Åsgard Subsea Compression Project

Type of Contract Pipeline engineering and services – Detail design

Client Statoil

Start 2011

Finished 2014



Description

The Åsgard Subsea Compression Project has been established to maintain the production rate from the Midgard and Mikkel fields above a critical minimum. The flow problem occurs at low production rates and will cause MEG, water and condensate to accumulate in the pipelines. When production rates drops below the hydraulic minimum flow rate in a flowline, surge waves of liquid (condensate and water/MEG) will arrive at the platform, causing flow instabilities in the process/separation facilities at Åsgard B. The minimum flow condition for Mikkel/Midgard will occur in 2015.

To overcome this problem, a Subsea gas Compression Station (SCSt-A) is planned at the Midgard Field for compression of the Midgard and Mikkel well streams.



Scope of Work

The scope consisted of conducting the detail design for the subsea pipeline system. The work started with a refinement and update of the FEED results from 2010. The scope comprises overall layout, routing and design of flowlines, MEG lines, power cables, umbilicals and fiber optical cable (FOC) to/from the compressor station, existing templates/PLEM’s, hot-taps on the Midgard loop and Åsgard A and B, including all associated seabed intervention work. Further design of all tie-ins and expansion spools (21 off), PLEM/PLET/Riser Base structures (19 off) and verification of the compressor manifold station (SCMS). A new spool design guideline to be developed as part of the project in cooperation with DNV. Development of MTO’s, input to ITT’s and assistance to Company with contracts for prefabrication of structures and installation of lines and structures, and follow-on engineering services during the fabrication and installation phases.