TY - JOUR
T1 - Time-And-Space Averaging Applied to Intermittent Multiphase Flow Experiments
AU - Wang, Tingting
AU - McClure, James E.
AU - Da Wang, Ying
AU - Berg, Steffen
AU - Chen, Cheng
AU - Mostaghimi, Peyman
AU - Armstrong, Ryan T.
N1 - Publisher Copyright:
© 2024. The Authors. Water Resources Research published by Wiley Periodicals LLC on behalf of American Geophysical Union.
PY - 2024/6
Y1 - 2024/6
N2 - Various researchers have studied fluctuations in pore-scale phase occupancy during multiphase flow in porous media using synchrotron-based X-ray microcomputed tomography (micro-CT). However, the impact of these fluctuations on the concept of a representative volume is not yet fully understood. In this study, we performed spatial and temporal averaging of multiphase flow experiments visualized with synchrotron-based micro-CT, focusing on oil saturation as the key parameter to determine a representative time-and-space average. Our findings revealed that a saturation value representative of both time and space was achieved during fractional flow experiments in drainage mode with fractional flows of 0.8, 0.5, and 0.3. Furthermore, we computed a range of relative permeabilities on the basis of whether momentaneous saturation or time-and-space averaged saturation was utilized for direct simulation. Our results highlighted the importance of time-and-space averaging in determining a representative relative permeability and indicated that the temporal and spatial scales covered in a typical micro-CT flow experiment were sufficient to obtain a representative saturation value for sandstone rock under intermittent flow conditions.
AB - Various researchers have studied fluctuations in pore-scale phase occupancy during multiphase flow in porous media using synchrotron-based X-ray microcomputed tomography (micro-CT). However, the impact of these fluctuations on the concept of a representative volume is not yet fully understood. In this study, we performed spatial and temporal averaging of multiphase flow experiments visualized with synchrotron-based micro-CT, focusing on oil saturation as the key parameter to determine a representative time-and-space average. Our findings revealed that a saturation value representative of both time and space was achieved during fractional flow experiments in drainage mode with fractional flows of 0.8, 0.5, and 0.3. Furthermore, we computed a range of relative permeabilities on the basis of whether momentaneous saturation or time-and-space averaged saturation was utilized for direct simulation. Our results highlighted the importance of time-and-space averaging in determining a representative relative permeability and indicated that the temporal and spatial scales covered in a typical micro-CT flow experiment were sufficient to obtain a representative saturation value for sandstone rock under intermittent flow conditions.
KW - intermittency
KW - multiphase flow
KW - relative permeability
KW - representative volume
KW - synchrotron-based micro-CT
KW - time-and-space averaging
UR - http://www.scopus.com/inward/record.url?scp=85195657753&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85195657753&partnerID=8YFLogxK
U2 - 10.1029/2023WR036577
DO - 10.1029/2023WR036577
M3 - Article
AN - SCOPUS:85195657753
SN - 0043-1397
VL - 60
JO - Water Resources Research
JF - Water Resources Research
IS - 6
M1 - e2023WR036577
ER -