Two‐phase flow properties of a sandstone rock for the CO₂/water system: Core‐flooding experiments, and focus on impacts of mineralogical changes

Abstract

The two-phase flow characterization (CO 2 /water) of a Triassic sandstone core from the Paris Basin, France, is reported in this paper. Absolute properties (porosity and water permeability), capillary pressure, relative permeability with hysteresis between drainage and imbibition, and residual trapping capacities have been assessed at 9 MPa pore pressure and 28 C (CO 2 in liquid state) using a single core-flooding apparatus associated with magnetic resonance imaging. Different methodologies have been followed to obtain a data set of flow properties to be upscaled and used in large-scale CO 2 geological storage evolution modeling tools. The measurements are consistent with the properties of well-sorted water-wet porous systems. As the mineralogical investigations showed a nonnegligible proportion of carbonates in the core, the experimental protocol was designed to observe potential impacts on flow properties of mineralogical changes. The magnetic resonance scanning and mineralogical observations indicate mineral dissolution during the experimental campaign, and the core-flooding results show an increase in porosity and water absolute permeability. The changes in two-phase flow properties appear coherent with the pore structure modifications induced by the carbonates dissolution but the changes in relative permeability could also be explained by a potential increase of the water-wet character of the core. Further investigations on the impacts of mineral changes are required with other reactive formation rocks, especially carbonate-rich ones, because the implications can be significant both for the validity of laboratory measurements and for the outcomes of in situ operations modeling.

Measurements of CO2‐brine relative permeability in Berea sandstone using pressure taps and a long core

“…15,21,25,26,29,36 Figure 7(a) shows, using this bump test method, the endpoint CO 2 relative permeability by Krevor et al 15 and Ruprecht et al, 26 and the CO 2 relative permeability data by Pini et al, 21 match the data obtained here and the oil relative permeability data by Oak et al 31 But these measurements only affect the endpoint CO 2 relative permeability. Recent reported measurements have used bump test methods to adjust for the capillary end effect, in which the CO 2 flow rate is gradually increased (or 'bumped up') to achieve lower water saturation and higher CO 2 relative permeability at the core inlet.…”

“…15,18,20,21,25,26,28,29 The effect of these results is seen when put in comparison with other recent studies. There is no need for adjustments for end effects as the end effects are avoided experimentally.…”

“…15,18,26,28,29 Particularly, experiments by Reynolds et al 28 show even lower CO 2 relative permeabilities than other experiments though it must be pointed out that they used a Bentheimer sandstone rather than a Berea sandstone. 15,18,26,28,29 Particularly, experiments by Reynolds et al 28 show even lower CO 2 relative permeabilities than other experiments though it must be pointed out that they used a Bentheimer sandstone rather than a Berea sandstone.…”

“…1, which shows many recent measured CO 2 relative permeabilities in sandstone cores; 15,18,21,25,26,28,29 included for comparison is the well-referenced measurement of oil relative permeability in Berea sandstone by Oak et al 31 The reported CO 2 relative permeabilities in Berea sandstone (open gray symbols) and non-Berea Original Research Article: Measurements of CO 2 -brine relative permeability in Berea sandstone using pressure taps and a long core X Chen et al Figure 1. 1, which shows many recent measured CO 2 relative permeabilities in sandstone cores; 15,18,21,25,26,28,29 included for comparison is the well-referenced measurement of oil relative permeability in Berea sandstone by Oak et al 31 The reported CO 2 relative permeabilities in Berea sandstone (open gray symbols) and non-Berea Original Research Article: Measurements of CO 2 -brine relative permeability in Berea sandstone using pressure taps and a long core X Chen et al Figure 1.…”

“…1, which shows many recent measured CO 2 relative permeabilities in sandstone cores; 15,18,21,25,26,28,29 included for comparison is the well-referenced measurement of oil relative permeability in Berea sandstone by Oak et al 31 The reported CO 2 relative permeabilities in Berea sandstone (open gray symbols) and non-Berea Original Research Article: Measurements of CO 2 -brine relative permeability in Berea sandstone using pressure taps and a long core X Chen et al Figure 1. 15,18,21,25,26,28,29 sandstones (gray star and cross symbols) show two different trends (the gray dashed lines are guides for the eye), which are both well below the reported oil relative permeability over most of the range. 15,18,21,25,26,28,29 sandstones (gray star and cross symbols) show two different trends (the gray dashed lines are guides for the eye), which are both well below the reported oil relative permeability over most of the range.…”