””HYDRATPRODUKSJON”HYDRATPRODUKSJON”Lagring og transport av naturgassLagring og transport av naturgass

Prof. Jón Steinar Guðmundsson

NTNU

NFR, Olje og gass programseminar

Stavanger, 3.-4. april 2003

NGH R&D at NTNUNGH R&D at NTNU Phase Ia (1990-1991). Early work funded by the SPUNG program

of the Research Council of Norway. Phase Ib (1991-1993). Continued early work funded by Statoil’s

Research Center in Trondheim. Phase Ic (1993-1996). Laboratory and process design work

funded by Aker Engineering. Phase IIa (1997-1999). Joint Industry Project funded by Aker

Engineering and six international oil companies and the Research Council of Norway.

Phase IIb (1999-2002). Doctoral project funded by the Research Council of Norway.

Phase III (2002…). NTNU + Aker Kværner Technology, special projects and international co-operation.

Hydrate Hydrate EEquilibrium quilibrium CCurveurve

0

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Temperature [°C]

Pre

ss

ure

[b

ar]

Natural gas

Methane

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Temperature [°C]

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180 Sm3 of gas

1 m3 of hydrate

Production of HydratesProduction of HydratesIndustrial ProcessIndustrial Process

Natural Gas Freezing

unit

Separator

unit

Reactor

unit

Water

Slurry Hydrate

Water

Frozen Hydrate

Hydrate LaboratoryHydrate Laboratory

Hydrate LaboratoryHydrate Laboratory

Hydrate Dr.Ing. Theses at NTNUHydrate Dr.Ing. Theses at NTNUDepartment of Petroleum Engineering and Applied GeophysicsDepartment of Petroleum Engineering and Applied Geophysics

Aftab A. Khokhar 1998: Storage properties of natural gas hydrates

Vibeke Andersson 1999: Flow properties of natural gas hydrate slurries

Odd Ivar Levik 2000: Thermophysical and compositional properties of natural gas hydrates

Marit Mork 2002: Formation rate of natural gas hydrate

NTNU’s Hydrate LaboratoryNTNU’s Hydrate Laboratory9.5 litre continuous stirred tank reactor9.5 litre continuous stirred tank reactor

Results –experimental conditionsResults –experimental conditions

Steady-state operation Methane and natural gas

mixture (92% C1, 5% C2, 3% C3)

Gas injection rate 27–339 Nl/min

Subcooling 2.1-5.6 °C Stirring rate 400, 800 RPM

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Temperature (°C)

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ure

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Methane gas

Results –effect of gas Results –effect of gas compositioncompositionPressure 70 bar, subcooling 3 °C, stirring rate Pressure 70 bar, subcooling 3 °C, stirring rate 400 RPM400 RPM

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0 50 100 150 200 250 300Gas injection rate (Nl/min)

Gas

co

nsu

mp

tio

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ate

(Nl/m

in)

methane gas

natural gas mixture

BackgroundLab and procedure

Experimental resultsMass transfer model

Production of hydratesConclusions

NGH CrystalsNGH Crystals2670x Magnification2670x Magnification

20 m 20 m

Summary experimental resultsSummary experimental resultsRate of hydrate formationRate of hydrate formation

Proportional to gas injection rate

Highly influenced by pressure

Less influenced by stirring rate

Not influenced by gas composition

Not influenced by subcooling

Not influenced by crystal concentration

Rate of hydrate formation is gas-liquid mass transfer limited

Mass transfer modelMass transfer modelConceptConcept

CbGas bubble

liquid water

Hydrate crystalCb

Csol

Ceq

Tg

Gas bubbleHydrate crystal

TeqTbTb

Tsol

kL kS

BackgroundLab and procedure

Experimental resultsMass transfer model

Production of hydratesConclusions

Model and experimental dataModel and experimental data

tot sol eq

gsg

0.18011.124g

tot sg sol eq

R K (C C ) V

PK v

V

PR 363.3 v C C 9.5

V

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0 100 200 300 400Gas injection rate (Nl/min)

Ga

s c

on

su

mp

tio

n r

ate

(N

l/min

)

70 bar

90 bar

90 bar *

* Parlaktuna and Gudmundsson (1998)

Overall mass transfer coefficient:

Gas consumption rate in CSTR:

Overall rate of hydrate formation for total liquid volume:

Non-Pipeline TechnologiesNon-Pipeline Technologies

CNG Compressed Natural GasGTL Gas-to-Liquid (incl. MOH)GTWGas-to-Wire (DC and AC)LNG Liqufied Natural Gas (GTL?)NGH Natural Gas Hydrate

CAPACITY-DISTANCE DIAGRAM CAPACITY-DISTANCE DIAGRAM Gudmundsson and Mork (2001)Gudmundsson and Mork (2001)

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Distance (km)

Cap

acit

y (B

CM

/yea

r)

PIPE LNG

CNG, GTW, NGH GTL

ALL

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Distance (km)

Cap

acit

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CM

/yea

r)

PIPE LNG

CNG, GTW, NGH GTL

ALL

Chain LNG NGH Difference

Production 1144 (55%) 992 (54%) 152(13%)

Carriers 660 (32%) 628 (34%) 32 (5%)

Regasification 285 (13%) 218 (12%) 67 (24%)

Total 2089 (100%) 1838 (100%) 251 (12%)

Capital cost of NGH and LNG chains for 400 MMscfs production and transport over 3243 nautical miles (6000 km). Cooling water

temperature 35 C (5 C in 1996 study). Million US dollars mid-2002 (Aker Kværner Technology AS)

22nd World Gas Conference Tokyo, June 1-5, 2003 

HYDRATE NON-PIPELINE TECHNOLOGY FORTRANSPORT OF NATURAL GAS

 Jón S. Gudmundsson, Norwegian University of Science and Technology

Oscar F. Graff, Aker Kvaerner Technology AS

 SUMMARY

 The economics of natural gas transport depends greatly on the annual volumes and transport distances. Pipelines are readily used for distances less than 1000 km and large volumes, while LNG (liquefied natural gas) technology is used for much larger distances. Other non-pipeline technologies are considered suitable for other annual volumes and transport distances. Natural gas hydrate (NGH) technology represents a new non-pipeline technology that is suitable for the transport of small-to-medium annual volumes of natural gas over moderate distances. Surveys of natural gas resources world-wide indicate that about 80% of new discoveries will be smaller than the minimum required to make LNG transport economical (mature technology). Hence the great interest in NGH and similar new technologies. Several groups are developing NGH technology world-wide, including NTNU and Aker Kvaerner Technology in Norway. NGH technology is lower in cost than LNG technology, based on mid-1995 and mid-2002 cost studies for large-scale natural gas chains (NGH will be even more competitive for small-to-medium sized chains). When NGH technology matures its costs are expected to decrease and be even more favourable compared to LNG technology.

ON-GOING R&D PROJECTSON-GOING R&D PROJECTSNTNU, Dept.Pet.Eng., Prof. GudmundssonNTNU, Dept.Pet.Eng., Prof. Gudmundsson

Hydrate Technolog, NTNU + Aker Kværner

Technology AS, NFR stipends

PressurePulse Technology, NTNU +

Markland AS + EU’s SurgeNet

Pressure Loss Reduction Technology, JIP

(Statoil, BP, TFE, GdF, Enagas), NFR

stipend