Subsea Gas Compression, Modulation and Tie-in system
Date & Time
Thursday, March 3, 2022, 8:30 AM - 9:00 AM
Alireza Mazaheri

While the development of subsea compression technology in deep-water advances a more efficient means of gas production, performing future intervention introduces new challenges to overcome. This gap has been recognized and a solution developed by configuring the Jansz-Io Subsea Compression Station layout to achieve any future intervention & interchangeability with no or minimal impact on production. The Greater Gorgon Development, including the Jansz-Io field, is located off the northwest coast of Western Australia. The primary objective of Jansz-Io Compression (J-IC) is to enhance the recoverability of the field and maintain long-term natural gas supply to the Gorgon liquefied natural gas (LNG) facility on Barrow Island through development of a Subsea Compression Station (SSCt), which utilizes three parallel subsea dry gas compressors. The SCSt has been developed based on a modular design philosophy where key elements are individually retrievable within modules for maintenance and repair. This approach allowed to meet challenges associated with: · Fabrication optimization (constructability and quality) · Testing · Installation · IMR and operation of process modules and control modules, as well as the total system availability Aker Solutions has developed the Horizontal Connection System (HCS) as their primary method for tie-ins systems & connection mechanisms. To facilitate the SCSt Modularization & Interchangeability objective, a unique version of the Horizontal Connection System has been designed so that the interconnecting spools between each module can slide horizontally, allowing the subject module to be retrieved without impacting the compression station’s operation continuity. The outcome of such design provides flexibility in operation and in future subsea intervention; allows the main process components to be independently retrievable; and takes into consideration the limited availability of intervention vessels in Western Australia. The lessons learned from the Åsgard Subsea Compression project were leveraged to define a suitable design for JIC-SCSt development, and to ensure that high reliability design requirements were safely achieved. This paper demonstrates how the challenges presented by the J-IC SCSt were met through a range of innovative engineering strategies which ensure safe execution and achieves the 50-year design life and high reliability requirements of the LNG development.

Location Name
Moody Ballroom