Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Language: English
    In: International Journal of Greenhouse Gas Control, March 2016, Vol.46, pp.175-186
    Description: We investigate capillary trapping and fluid migration via x-ray computed microtomography (x-ray CMT) of nonwetting phase (air) and wetting phase (brine) in Bentheimer sandstone cores which have been treated to exhibit different degrees of uniform wettability. x-Ray CMT scans were acquired at multiple steps during drainage and imbibition processes, as well as at the endpoints; allowing for assessment of the impact of wettability on nonwetting phase saturation and cluster size distribution, connectivity, topology and efficiency of trapping. Compared with untreated (water-wet) Bentheimer sandstone, cores treated with tetramethoxylsilane (TMS) were rendered weakly water-wet, and cores treated with octadecyltrichlorosilane (OTS) demonstrate intermediate-wet characteristics. As apparent contact angle increases, drainage flow patterns deviate from those derived for water-wet systems, total residual trapping and trapping efficiency decrease, and buoyancy plays a larger role during nonwetting phase mobilization; this has significant implications for CO migration and trapping during CO sequestration operations.
    Keywords: Wettability ; Drainage Flow Pattern ; Capillary Trapping ; Residual Trapping ; Pore Scale ; Geologic Co2 Sequestration ; Engineering
    ISSN: 1750-5836
    E-ISSN: 1878-0148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: International Journal of Greenhouse Gas Control, June 2014, Vol.25, pp.93-101
    Description: This work utilizes synchrotron-based x-ray computed microtomography (x-ray CMT) imaging to quantify the volume and topology of supercritical carbon dioxide (scCO ) on a pore-scale basis throughout the primary drainage process of a 6 mm diameter Bentheimer sandstone core. Experiments were performed with brine and scCO at 8.3 MPa (1200 psi) and 37.5 °C. Capillary pressure–saturation curves for the scCO -brine system are presented and compared to the ambient air-brine system, and are shown to overlay one another when pressure is normalized by interfacial tension. Results are analyzed from images with a voxel resolution of 4.65 μm; image-based evidence demonstrates that scCO invades the pore space in a capillary fingering regime at a mobility ratio = 0.03 and capillary number = 10 to an end-of-drainage brine saturation of 9%. We provide evidence of the applicability of previous two-dimensional micromodel studies and ambient condition experiments in predicting flow regimes occurring during scCO injection.
    Keywords: Supercritical Co2 ; Carbon Sequestration ; Capillary Fingering ; Drainage ; X-Ray Microtomography ; Engineering
    ISSN: 1750-5836
    E-ISSN: 1878-0148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: International Journal of Greenhouse Gas Control, November 2015, Vol.42, pp.1-15
    Description: Geological carbon sequestration is being considered worldwide as a means of mitigating anthropogenic emission of greenhouse gases. During sequestration, carbon dioxide (CO ) gas effluent is captured from coal-fired power plants or other concentrated emission sources and injected into saline aquifers or depleted oil reservoirs for long term storage. In an effort to fully understand and optimize CO trapping efficiency, the capillary mechanisms that immobilize subsurface CO were analyzed at the pore-scale. Pairs of proxy fluids representing the potential range of in-situ conditions of supercritical CO (nonwetting fluid) and brine (wetting fluid) were used during experimentation. The two fluids were imbibed and drained from a flow cell apparatus containing a sintered glass bead core. Fluid parameters (such as interfacial tension and fluid viscosities) and flow rate were altered to characterize their relative impact on capillary trapping. Computed x-ray microtomography (microCT) was used to quantify immobilized nonwetting fluid volumes after imbibition and drainage events. MicroCT-analyzed data suggests that capillary trapping in sintered glass bead (a mildly consolidated porous medium) is dictated by the capillary number ( ), the viscosity ratio ( ), and the Bond number ( ) of the system, reflecting that all three viscous, capillary, and gravity forces affect the displacement process to varying degree as their relative importance changes. The amount of residual trapped nonwetting phase was observed to increase with increasing nonwetting fluid viscosity, and with decreasing density difference of the fluids; this suggests that CO sequestration can potentially be engineered for optimal trapping through alterations to the viscosity or density of supercritical CO .
    Keywords: Co2 Sequestration ; Capillary Trapping ; Proxy Fluids ; Viscosity ; Density ; Bond Number ; Capillary Number ; Viscosity Ratio ; Engineering
    ISSN: 1750-5836
    E-ISSN: 1878-0148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages