Abstract.As an important part of unconventional oil and gas resources, deep oil and gas has attracted wide attention in China 's energy field in recent years. Deep oil and gas resources are mostly in complex strata, complex pressure systems and other high-difficulty areas. The drilling strata are more complex, and multi-scale fractures or even karst caves are generally developed. The engineering environment is harsh and the drilling engineering is complex. When drilling into broken and fractured formations, the problem of leakage is particularly prominent. The lost circulation in fractured-vuggy … Read more →

Abstract.To address challenges in traditional building crack detection such as low efficiency and subjective lifespan estimation, this study proposes an integrated UAV-based method for structural aging prediction. The system employs high-resolution imaging equipment to capture concrete building surfaces, with image processing algorithms extracting critical parameters including crack length, width, and density. By combining these measurements with concrete aging mechanisms and crack propagation patterns, a predictive model for structural lifespan is developed. Using three concrete residential buildings … Read more →

Abstract.The natural gas resources in the Upper Paleozoic Permian Shanxi Formation Section 2 and Shihezi Formation Section 8 of the Mizhi gas field in the eastern part of the Ordos Basin are abundant. However, the geological conditions for natural gas accumulation are complex, and the favorable exploration direction is not clear, which has led to no significant breakthroughs in the development of the main layer of the Mizhi gas field for the time being. To clarify the main controlling factors of the low-abundance gas reservoirs in the Mizhi Gas Field of the Ordos Basin, through drilling, logging, … Read more →

Abstract.Identifying key nodes in complex networks is a fundamental and challenging problem in network science, and it has garnered widespread interest over the past few years. The existing centrality methods in assessing node importance still are inadequate in comprehensively utilizing node features, and struggle to achieve optimal performance across different network types. In response, this paper proposes a gravity centrality based on node comprehensive features and node weight. The model incorporates the local information and positional attributes of a node into its quality, and considers using the … Read more →

Abstract.Shale reservoirs, due to their highly compact nature, present challenges for traditional waterflooding development, as it is difficult to establish an effective displacement pressure system. This results in a rapid decline in production and low average single-well productivity, severely limiting development efficiency. Therefore, there is an urgent need to explore innovative development technologies that can quickly replenish reservoir energy and enhance recovery rates. CO2 injection offers an effective solution to this problem. It not only helps maintain reservoir pressure but also improves … Read more →

Abstract.An earthquake is a sudden natural disaster that endangers the construction of the national economy and the safety of people's lives and property. In addition to causing personal casualties, earthquakes also damaged buildings; The interruption of public facilities such as transportation, power supply, water supply, gas supply, oil transmission, communications, etc., and then causing secondary disasters such as water, fire and disease, bringing extremely serious consequences to social life. Therefore, it is particularly important to analyze the seismic response of buildings, establish seismic … Read more →

Abstract.Tight sandstone gas resources hold significant potential, but their reservoir development is often hindered by low porosity, low permeability, and strong microscopic heterogeneity. The microscopic pore structure is a critical factor influencing gas-driven water seepage behavior; however, the quantitative relationship between pore structure and two-phase (gas-water) flow remains unclear. This study focuses on the Upper Shihezi Formation (He 8 Member) tight sandstone in the Yan'an Gas Field, Ordos Basin. Using nuclear magnetic resonance (NMR) technology, we systematically analyzed the pore … Read more →

Abstract.This study aims to enhance the energy capture performance of oscillating hydrofoils for marine current and wave energy applications through geometric optimization. A straight hydrofoil is selected as the baseline, a swept leading-edge hydrofoil is used as the reference, and a kinked leading-edge modification is introduced. The computational domain and mesh refinement are constructed in ANSYS Workbench, and unsteady CFD simulations in Fluent are performed to evaluate lift, drag, moment power coefficient, and total power coefficient. Results indicate that the 15° swept hydrofoil improves lift … Read more →

Abstract.With the increase in mining depth, the threat of coal-rock dynamic disasters in the heading faces of high-gas coal mines is becoming increasingly severe, and their manifestation mechanisms are tending to become more complex, making it difficult for traditional single prediction methods to provide effective early warnings. Taking the 2-228 high-gas isolated island heading face of Liyazhuang Coal Mine under Huozhou Coal Electricity Group as the engineering background, this study conducted research on dynamic disaster early warning and control based on microseismic monitoring technology. By … Read more →

Abstract.In recent years, with the increasing scarcity of land resources, the development intensity of underground space has been continuously enhanced. It has become an inevitable future trend for foundation pits to be characterized by large quantities and great depths. As the depth of foundation pits increases, the dewatering depth also continues to expand, the dewatering duration prolongs, and the water extraction volume gradually increases. Consequently, the problem of surrounding rock and soil mass deformation caused by foundation pit dewatering has become increasingly severe.Foundation pit … Read more →

Abstract.As most continental oilfields in China enter the high water-cut stage, the distribution of remaining oil becomes highly dispersed and fragmented. Traditional reservoir characterization based on "layer-sand group" levels is no longer sufficient to meet the precision requirements for potential tapping.To address the challenges of sub-seismic resolution and inter-well uncertainty, this paper systematically reviews the theories, methods, and development trends of sandbody architecture characterization. First, the hierarchical architecture theories are synthesized, clarifying the correspondence … Read more →

Abstract.Shale is an important rock in oil and gas exploration and development. Its mechanical properties directly affect the safety and efficiency of oil and gas extraction. Due to the special internal structure, complex mineral composition and bedding structure of shale, the relationship between different stress directions and the bedding plane significantly influences its mechanical behavior. Therefore, this study aims to explore this influence law. In the research, shale specimens with different bedding angles were designed. Through uniaxial compression tests, the relationships between stress … Read more →

Abstract.Ultra-low permeability sandstone reservoirs represent a crucial replacement resource for petroleum in China. However, due to extremely low reservoir permeability and severe fluid channeling, conventional development methods yield a recovery factor of less than 30%, posing significant challenges. While CO₂ flooding is a key enhanced oil recovery (EOR) technology for such reservoirs, it faces limitations including gas channeling, high minimum miscibility pressure (MMP), and water blocking effects. Carbonated water flooding (CWF), as a novel EOR technique, had not been systematically studied for … Read more →

Abstract.The artificial ground freezing (AGF) method is essential for reinforcing subway connecting passages in special geological conditions. Heat convection and groundwater seepage complicate the evolution of the freezing temperature field at interfaces, threatening construction safety. This paper reviews domestic and foreign research on the field from numerical simulation, on-site monitoring, and theoretical aspects, emphasizing the significance of studying the coupled effect of seepage and convective heat transfer for safe construction. Read more →

Abstract.This study focuses on the Triassic Yanchang Formation in the Ordos Basin, employing elemental geochemical methods to investigate its paleoenvironmental evolution characteristics. The research systematically reviews the tectonic evolution and stratigraphic framework of the Ordos Basin, followed by collecting samples from typical profiles for analysis of major elements, trace elements, and rare earth elements. Results indicate that the geochemical characteristics of the Yanchang Formation exhibit distinct vertical variation patterns. Indicators such as the Chemical Index of Alteration (CIA) and … Read more →

Abstract.Aiming at the problems of low efficiency, poor safety and insufficient quantitative accuracy of traditional manual pavement crack detection, an automatic identification and quantitative method for pavement cracks integrating UAV aerial photography technology and improved U-Net deep learning model is proposed. The DJI Phantom 4 RTK UAV is used to collect high-resolution images under different pavement types and lighting conditions. A dataset containing 2000 original images is constructed with pixel-level annotation, and expanded to 8000 images through data augmentation technology to improve the … Read more →

Abstract.Due to their minute throats and strong heterogeneity, tight reservoirs are prone to forming bypass channels during conventional water flooding, resulting in low recovery rates. To elucidate the microscopic oil displacement mechanism of surfactants, this study constructed a heterogeneous microfluidic model featuring typical throat characteristics. Visualization experiments were conducted to compare the performance of water flooding versus surfactant flooding. Results indicate: - Water flooding leaves residual oil predominantly in networked and columnar patterns, achieving a final recovery rate … Read more →

Abstract.The construction industry, particularly the production of Portland cement, is a significant contributor to global carbon dioxide emissions and natural resource depletion. This study investigates the feasibility and effectiveness of partially replacing cement with two widely available by-products: Fly Ash (FA), a industrial waste from coal combustion, and Rice Husk Ash (RHA), an agricultural residue. The primary objective is to develop concrete mixes that not only reduce the environmental footprint but also maintain or enhance the mechanical and durability properties. Experimental programs were … Read more →

Abstract.The clayey silt composite layer is widely distributed in the Central Plains of China, especially in the eastern new urban area of Zhengzhou. The stratigraphic structure is generally a multi-layer system interbedded with clayey soil, silt, and fine silty sand, predominantly composed of clayey soil. The thickness of a single clayey soil layer can reach up to 68m. This considerable thickness implies that the creep process during foundation pit dewatering will persist continuously. The main structure of a metro station in the Zhengzhou Eastern Area is adjacent to high-speed railway bridge piles. … Read more →