About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

DOI: 10.1306/08181515024

Variation of organic matter density with thermal maturity

Mark D. Rudnicki1

1ExxonMobil Upstream Research Company, 22777 Springwoods Village Parkway, Spring, Texas 77389; [email protected]

ABSTRACT

An estimate or measurement of organic matter density is required for converting between the weight percent of total organic carbon (TOC) and the volume percent of organic matter for wireline log calibration; it is therefore important to recognize when significant changes in organic matter density occur. A method is presented for calculating organic matter density from measurements of crushed-rock dry grain density and Soxhlet-extracted TOC. I have investigated the thermal evolution of organic matter by tracking changes in the intrinsic density of organic matter as a function of thermal maturity. Organic matter density shows two step increases that correspond to the generation of liquid hydrocarbons in the oil window (up to ∼1.2% vitrinite reflectance [Ro]) and the conversion of organic matter to graphitelike carbon (more correctly, “turbostratic carbon”) at high thermal maturity (>4% Ro). Profound structural changes of organic matter may, in part, determine the maturity limits of source-rock tight liquids and shale-gas plays, particularly at high thermal maturity, where gas is hosted within the organic matter–hosted pore system.

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].