World Petroleum Congress Block 3 Review & Forecasting Panel 9, September 5, 2002

Economic use of hydrates: dream or reality?          Introduction


Hydrates : Some questions from an independent O&G explorer
by Jean Laherrere        e-mail:

-How to classify the product ?

-Location: Permafrost or Deepwater ?

-Origin : biogenic, thermogenic, associated with a Gas System ?

-Core Description : crystal, vein fillings, laminae or massive ?

-Reservoir type: unconsolidated mud or sand ?

-Seafloor occurrence: faults, gas vents, mud volcanoes, pockmarks ?

-Trap: fault, diapir, anticline, stratigraphic ?

-Concentration: < 10% or > 50%?

-How to define the accumulation ?

-Why is an industrial approach not applied ?

-thickness of sediments / source-rock / gas window / expulsion / migration / trap / seal / trap-migration timing….

-reservoir porosity / permeability / water, oil, gas saturation / volume factor...

-Why is the oil industry so little involved ?

Save for working on methane hydrates nuisance

-too much stranded gas in frontier areas ?

-economic or technical concerns ?

-too uncertain, too long-term ?

-Why is Academia so deeply involved ?

-easier to get funds in hydrate research judged by the number of publications (Williams 2002) ?

-absence of the oil industry ?

-Why such a range of estimates?

-is the range of estimates properly evaluated ?

-What about the trend?  Milkov and Sassen (2001)

-What about accumulation ?

-Why two different definitions ?

-Oil industry = area where hydrocarbons are producible (gasfield concentration >80%)

-Hydrate = area where hydrates are present whatever their concentration (usually <5%)

-Are areas, volumes, volumes/km2  properly explained and understood ?

-World Hydrate areas = 2/3 deepwater sedimentary basins ( 55 M.km2), is it an occurrence or an accumulation?

-Estimated world hydrate volume per square km was reduced from 1 in 1997 to 0.005 G.m3/km2 in 2000 (to be compared to 1 for Mensa deepwater GoM gasfield): will it continue ?

-How to compare with O&G reserves  ?

Are Hydrate resources to be compared to

-world conventional gas reserves or

-total gas volume generated and dispersed within the producing provinces, (= 100 times ultimate gas reserves !) ?

reserve= what will be produced from accumulations
resource = what is estimated in the ground in known and unknown accumulations….

-Over what time period ?

-The US Hydrate multi-year research program wants production by 2015 with low budgets compared to E&P deepwater expenditures. Experts forecast 2030.

-Which date to expect ?

-Where does methane come from ?

-What is the sedimentary thickness ?

-Why is the sedimentary sequence not investigated by geophysics calibrated with deep wells ?

-Why are Blake Ridge drilled sediments 10 times younger than the age of the fluids (Fehn 2000)

-What reservoir ?

-What are the physical characteristics of the reservoir?

-What is the behaviour of a solid (mostly crystal, lighter than water) occupying few % of the pore?

-What is methane solubility in deep seawater?

-How to measure its physical characteristics?

-How to improve the proxy measures: logging, chlorinity, seismics and their calibration from better cores?

-Why is a lack of measures of methane concentration in the seawater and atmosphere in hydrate areas?

-What seal ?

-Why no hydrates on the first 200 m of Blake Ridge, when present on the seafloor at Cascadia and Hydrate Ridge?           

-Is the hydrate resource stable or depleted and constantly recharged?

-Where does the methane go in seawater ?

-What seal when gas vents ?

Leg 204 program: gas vents though GHSZ and bubble plumes

-What physical laws?

-How different are theoretical laws from laboratory and in situ measurements (chaotic behavior of hydrates: Brewer 2001)

-Why are there so few measurements in deepwater?

-At which water depth CH4 hydrate becomes heavier than water ? 3000 m for CO2 hydrates?

-What productivity per well ?

-Will hydrates need the high productivity for deepwater gas production? 1 M.m3/d /well in Mensa, GoM, 0.03 M.m3/d/well Messoyakha, Siberia)

-What is the minimum acceptable productivity / well?

-What about economics?

-Can we assume that, if production is not economic to day, it will be tomorrow when oil and gas price goes up

-Net energy loss?

-Can economics change geology ?

-Concentrated hydrates ?

Hovland Statoil 2000 recommends  “where to seek concentrated gas hydrates”. Where are they ?

-What impact on gas production and global warming ?

What of the IPCC 2000 forecasts on a “Methane Age” from hydrates (Nakicenovic 2000)?


-This is the place to obtain some of the answers from Georgy Cherkashov
and maybe from the floor….



-Brewer P. (MBARI) 2001 « Physical properties of CO2 hydrate films » Final Report for the September 2001 Workshop on Physical and Chemical Property Measurements for the Gas Hydrate R & D

-Fehn et al Science magazine Sept 29, 2000 p2332-2335

-Hovland M. “Are there commercial deposits of methane hydrates in ocean sediments?” Energy Exploration & Exploitation, Special issue on Gas hydrates Nov-Dec vol 18 n°4 p339-347

-Laherrère J.H. 2001 “Estimates of Oil Reserves ” IIASA International Energy Workshop June 19-21 2001 Laxenburg

-Milkov A.V. & Sassen R. 2001 “Economic geology of the Gulf of Mexico and the Blake Ridge gas hydrate provinces” Gulf Coast association of geological societies Volume L1, 2001

-Nakicenovic, et al 2000 "Global Natural Gas Perspectives" International Gas Union for the Kyoto Council and the International Institute for Applied Systems Analysis, October 2-5

-ODP Leg 204 scientific prospectus 2002 : Drilling gas hydrates on Hydrate Ridge, Cascadia continental margin » Feb., fig 3D : Acoustic "bubble" plumes from three sites on the Oregon margin

-Williams T. (Interview) « Onshore Hydrates:  DOE ready to exploit Arctic’s potential » Hart’s E&P June 2002