Perdido Startup: Flow Assurance and Subsea Artificial Lift Performance

Abstract

The Perdido Regional Host is in the ultra-deepwater Gulf of Mexico, and produces from two Lower Tertiary horizons in multiple drill centers; some directly under the host SPAR, and others offset up to 7 miles and in water depths between 7800 and 9600 ft. All of the production is from relatively low-energy reservoirs, and posed considerable productivity challenges. The approaches to managing flow assurance risk and maximizing recoverable volumes were driven by the economically challenged environment in which the system was conceived and designed, and resulted in a unique host configuration relying on subsea wells and five high-powered ESP artificial lift systems with slug catching and two-phase separation accomplished on the seafloor. The final commissioning and early production characteristics of the system as related to the design intent and operational expectations will be described.The commissioning and early production phases of the development provided opportunities to validate Perdido subsea hydraulic models and operational methods that were considerably different from the typical approach employed by major oil companies in deepwater. Novel monitoring and surveillance tools generated by the project were benchmarked using early production data, and learnings were recycled into improvements to these models. This project is a considerable extension to previous systems, and due to the cost constraints of the risked recoverable volumes and high cost of operating in the ultra deep environment, it was imperative to advance the state of the art of flow assurance and operability.

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