About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 68 (1984)

Issue: 8. (August)

First Page: 1024

Last Page: 1028

Title: Dynamic Interpretation of Organic-Matter Previous HitMaturationNext Hit and Evolution of Oil-Generative Window

Author(s): J. E. Ejedawe, S. J. L. Coker (2)

Article Type: Meeting abstract


Two phases are recognized in the Previous HitmaturationNext Hit of organic matter and evolution of the oil-generative window (OGW): (a) a basinal subsidence phase during which potential source rocks undergo burial through a static initial OGW, and Previous HitmaturationNext Hit is due essentially to increasing temperature with depth, and (b) a postsubsidence phase during which the OGW moves vertically upward through the static sedimentary fill, and Previous HitmaturationNext Hit is due to time effects. Only the final shallow position of OGW can be defined by geochemical indices of maturity.

The hydrocarbon generation sequence progresses from bottom to top, beginning with the lighter hydrocarbons (or even thermogenic gas) at the initial OGW at depth, followed by progressively heavier hydrocarbons as the OGW moves vertically upward.

This dynamic model of hydrocarbon generation permits modeling of past positions of OGW relative to basin evolution through interpretation of oil-genesis nomographs. It also provides genetic explanation for the increase in API gravity with depth, areal variation of Previous HitmaturationTop facies, variation in temperature at present tops of OGW with age of source rocks, and gas/oil volume ratios of sedimentary basins.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].