Faster start-up

Ronnie Bains, of Emerson Process Management, explains how the use of dynamic simulations and operator training systems can support engineering and workforce training to help bring offshore assets online quicker.

Glen Lyon sets sail from South Korea. Image from BP.

For any new offshore project there is the requirement to bring the asset online safely and as quickly as possible. Reduced engineering, commissioning and start-up periods directly affect when an asset can reach nameplate capacity. Making reductions to project schedules, while extending the level of design integrity, innovation and design quality, presents a difficult challenge.

Dynamic simulation can play a key role in helping to meet these challenges. Having evolved and become more accessible over recent years, the technology can be applied to a growing range of process industry applications. For the process industry, including offshore oil and gas, dynamic simulation solutions comprise of an integrated control and safety system (ICSS) communicating with a model of the process facility, which is designed to reflect actual plant process dynamics and to provide realistic feedback for the ICSS.

The human machine interface (HMI) and control logic will be a replica of what the operator would see in the real control room, creating an environment where an experienced operator would not be able to tell the difference between the real plant and the simulated plant.

Life cycle of a project

Dynamic simulation solutions can be used throughout the lifecycle of a project, from an initial standalone process model built to perform verification studies of process and control system design, to commissioning and operating procedure verification, or “virtual commissioning,” and training, the traditional use of dynamic simulation.

In the initial design phase, the process model can be integrated with the control system configuration at various stages during the ICSS development. That allows it to be used as a tool to provide enhanced verification of the ICSS configuration, in addition to the traditional acceptance testing. This can include verifying alarm and trip settings, providing initial controller tuning values and enhanced verification of control logic. As more data becomes available, the dynamic simulation of the process can evolve and support different activities through the typical phases of a project.

In commissioning phases, dynamic simulation can do “virtual commissioning,” where issues that would otherwise be highlighted during commissioning can be identified and addressed prior to commissioning.

BP’s Glen Lyon FPSO, moored west of Shetland. Image from BP.

Training

Operators are usually required to be certified to ensure that they meet company standards for competence. Operator training solutions (OTS) are increasingly used to support this, but realistic dynamic process simulation and operating scenarios are key to their effectiveness.

OTS consists of a software-based representation of the dynamic and behavior of a process, residing on dedicated computer hardware and are usually integrated with a replica of the ICSS. OTS enables operations personnel to gain experience in an offline, non-intrusive environment, and expose them to what they will experience in their actual control room. Operators learn about control and safety system operating concepts, while gaining experience of their actual process in preparation to effectively handle incidents, process upsets, and the management of abnormal situations.

Training on a process-specific training platform raises skills levels, leading to faster and smoother start-ups, less downtime, less off-spec products, less supervision and increased energy efficiency. An American Petroleum Institute study found there was a US$350,000/year per operator positive financial impact when an operator was upskilled from an average level to an advance level.

Improved operator effectiveness also leads to increased plant-wide safety. Dynamic simulation can also replicate very unusual situations with transients, such as start-ups and shutdowns, that operators may rarely otherwise experience.

How does it work in practice? The following examples demonstrate how dynamic simulation has supported the engineering phase of two BP projects to reduce commissioning time and how an OTS was used for operator training and competency assessment, so that operators were better prepared and able to minimize production trips.

Glen Lyon

An OTS with dynamic simulation is currently supporting the Glen Lyon floating production, storage and offloading (FPSO) deployment. The Glen Lyon FPSO will be installed in the West of Shetland, replacing the Schiehallion FPSO, as part of a redevelopment of the Schiehallion and Loyal fields. At 270m-long and 52m-wide, the unit, which arrived on station in June of last year, with start-up expected this year, is one of the largest FPSOs in the North Sea.

A high fidelity dynamic simulation was developed by Emerson to support a number of activities including engineering and training.

Emerson is providing a fully operational training replica of the Glen Lyon project, in BP’s Aberdeen offices, prior to start-up. Training provided by the OTS could help BP personnel achieve safe, efficient operations and take full advantage of the ICSS that Emerson is providing for the new vessel. The OTS includes a virtualized DeltaV system that will control production, and a DeltaV SIS process safety system for process and emergency shutdowns. Personnel will learn both DeltaV operating concepts and the actual process, preparing operators to effectively handle abnormal situations and process upsets, as well as providing decision support.

Before the dynamic simulation/process model was developed and the complete multi-unit OTS delivered, Emerson provided BP with a simple separate standalone unit without dynamic simulation. This was used to evaluate graphics, provide HMI familiarization and support pre-tow training and ICSS engineering.

The standalone unit was based in Aberdeen, but networked to allow remote access by operators located throughout the UK and also in Korea, where the FPSO was being built. This enabled a larger group of BP operating technicians to carry out training, evaluation and competency assessment.

It is anticipated that the dynamic simulation will provide future benefits for BP in Glen Lyon’s project stage as well as ongoing operations.

Schiehallion was discovered in 1993, and Loyal a year later, with production starting in 1998 from the Schiehallion FPSO, which the Glen Lyon will replace. Schiehallion and Loyal together had more than a billion barrels in place and recovery to date had been about 15%.

As a result of the redevelopment, which could include polymer enhanced oil recovery, BP hopes it can maximize recovery to above 30% and extend production out to at least 2035.

The Glen Lyon FPSO was constructed at Hyundai Heavy Industries shipyard in Ulsan, South Korea, over a four-year period, amounting to some 21 million hours.

Ronnie Bains is the dynamic simulation and process optimization business manager at Emerson. Bains has an Executive MBA from the University of Leicester Business School and a bachelor’s in chemical engineering from Loughborough University.