Journal
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
Volume 155, Issue -, Pages 89-99Publisher
ELSEVIER
DOI: 10.1016/j.petrol.2016.09.008
Keywords
CO2 geosequestration; Capillary trapping; Sensitivity analysis; Heterogeneity; Sedimentary architecture
Categories
Funding
- Center for Geological Storage of CO2, an Energy Frontier Research Center - U.S. Department of Energy, Office of Science, Basic Energy Sciences [DE-SC0C12504]
Ask authors/readers for more resources
A number of important CO2 reservoir candidates exhibit sedimentary architecture reflecting fluvial deposition, which typically includes small-scale (decimeter to meter) textural fades among different rock types. As a result, highly contrasting spatial distribution of intrinsic permeability and constitutive relationship parameters (capillary pressure and relative permeability characteristic curves) are common for this type of reservoir. Previously, we showed that small-scale heterogeneity organized in fluvial depositional architecture controls the dynamics of a CO2 plume during the injection and postinjection periods. This is due to (1) highly anisotropic effective permeability causing CO2 to move in laterally, and (2) trapping by capillary pinning, which is in addition to snap-off capillary trapping. The detailed petrophysical and geological parameters of any specific reservoir are typically uncertain, which motivates studies of parameter sensitivity. The goal of this paper is to analyze the sensitivity of capillary trapping and dissolution to the variability in basic petrophysical parameters and rock composition in highly heterogeneous fluvial-type reservoirs. We show that (1) the larger the contrast in permeability between rock types the larger the CO2 plume and the larger the rate of capillary trapping and dissolution; (2) an increase in capillary pressure contrast increases pinning trapping; and (3) the variability in the proportion between high- and low-permeability rocks (difference in connectivity of high-permeability clusters) does not affect snap-off trapping and dissolution, although it does strongly affect their spatial distributions. Though dissolution and snap-off capillary trapping may vary by up to 40% because of parameter variability, the trapping by capillary pinning may vary by an order of magnitude. (C) 2016 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available