International Journal of Coal Science & Technology

Abstract At present, there is no method to accurately characterize the liquid film thickness of shale nanopores with different mineral compositions. This article describes the wetting modification of a 500nm homogeneous quartz model, measures the liquid film thickness under different pressure gradients, and establishes experimental expressions. Based on the experimental results, a prediction meth…

Abstract The heterogeneity of macerals represents a key challenge to accurately evaluating the hydrocarbon generation potential of coal. Conventional methods often overlook these differences, leading to biased understanding of its hydrocarbon generation characteristics. Therefore, this study integrates maceral identification, thermal simulation experiments, and machine learning algorithms to deve…

Abstract This study investigates the height evolution of the water-conducting fracture zone (WCFZ) under super-high mining conditions in the 1101 longwall face of Zhundong No. 2 Mine. Based on 28 measured datasets, a multivariate nonlinear regression model is proposed, outperforming traditional empirical formulas in accuracy. Numerical simulations reveal four developmental stages of the WCFZ: ini…

Abstract Textural analysis of pyrite has been carried out in the lignites of Kachchh Basin to decipher its micro-morphological character. The study entails the intermediate stage and authigenic sunflower structured pyrite. The origin, characteristics, shape and distribution of pyrite within Tertiary lignites has been comprehensively explored through petrography, ultimate analysis and scanning ele…

Abstract Distributed strain sensing (DSS), benefiting from its high sensitivity, high spatial resolution, real-time capability, and continuous distributed measurement, has become an important technique for hydraulic fracturing diagnostics. To provide a comprehensive understanding of recent advances in DSS for hydraulic fracturing monitoring, this paper reviews three representative DSS technologie…

Abstract Geoheritage studies offer a novel perspective for the understanding of coal resources. The related scientific knowledge needs systematization. A major bibliographical database “Scopus” was employed to identify the principal sources of this knowledge published internationally. A total of 42 relevant publications (chiefly journal articles) were selected. It was established that this geoher…

Abstract CO 2 huff and puff (HnP) is widely recognized as an effective strategy for enhancing shale oil recovery. However, a comprehensive understanding of its multi-scale performance in fractured shale reservoirs remains limited. To bridge this gap, this study investigates the enhanced oil recovery (EOR) potential of CO 2 HnP, with a particular focus on the influence of fractures. A series of la…

Abstract This study presents a comprehensive analysis of field data obtained from a substantial hydraulic fracturing campaign in a hard rock mining operation, aiming to enhance prediction, understanding and optimise operational practices through parametric analysis and Machine Learning. Findings reveal that structural control predominates during the initiation stage, limiting the influence of ope…

Abstract Helium-bearing shale reservoirs are gaining attention as unconventional strategic resources, yet the fundamental mechanisms governing helium occurrence and migration remain poorly resolved. In this study, we integrate high-pressure adsorption–diffusion experiments (308 K, 1300 psi) with molecular simulations under reservoir-relevant conditions (70 MPa, 403–423 K) to investigate helium be…

Abstract One of the most demanding environmental and economic challenges of this era is that of supplying the increasing global energy demand while reducing and neutralizing the CO 2 footprint. In this regard, the provision of a secure and diversified energy supply and the sequestration of CO 2 into geological formations are currently of great significance. However, the buoyant nature of CO 2 und…

Abstract Understanding the wettability of carbon dioxide (CO 2 ) and the interfacial properties between reservoir rocks and fluids is crucial for the effective geological carbon sequestration (GCS). The most accurate way to measure these properties is the laboratory experiments under simulated reservoir conditions. However, experimental measurement of CO 2 wettability in storage/caprock, influenc…

Abstract Excavation is one of the key factors inducing slope instability in open-pit mines, particularly for intermediate bridge-supported slopes subjected to dual excavation disturbances. Improper handling of such conditions may lead to large-scale landslides. Therefore, it is essential to investigate the instability evolution mechanism of intermediate bridge-supported slopes under dual excavati…

Abstract Coals are known to be source rocks for natural gas, but also for liquid petroleum. Laboratory experiments under controlled physical and chemical conditions can help to understand maturation and hydrocarbon generation in these rocks. Whole-rock cuboids of two bituminous coal samples (0.60% and 0.80% vitrinite reflectance) were subjected to semi-closed hydrous pyrolysis under isothermal co…

Huff-n-puff (HnP) is currently an important means to enhance the oil recovery of tight oil reservoirs. In this study, taking tight sedimentary tuff oil reservoirs in Santanghu Basin, China as an example, the oil production law, pore utilization characteristics, and influencing factors of water, N2, CO2, N2–water alternating, and CO2–water alternating HnP (WHP, NHP, CHP, NWAHP, CWAHP) are comprehe…

Abstract Unlike conventional gas reservoirs where gas saturation exists at its maximum value initially, coalbed methane (CBM) reservoirs are unique in a way that gas saturation in reservoir starts from zero and builds up to reach a peak value as the adsorbed gas in the coal matrix desorbs into the coal cleat system due to depressurization of coal reservoirs through CBM wells. In comparison to con…

Abstract Oil-soluble catalyst is a promising alternative to non-oil-soluble catalyst due to excellent dispensability in coal-oil slurry and relatively high activity. To reveal evolution behavior of active phase of the oil-soluble Fe-based catalysts in direct liquefaction of Shangwan coal, three oil-soluble Fe-based catalysts (FeLA, FeOA, FeSA) were synthesized via saponification method with linol…

Abstract The long-term creep-induced instability of slopes containing weak layers posed significant safety risks in open-pit mining operations. A key scientific difficulty lies in understanding the coupled mechanisms of excavation-induced stress redistribution and internal time-dependent deformation in weak-layered strata, an area that remains insufficiently studied due to limitations in replicat…