Combined heat and power plant on offshore oil and gas installations

Eirik R. Følgesvold, Håvard S. Skjefstad, Luca Riboldi, Lars O. Nord

Abstract


Implementation of energy efficient technologies is an issue of growing importance for the offshore oil and gas industry. Rising
awareness of increasing levels of CO2in the atmosphere is a major driver in this move, with a main aim being to reduce the
amount of released CO2 per unit of oil or natural gas produced. Subsequently, the addition of steam bottoming cycles to
exploit exhaust heat from gas turbines offshore has become an attractive alternative. This paper will investigate two different
combined cycle configurations, namely the extraction steam turbine- and the backpressure steam turbine-cycle. Both cycles
were modelled using the process simulation software Ebsilon Professional with a single GE LM2500+G4 gas turbine as a
topping cycle, and a once-through heat recovery steam generator to exploit GT exhaust heat.At design, the steam turbines
produced 8.2 MW and 6.0 MW respectively, achieving net thermal efficiency of 45.5%/42.1%. This was a 12.3 pp/8.9 pp
increase compared to the simple cycle GE LM2500+G4 configuration.
The findings suggest that a backpressure steam turbine could be an attractive option for oil producing facilities with high
demand for process heat, while an extraction steam turbine configuration is more suited to gas producing facilities with lower
heat requirements and a higher demand for power and flexibility. Additionally, both cycles displayed a substantial reduction in
emitted CO2 per MWh produced, with reductions 26% and 21% compared to the simple cycle configuration achieved for the
extraction and backpressure cycle respectively.

Keywords


combined cycle; process simulation; heat recovery; compact steam cycle; cogeneration; off-design; extraction steam turbine; back-pressure steam turbine

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References


N. P. Directorate, Facts 2014 - the norwegian petroleum sector.

P. Kloster, et al., Energy optimization on offshore installations with emphasis on offshore combined cycle plants, in: Offshore Europe Oil and Gas Exhibition and Conference, Society of Petroleum Engineers, 1999.

R. Farmer, North sea platforms are converting mech drives to comb cycle operation, Gas Turbine World November-December 1216.

S. Lloyd, Co-generation in offshore process platforms, in: 5th International Symposium and Exposition on Gas Turbines in Cogeneration, Repowering, and Peak-Load Power Generation, 1991, pp. 281–286.

J. D. Bimüller, L. O. Nord, Process simulation and plant layout of a combined cycle gas turbine for offshore oil and gas installations, Journal of Power Technologies 95 (1) (2015) 40–47.

L. O. Nord, O. Bolland, Steam bottoming cycles offshore-challenges and possibilities, Journal of Power Technologies 92 (3) (2012) 201.

L. O. Nord, O. Bolland, Design and off-design simulations of combined cycles for offshore oil and gas installations, Applied Thermal Engineering 54 (1) (2013) 85–91.

L. O. Nord, E. Martelli, O. Bolland, Weight and power optimization of steam bottoming cycle for offshore oil and gas installations, Energy 76 (2014) 891–898.

T.-V. Nguyen, L. Tock, P. Brehaus, F. Maréchal, B. Elmegaard, Oil and gas platforms with steam bottoming cycles: System integration and thermoenvironomic evaluation, Applied Energy 131 (2014) 222–237.

T.-V. Nguyen, M. Voldsund, P. Brehaus, B. Elmegaard, Energy efficiency measures for offshore oil and gas platforms, Energy In Press.

R. K. Bhargava, M. Bianchi, L. Branchini, A. De Pascale, V. Orlandini, Organic rankine cycle system for effective energy recovery in offshore applications: a parametric investigation with different power rating gas turbines, in: ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, The America Society of Mechanical Engineers, 2015.

L. Pierobon, A. Benato, E. Scolari, F. Haglind, A. Stoppato, Waste heat recovery technologies for offshore platforms, Applied Energy 136 (2014) 228–241.

L. Pierobon, T. V. Nguyen, U. Larsen, F. Haglind, B. Elmegaard, Multiobjective optimization of organic rankine cycles for waste heat recovery: Application in an offshore platform, Energy 58 (2013) 538–549.

J. E. Barrera, E. Bazzo, E. Kami, Exergy analysis and energy improvement of a brazilian floating oil platform using organic rankine cycles, Energy 58 (2015) 67–79.

T.-V. Nguyen, T. G. Fülöp, P. Breuhaus, B. Elmegaard, Life performance of oil and gas platforms: Site integration and thermodynamic evaluation, Energy 73 (2014) 282–301.

M. Voldsund, T.-V. Nguyen, B. Elmegaard, I. S. Ertesvåg, A. Røsjorde, K. Jøssang, S. Kjelstrup, Exergy destruction and losses on four north sea offshore platforms: A comparative study of the oil and gas processing plants, Energy 74 (2014) 45–58.

T.-V. Nguyen, L. Pierobon, B. Elmegaard, F. Haglind, P. Breuhaus, M. Voldsund, Exergetic assessment of energy systems on north sea oil and gas platforms, Energy 62 (2013) 23–36.

EBSILON® Professional, Version 10.0 - release (patch 6) (2014).

O. Bolland, Thermal power generation, Compendium, Department og Energy and Process Engineering - NTNU.

R. Kehlhofer, F. Hannemann, B. Rukes, F. Stirnimann, Combined-cycle gas & steam turbine power plants, Pennwell Books, 2009.


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