Project Overview
Ballymore is a major Chevron-operated deepwater development in the Gulf of Mexico. Grispen was engaged through SS7 to deliver offshore and subsea rigging design for the production manifold, one of the most structurally and operationally critical pieces of subsea hardware on the field, requiring both a base case lift configuration and a fully engineered abandonment and recovery (A&R) contingency case.
The Engineering Challenge
Subsea manifolds are large, heavy, multi-interface structures. The rigging design needed to address two distinct operational scenarios: the planned installation lift, and a contingency abandonment and recovery case that may never be executed but must be fully engineered and approved in advance, in case an installation is aborted partway and the structure must be safely recovered to surface.
Grispen's Solution
Grispen's team developed the manifold lifting general arrangement for both the base case and the A&R contingency case, using Mathcad Prime for the structural and rigging calculations. Each case required independent verification of sling loads, padeye capacity, and centre-of-gravity behaviour under the applicable DNV-ST-N001 load and safety factors, ensuring Chevron's installation contractor had fully certified procedures for both the primary and contingency scenarios before mobilisation.
Scope of Work Delivered
- Manifold base case lifting general arrangement
- Abandonment & Recovery (A&R) contingency case design
- Offshore and subsea rigging design per DNV-ST-N001
- Sling and padeye capacity verification (Mathcad Prime)
- PLET pallet interface structural analysis
- ISO lock guide frame structural assessment
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.
Ballymore showcases Grispen's ability to engineer not just the primary installation case, but the full envelope of contingency scenarios that a tier-1 operator like Chevron requires before approving an offshore campaign, a level of rigour expected on major Gulf of Mexico deepwater developments.