A. Vahedian

Impact of Entrained Hydrocarbon and Organic Matter Components on Reservoir Quality of Organic-Rich Shales: Implications for Sweet Spot Identification in the Duvernay Formation Canada

Hydrocarbon storage capacity of organic-rich shales depends on porosity and surface area for fluid (ad)sorption, whereas pore (throat) size distribution/connectivity influences permeability. The pores in organic matter (OM) are expected to develop during thermal maturation as generated hydrocarbons are expelled from the kerogen. However, the ability of industry to identify “sweet spots” within these reservoirs is still hampered by insufficient understanding of the effect of type/content of entrained hydrocarbon/OM components on reservoir quality. The primary objective of the current study is therefore to investigate the impact of entrained hydrocarbon/OM on storage and transport properties of organic-rich shales. To accomplish this goal, a comprehensive dataset was collected for a diverse sample suite from the Duvernay Formation (a prolific Canadian organic-rich shale reservoir), before and after sequential pyrolysis utilizing a new Rock-Eval procedure (“extended slow heating” (ESH) cycle; Sanei et al., 2015). Using the ESH cycle, different hydrocarbon/OM components can be distinguished more easily during the pyrolysis process: 1) free light oil (up to 150 °C), 2) fluid-like hydrocarbon residue (FHR, 150-380 °C) and 3) solid bitumen (380650 °C).