Shale for oil/gas recovery, CO2/H2 storage and hydrocarbon conversion

Depleting conventional oil and gas reserves mandate that alternative energy resources are explored to supply the increasing global energy demand. Shales are fine grained sedimentary rocks containing a significant amount of kerogen, which is a naturally occurring, solid and insoluble organic matter that can yield oil and gas upon undergoing thermal processes. For this reason, shale reservoirs are considered a highly promising potential source of unconventional oil and gas.

Shales are characterized by their low permeability which limits the flow of oil and gas within the reservoir. These reservoirs require careful and precise manipulation of capillary forces in order to successfully extract the desired amount of fluid. In this regard, compressed or supercritical carbon dioxide possesses great potential for employment in enhancing oil and gas recovery from shales. Further on, current global efforts to reduce anthropogenic CO₂ necessitate the consideration of storing the greenhouse gas in geological formations via the so-called Geological Carbon Storage (GCS). The aforementioned reasons render the coupling of CO₂-EOR and GCS an attractive option for achieving a net-zero carbon economy. All governing mechanisms and relevant thermophysical and transport properties are currently under investigation. Additionally, the storage capacity and storage integrity of shales towards hydrogen and the H₂-supported conversion of organic matter are being investigated.