Benefits of Life Cycle Dynamic Simulation for FPSO Projects & Offshore Developments
Authors: Thiabaud P.. , Gros F.. , Tourdjman J.. , Guaraldo M.. 
Published: September 2011

Floating Production Storage and Offloading facilities (FPSO) and deep offshore projects are demanding and very sizeable investments that have to be optimized and protected.

The design and operation of FPSO's face technical challenges that require numerous and detailed process, control, safety and flow assurance simulations to secure investments and maximize production. Such calculations rely on a global understanding of production processes that an integrated model from well-bore to topside facilities can supply.

This paper focuses on key engineering issues that an FPSO project team needs to address as part of the overall development. Dynamic simulation is an essential part of the engineering process. This will be demonstrated with a review of dynamic process and flow assurance simulations applied to FPSO projects. A life-cycle simulator is a virtual plant that is used throughout the different engineering and operational phases. One dynamic process model is developed and leveraged through the entire project cycle from conceptual, Front End Engineering and Design (FEED), through commissioning phases all the way to operations and long-term operations support.

From the early design stage, the models constitute a virtual field to determine the best production scheme. Based on the chosen design, this virtual plant is used to develop and validate reliable, safe and optimal operating procedures long before the actual plant comes on line. To aid in safe and effective commissioning, the virtual plant is employed to verify control & safety logic, pre-tune instrumentation, and train operations personnel. Once the plant comes on line and normal operations begin, the virtual plant is then used in a variety of ways to improve day-to-day performance. This is accomplished by testing, validating and instructing the operators in basic good operating practices and optimization theories, for anticipating upcoming production changes, and testing various operating strategies.

Dynamic simulation benefits for FPSO projects will be highlighted, from FEED stage, stand-alone equipment, holistic simulation models and support to operation. The simulation domain may vary from a single compressor to design validation, from sequence and control parameters to the entire FPSO topsides and associated sea lines to examine the impact of liquid slug occurrence on the compression section.

RSI is currently involved in five on-going FPSO projects for West Africa, Brazil and Norway. This paper presents lessons learned from previous and current life cycle dynamic simulation projects, most particularly for FPSO and offshore platforms. This paper explains different applications of dynamic simulation based on most recent FPSO and offshore projects using INDISS™, the RSI dynamic simulation platform.

The paper covers examples of High Integrated Pressure Protection Systems (HIPPS), centrifugal compressor studies and integrated subsea-topsides studies, and also addresses several emerging dynamic simulation technologies.

Previous and current life cycle dynamic simulation projects provide valuable feedback for challenging projects involving new technologies such as subsea processing, offshore gas-to-liquids (GTL) conversion or Floating LNG (FLNG) facilities.

Those who have harnessed the Power of Simulation understand its real added value. The investment cost is minimal, less than 1% of initial CAPEX when compared to the unexpected operating and environmental costs associated with design errors and rework that lead to plant upsets and unplanned downtime.