Australia's National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) has released the Crux Offshore Project Proposal for public comment. The proposal was submitted by Shell Australia Pty Ltd and is open for comment for a period of six weeks ending 18 March 2019.
Shell, together with joint venture partners Seven Group Holdings Energy and Osaka Gas, are progressing plans for the prospective development of the Crux gas field, located approximately 160 kilometers northeast of the Prelude field in the northern Browse Basin, offshore Western Australia. The Crux field is located in Commonwealth waters in the northern Browse Basin, 190 kilometers offshore northwest Australia and 620 kilometers north-northeast of Broome.
The Crux project has been identified as the primary source of backfill gas supply to the Prelude floating liquefied natural gas (FLNG) facility. The proposed Crux project consists of a not normally manned (NNM) platform in water depths of approximately 165 meters of water; with five production wells, minimal processing and utility systems, tied back to the existing Prelude FLNG facility via a 165 kilometer export pipeline. Crux will be operated remotely from the Prelude FLNG facility. Front-end engineering and design for the project is expected to commence in 2019 with the financial investment decision (FID) currently scheduled to occur in 2020. The project is anticipated to have a 20-year design life. However, subject to the future investment decisions, the project may extend.
The current project concept comprises:
There is also a potential for future subsea developments that will provide hydrocarbons to the Crux platform. These developments are expected to comprise subsea production wells, completed with subsea trees, and associated subsea tie-back to the platform (e.g. flowlines, risers and manifolds).
From FID it will take approximately four to five years for the platform to be fully designed, constructed off-site and towed to location. While the platform is being built, the subsea production wells would be drilled and suspended until installation of the platform facilities, after which the wells would be completed, hooked-up to the platform and brought online. Decommissioning will be undertaken at the end of field operations.
The key execution stages of the project are:
Additional gas reservoirs within the in-field development area may be tied back to the Crux platform. The development of these reservoirs will broadly involve the same key stages and activities as those used in the development of the Crux field, with the exception of completion with subsea trees.