Project Overview
The Baleine field, offshore Côte d'Ivoire, is one of the most significant deepwater oil and gas discoveries in West Africa in recent years. As SAIPEM mobilised to deliver the SURF (Subsea, Umbilicals, Risers and Flowlines) scope for Phase 1 and Phase 2, Grispen was engaged to deliver the offshore lifting and rigging engineering for the Production Line Receiver structures, the subsea hardware that terminates flowlines and risers on the seabed.
The Engineering Challenge
PLR structures present a particular lifting engineering challenge: an irregular, asymmetric geometry with multiple connection interfaces, lifted from a construction support vessel into deepwater conditions where dynamic amplification, sling angle sensitivity and centre-of-gravity control all interact. Any miscalculation in the rigging arrangement risks excessive sling loads, structural overstress at the padeyes, or an unstable lift attitude during lowering.
Grispen's Solution
Grispen's structural team produced the full lifting and rigging design package to DNV-ST-N001, including 3D structural modelling of the PLR arrangement in ANSYS, deflection and stress analysis under the governing lift case, padeye verification, and sling configuration optimisation to control lift attitude within acceptable tolerances. The deliverable included simplified structural assessment models to confirm global behaviour matched detailed local FEA results, giving SAIPEM's engineering team full confidence in the lift procedure before offshore mobilisation.
Scope of Work Delivered
- 3-D structural modelling of PLR lifting arrangement (ANSYS)
- Structural simplification model for deflection cross-check
- Padeye design and verification to DNV-ST-N001
- Sling configuration and lift attitude optimisation
- Dynamic Amplification Factor (DAF) derivation for the lift case
- Lifting and rigging design report, IFA issue
Our Delivery Process
Every Grispen engineering scope, regardless of size or client, passes through the same structured five-stage delivery method, ensuring consistent quality and full traceability from kick-off to final issue.
This project demonstrates Grispen's core deepwater lifting engineering capability: complex, asymmetric subsea structures lifted to DNV-ST-N001 with full FEA-backed verification, delivered to a tier-1 EPC contractor (SAIPEM) on a major West African deepwater development.