American Association of Petroleum Geologists (AAPG)
With the increasing importance of unconventional resource plays, efforts have been made to better estimate the storage capacity of unconventional reservoirs. Proper estimation of oil/gas in-place requires, among other considerations, improved determination of the expulsion capacity and porosity of tight reservoirs. In organic-rich rocks, permeability of the hydrocarbon-wet pore network (i.e., organic pores) can be significantly higher than that of the inorganic matrix and fracture pore network. Therefore, organic porosity can be an important factor on the economic viability of unconventional plays.
Understanding Expulsion Capacity and Organic Porosity in Unconventional Petroleum Systems