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.
For more information, request a copy of the abstract or the AAPG 2018 Poster.
In the video below, the original Duvernay shale pores are filled with oil. Liquid is pushed through these pores to extract the oil, which is represented in blue. The three components in the video are hydrocarbon molecules, oil, and pores.