Duvernay Shale

Gas behavior is important for many reservoirs but is challenging to characterize due to limited understanding of the nanophysics governing the mechanisms of storage and mobility. For Duverney shale, the over-pressurized liquid rich behavior revealed by well test data is dramatically different from the relatively better understood dry gas shale. Conventional two-component gas-in-place model, i.e., free gas plus surface adsorbed gas, under-predicts storage. This project introduces capillary condensation in nano-scale pores as the third component to the conventional gas-in-place model. The microstructure of organic porosity from a Duvernay sample is visualized using FIB-SEM. Distributions of pores and pore throats are reconstructed from FIB-SEM using an artificial intelligence-based image processing technique. Direct numerical modeling on imaging data using computational fluid dynamics (CFD) characterizes hydrocarbon transport through organic porosity network, while capillary condensation conditions are dynamically applied. In this study, the gas-in-place contribution from capillary condensation and its blockage effect on mobility were quantified.