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CO 2 flooding properties of Liujiagou sandstone: influence of sub‐core scale structure heterogeneity
Author(s) -
Wei Ning,
Gill Magdalena,
Crandall Dustin,
McIntyre Dustin,
Wang Yan,
Bruner Kathy,
Li Xiaochun,
Bromhal Grant
Publication year - 2014
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.1407
Subject(s) - core sample , porosity , geology , permeability (electromagnetism) , aquifer , petrography , capillary pressure , saturation (graph theory) , soil science , petroleum engineering , geotechnical engineering , mineralogy , petrology , porous medium , groundwater , core (optical fiber) , materials science , composite material , mathematics , combinatorics , membrane , biology , genetics
The Liujiagou formation is an important CO 2 aquifer storage unit in the Ordos Basin in central China. Thus far, it has stored over 90% of the total injected CO 2 from the Shenhua carbon capture and storage (CCS) project, which is the first full‐chain CCS project in China. Understanding the basic properties of CO 2 flooding is critical for site characterization and evaluation. A core‐scale characterization and CO 2 flooding study of Liujiagou sandstone is the first step to understanding the flooding properties in a CO 2 aquifer storage project. The pore geometry of a sample was characterized using medical, industrial, and micro X‐ray computed tomography (X‐CT) scanners, as well as mercury intrusion porosity and thin section petrography. To study the flooding process, a CO 2 core flooding experiment using medical X‐CT scanning was conducted with a Liujiagou sandstone sample. Based on the CT data, experimental data, simplified models and COMSOL software, a three‐dimensional sub‐core scale numerical model that considered porosity, permeability, and capillary pressure heterogeneity was constructed for numerical simulation of CO 2 flooding under different scenarios. Laboratory experiments and numerical simulations on a Liujiagou sample revealed the following. The Liujiagou sandstone is a low‐porosity and low‐permeability sandstone with very high heterogeneity. The sub‐core porosity heterogeneity significantly affects CO 2 migration. The relative permeability and saturation distribution are significantly affected by the injection velocity of CO 2 and are different from those of other sandstones, such as Berea. The analyzed Liujiagou sandstone sample has a very low storage efficiency factor at the core scale.