Subsea processing of well fluids

Patent metadata

Field	Value
Publication number	US-11091995-B2
Application number	US-201816116854-A
Country	US
Kind code	B2
Filing date	Aug 29, 2018
Priority date	Dec 21, 2012
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

A wax control element for subsea processing of well fluids in a wellstream comprises a bundle of flowlines within an elongate tensile structure. That structure defines inlet and outlet ends and has cooling and heating provisions that act on the flowlines, in use, to promote deposition of wax in the flowlines and subsequent entrainment of wax in the wellstream.

First claim

The invention claimed is:

1. A method of installing or developing a subsea oil or gas production system by installing a prefabricated wax control unit at an installation location, the unit comprising an elongate wax control element disposed between a first towhead at an upstream end of the element and a second towhead at a downstream end of the element, the method comprising:
towing the unit to the installation location with an elongate tensile structure of the wax control element in tension between the towheads;
sinking the unit at the installation location;
connecting the towheads to other elements of the production system so that the unit may be operated to pass the well fluid along the wax control element; and
passing well fluid along the wax control element between the towheads while cooling and periodically heating flowlines of the wax control element;
wherein cooling the flowlines comprises pumping cooling water along the wax control element in mutually opposed directions between the towheads.

2. The method of claim 1 , comprising performing hydrate control on the well fluid in the first, upstream towhead.

3. The method of claim 2 , wherein power and chemicals are distributed to templates and wellheads of the system from the second, downstream towhead.

Assignees

• Subsea 7 Norway As

Inventors

• Sathananthan Ratnam
• Pollock James Arkley
• Daasvatn Sigbjorn

Classifications

• E21B36/00 Primary

  Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones · CPC title

• E21B43/013

  Connecting a production flow line to an underwater well head · CPC title

• B63B35/03

  Pipe-laying vessels (laying pipes under water F16L1/12) · CPC title

• F28D1/022

  for immersion in a natural body of water, e.g. marine radiators · CPC title

• E21B43/00 Primary

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title