316 



Results from our research may have national significance as well. They suggest 

 that reductions in natural seepage due to oil production must be accounted for when 

 determining greenhouse gas emission inventories. Methane is a greenhouse gas that is 20 

 to 30 times as potent as carbon dioxide. Around Platform Holly methane emission due to 

 natural seepage has decreased by about 15 to 25 tons per day. This decrease is equivalent 

 to 12-20% of the global warming potential produced by burning the oil that comes from 

 this field each day. The reduction in natural seepage may persist after oil production has 

 stopped and a key research issue is understanding the long term relationship between oil 

 production and natural seepage. 



We emphasize that our study is focused on a small region around a single platform. 

 It is not known if the changes in seepage rates at the South EUwood Field are typical of 

 other oil fields around the world. To the best of our knowledge, there is no research 

 directed at understanding changes in natural hydrocarbon seepage around oil fields, either 

 in the United States or overseas, except at Platform Holly. We feel that interdisciplinary 

 studies spanning the areas of oceanography, geophysics, geology, biology, and 

 climatology are necessary to understand the global significance of this issue. 



In summary, we feel that our project is a good example of a cooperative research 

 effort being conduaed by members of the scientific community and industry. It also 

 illustrates how basic scientific research can produce in practical results with policy 

 implications. Thank you for your attention. 



References 



Allen, A.A., R.S. Schueter, and P.G. Mikolaj, 1970. Natural oil seepage at Coal Oil 

 Point, Santa Barbara, California, Science, vl70, p.974-977. 



Fischer, P. J., 1978. Oil and tar seeps, Santa Barbara Basin, California, in California 

 Offshore Gas, Oil, and Tar Seeps, California State Lands Commission, Sacramento, 

 California, p. 1-62. 



Hartman, B.. and D. Hammond, 1981, The use of carbon and sulfiir isotopes as 

 correlation parameters for the source identification of beach tar in the Southern 

 California Borderland, Geochim. et Cosmochim. Acta, v45, p 309-319. 



Killus, J.P., and G.E. Moore, 1991. Factor analysis of hydrocarbon species in the south- 

 central coast air basin, J. of Applied Meteorology, v30, p.733-743. 



Wilson, R.D., P.H. Monaghan. A. Osanik, L.C. Price, and M.A. Rogers, 1974. Natural 

 Marine Oil Seepage, Science, v. 184, p. 857-865. 



