The Sole gas field is located in the Eastern part of the Gippsland Basin, 40 km offshore in over 120 m water depth. The project development includes: two subsea wells, 65 km long carbon steel pipeline and associated control umbilical, upgrade to the Orbost gas plant, two horizontally directionally drilled (HDD) shore crossings for the pipeline and control umbilical.
- HDD Tail Exit Stability: The HDD exit was located in shallow water which resulted in high environmental loads over a significant length of the pipeline
- Hydrogen Induced Cracking (HIC): For the offshore reeled pipeline, the environmental tests indicated that the welds were susceptible to HIC
- Engineering Critical Assessment (ECA) for Reeling: Performance of second-party ECA verification and securing Independent Verification Body (IVB) approval in very tight timescale driven by installation schedule
- Execution flexibility: A key requirement of the FEED package was to carry options for S-lay or reel lay and Corrosion Resistant Alloy (CRA) or Carbon Steel (CS) with corrosion allowance. This allowed for opening of the market to a wider range of contractors, installation equipment and methods thus increasing competition and lowering of costs.
- HDD: 3D dynamic stability analysis using IntecSea’s INSTAB tool, developed and verified in-house for efficient and robust pipeline stability analyses
- HIC: IntecSea’s in-house welding and materials SMEs provided the expertise to critically review the welding procedures and test reports
- ECA: IntecSea’s in-house expertise, software availability and close working relationship with the IVB was utilised to meet the response time and quality objectives
- Execution flexibility: Multiple design options were run in parallel in order to protect the project schedule
- HDD: Delivered a robust and efficient temporary anchoring solution within a very tight schedule
- HIC: Presided over successful retesting of the welds using HIC and SSC resistant welding procedures
- ECA : The ECA was verified and IVB approval was secured within the very tight timescale required to ensure the installation schedule was not affected
- Execution flexibility: The FEED package incorporated multiple design options to allow for delay in key execution strategy decisions and a wider contracting market thus lowering execution costs.