Experimental Analysis and Numerical Simulation of the Stability of Geological Storage of CO₂: A Case Study of Transforming a Depleted Gas Reservoir into a Carbon Sink Carrier

Abstract

Geological storage of CO 2 is one of the most economical, feasible, and effective measures to slow down global warming. In this study, a combined long core model was designed to study the seepage characteristics of supercritical CO 2 displacement. Moreover, the stability of permanent storage of cushion gas layers formed by supercritical CO 2 injection has been systematically studied. The research results showed that in the supercritical temperature and pressure range of CO 2 , the front edge of CO 2 displacement can form a relatively stable seepage zone. Supercritical CO 2 displacement can achieve a high gas-storage rate and stable CO 2 storage. At the same time, the recovery rate of remaining natural gas has been significantly improved. As the injection pressure increased, supercritical CO 2 inhibited the reverse diffusion of natural gas molecules. Therefore, the breakthrough of the supercritical CO 2 displacement front under a high pressure lagged behind. However, due to the increase in the density difference of gas molecules, the forward diffusion of supercritical CO 2 has been enhanced. Temperature will not significantly affect the displacement and storage effects of supercritical CO 2 in gas reservoirs. The increase in injection pressure and reasonable control of the injection rate can delay the breakthrough of supercritical CO 2 displacement. These measures are conducive to the stable storage of CO 2 and the improvement of remaining natural gas recovery. The implementation of CO 2 geological storage is suitable for the later stage of gas reservoir depletion development. The high-density gravitational heterogeneity of supercritical CO 2 enables the injected CO 2 to form a stable high-density cushion gas layer in the gas reservoir, which can achieve stable CO 2 storage for more than 100 years.

Investigation of an Indian Site with Mafic Rock for Carbon Sequestration

“…Research has been conducted on CO 2 storage estimation for mineral trapping mechanism using different methods and models such as the volumetric method and the numerical simulation models based upon the field data. These numerical models were developed to simulate the amount of CO 2 stored in the various phases such as free, trapped and dissolved using commercial and open-source reservoir simulators like CMG, Eclipse, PHREEQC, TOUGHREACT, etc. − These numerical simulators are complex and time-consuming because of their usage of iterative operation and requirement of the multilevel interactions of physio–chemo–mechanical models. Additionally, thermodynamic modeling of mineralization has shown significant difference from the experimental data which may be attributed to various factors including grain-size, surface area, and presence of other ions in the core sample.…”

A Numerical Modeling of CO2 Injection into the Depleted Donghae-1 Gas Field

“…고갈가스전의 천연가스 생 산량을 통해 이산화탄소 주입량을 예측하는 분석식을 시뮬 레이션을 통해 검증하였으며 (Lekic et al, 2019), 생산이 종료된 가스 저류층 내 잔존 가스 포화도(Residual gas saturation)에 따른 저장용량 변화에 관한 시뮬레이션 연구 가 수행되었다 (Raza et al, 2018). 또한 생산 중인 가스전에 이산화탄소를 주입했을 경우 가스 생산량 및 이산화탄소 저장용량 변화에 관한 시뮬레이션 연구가 진행되어 왔다 (Ӧzkiliҫ and Gumrah, 2009, Amer et al, 2018, Hamza et al, 2020, Sun et al, 2021 타났으며, 생산종료 이후의 저류층 압력을 예측하였다 (Table 7, Fig. 4).…”