Subsea Online Fluid Analyser (SOFA)
CMR has, in cooperation with the University of Bergen, developed a concept for subsea online fluid analysis.
Information about the quality of the fluids produced from oil and gas wells is crucial for optimal production and production control. In the SOFA, A small fraction of the fluid from a pipeline is allowed to flow into a measurement chamber before closing the valves and letting the fluids separate. After the fluids have separated, several measurement technologies are used in order to collect as much information about each fluid phase as possible, e.g.:
- Acoustic velocity of sound
- Acoustic pulse-echo
- Gamma based Dual Modality Densitometry (DMD)
- Various electromagnetic technologies including Time Domain Reflectometry (TDR)
The measurement results can be used to feed continuously updated fluid properties into multiphase flow meters for more accurate measurements, or they can be used directly to improve process control and well management. Parts of the concept can also be used for more dedicated measurements such as characterization of water. The technology development is being continued during various fluid characterization activities.
I.Meric, G.A. Johansen, M.B. Holstad, J. Wang and R.P. Gardner, Produced water characterization by prompt gamma-ray neutron activation analysis, Measurement Science and Technology 22 (2011), 125701
J. Spilde, K.-E. Frøysa, M.B. Holstad, G.A. Johansen, B.T. Hjertaker and S.H. Stavland, A novel subsea on-line multiphase fluid sampling and analysis system, Underwater Technology Conforence, Bergen, Norway, June 2008
M.B. Holstad, Gamma-ray scatter methods applied to industrial measurement systems, Dr. Scient dissertation, Department of Physics and Technology, University of Bergen, Norway (2004)
M.B. Holstad and G.A. Johansen, Produced water characterization by dual modality gamma-ray measurements, Measurement Science and Technology 16 (2005), pages 1007-1013