Chevron Wheatstone subsea flowlines and pipelines concept: FEED, detailed design, procurement, and construction management support
- Engineering Critical Assessment (ECA) of infield flowlines: ECA of the 24-inch CRA clad and 14-inch CRA lined flowlines was challenging due to the high values of out-of-roundness and non-overmatching CRA welds (at high temperature operating condition).
- Lateral buckling and axial walking of the high temperature, high pressure (HTHP) flowlines: The flowlines operate at high temperature and pressure, making the flowlines susceptible to lateral buckling and axial walking.
- Stability of the export trunkline: he trunkline crosses existing pipelines and approaches the shore in shallow water, making efficient stability design challenging.
- ECA of infield flowlines: The ECA study was performed considering information from DNV JIP on CRA pipe, information from the public domain and in-house expertise. A state-of-the-art load-controlled 3D fracture mechanics based numerical model was constructed and verified. Detailed material test results and post-test analyses including statistical analysis were used to derive characteristic properties for ECA calculations.
- Lateral buckling and axial walking of the HPHT flowlines: A systematic review of alternate methods and the implications of their application to the Wheatstone flowlines was performed. Detailed assessment of the selected design was performed using IntecSea’s in-house expertise and models to ensure a robust lateral buckling and axial walking solution.
- Stability of the export trunkline: 3D dynamic stability analysis using IntecSea’s INSTAB tool, developed and verified in-house for efficient and robust pipeline stability analyses, was performed.
- ECA of infield flowlines: A detailed set of optimised flaw sizes was derived. This, combined with continuous support during the installation campaign yielded a significant benefit to the installation schedule. The lay rate of the 14-inch flowlines was double the original estimate resulting in significant cost savings.
- Lateral buckling and axial walking of the HPHT flowlines: Robust and effective lateral buckling and axial walking solution achieved.
- Stability of the export trunkline: Robust and effective stability solution achieved including at pipeline crossing and shore approach.