There is a global trend for integrated subsea alliances to be involved in projects earlier, with a broader scope and in closer collaboration with the operating company. Sometimes, this is achieved by enabling contractors to develop and propose their own field development concept, known as a supplier-led solution (SLS). This paper refers to a case study that demonstrates an effective way to improve project economics.

A benchmark field layout plan was first generated using the customer's reference case. Then, a fully unconstrained SLS was developed to challenge and improve this reference case based on six main factors:

• Integrated production system modelling
• Fit-for-purpose project and design scoping
• Alternative field architecture
• Use of standardization
• Use of supplier or industry specification
• Integrated project execution

A production assessment, cost estimation, and schedule were developed first for the reference case, fully compliant with the customer specifications, and with no deviation to the scope of work, and second, for the completely unconstrained SLS.

Comparing the SLS to the reference case for this case study, the main improvements were as follows:

• Accelerated production thanks to integrated modelling and the introduction of subsea boosting technology
• Significant improvement in capex of approximately 41%
• Accelerated schedule due to a proposed innovative bidding process and a reduced equipment lead time enabled by standardization
• Lower project risk profile by improving the execution predictability primarily due to the integrated subsea offering

The combination of these improvements resulted in better project economic viability and allowed lower contingency cost accruals due to proactive risk management. The SLS also helped the operating company to build a viable development scenario in order to pass through the next project stage gate.

This paper demonstrates how an integrated subsea alliance with a broad spectrum of capabilities from the reservoir to the surface can deliver value through fully integrated earlier engagement. The methodology presented in this paper can be customized for any offshore prospect; the only prerequisites are early engagement, access to required data, and the freedom for the contactors to develop their own solution, in coordination with the operating company. A key feature of the proposed methodology is to link the SLS to reservoir representation, which avoids the common pitfall of delivering capex savings at the expense of larger production (revenue) losses.