Premium
The effects of porosity and permeability changes on simulated supercritical CO 2 migration front in tight glutenite under different effective confining pressures from 1.5 MPa to 21.5 MPa
Author(s) -
Xu Liang,
Li Qi,
Myers Matthew,
Tan Yongsheng,
He Miao,
Umeobi Happiness Ijeoma,
Li Xiaochun
Publication year - 2021
Publication title -
greenhouse gases: science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 32
ISSN - 2152-3878
DOI - 10.1002/ghg.2043
Subject(s) - supercritical fluid , porosity , permeability (electromagnetism) , saturation (graph theory) , compressibility , volumetric flow rate , mineralogy , chemistry , analytical chemistry (journal) , materials science , composite material , chromatography , thermodynamics , biochemistry , organic chemistry , combinatorics , membrane , physics , mathematics
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 extended to different ECP values ranging from 1.5 to 21.5 MPa. Numerical simulation results show that SC‐CO 2 displaced water in an inverted triangle‐like shape. Under different ECPs of 1.5, 5.5, 9.5, 13.5, 17.5 and 21.5 MPa, the simulated breakthrough times were 36.8, 44.6, 54.8, 56.4, 59.0 and 59.4 mins with an average SC‐CO 2 saturation of 13.18, 16.71, 18.71, 19.72, 21.99 and 22.19%, respectively. SC‐CO 2 breakthrough occurred quicker for lower ECP values resulting in a smaller SC‐CO 2 saturation. Likewise, with larger ECP value, SC‐CO 2 breakthrough occurred later, and a higher SC‐CO 2 saturation was seen. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.