Characterising the role of parametric functions in the van Genuchten empirical model on CO2 storage performance

Depending on rock pore compressibility, a change in effective confining pressure (ECP) can have a significant influence on supercritical CO 2 (SC-CO 2) migration characteristics in natural reservoirs. In this study, a tight glutenite sample was used to conduct porosity/permeability measurements under different ECPs of 1.5, 5.5, 9.5, 13.5, 17.5 and 21.5 MPa. Then a SC-CO 2 drainage core flooding experiment, which was monitored using nuclear magnetic resonance (NMR) technique, was conducted at an ECP of 5.5 MPa. Measurement results show that the porosity and permeability of the sample were comparatively low (at an ECP of 1.5 MPa, 8.3% and 2.4 mD, respectively). With increasing ECP, the porosity/permeability decreased rapidly initially then more slowly at the larger ECP value. NMR results shows that SC-CO 2 preferentially displaced water creating flow channels inside the sample. At SC-CO 2 breakthrough, the average residual water saturation was 69.86%. Following breakthrough, SC-CO 2 continued to displace the water creating more substantial flow channels until they were sufficient to transport the SC-CO 2 at the fixed flow rate, resulting in a residual water saturation of 42.72%. A two-dimensional computational model was then established based on these experimental results to simulate the fluid behaviors at an ECP of 5.5 MPa, and then the model was

\bar{S_{w}} = \frac{S_{w} - S_{r, w}}{1 - S_{r, w} - S_{r, C O_{2}}}

\bar{S_{normalC O_{2}}} = \frac{S_{C {normalO}_{2}} - S_{r, C {normalO}_{2}}}{1 - S_{r, w} - S_{r, C {normalO}_{2}}}

P_{c} = P_{e c} {((), {\bar{S_{w}}}^{- \frac{1}{m}} - 1)}^{1 - m}

k_{r, w} = {\bar{S_{w}}}^{l} {((), 1 - {(1 - {\bar{S_{w}}}^{\frac{1}{m}})}^{m})}^{2}

k_{r, C O_{2}} = {\bar{S_{C O_{2}}}}^{l} {((), 1 - {(1 - \bar{S_{normalC O_{2}}})}^{\frac{1}{m}})}^{2 m}

w...…”

Section: Methodsmentioning

confidence: 99%

“…Previous studies have shown that the degree of influence of the parameters in the VG model on simulation results are

P_{e c}, S_{r, C {normalO}_{2}}

and

m

, in descending order 40,41 . The capillary entry pressure used in the simulations was obtained by constant‐pressure mercury intrusion porosimetry (MIP).…”

Section: Methodsmentioning

confidence: 99%

Section: Capillary Pressure and Relative Permeabilitymentioning

confidence: 99%

Section: Capillary Pressure and Relative Permeabilitymentioning

confidence: 99%

See 2 more Smart Citations

The effects of porosity and permeability changes on simulated supercritical CO₂ migration front in tight glutenite under different effective confining pressures from 1.5 MPa to 21.5 MPa

Myers

et al. 2020

“…An attractive mitigation option under consideration globally is the capture of CO 2 from stationary sources, such as fossil fuel power plants, and its subsequent injection into deep, stable geologic formations, where its safe storage could be guaranteed for hundreds to thousands of years. 2,3 Geological storage of carbon was first proposed in the late 1970's 4 and the first research in this area started in the 1990's. 5 Thanks to recent technological advancements in model development and computer power and speed, it is now possible to better predict the behaviour of the injected CO 2 into these proposed underground storage sites.…”

mentioning

confidence: 99%

A study on the impact of storage boundary and caprock morphology on carbon sequestration in saline aquifers

Ahmadinia

Shariatipour

2020

Self Cite

Structural trapping is known to be the primary storage mechanism in geological carbon sequestration (GCS), where the injected CO 2 rises upwards due to buoyancy forces and becomes trapped under an ultra-low permeability layer. Although it is relatively common in GCS studies to assume a planar caprock for the synthesised models, in a real scenario this is not always the case as the caprock might exhibit some small-or large-scale topography changes. Moreover, little is known about the impact of the caprock morphology on the CO 2 plume migration and the storage capacity. In this work, we performed a preliminary study of the effects of boundary conditions on the CO 2 plume migration and dissolution. This was performed because most of the case study models which are employed for GCS studies are part of larger reservoirs. The obtained results were used in the simulation models of the second part of the work, to model an infinite-acting reservoir appropriately. Three different volume modifier values of 10 5 , 10 7 and 10 9 were considered on either one side or both sides of the reservoir for both horizontal and tilted caprock models. The CO 2 dissolution in the tilted models was seen to be higher once the multiplier was on the opposite side of the slope. Horizontal models closed on one side (closed faults, salt walls, etc.) were also found to exhibit more significant dissolution than models which were open from both sides. We subsequently investigated the impact of caprock morphology on the CO 2 plume advancement and its structural and dissolution trapping mechanisms by performing numerical simulations on nine synthetic models. The dissolution and migration distance are seen to be at a maximum for tilted reservoirs, where the CO 2 has more space to migrate upwards and to interact with more formation water. The lowest dissolution occurred where the significant portion of the injected CO 2 was trapped in a sand ridge or an anticline. Moreover, the possibility and also the amount of structural trapping was evaluated using an analytical method, and the results showed a fair match with the ones from the numerical simulation. We believe that this methodology could be applied for site screening prior to performing numerical simulations.

Assessing the impact of relative permeability and capillary heterogeneity on Darcy flow modelling of CO₂ storage in Utsira Formation

Onoja

Shariatipour

2019