D5.4 - Permeability changes during injection & reactive flow simulation, Zalecze & Zuchlow site
S. Bekri, S. Renard, F. Delprat-Jannaud (IFPEN), J. Kummerov (GFZ)
The study relied on experiments conducted in GFZ laboratory and modelling performed by IFPEN. Six core samples were collected covering a range depth of 1737 to 1750 m. On these samples GFZ performed a baseline characterization of the reservoir formation of the Pakoslaw gas field at the Zalecze-Zuchlow site to identify the mineral composition and the main petrophysical reservoir parameters. Density, porosity, and electrical saturation exponent were determined at ambient conditions. Permeability, elastic velocities, electrical formation resistivity factor, and capillary pressure were measured at simulated reservoir conditions and were partly used for the pore network modelling performed at IFPEN.
Additionally, a long-term percolation experiment of a reservoir sample was conducted at simulated reservoir conditions to study the impact of CO2-exposure on hydraulic and electrical conductivity, sample mineralogy, and fluid chemistry. This experiment delivered input data for the 1D coreflood simulation performed at IFPEN.
IFPEN performed pore network modelling (PNM) to simulate mass transfer with mineral reaction in a single phase flow through porous medium which is here a sandstone sample, "PaK6-S12p" from reservoir formation of the Pakoslaw gas field. IFPEN also performed 1D coreflood simulation to model successive cycles of injection of saline water with and without an aqueous-CO2 fraction according to the experimental study performed by GFZ.
The petrophysical characterisation of the reservoir formation comprised the determination of density, porosity, electrical saturation exponent at ambient conditions and the measurement of permeability, elastic velocities, electrical formation resistivity factor, and capillary pressure at simulated in situ reservoir conditions. Combined laboratory and simulation work gives a good overview of the reactivity of the Pakoslaw Formation as the analog for Załęcze-Żuchlów in case of an injection of a solubilised CO2 containing a fraction of O2.