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“Observer Design for Multiphase Flow in Vertical Pipes with Gas Lift - Theory and Experiments”

Authors: Ole M. Aamo, G.O. Eikrem, H.B. Siahaan and Bjarne A. Foss,
Affiliation: NTNU, Department of Engineering Cybernetics
Reference: 2005, Vol 26, No 2, pp. 65-80.

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Keywords: Nonlinear observer design, Multiphase flow, Petroleum technology

Abstract: Unstable regimes occurring for multiphase flow in vertical risers have successfully been stabilized using conventional linear control techniques. However, these control systems rely on downhole measurements which are at best unreliable, if at available. In this paper, we design a nonlinear observer for the states of the multiphase flow that relies on topside measurements only, and apply it to estimate downhole pressure for feedback control. A key feature of the design is that it exploits the structure of the model to obtain robustness with respect to the internal flows in the system. Combining the nonlinear observer with conventional PI control of the downhole pressure, we demonstrate in laboratory experiments the potential for increasing production from gas-lift wells by stabilizing the multiphase flow.

PDF PDF (1994 Kb)        DOI: 10.4173/mic.2005.2.1

DOI forward links to this article:
  [1] Giovani G. Gerevini, Marcelo Farenzena and Jorge O. Trierweiler (2018), doi:10.1016/j.petrol.2018.01.054

[1] AAMO, O. M., ARCAK, M., FOSSEN, T.I. KOKOTOVIC, P. V. (2001). Global output tracking control of a class of Euler-Lagrange systems with monotonic non-linearities in the velocities, International Journal of Control, 7.7, pp. 649-658 doi:10.1080/00207170010026130
[2] BERGE, H.I. HALVORSEN, G. (2004). Downhole monitoring and acquisition, Presentation at NTNU on January 29, 2004, http://www.statoil.no/filer/1075472044-Statoils_situasjon_presentasjon_ifb, idekonk.pdf.in Norwegian.
[3] DALSMO, M., HALVORSEN, E. SLUPPHAUG, O. (2002). Active feedback control of unstable wells at the Brage field, SPE paper no. 77650.
[4] EIKREM, G.O., FOSS, B., IMSLAND, L. HU. B. GOLAN, M. (2002). Stabilization of gas lifted wells, Proceedings of the 15th IFAC World Congress, Barcelona, Spain.
[5] EIKREM, G.O., IMSLAND, L. FOSS, B. (2004). Stabilization of gas lifted wells based on state estimation, Proceedings of the International Symposium on Advanced Control of Chemical Processes, Hong Kong, China.
[6] HAVRE, K. DALSMO, M. (2001). Active feedback control as the solution to severe slugging, SPE paper no. 71540.
[7] HAVRE, K., STORNES, K.O. STRAY, H. (2000). Taming slug flow in pipelines, ABB Review, 4.
[8] IMSLAND, L. (2002). Topics in Nonlinear Control: Output Feedback Stabilization and Control of Positive Systems, Ph.D. thesis, NTNU.
[9] JANSEN, B., DALSMO, M., NěKLEBERG, L., HAVRE, K., KRISTIANSEN, V. LEMETAYER, P. (1999). Automatic control of unstable gas lifted wells, SPE. paper no. 56832.
[10] JANSEN, F.E., SHOHAM, O. TAITEL, Y. (1996). The elimination of severe slugging-Experiments and modeling, International Journal of Multiphase Bow, 22(6), pp. 1055-1072. KINDEREN, W. J. G. J. and DUNHAM, C. L. (1998). Real-time artificial lift optimization, SPE paper no. 49463.
[11] SAGATUN, S.I. (2004). Riser slugging-a mathematical model and the practical consequences, SPE paper no. 87355.
[12] SARICA, C. TENGESDAL, J.ě. (2000). A new technique to eliminate severe slugging in pipeline/riser systems, SPE paper no. 63185.
[13] SKOFTELAND, G. GODHAVN, J.-M. (2003). Suppression of slugs in multiphase flow lines by active use of topside choke-Field experience and experimental results, Proceedings of Multiphase ┤03, San Remo, Italy.
[14] STORKAAS, E., SKOGESTAD, S. ALSTAD, V. (2001). Stabilizing of desired flow regimes in pipelines, Proceedings of AlChE Annual Meeting, Reno, Nevada, USA.
[15] XU, Z. G. Se.. GOLAN, M. (1989). Criteria for operation stability of gas lift, SPE paper no. 19362.

  title={{Observer Design for Multiphase Flow in Vertical Pipes with Gas Lift - Theory and Experiments}},
  author={Aamo, Ole M. and Eikrem, G.O. and Siahaan, H.B. and Foss, Bjarne A.},
  journal={Modeling, Identification and Control},
  publisher={Norwegian Society of Automatic Control}


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