The aim of this work package was to acquire the experimental evidence leading to the establishment of comparability between flow measurements made in different multiphase test labs. As well as establishing data to confirm comparability, it was inevitable there would also be anomalies highlighted by the data. Anomalies identified in the experimental intercomparison required rigorous investigation and rationalisation.
The aim of this work package was to improve the theoretical and experimental mapping of multiphase flow patterns. In particular, to map the flow patterns applicable to the range of lab conditions covered in the intercomparisons in WP1, so that:
- The measurement differences caused by differences of flow pattern would be more clearly understood.
- The parametric modelling method most appropriate to the prevailing flow pattern, could be adopted (in WP3) when measurement sensitivity to other parameters were analysed for a given flow pattern.
The pattern of flow at the meter is fundamental to uncertainty in multiphase metering. Generally, the more homogenised the flow, the lower the uncertainty is. This is the principle behind the use of a ‘blinded-T’ configuration before vertical pipe metering sections; to mix the fluids and reduce the velocity difference (slip) between them.
The aim of this work package was to improve the description of the quantitative influence of relevant flow condition parameters and to contribute to an essential reduction of measurement uncertainty in multiphase flow measurement.The main tools used for this were computational fluid dynamics (CFD) for the flow simulation and the spectral method, and the polynomial chaos approach, for the uncertainty quantification. This was to rationalise the effect of known differences between labs on the intercomparison measurements by:
- Developing CFD models to quantify the effect of the different multiphase flow parameters on Venturi differential pressure measurements, for each known flow pattern.
- Quantifying uncertainties caused by uncertain parameters (process conditions, fluid properties etc.)
The aim of this work package was to evaluate and improve experimental methods of flow visualisation that can be used as tools for investigation and verification of flow patterns. Specifically, to realise real-time cross and through-sectional imaging for mixtures and flow velocities appropriate to multiphase oil and gas production. Based on stakeholder feedback the JRP focussed on electrical tomography as the technology most likely to yield applicable results. Two variants were studied; dual-modality tomography, which combines ERT (Electrical Capacitance Tomography) and ECT (Electrical Capacitance Tomography); and dedicated high‑speed ECT. The former enables measurements to be made across the range of oil-continuous and water-continuous phase mixtures, the latter is more specialised for use with oil-continuous mixtures.