State of the Art Flow Loop Experiments with Real Fluids to Enable Simulator Matching with Field Conditions

An experimental campaign was conducted in Equinor’s high pressure flow loop in Porsgrunn with the objective of establishing a high-quality real gas condensate data set for use in modelling steady state flow as well as the specific surge wave phenomena in the Mikkel and Midgard (part of Åsgard) fields on the Norwegian continental shelf. The Mikkel and Midgard fields have been naturally flowing to Åsgard B since 2003 with introduction of the Åsgard Subsea Compression station in 2015 as a major upgrade. The surge wave phenomenon is per today observed in flowlines both upstream and downstream the compressor station, representing challenges with respect to liquid level control, both in the scrubber upstream the compressor station as well as topside Åsgard B. Several flowlines are operated with so called ”minimum flow limitations”, representing the minimum production rates at which the flowlines can be operated with acceptable liquid content and flow fluctuations due to surge waves. In order to plan future operations and restructuring initiatives, predictive tools able to capture these phenomena from a quantitative point of view are required. Data based on realistic fluid properties and conditions, have been vital for achieving the required flow simulator improvements in close collaboration with the software vendor modelling team. The first part of the paper gives a detailed description of the experimental matrix, the experimental execution, and the data analysis. Emphasis is also given to describe the state-of-the-art instrumentation used to achieve a unique set of high quality three-phase pipe flow data. The second part of the paper describes a modelling effort utilizing User Defined Functions in the multiphase flow simulator to tune/modify the closure laws to better match the experimental data. The improved model is compared and verified with the Åsgard field data. The model will be used to aid future operations of the field.