”HYDRATPRODUKSJON” Lagring og transport av naturgass Prof. Jón Steinar Guðmundsson NTNU NFR, Olje og gass programseminar Stavanger, april 2003

NGH R&D at NTNU Phase Ia ( ). Early work funded by the SPUNG program of the Research Council of Norway. Phase Ib ( ). Continued early work funded by Statoil’s Research Center in Trondheim. Phase Ic ( ). Laboratory and process design work funded by Aker Engineering. Phase IIa ( ). Joint Industry Project funded by Aker Engineering and six international oil companies and the Research Council of Norway. Phase IIb ( ). Doctoral project funded by the Research Council of Norway. Phase III (2002…). NTNU + Aker Kværner Technology, special projects and international co-operation.

Hydrate Equilibrium Curve 180 Sm 3 of gas 1 m 3 of hydrate

Production of Hydrates Industrial Process Natural Gas Freezing unit Separator unit Reactor unit Water SlurryHydrate Water Frozen Hydrate

Hydrate Laboratory

Hydrate Dr.Ing. Theses at NTNU Department 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 Laboratory 9.5 litre continuous stirred tank reactor

Results –experimental conditions Steady-state operation Methane and natural gas mixture (92% C1, 5% C2, 3% C3) Gas injection rate 27–339 Nl/min Subcooling °C Stirring rate 400, 800 RPM Natural gas mixture Methane gas

Results –effect of gas composition Pressure 70 bar, subcooling 3 °C, stirring rate 400 RPM Background Lab and procedure Experimental results Mass transfer model Production of hydrates Conclusions

NGH Crystals 2670x Magnification 20  m

Summary experimental results Rate 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 model Concept CbCb C g Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS CbCb C g Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS CbCb C g Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS CbCb C g Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS CbCb C g Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS CbCb Gas bubble liquid water Hydrate crystal CbCb C sol C eq T g Gas bubble Hydrate crystal T eq TbTb TbTb T sol kLkL kSkS Background Lab and procedure Experimental results Mass transfer model Production of hydrates Conclusions

Model and experimental data 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 Technologies CNGCompressed Natural Gas GTLGas-to-Liquid (incl. MOH) GTWGas-to-Wire (DC and AC) LNGLiqufied Natural Gas (GTL?) NGHNatural Gas Hydrate

CAPACITY-DISTANCE DIAGRAM Gudmundsson and Mork (2001)

ChainLNGNGHDifference Production1144 (55%)992 (54%)152(13%) Carriers660 (32%)628 (34%)32 (5%) Regasification285 (13%)218 (12%)67 (24%) Total2089 (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)

22 nd World Gas Conference Tokyo, June 1-5, 2003 HYDRATE NON-PIPELINE TECHNOLOGY FOR TRANSPORT 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 PROJECTS NTNU, 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