Marine Subsea Assemblies

Abstract

A lower riser assembly connects a riser to a seabed mooring and to a subsea hydrocarbon fluid source. The assembly includes sufficient intake ports to accommodate flow of hydrocarbons from the hydrocarbon fluid source, as well as optional flow assurance fluid. The upper end of the member has a profile suitable for fluidly connecting to the riser. The lower end of the member includes a connector suitable for connecting to the seabed mooring. An upper riser assembly connects the riser to a near-surface subsea buoyancy device and to a surface structure. The assembly includes sufficient outtake ports to accommodate flow of hydrocarbons from the riser through a subsea flexible conduit to the surface structure. The upper end of the member includes a connector for connecting to a subsea buoyancy device. The lower end of the member comprises a profile suitable for fluidly connecting to the riser.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a 35 U.S.C. §371 national stage application of PCT / US2011 / 055693 filed Oct. 11, 2011, which claims the benefit of U.S. Provisional Application No. 61,392,443 filed Oct. 12, 2010, U.S. Provisional Application No. 61 / 392,899 filed Oct. 13, 2010, and U.S. application Ser. No. 13 / 156,258 filed Jun. 8, 2011, all of which are incorporated herein by reference in their entireties for all purposes.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.BACKGROUND INFORMATION[0003]1. Technical Field[0004]The present disclosure relates in general to assemblies useful in marine hydrocarbon exploration, production, well drilling, well completion, well intervention, and containment and disposal. More particularly, the present disclosure relates to upper and lower riser assemblies useful with risers in the above-listed end uses.[0005]2. Background Art[0006]Free-standing riser (FSR) systems have been used d...

AI Technical Summary

Benefits of technology

[0033]Certain embodiments comprise a hot stab assembly for injection of a functional fluid, the hot stab assembly allowing for a smaller flow rate of functional fluid than is possible through the annulus vent sub.

Problems solved by technology

Riser systems that work for one reservoir / well / environment may not be suitable for use with other wells, even those wells located proximate thereto.

In the containment and disposal context, subsea risers (free-standing or not) have not been known as suitable for such use.

In particular, prior containment efforts did not address fluid properties produced by the combination of hydrocarbons with sea water at deep-ocean pressures and temperatures that contribute toward formation of gas hydrates.

Therefore, there remains an unmet need for more robust upper and lower riser assembly designs, particularly when flow assurance is a concern, both during normal production operations and during containment and disposal periods.

Images