World Petroleum Congress Block 3 Review & Forecasting Panel 9, September 5, 2002
: Some questions from an independent O&G explorer
by Jean Laherrere e-mail: firstname.lastname@example.org
-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
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 http://en-env.llnl.gov/gas_hydrates/pdf/gas_hydrate_workshop.pdf
-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 http://www.iiasa.ac.at/Research/ECS/IEW2001/pdffiles/Papers/Laherrere-long.pdf
-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 http://www-odp.tamu.edu/publications/prosp/204_prs/figf3.html
-Williams T. (Interview) « Onshore Hydrates: DOE ready to exploit Arctic’s potential » Hart’s E&P June 2002