New BP system improves operational efficiency
BP is deploying a new computer system, called the Apex system, to improve operational efficiencies in the company’s global oil field operations. In Alaska the system is starting to help the company streamline the manner in which it routes fluids around the Prudhoe Bay field infrastructure, Amy Adkinson, BP systems optimization engineer, has told Petroleum News.
Much effort in maximizing field production goes into the planning and use of production and injection wells, to best access oil remaining in the field reservoir, and into the optimum use of water injection, gas injection and enhanced oil recovery techniques to maintain reservoir pressures and entice as much oil as possible to the surface.
The routing of fluidsBut there is a whole other aspect of operational efficiency involving the routing of fluids coming from the wells through the complex of pipework and production facilities that enable oil to be separated and transported to the trans-Alaska pipeline for export from the North Slope, while also recycling produced water and gas back through the field.
The pipelines and facilities have operating limitations, but presumably work at optimum efficiency if fully used. At the same time, if some component of the infrastructure is working at full capacity, that may limit the possibility of bringing some wells on line, a factor that in turn impacts the potential to maximize field production.
Prudhoe Bay is particularly complex, with hundreds of wells, multiple gathering centers and flow stations, and a field pipeline network that can enable choices over how to route fluids through various facilities for maximum efficiency. In addition, as the field matures, it now produces much more gas and water than oil, making the management of the various fluids particularly important. The idea is to route the fluids in a manner that supports the appropriate mix of well and facility usage, keeping the best wells in operation, Adkinson explained.
Faster processingAlthough BP has modeling systems for managing the fluid flow, these systems are slow to use. The new Apex system, which is being tuned to the complexities of the Prudhoe Bay field, is much faster. Essentially, engineers can simulate different operational scenarios, evaluate the results and decide on an optimum course of action.
“Apex can unlock that efficiency, so that we can ask a question of our system, model it and have an answer in a matter of a day, versus a week,” Adkinson said. Also the field operators are able to move from static modeling of the fluid flows, to more dynamic modeling, assessing how the fluid flows will evolve over time.
Hooked into well modelsThe system models fluid flows from the interfaces between wells and the reservoir through to first stage fluid separation. The system is hooked into the production models for individual wells, enabling well production to be simulated, feeding fluid production data into the surface infrastructure simulation.
Currently the focus is on gas flows through to the field’s central gas processing facility, although attention is also moving to using the new system to help figure out how to deal with produced water.
“We’ve got a team of engineers that are working on (the system) … trying to find all of the useful ways we can use it … to leverage what we already have,” Adkinson said.
For example, if there is a plan to bring on new production in one part of the field, it is possible to use the system to simulate the impact of this on field operations as a whole - because of facility and pipeline constraints it is possible that bringing on the new production might force production to be backed out somewhere else in the field. And one concern is to ensure that the velocity of fluids through the pipelines is maintained below prescribed limits, to ensure that pipeline corrosion inhibitors mixed into the fluids will work effectively.
Rapid evaluationsOnce the Apex system is fully operational, a reservoir engineer will be able to use the system to quickly evaluate the impact of some planned well work on the surface systems, more accurately assessing the impact on overall production at the field.
And it will be possible to use the system to evaluate the impact on production of reconfiguring some aspect of the surface infrastructure.
The Apex system represents the next step in optimizing Prudhoe Bay operations, using technology in a new way to find things that are not intuitively evident, and then to test the impact of changes before putting those changes into effect, Adkinson said. - ALAN BAILEY