President’s Column – March 2013

Title: 3D Seismic Symposium’s 19th Anniversary

Author: Debra Higley

Publication: The Outcrop, March 2013, p. 4-5

PCMarch 5th marks the 19th anniversary of the 3D Seismic Symposium. Hosted by the  Denver Geophysical Society and RMAG, this cooperative event meshes geological and geophysical science of new and classic resource plays, technological diversity, and some fabulous 3D images and interpretations. It is fascinating how minor modifications in the properties of the 3D cubes can change the characteristics and resulting conclusions from seismic data.

Particularly for those of us that live in the subsurface (at least in terms of our science), our research is commonly data and data-interpretation intensive. The U.S. Geological Survey assessment of undiscovered resources for basins across the US and the World utilizes some fairly massive proprietary well history and petroleum production databases in our Total Petroleum System (TPS) methodology. As is the case with seismic interpretation, quality of data can vary widely. Well and production data for the Denver Basin Province is fairly clean, and cozy. If you play with data and basins long enough you can develop a fondness. Even though there are more than 45,000 oil and (or) gas productive wells in the Denver Basin Province, the vast majority of these produce from Cretaceous reservoirs; Paleozoic exploration and production is scattered, and recently increasing, near the fringes of the petroleum productive basin. There are almost no deep well data within the basin (more Denver Basin seismic publications would be helpful). In comparison, the Anadarko Basin Province is very mature with more than four times the number of producing wells than the Denver Basin Province, and the vast majority of these are from Paleozoic reservoirs; Cretaceous Niobrara Shale biogenic gas is present in the northwest basin. Data quality is more variable for the Anadarko Basin Province due mainly to reported  commingling of production for multiple producing intervals and misnamed reservoir formations, which complicates assessment of current reserves
and remaining resources (Higley and others, 2011). Further USGS assessment research on the Denver Basin and Anadarko Basin provinces is accessible from http://energy.usgs.gov/, and future Anadarko Basin research will include USGS DDS-69-EE, which is currently in review.

Should you be interested in the methodology behind USGS resources assessments, a few sources follow. These and other U.S. and World petroleum resource assessments utilize the TPS methodology (Magoon and Schmoker, 2000); TPS differs from play assessment methodology in its greater emphasis on petroleum sources. TPS is somewhat of a family tree, a genealogy of determining which petroleum source rock(s) fathered which current and potential future reservoir(s). Each TPS contains one or more assessment units (AU) that comprise the reservoir strata, or groups of strata, that are assigned based on a common petroleum source rock(s), contained reservoir unit(s), and major seals and other boundaries that vertically and laterally segregate oil and gas from other AUs. Incorporated into the assessments are areas that are thermally mature for oil and (or) gas generation. Some of these thermal maturation data are derived using the USGS Energy Geochemical Database (http://energy.cr.usgs.gov/prov/og/). Assessments are further divided into conventional and continuous (unconventional) accumulations (Charpentier and Cook, 2010). Production through time from existing fields is also incorporated as known and grown accumulation sizes (Klett and others, 2011).


References
Charpentier, R.R., and Cook, T.A., 2010, Improved USGS methodology for assessing continuous petroleum resources, version 2.0: U.S. Geological Survey Data Series 547, 22 p. and program. Revised November 2012. http://pubs.usgs.gov/ds/547/ (accessed 1/12/2013).

Higley, D. K., Gaswirth, S. B., Abbott, M. M., Charpentier, R. R., Cook, T. A., Ellis, G. S., Gianoutsos, N. J., Hatch, J. R., Klett, T. R., Nelson, Philip, Pawlewicz, M. J., Pearson, O. N., Pollastro, R. M., and Schenk, C. J., 2011, Assessment of undiscovered oil and gas resources of the Anadarko Basin province of Oklahoma, Kansas, Texas, and Colorado, 2010: U.S. Geological Survey Fact Sheet 2011–3003, 2 p. http://pubs.usgs.gov/fs/2011/3003/ (accessed 1/12/2013).

Klett, T.R., Attanasi, E.D., Charpentier, R.R., Cook, T.A., Freeman, P.A., Gautier, D.L., Le, P.A., Ryder, R.T., Schenk, C.J., Tennyson, M.E., and Verma, M.K., 2011, New U.S. Geological Survey method for the assessment of reserve growth: U.S. Geological Survey Scientific Investigations Report 2011-5163, 8 p., accessed August 1, 2012, at http://pubs.usgs.gov/sir/2011/5163/ (accessed 1/12/2013)

Magoon, L.B., and Schmoker, J.W., 2000, The Total Petroleum System—The Natural Fluid Network that Constrains the Assessment Unit: U.S. Geological Survey World Petroleum Assessment 2000 – description and results: U.S. Geological Survey DDS-60, 4 CD-ROMs, 24 p. http://energy.cr.usgs.gov/WEcont/chaps/PS.pdf (accessed 1/12/2013).