USE OF 4-D PETROLEUM SYSTEM MODELS IN OIL AND GAS, CLIMATE, AND HYDROLOGIC RESEARCH

Summary

The U.S. Geological Survey (USGS) assesses petroleum resources for basins around the world. This research is based on integration of and understanding the interplay of diverse data. Statistical, mapping, and other methods are used to interpret information. We also use 1-D, 2-D (map and cross section), 3-D geologic, and 4-D petroleum system (PS) models. Spatial information can be modeled at any scale, and models are mainly constrained by data quality and distribution, and computer processing abilities (Higley and others, 2006). PS models are PVT (pressure-volume-temperature) models that use Darcy and flow-path algorithms to model through time oil and gas (1) generation and expulsion from petroleum source rocks, (2) migration, (3) accumulation in source and reservoir rocks, and (4) loss to the atmosphere. These results are important to understanding the history of basins.

Our 4-D petroleum models allow visualization through time of geologic information that includes (1) extent, thickness, and structure of formations; (2) distribution of porosity, permeability, and lithostatic, hydrostatic, and capillary pressures; (3) vertical and lateral influences of open and closed faults on fluid flow; and (4) impact of hydrodynamics on petroleum migration. Formations in PS models are defined as petroleum source, reservoir (aquifer), and seal layers, all with assigned lithofacies; this detail is useful for hydrologic and CO₂ sequestration research. Petroleum system results (Higley and others, 2005a; 2009) and structure and isopach grids of the Western Canada Sedimentary Basin (WCSB) are available for other modeling and mapping research (Higley and others, 2005b). Modeled loss of methane to the atmosphere through time is incorporated in climate studies; the USGS 4-D PS model of the WCSB is shared with GFZ-Potsdam for use in their Methane on the Move (MoM) climate studies (http://www.gfz-potsdam.de/). Our 4-D PS model of the Anadarko Basin of Oklahoma, Kansas, Texas, and Colorado will be shared with the Kansas Geologic Survey for their research in CO₂ sequestration.

References Cited

Higley, Debra K., Henry, Mitchell, Roberts, Laura N. R., and Steinshouer, Douglas W., 2005a, 1-D/3-D Geologic Model of the Western Canada Sedimentary Basin: RMAG The Mountain Geologist invited paper, April 2005, v. 42, no. 2, p. 53-65.

Higley, D. K., Henry, M. E., and Roberts, L. N. R., 2005b, Petroleum System Modeling of the Western Canada Sedimentary Basin—Isopach Grid Files: U.S. Geological Survey Open-File Report 2005-1421, 14 p. http://pubs.usgs.gov/of/2005/1421/ [accessed 12/08].

Higley, D. K., Lewan, M., Roberts, L. N. R., and Henry, M. E., 2006, Petroleum System Modeling Capabilities for Use in Oil and Gas Resource Assessments: U.S. Geological Survey Open-File Report 2006-1024, 18 p. http://pubs.usgs.gov/of/2006/1024/ [accessed 12/08].

Higley, D. K., Lewan, M. D., Roberts, L. N.R., and Henry, M., 2009, Timing and Petroleum Sources for the Lower Cretaceous Mannville Group Oil Sands of Northern Alberta Based on 4-D Modeling: American Association of Petroleum Geologists Bulletin, v. 93, no. 2, 28 p.