Surficial geochemical survey objectives
Exploring for Oil and Gas Traps | |
Series | Treatise in Petroleum Geology |
---|---|
Part | Predicting the occurrence of oil and gas traps |
Chapter | Surface geochemical exploration for petroleum |
Author | Dietmar Schumacher |
Link | Web page |
Store | AAPG Store |
Principal objectives
The principal objectives of a geochemical exploration survey are to
- establish the presence, distribution, and composition of hydrocarbons in the area of exploration or development interest and
- determine the probable hydrocarbon charge to specific exploration leads and prospects.
Reconnaissance objectives
The objective of a reconnaissance survey is to find seeps and microseeps that provide direct evidence that thermogenic hydrocarbons have been generated, i.e., they document the presence of a working petroleum system. Additionally, the composition of these seeps can indicate whether a basin or play is oil prone or gas prone.[1] Hydrocarbons from surface and seafloor seeps can be correlated with known oils and gases to identify the specific petroleum system(s) present. Seepage data allow the explorationist to screen large areas quickly and economically, determining where additional and more costly exploration is warranted. For example, results of preseismic geochemical surveys can guide the location and extent of subsequent seismic acquisition by ensuring that areas with significant hydrocarbon anomalies are covered by seismic data.
Published examples of reconnaissance surface geochemical surveys include Abrams[2] Piggot and Abrams[3] Schiemer et al. (1995), Thrasher et al.[4] and Williams et al.[5]
Evaluating leads and prospects
If the objective is to evaluate individual exploration leads and prospects, the results of geochemical surveys can identify those leads associated with strong hydrocarbon anomalies and thereby enable high-grading prospects on the basis of their association with hydrocarbon indicators. Regional geochemical surveys can help determine which leases should be renewed and which ones do not warrant additional expense. Detailed seepage surveys can also generate geochemical leads for evaluation with geologic and seismic data—leads that might otherwise go unnoticed. Published examples of these kinds of applications include Foote[6] Lopez et al.[7] Potter et al.[8] Rice[9] and Saunders et al.[10]
Evaluating development projects
For development projects, detailed microseepage surveys can help evaluate infill or step-out drilling locations, delineate productive limits of undeveloped fields, and identify bypassed pay or undrained reservoir compartments. Hydrocarbon microseepage surveys have the potential to add value to 2-D and 3-D seismic data by identifying those features or reservoir compartments that are hydrocarbon charged. Published studies of development applications are few but include Belt and Rice[11] Rice[12] Schumacher et al.[13] and Tucker and Hitzman.[7]
See also
- Designing surface geochemical surveys
- Hydrocarbon detection methods
- Selecting a survey method
- Designing a geochemical survey
- Interpretation guidelines
References
- ↑ Jones, V., T., Drozd, R., J., 1983, Predictions of oil or gas potential by near-surface geochemistry: AAPG Bulletin, vol. 67, p. 932–952.
- ↑ Abrams, M., A., 1992, Geophysical and geochemical evidence for subsurface hydrocarbon leakage in the Bering Sea, Alaska: Marine and Petroleum Geology Bulletin, vol. 9, p. 208–221., 10., 1016/0264-8172(92)90092-S
- ↑ Piggott, N., Abrams, M., A., 1996, Near-surface coring in the Beaufort and Chukchi Seas, northern Alaska, in Schumacher, D., Abrams, M., A., eds., Hydrocarbon Migration and Its Near-Surface Expression: AAPG Memoir 66, p. 385–399.
- ↑ Thrasher, J., A., Strait, D., Lugo, R., A., 1996, Surface geochemistry as an exploration tool in the South Caribbean, in Schumacher, D., Abrams, M., A., eds., Hydrocarbon Migration and Its Near-Surface Expression: AAPG Memoir 66, p. 373–384.
- ↑ Williams, A., Kloster, A., Duckworth, R., Piggott, N., 1995, The role of the Airborne Laser Fluorosensor (ALF) and other seepage detection methods in exploring frontier basins, in Hansjien, S., ed., Petroleum Exploration and Exploitation in Norway: NPF Special Publication 4, p. 421–431.
- ↑ Foote, R. S., 1996, Relationship of near-surface magnetic anomalies to oil- and gas-producing areas, in Schumacher, D., Abrams, M. A., eds., Hydrocarbon Migration and Its Near-Surface Expression: AAPG Memoir 66, p. 111–126.
- ↑ 7.0 7.1 Lopez, J., P., Hitzman, D., C., Tucker, J., D., 1994, Combined microbial, seismic surveys predict oil and gas occurrences in Bolivia: Oil & Gas Journal, October 24, p. 68–70.
- ↑ Potter, R., W., IIHarrington, P., A., Silliman, A., H., Viellenave, J., H., 1996, Significance of geochemical anomalies in hydrocarbon exploration: one company's experience, in Schumacher, D., Abrams, M. A., eds., Hydrocarbon Migration and Its Near-Surface Expression: AAPG Memoir 66, p. 431–439.
- ↑ Rice, G., 1989, Exploration enhancement by integrating near-surface geochemical and seismic methods: Oil & Gas Journal, v. 87, no. 14 (April 3), p. 66–71.
- ↑ Saunders, D., F., Burson, K., R., Brown, J., J., Thompson, C., K., 1993, Combined geological and surface geochemical methods discovered Agaritta and Brady Creek fields, Concho County, Texas: AAPG Bulletin, vol. 77, p. 1219–1240.
- ↑ Belt, J., Q., Rice, G., K., 1996, Offshore 3D seismic, geochemical data integration, Main Pass project, Gulf of Mexico: Oil & Gas Journal, vol. 94, no. 14, p. 76–81, and vol. 94, no. 15, p. 100–102.
- ↑ Rice, G., 1986, Near-surface hydrocarbon gas measurement of vertical migration, in Davidson, M. J., ed., Unconventional Methods in Exploration for Petroleum and Natural Gas IV: Dallas, Southern Methodist Univ. Press, p. 183–200.
- ↑ Schumacher, D., Hitzman, D., C., Tucker, J., Roundtree, B., 1997, Applying high-resolution surface geochemistry to assess reservoir compartmentalization and monitor hydrocarbon drainage, in Kruizenga, R., J., Downey, M., W., eds., Applications of Emerging Technologies: Unconventional Methods in Exploration for Oil and Gas V: Dallas, Texas, Southern Methodist Univ. Press, p. 309–322.