Project title: Investigation of CO2-Enhanced Shale Gas Recovery (CO2-ESGR) processes through CO2/CH4 exchange studies in shales under laboratory-simulated in situ stress-pressure-temperature conditions
Source of funding: National Science Centre
Call: OPUS 29
Project number: 2025/57/B/ST10/02593
Implementation period: January 1, 2026 – December 31, 2029
Project budget: PLN 1 810 060
Project manager: D. Sc. Eng. Mateusz Kudasik, Associate Professor
Abstract
The growing demand for energy, as well as the advancing climate issues resulting from greenhouse gas (GHG) emissions, contribute to the search for new sources of natural gas reserves, while reducing emissions and utilizing industrially captured CO2. One potential method for CO2 storage is geological sequestration in shale formations, where large deposits of methane (CH4) occur. The process of high-pressure CO2 injection into deep (even up to 4,000 m) shale formations is intended to stimulate the processes of CO2/CH4 exchange, as a result of which CO2 is trapped in the pore space of the shales, and shale gas (consisting mainly of CH4) is displaced and captured (CO2-ESGR technology). The unsuccessful attempts to extract shale gas in Poland, carried out between 2013 and 2017, led to the abandonment of further attempts to exploit this energy source. However, in light of the global energy crisis and the technological advancements that have occurred over the past decade, the topic of shale gas exploitation in Poland is being revived. Therefore, it is crucial that the exploitation of poorly explored shale gas deposits in Poland, as well as the application of new technological solutions such as CO2-ESGR, must be preceded by detailed laboratory tests, in conditions corresponding to in situ, as well as a series of numerical simulations. The aim of the project is to conduct laboratory studies of the CO2-ESGR technology under stress-pressure-temperature conditions corresponding to in situ, at depths of up to 4000 meters. In such conditions, the stress exerted on the rocks is about 100 MPa, the shale gas pressure is about 10-50 MPa, and the temperature is up to 130oC. As part of the project, two unique research setups (IMG-SSR and IMG-GEX) will be built, which will enable simulating in situ conditions and conducting studies on the structural and sorption properties of shale on one of these stand, as well as performing seepage and CO2/CH4 exchange experiments on the second station. The studies will be conducted on 6 samples of core fragments of shales from Poland, mainly from the Baltic-Podlasie-Lublin basin region. The results of the structural and sorption studies obtained on the IMG-SSR analyzer on samples under stress-pressure-temperature conditions corresponding to in situ, compared with the results of studies of samples under stress-free conditions, will enable the determination of the impact of stress on the volume change, porosity, and pore volume in the rock. Moreover, it will be possible to determine the extent to which laboratory-measured parameters differ from those of the rock under in situ conditions deep underground. Permeability tests will be conducted on the IMG-GEX apparatus using the steady-state flow method, with permeability coefficients determined using Darcy’s law, as well as the absolute permeability of Klinkenberg. By comparing the permeability of cores perpendicular and parallel to the bedding, as well as the fracture permeability of these cores, the impact of the fracturing process on the stimulation of gas flow in various directions within the shale formation will be determined. The most important experiments of the project, CO2/CH4 exchange, will be carried out on the IMG-GEX apparatus and will consist of injecting CO2 into a shale sample, which will be initially saturated with CH4. This process is intended to induce gas mixture (CO2/CH4) exchange in the pore space and CO2/CH4 exchange sorption on the surface of the shale pores. These experiments will be conducted under laboratory-simulated in situ stress-pressure-temperature conditions, making them pioneering laboratory experiments. Based on these experiments, the efficiency of the CO2-ESGR process will be evaluated, as well as the exchange selectivity and the rate and spatial range of the exchange zone. The results of the CO2/CH4 exchange experiments will serve as the basis for the construction of a numerical model. The final stage of the project will involve the development of a numerical model based on the results of the conducted analyses. Numerical simulations will allow for the reconstruction of CO2-ESGR processes under in situ conditions on a macro scale. The outcome of the project will be the results of these simulations, which will make it possible to determine the temporal and spatial rate of the CO2-ESGR process under field conditions. This, in turn, will enable an assessment of the feasibility and applicability of this technology in Poland.
Contact person: D. Sc. Eng. Mateusz Kudasik, Associate Professor