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Woods Hole
Oceanographic Institution
Woods Hole, MA 02543 USA

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Research Projects

Oil and gas seep mapping in a sediment-covered hydrothermal area: Guaymas Basin
We are testing a new method of oil and gas seepage detection using fluorescence detection of oil and of bottom pore fluids shoved upward from sediments by upward moving gas. Two fluorometers were deployed, a Sea Tech which "sees" dissolved organic matter (DOM) and a Chelsea Instruments fluorometer which "sees" oil. Plots are generated of fluorescence signal versus either water depth or time. These two instruments were deployed from the unmanned submersible, Jason, during an April 1998 R/V ATLANTIS research cruise, in the Guaymas Basin in the Gulf of California. The overall purpose of the cruise was to study and map hydrothermal vents in this area. Figures and tables and a summary of the paper published by the Marine Technology Society (MTS, Aug 1998) are available. Results have also been published as a virtual document.

  Organic geochemical indicators of dynamic (i.e. present day) fluid flow in Gulf of Mexico petroleum reservoirs (with the The Global Basins Research Network, GBRN) This is a collaborative project with other universities and oil companies.

Using 4D database software from ACI, Inc. our geochemistry databases are available online to authorized colleagues.
Geochemistry Data Server Access(access is password protected)
  Organic characteristics of large (several km) subsurface pressure chambers or "bottles" which remain out of hydrodynamic with surrounding sediments over geologic time. Recent collaborative research with Cornell University has led to a "Hydrocarbon Plugging Hypothesis" in which phase changes between gas-oil mixtures caused by changes in subsurface pressure are proposed as an important plugging mechanism. In addition, study of porosity versus depth profiles the US Gulf Coast strongly suggest gas generation (rather than compaction) to be both a cause of deep overpressures and an important driving force for oil and gas migration. Techniques are being developed to merge geochemistry data from this region with seismic data that has been interpreted at Cornell.
  Organic geochemical indicators of dynamic (i.e. present day) fluid flow in Gulf of Mexico petroleum reservoirs (with the The Global Basins Research Network, GBRN) This is a collaborative project with other universities and oil companies.
  Organic geochemical techniques are being applied to sediments, fluids, and gases collected from the Middle Valley Hydrothermal area in the eastern pacific about 200 miles west of British Columbia collected by the Ocean Drilling Project in Summer of 1991 (ODP Leg 139). A paleotemperature scale has been developed using organic petrographic techniques (i.e. vitrinite reflectance and spore fluorescent measurements). Changes gases, kerogen, and bitumen are being compared for various thermal and venting regimes. These changes are also being compared to those produced in laboratory heating or hydrous pyrolysis experiments.
  Laboratory hydrous pyrolysis technique using a flexible reaction cell which permits samples to be withdrawn at the temperature and pressure of an experiment, avoiding ambiguous retrograde reactions caused by the sampling process. These experiments also differ significantly from previous hydrous pyrolysis experiments because pressure is maintained above the two-phase boundary of water, ensuring that only liquid water exists in the reaction cell. In contrast, hydrous pyrolysis experiments performed in fixed volume reaction vessels require that a vapor phase exist above liquid water. As a result volatile species such as the low molecular weight hydrocarbons partition extensively into the vapor phase effectively reducing their chemical interaction with solid reactants, dissolved species, and liquid water.
  Gas is mobile and therefore difficult to measure in the geologic samples. A number of new analytical techniques have been developed or applied in new ways to this research.
  Baseline studies have been conducted on organic compounds present in Massachusetts Bay sediments and water column particulates.

Research in progress includes:

    1. gas hydrate distribution and influence on the environment
    2. determination of kinetic parameters of gas generation from several rocks kerogens
    3. water as a hydrogen source for gas generation in the presence of some minerals
    4. influence of redox on vitrinite reflectance measurements
    5. reactions of sulfur during hydrous pyrolysis of Monterey shales

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