India's farthest and deepest offshore platform is nearing completion on fast track, and is expected to go on-stream by the end of this month. ONGC's Rs 1,064-crore D1 Development Project includes installation to connect the three platforms to the existing floating production, storage and offloading (FPSO) facility through a Pipeline End Manifold (PLEM). All new platforms, the PLEM and the existing D1 Platform will be connected with a network and subsea rigid and flexible pipelines and composite cables totalling about 14.5 km. It is also the first FPSO project in India.
CEO Alwyn Bowden said Essar Projects is completing this project on a fast-track basis within 24 months on EPC, installation and commissioning of three unmanned four-legged fixed Jacket SMART Platforms at approximately 90 m depth, 200 km off Mumbai. The project entails management of several suppliers and technical experts from around the world. The jackets are fabricated at the CUEL Yard in LaemChabang, Thailand, while the three decks are made at the Profab Yard in Batam, Indonesia.
D1B platform will receive the 35,000 bopd of crude produced by the D1, D1C and D1D platforms and this will then be transferred for processing to the D1 field FPSO via the PLEM. The D1B deck weighs approximately 1,500 mt and is due to be installed on the D1B platform in entirety. The platform is likely to rank amongst the heaviest Wellhead Platforms to be installed in Bombay High using the lift installation method.
PCB Nair, CEO & MD, Essar Offshore & Subsea Ltd, the Offshore & Subsea Business Unit of Essar Projects, introduced the platform to media persons and said, "This is a standalone platform — unlike other India platforms, there are no piplelines connecting it to the mainland."
Quality checks are critical and mind-boggling, Nair explained, and are carried out both by the developer, ONGC, as well as by the contractor, at engineering and process stages. Material had to be returned or a process repeated several times in this project.
About 17,000 tonnes of steel was used in fabrication. The jackets and decks have been transported over 3,500 nautical miles to reach Bombay High, the destination. The jackets are embedded into the sea bed at a depth of 90 metres and the decks are placed on the jacket to complete the platform. One of the jackets — D1B — has already been installed and subsea lines of 14.5 km have been laid to connect the three platforms.
Discharge arrangements into seawater need to be cleaned and made safe, as is the gas flare. Flares are used to burn the potentially toxic nitric gas.