In working with organic shales the information about rock composition is generally supplied in a mix of volume percentages and weight percentages. Total organic carbon (TOC) is typically supplied as a weight percentage of the total sample weight, Fourier transform infrared spectroscopy derived (FTIR) mineralogy as a weight percentage of the samples inorganic weight, and porosity is defined as a volume percentage. In building regressions and combining datasets it is generally necessary to convert to a consistent composition reference system.
In this note ϕk, the porosity due to the organic material is expressed in terms of the intrinsic porosity of the organic material ϕ ki, the mass fraction of the organic material Fo, the matrix density of the organic material, Pk, and the bulk density of the inorganic material Pib. This expression is used with experimental data of the methane porosity, TOC, and realistic estimates for Pk and Pib to estimate the intrinsic organic porosity. Five Barnett Shale samples from a single well all had intrinsic organic porosity of approximately 30%. A high porosity is consistent with ion-milled SEM images of Barnett Shale samples (Passey et al., 2010, Sondergeld et al., 2010).
|File Size||812 KB||Number of Pages||4|
Looking for more?
Some of the OnePetro partner societies have developed subject- specific wikis that may help.
|PetroWiki was initially created from the seven volume Petroleum Engineering Handbook (PEH) published by the Society of Petroleum Engineers (SPE).
|The SEG Wiki is a useful collection of information for working geophysicists, educators, and students in the field of geophysics. The initial content has been derived from : Robert E. Sheriff's Encyclopedic Dictionary of Applied Geophysics, fourth edition.