Changes

==Determining data reliability==

==Determining data reliability==

In any correlation study, we must decide which data are most reliable for answering the questions about genetic relationships and which data have been affected by postgenetic transformations, such as expulsion, migration, [http://www.oiltracers.com/services/exploration-geochemistry/oil-biodegradation.aspx biodegradation], water washing, and thermal cracking. In addition, we must resolve other complicating issues, such as differences in maturity of the samples being compared, facies variations in source rocks, possible mixing of oils from different sources in a single reservoir, and the intrinsic differences between oils and source rock bitumens. These topics are discussed in more detail in Curiale.<ref name=ch08r11>Curiale, J., A., 1993, Oil to source rock correlation. Concepts and case studies, in Engel, M., H., Macko, S., A., eds., Organic Geochemistry: New York, Plenum Press, p. 473–490.</ref><ref name=ch08r12>Curiale, J., A., 1994, [http://archives.datapages.com/data/specpubs/methodo2/data/a077/a077/0001/0250/0251.htm Correlation of oils and source rocks—a conceptual and historical perspective], in Magoon, L., B., Dow, W., G., eds., The [[Petroleum system]]—From Source to Trap: [http://store.aapg.org/detail.aspx?id=1022  AAPG Memoir 60], p. 251–260.</ref>

In any correlation study, we must decide which data are most reliable for answering the questions about genetic relationships and which data have been affected by postgenetic transformations, such as expulsion, migration, [http://www.oiltracers.com/services/exploration-geochemistry/oil-biodegradation.aspx biodegradation], water washing, and thermal cracking. In addition, we must resolve other complicating issues, such as differences in maturity of the samples being compared, facies variations in source rocks, possible mixing of oils from different sources in a single reservoir, and the intrinsic differences between oils and source rock bitumens. These topics are discussed in more detail in Curiale.<ref name=ch08r11>Curiale, J. A., 1993, Oil to source rock correlation. Concepts and case studies, in M. H. Engel, and S. A. Macko, eds., Organic Geochemistry: New York, Plenum Press, p. 473–490.</ref><ref name=ch08r12>Curiale, J. A., 1994, [http://archives.datapages.com/data/specpubs/methodo2/data/a077/a077/0001/0250/0251.htm Correlation of oils and source rocks—a conceptual and historical perspective], in L. B. Magoon, and W. G. Dow, eds., The Petroleum system—From Source to Trap: [http://store.aapg.org/detail.aspx?id=1022  AAPG Memoir 60], p. 251–260.</ref>

==Positive correlations==

==Positive correlations==