Dalmatian Subsea Boosting: Project Execution and Early Operational Experience from the First High-Boost Multiphase Boosting System Deployed in the Gulf of Mexico
Authors: Hagland Arill Småland , Cooper Ross , Clarke Mike , Hausberg Svein , Tvedt Jostein , Tovslid Audun 
Published: April 2019

In 2016 the Subsea Integration Alliance (SIA) was awarded the industry's first deepwater integrated subsea engineering, procurement, construction, installation, and commissioning (EPCIC) multiphase boosting system contract. The scope of the contract called for the supply and installation of a subsea multiphase boosting system in the Dalmatian Field in the Gulf of Mexico and represents the world's longest deepwater subsea boosting tieback. Several studies were conducted to look at increased oil recovery (IOR), with subsea boosting yielding the best economic benefits and lowest overall risk profile. The subsea boosting system has now been installed and has significantly improved the operator's ultimate recovery.

The Dalmatian Field was developed in deepwater Gulf of Mexico by Murphy and partners and commenced production in April 2014. The field was developed as a subsea tieback in water depths of approximately 6,000 ft, with a record tieback distance of 22 mi to the Petronius Field compliant tower platform in shallower waters of approximately 1,800 ft.

The challenge of increased recovery in subsea fields has driven the advancement of subsea processing technologies, especially in the subsea boosting domain. The successful operation of subsea multiphase boosting systems on a global scale, coupled with the significant added value these systems generate, has driven technological advances in terms of higher differential pressures and longer step-outs.

The subsea boosting system was installed in October 2018 and significantly improving the operator's ultimate recovery. Working in close collaboration with the operating company, the SIA has demonstrated that this type of project execution, also referred to as a supplier-led-solution (SLS), can be an effective way to accelerate project completion, reduce schedule and installation risk, and improve overall project economics.

This project was completed in a very short execution time of less than 23 months from contract award to pump startup. This was achieved using mature technology in combination with a novel integrated contract model. In addition, a front-end engineering design (FEED) study was performed to define the project scope that included integrated asset modeling to fully explore the potential of the system that enabled the project to be sanctioned.

The Dalmatian subsea boosting system represents a game changer in the subsea processing domain because it is an important leap forward in the efforts to improve recovery and enable long deepwater tiebacks. For field developments in remote, deep, and hostile locations, this technology represents a key enabler.

This paper explains the application of the subsea boosting system in the Dalmatian Field and discusses how the Alliance's SLS approach to project delivery using fit-for-purpose solutions based on existing design ensured a seamless delivery and installation of a deepwater boosting system for the operator.