Liquid nitrogen (LN₂) cryogenic fracturing has emerged as a promising technique for waterless stimulation in coalbed methane (CBM) reservoirs, primarily by increasing the pore space through freeze-thaw induced effects, thus improving methane recovery from deep coal seams. However, the underlying mechanisms of in-situ gas and water-bearing coal reservoir modification, particularly the dynamic...
During the development of coalbed methane and the process of hydraulic fracturing, due to the physical and chemical damage caused by the mechanical properties of the coal seam itself, stress mechanical failure, etc., it is prone to the production of sediment particles such as coal fines and clay minerals. These particles are washed away from the coal rock body by fluids, remaining and block in...
Injecting CO2 into coal reservoirs has the dual benefits of not only enhancing coalbed methane recovery but also achieving geological storage of CO2 to reduce greenhouse gas emissions. Deep coal reservoirs are usually saturated with water, and CO2 is usually in a supercritical state under high pressure and temperature at deep burial depths. Understanding the structural changes in deep coal...
In the context of climate emergency, bio-based building materials offer strong potential to reduce the carbon footprint of the construction industry while regulating temperature and humidity fluctuations. Their hygrothermal behavior results from coupled fluid–solid–thermal processes: moisture is transported in the pore space as a mixture of dry air and water vapor, and within the solid matrix...
An instability may arise when a hot viscous fluid enters a thin gap and cools through heat transfer to a colder surrounding environment. Fluids whose viscosity increases strongly upon cooling create a positive feedback in which warmer regions flow faster and cool more slowly, leading to the formation of thermo-viscous "fingers". Here we investigate this mechanism in the long time, small Biot...
Permeability and diffusion evolution in well cement during CO₂ exposure using time-resolved micro-CT
The long-term sealing performance of wellbore cement is critical for underground hydrogen storage (UHS) and carbon capture and storage (CCS), where exposure to reactive CO₂ environments can substantially modify cement...
Fibrous bio-based insulation materials are highly porous media in which thermal transport arises from coupled contributions of the solid network, the interstitial gas phase, and moisture stored as bound water within the fibers. In such systems, heat transfer is governed both by the microstructural organization imposed during material processing and by the hygrometric state of the solid phase....
Suction caisson foundations are widely used in deep-sea oil and gas development and offshore wind power projects due to their high construction efficiency and excellent load-bearing capacity. Natural gas hydrates are widely found in deep-sea sediments and are prone to dissociation under engineering disturbances and temperature and pressure changes, leading to increased sediment pore pressure,...
Karst aquifer gas storage reservoirs operated for peak shaving undergo long-term cyclic injection and production. The pore pressure oscillates between upper and lower bounds, driving a looped evolution of effective stress paths and consequently inducing hysteretic changes in porosity and permeability as well as irreversible accumulated damage. These effects manifest as deliverability...
Vesicular volcanic reservoirs, characterized by well-developed micro-fracture and vug combinations, exhibit favorable connectivity and high hydrocarbon enrichment. However, drilling in such formations frequently encounters downhole incidents such as lost circulation and pipe sticking, with high and severe loss rates, complex leakage mechanisms, and low success rates in primary plugging...
Rock-like materials are widely distributed on Earth and have long attracted attention in geotechnical engineering, particularly in the context of high slopes and deep underground projects. Under complex geological and environmental conditions, rocks often exhibit distinctive mechanical behaviors, such as brittle-ductile transition, inherent and induced anisotropy, and multi-field coupling...
Thermal loading in low-permeability clayey soils induces complex coupled thermo-hydro-mechanical responses that are critical for energy geotechnical applications. In particular, temperature-induced pore pressure generation and the evolution of the lateral earth pressure coefficient at rest (K₀) play a central role in the performance and stability of systems such as geothermal wells [1],...
Freeze-drying involves strongly coupled heat and mass transfer in evolving porous structures, where the interplay between rarefied gas flow, solid conduction, and phase-change kinetics governs the sublimation front dynamics and overall drying rate. In this work, we present a physics-based pore-network modeling framework for freeze-drying and validate it against controlled laboratory...
Thermal convection in porous media is a ubiquitous process governing heat and mass transport in natural and engineering systems, such as geothermal energy extraction, geological CO2 sequestration, and permafrost thawing. While the classical Grossmann-Lohse (GL) theory and extensive numerical studies have characterized Rayleigh-Darcy convection over flat, smooth boundaries, realistic geological...
The decline of mature oil fields has intensified the development of enhanced oil recovery (EOR) methods capable of improving sweep efficiency under harsh reservoir conditions. Polymer flooding is widely applied to control the mobility ratio between injected water and oil; however, conventional polyacrylamide-based polymers often exhibit limited performance in high-temperature and high-salinity...
Air intake temperature has significant effects on engine's performance characteristics; control and reduction of exhaust emissions, stability, lower fuel consumption and increase of combustion efficiency. For turbocharged engines, intercoolers are the imperative devices used to cool charging air. There are a big variety of scientific studies for calculating and determining intercooler...
Rising anthropogenic CO2 emissions and efforts to mitigate associated greenhouse gas effects have led to a large number of projects which aim to capture and store emitted CO2 into stable geological formations1,2. Underground storage of CO2 requires careful site selection where a porous and permeable medium is required for storage (the reservoir) and a non-porous and impermeable overlying...
The study of argillaceous rocks is experiencing increased interest due to its potential as host rock for nuclear waste disposal facilities. Low permeability and self-sealing capabilities mitigate the risk of radioactive materials transport to the biosphere. Nevertheless, damage phenomena to the host rock need to be assessed, not only during the excavation, waste deposition, and repository...
