Skip to main content Accessibility help
×
Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-25T04:09:47.436Z Has data issue: false hasContentIssue false

14 - Maturity-related biomarker parameters

Published online by Cambridge University Press:  05 April 2013

K. E. Peters
Affiliation:
United States Geological Survey, California
C. C. Walters
Affiliation:
ExxonMobil Research & Engineering Co.
J. M. Moldowan
Affiliation:
Stanford University, California
Get access

Summary

This chapter explains how biomarker analyses are used to assess thermal maturity. The parameters are arranged by groups of related compounds in the order (1) terpanes, (2) polycadinenes and related products, (3) steranes, (4) aromatic steroids, (5) aromatic hopanoids, and (6) porphyrins. Critical information on specificity and the means for measurement are highlighted before the discussion of each parameter.

Thermal maturity describes the extent of heat-driven reactions that convert sedimentary organic matter into petroleum. For example, kerogen in fine-grained source rocks can be converted thermally to oil and gas, which migrate to coarser-grained reservoir rocks (Figure 1.2). Early diagenetic processes convert bacterial and plant debris in sediments to kerogen (insoluble, particulate organic matter) and bitumen (extractable organic matter). Thermal processes generally associated with burial then convert part of this organic matter to petroleum and, ultimately, to gas and graphite. Petroleum is a complex mixture of metastable products that evolve toward greater thermodynamic stability during maturation.

Note: It is thought that both kerogen and oil are unstable during catagenesis and progressively decompose to pyrobitumen and gases (e.g. Hunt, 1996; Tissot and Welte, 1984). Mango (1991) proposed that hydrocarbons in oil are much more thermally stable than their kerogenous precursors. He believes that oil and gas originate by direct thermal decomposition of kerogen but that hydrocarbons in oils do not thermally decompose to gas in the Earth. This scenario does not exclude some oxidative decomposition of hydrocarbons during thermochemical sulfate reduction (e.g. Orr, 1974; Krouse et al., 1989).

Type
Chapter
Information
The Biomarker Guide , pp. 608 - 640
Publisher: Cambridge University Press
Print publication year: 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×