Changes

  | part    = Predicting the occurrence of oil and gas traps

  | part    = Predicting the occurrence of oil and gas traps

  | chapter = Surface geochemical exploration for petroleum

  | chapter = Surface geochemical exploration for petroleum

  | frompg  = 18-1

  | frompg  = 18-14

  | topg    = 18-27

  | topg    = 18-14

  | author  = Dietmar Schumacher

  | author  = Dietmar Schumacher

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch18/ch18.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch18/ch18.htm

* establish the presence, distribution, and composition of hydrocarbons in the area of exploration or development interest and

* 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.

* determine the probable [[Calculating charge volume|hydrocarbon charge]] to specific exploration leads and prospects.

==Reconnaissance objectives==

==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.<ref name=ch18r17>Jones, V., T., Drozd, R., J., 1983, Predictions of oil or gas potential by near-surface geochemistry: AAPG Bulletin, vol. 67, p. 932–952.</ref> 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.

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.<ref name=ch18r17>Jones, V., T., Drozd, R., J., 1983, [http://archives.datapages.com/data/bulletns/1982-83/data/pg/0067/0006/0900/0932.htm Predictions of oil or gas potential by near-surface geochemistry]: AAPG Bulletin, vol. 67, p. 932–952.</ref> 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<ref name=ch18r1>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</ref> Piggot and Abrams<ref name=ch18r28>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.</ref> Schiemer et al. (1995), Thrasher et al.<ref name=ch18r45>Thrasher, J., A., Strait, D., Lugo, R., A., 1996a, 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.</ref> and Williams et al.<ref name=ch18r49>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.</ref>

Published examples of reconnaissance surface geochemical surveys include Abrams<ref name=ch18r1>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</ref> Piggot and Abrams<ref name=ch18r28>Piggott, N., Abrams, M., A., 1996, [http://archives.datapages.com/data/specpubs/memoir66/30/0385.htm 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: [http://store.aapg.org/detail.aspx?id=75 AAPG Memoir 66], p. 385–399.</ref> Schiemer et al. (1995), Thrasher et al.<ref name=ch18r45>Thrasher, J., A., Strait, D., Lugo, R., A., 1996, [http://archives.datapages.com/data/specpubs/memoir66/29/0373.htm Surface geochemistry as an exploration tool in the South Caribbean], in Schumacher, D., Abrams, M., A., eds., Hydrocarbon Migration and Its Near-Surface Expression: [http://store.aapg.org/detail.aspx?id=75 AAPG Memoir 66], p. 373–384.</ref> and Williams et al.<ref name=ch18r49>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.</ref>

==Evaluating leads and prospects==

==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<ref name=ch18r13>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.</ref> Lopez et al.<ref name=ch18r22>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.</ref> Potter et al.<ref name=ch18r29>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.</ref> Rice<ref name=ch18r33>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.</ref> and Saunders et al.<ref name=ch18r36>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.</ref>

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<ref name=ch18r13>Foote, R. S., 1996, [http://archives.datapages.com/data/specpubs/memoir66/09/0111.htm 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: [http://store.aapg.org/detail.aspx?id=75 AAPG Memoir 66], p. 111–126.</ref> Lopez et al.<ref name=ch18r22>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.</ref> Potter et al.<ref name=ch18r29>Potter, R., W., IIHarrington, P., A., Silliman, A., H., Viellenave, J., H., 1996, [http://archives.datapages.com/data/specpubs/memoir66/33/0431.htm 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: [http://store.aapg.org/detail.aspx?id=75 AAPG Memoir 66], p. 431–439.</ref> Rice<ref name=ch18r33>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.</ref> and Saunders et al.<ref name=ch18r36>Saunders, D., F., Burson, K., R., Brown, J., J., Thompson, C., K., 1993, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0077/0007/1200/1219.htm Combined geological and surface geochemical methods discovered Agaritta and Brady Creek fields, Concho County, Texas]: AAPG Bulletin, vol. 77, p. 1219–1240.</ref>

==Evaluating development projects==

==Evaluating development projects==

==See also==

==See also==

* [[Designing surface geochemical surveys]]

* [[Surficial geochemistry and hydrocarbon detection methods]]

* [[Hydrocarbon detection methods]]

* [[Selecting a surficial geochemistry survey method]]

* [[Selecting a survey method]]

* [[Designing a surficial geochemical survey]]

* [[Designing a geochemical survey]]

* [[Surficial geochemical interpretation guidelines]]

* [[Interpretation guidelines]]

==References==

==References==

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Surface geochemical exploration for petroleum]]

[[Category:Surface geochemical exploration for petroleum]]