Centrifugal compressors are normally the largest energy consumers in a processing facility. Identifying the optimal solution for the compression units as part of the complete process facility both reduces energy consumption as well as needs for later compressor and driver modifications.
“A well designed and selected configuration contributes significantly to reduce both CAPEX and OPEX whilst ensuring the plant operability and availability. Optimized facilities reducing CO2 emissions through minimized energy consumption and eliminated flaring. A testimonial for this unique solution”, states Facility Chief Engineer, international energy company.
Overall values and highlights
BPT domain experts have over years utilized a unique combination of high-fidelity compressor design and rating application (BPT-CODES). This software extension seamlessly integrates with industry-leading process simulators, along with well-proven workflows, forming a superb digital solution for optimizing and de-risking process facility design at an early stage. Now, this solution is available and used also by leading operators and engineering houses globally. The work process required to ensure compressor configuration fulfills the facility process lifecycle demands, must be aligned with realistic compressor performance curves to de-risk projects at an early conceptual stage.
Any conceptual design or even a modification project is at risk until both the process and the compressor operational envelopes and the corresponding drives have been properly assessed and aligned.
The BPT-CODES software provides an in-house ability to identify optimal compressor design, both holistically for the entire process facility, as well as in detail for the individual compressor stages. This closes the gap for the alignment of the process and the constraints of a compressor system in minutes, rather than weeks or even months.
In conclusion:
BPT-CODES compressor design and rating application enables huge economic benefits
- both during process facility development and operation.
Background
The software is originally based on the design practice for centrifugal compressors used in the upstream oil and gas hydrocarbon processing industry using classic design theory described in the 1960’ties. These design rules are still valid to create an imaginary compressor geometry for a selected design.
Since its first creation in the 1990’ties, CODES has successfully been used on several installations/projects, creating significant revenue improvements for operators.
Utilized within a process simulator, CODES allows for realistic compressor evaluations for new facilities as well as for existing plants subject to modifications, available thru the familiar graphical interfaces used for process simulation.
Accuracy
BPT-CODES automatically calculate compressor impeller configuration, i.e., number of impellers and rotational speed. The user is however free to change the variables, and the default values set by the application. The software incorporates domain expertise rules and will throw warnings if the user selects unreasonable parameters which will cause a non-feasible design.
BPT-CODES can also be matched to existing compressors performance maps using a built-in optimization routine. This is a handy functionality, ensuring work is carried out with benchmarked curves. Detailed reservoir drainage curves and strategies can be tested for optimal asset performance for upstream facilities with multiple wells and varying gas properties. When commissioning a model-based online digital twin, the software is used to finetune compressor performance maps.
Features
Instead of using distinct design cases for process plant design, BPT-CODES allows a plant operability envelope to be considered right from the conceptual stage. The result simplifies the dialogue with a compressor vendor, clarifying the operational demands. Automated compressor data sheet generation allows for precise communication. Compressor maps defined in a steady state simulator can be transferred to a dynamic process simulator in just minutes.
BPT-CODES allows the user to store the geometry file for a selected compressor design. For a new gas composition/property, or alternate suction conditions, the geometry file can be imported, allowing BPT-CODES to generate the resulting performance map for the original impeller designs. This conversion process is performed on an impeller-by-impeller basis, allowing a secure and accurate representation. This is very practical when witnessing a compressor test at the vendor site since a conversion between the fluid within a test loop and the intended gas properties in the field can be performed immediately.
BPT-CODES provides the parameters needed to define gas recycling for plant operation capacity lower than the control curve, even in a steady state process simulation.
Example project
In a recent dynamic design evaluation, the resulting flare capacity had omitted the compressor blocked outlet case. The relative flare capacity needed as a function of increased separator design pressures was a key. An assumption that a high separator design pressure would reduce the system inflow and consequently a smaller flare system was proved inadequate.
Using BPT-CODES, optimal separator design pressure was defined already at an early project phase, in this case, defined by the intersection between a relieving separator pressure control valve and the compressor capacity operation at maximum duty.
Without compressor performance envelopes available at an early project phase, overly designed flare systems and unnecessary heat protection insulation would easily result. Dynamic verification during detail engineering, using selected vendor performance curves, normally occurs too late in the project lifecycle to correct a non-optimal design.
There are two parameters that to a large extent characterize the impeller design, these are the impeller design diameter and the design speed. The selection of these parameters is closely linked to head and flow requirements.
Lessons learned:
Late design change in a project often leads to significant cost overruns.
Undetected, the facility would not comply with the API 621 safety requirements and could yield unsafe to operate.
Billington Process Technology (BPT) is an independent digital solution, simulation and service company with Headquarter outside Oslo, Norway. BPT has unique domain knowledge within production and process facilities. We are world-class users of process simulators, and among the specialties are compressor design as well as process safety. The BPT Digital Production Twin includes an unmatched solution for holistic sensor-correction providing invaluable data fundament for a number of advanced digital applications (ala machine learning) as well as calibrated steady-state and dynamic simulators for efficient production optimization. BPT is a frontrunner in modernizing field development approach together with innovating oil companies. A BPT specialty is to apply integrated multiphase flow and dynamic process simulators throughout the field development, commissioning, and life of field to validate and improve design as well as troubleshoot and perform production optimization.
For more information about this press release, please contact Knut Erik Spilling, BPTs Vice President for Sales & Marketing (e-mail: kes@bpt.no).