Organic Porosity Study: Porosity Development within Organic Matter of the Lower Silurian and Ordovician Source Rocks of the Poland Shale Gas Trend
Porosity in organic matter is often the predominant type of total porosity development in shale rocks. Due to the hydrophobic nature of organic matter, organic porosity is in most cases fully occupied by hydrocarbon where water resides in intraparticle and integranular pores of inorganic material. Therefore, understanding of porosity development in organic matter could help better describe a total porosity distribution in mudrocks and improve understanding of fluid saturation.
Organic porosity was calculated from FIB SEM images taken for the Lower Silurian and Ordovician source rock samples of the shale trend in Poland. The observation was made that organic porosity is a function of not only thermal maturity but also original organic composition. The transform was developed allowing for organic porosity determination where it is represented as the function of present day and original hydrogen indices.
The results were integrated with petrophysical interpretations of well logs to validate gas filled porosity calculations and verify desorption analysis data.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013