and application No. 1706795 (GB), filed on Apr. 28, 2017.
Prior Publication US 2023/0392490 A1, Dec. 7, 2023
Int. Cl. E21B 43/36 (2006.01); B01D 45/08 (2006.01); C10L 3/10 (2006.01); F17D 3/14 (2006.01)
CPC E21B 43/36 (2013.01) [B01D 45/08 (2013.01); C10L 3/107 (2013.01); F17D 3/145 (2013.01); C10L 2230/08 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A drain apparatus for use in a subsea gas pipeline to remove liquid from a multiphase flow in the subsea gas pipeline, the drain apparatus comprising:
a first channel for carrying a multiphase flow comprising liquid and gas phases, the first channel having a first end for connection to an upstream section of the subsea gas pipeline and a second end for connection to a downstream section of the subsea gas pipeline;
liquid extraction means for extracting the liquid phase from the multiphase flow in the first channel; and
a first storage tank disposed beneath the liquid extraction means, the first storage tank being arranged to receive liquid from the liquid extraction means;
wherein the internal diameter of the first channel is substantially the same as an internal diameter of a subsea pipe arranged to carry the multiphase flow in the subsea gas pipeline, such that a pig travelling along the subsea pipe can pass through the first channel,
wherein the first channel further comprises a first curved section disposed between the first end of the first channel and the liquid extraction means, and a second curved section disposed between the second end of the first channel and the liquid extraction means, such that the first curved section is disposed before the liquid extraction means and the second curved section is disposed after the liquid extraction means,
wherein the first and second curved sections are configured such that the liquid extraction means is vertically offset from the first and second ends of the first channel to accommodate a difference in height between the liquid extraction means and the subsea gas pipeline, such that, in use, the drain apparatus is configured to support the liquid extraction means a certain height above the seabed so as to accommodate the first storage tank without a need to excavate the seabed, and
wherein a bend radius of each of said first and second curved sections is configured such that the pig travelling along the subsea pipe can pass through each of said first and second curved sections.