Indexed by:期刊论文
Date of Publication:2016-12-01
Journal:JOURNAL OF APPLIED GEOPHYSICS
Included Journals:SCIE、EI、Scopus
Volume:135
Issue:,SI
Page Number:67-76
ISSN No.:0926-9851
Key Words:Supercritical CO2; CO2 distribution/saturation; Seismic wave velocity/attenuation; Porous rock; High-pressure vessel
Abstract:Understanding the relationship between seismic wave velocity or attenuation and CO2 saturation is essential for CO2 storage in deep saline formations. In the present study, we describe a novel upright high-pressure vessel that is designed to keep a rock sample under reservoir conditions and simultaneously image the entire sample using a medical X-ray CT scanner. The pressure vessel is composed of low X-ray absorption materials: a carbon-fibre enhanced polyetheretherketone (PEEK) cylinder and PEEK vessel closures supported by carbon-fibre reinforced plastic (CFRP) joists. The temperature was controlled by a carbon-coated film heater and an aramid fibre thermal insulator. The assembled sample cell allows us to obtain high-resolution images of rock samples during CO2 drainage and brine imbibition under reservoir conditions. The rock sample was oriented vertical to the rotation axis of the CT scanner, and seismic wave paths were aligned parallel to the rotation axis to avoid shadows from the acoustic transducers. The reconstructed CO2 distribution images allow us to calculate the CO2 saturation in the first Fresnel zone along the ray path between transducers. A robust relationship between the seismic wave velocity or attenuation and the CO2 saturation in porous rock was obtained from experiments using this pressure vessel. (C) 2016 Elsevier B.V. All rights reserved.