In order to find out the uranium metallogenic potential of the Lower Cretaceous in Kelulun Sag of Hailar Basin, the spatial distribution of sequence stratigraphy, types and distribution characteristics of sedimentary facies and favorable spatial location of uranium enrichment in the area were studied by using sequence stratigraphy and sedimentary facies analysis methods based on core, logging and seismic data. The results show that the third-order and fourth-order sequence stratigraphic division marks of the target strata in the Kelulun Sag are determined. The target strata are divided into one super sequence, two three-order sequences and four fourth-order sequences, and the distribution characteristics of sequence stratigraphy are clarified. The sedimentary system of fan delta-lacustrine facies is mainly developed in the target layer in the area. The sedimentary facies plane has the characteristics of near source, fast phase change and small distribution range. The braided channel sand bodies of the fan delta plain and the underwater distributary channel sand bodies of the fan delta front have good uranium metallogenic potential.

To address the issue of inaccuracies in groundwater level predictions due to the insufficient consideration of groundwater-related factors, clustering methods for observation wells based on spatial distance, hydrogeological attributes, and a hybrid of distance and attributes were proposed. The significance of inter-well connectivity in groundwater level prediction was validated. Four models were designed, which were applied to simulate and predict groundwater levels in the karst water region of Jinan and compared with actual observations. The prediction results indicate that the combined model incorporating the connectivity characteristics of karst aquifers, known as convolution-long short-term memory(ConvLSTM), outperforms the traditional long short-term memory(LSTM) model. Among the models, the mix-multivariate-convolution-long short-term memory(M-MV-ConvLSTM) model, which accounts for wells of the same category based on the hybrid distance-attribute clustering results (characterized by strong connectivity), achieves the highest prediction accuracy and the smallest error. The average root mean square error is approximately 0.457, and the Nash-Sutcliffe efficiency is approximately 0.216, demonstrating a higher prediction accuracy than the traditional LSTM model. The research results is positioned to serve as a reference for real-time groundwater level prediction in karst regions.

In order to explore the medication characteristics of expectorants in the Huatan prescriptions commonly used in treating ischemic stroke recently. “Huatan/Qutan/Ditan/Huotan/Daotan/Guntan/Banxia Baizhu Tianma Decoction/Xinglou Chengqi Decoction/Wendan Decoction/Erchen Decoction/Xiao xianxiong Decoction/Lingjiao Gouteng Decoction/Jieyu Dan” + “ischemic stroke/cerebral ischemia/cerebral infarction/cerebral embolism/cerebral thrombus” + “clinical” as the main topic on the China National Knowledge Network (from May 1, 1986 to April 1, 2024) was used to investigate the medication characteristics of expectorants, and selected literature meeting the criteria. Statistical analysis of the data was performed using Excel and IBM SPSS Modeler 18.0 software. The results show that Banxia and Tian nan-xing are the most frequently used expectorants in different stages of ischemic stroke, followed by Fuling, Shi chang-pu, Chenpi, and Gancao. The dosages of most expectorants are 10~15 g. In the analysis of Siqi and five flavors, Wen, Ping, Xin, Ku, and Gan have the highest frequency of occurrence in different stages of ischemic stroke. In the analysis of meridian tropism, the lung and spleen meridian have the highest frequency of occurrence. Most Huatan prescriptions are composed of 8~14 herbs in both the acute and rehabilitation stages, accounting for 82.51% and 78.05% of the total frequency, respectively. In the analysis of association rules, 25 traditional Chinese medicine combinations with strong correlation strength are obtained, and the most combinations of herbs are Huatan-Xifeng-Tongluo and Huatan-Huoxue-Qufeng. Most Huatan prescriptions are administered through the traditional decoction method and generally used in combination with Western medicine. It is concluded that the commonly used expectorants in Huatan prescriptions for treating ischemic stroke are mainly Banxia and Tian nan-xing, and the dosage ranges of most expectorants are 10~15 g. The number of herbs in Huatan prescriptions is mainly 8~14. The research results provide references and clinical data support for the application of expectorant Chinese medicine and Huatan prescriptions in the treatment of ischemic stroke and the development of research on treating ischemic stroke from the perspective of phlegm.

Rainfall is one of the main factors affecting landslide stability. To explore the deformation and stability laws of unsaturated soil landslides under different rainfall conditions, based on the theory of saturation-unsaturation and the intensity reduction method, focused on a traction landslide in eastern Jiangxi. The rock and soil parameters of the landslide hazard body were determined through field investigations and laboratory tests. AutoCAD software was used to restore the terrain and geological conditions of the Tongshan landslide in Xishan Village, Zhengfang Town, as accurately as possible. A three-dimensional mathematical model of seepage-deformation coupling for the landslide was established. The dynamic process of seepage deformation and stability of the unsaturated soil landslide under various rainfall conditions (different intensities, durations, and post-rain stoppage) was simulated. The results indicate that the pore water pressure at the slope surface increases gradually with rainfall intensity and duration. The drainage velocity increases, the saturated zone gradually transforms into the unsaturated zone, and the displacement and deformation increase progressively. After the rainfall stops, leakage in the landslide hazard body exhibits a delayed response. The displacement deformation after continuous rainfall first increases and then decreases, while the displacement following intermittent rainfall shows periodicity during the short-term post-rain stoppage period. In terms of landslide stability, the reduction trend of the stability coefficient of the slope body strength under different rainfall intensities and durations is similar, but the stability coefficient under the same intensity varies, with the overall trend showing a gradual decrease with increased duration. After the rain stopped, the stability coefficient of the uniform rainfall slope body decreases initially and then increases, whereas the stability of the intermittent rainfall slope body exhibits periodic variations.

In order to study the problem that the processing of 7075 aluminum alloy rings was affected by the large value of initial residual stress, the effect of reducing the residual stress was investigated by using the method of compression of 7075 aluminum alloy rings along the ring direction. ABAQUS simulation software was used to simulate the quenching and compression of 7075 aluminum alloy rings to obtain the initial residual stress field and the residual stress field after compression. The results show that the initial residual stresses generated by quenching can be effectively reduced by the method of compression in the ring direction. After the data before and after compression is compared, it is found that when the compression deformation amount is 1.312 5%, the amplitude of quenching residual stress decreases by 57% of the original residual stress value as a whole, and the amplitude of radial residual stress and circumferential residual stress decreases by about 58%. It is concluded that the method of circumferential compression can effectively reduce the residual stresses of aluminum alloy ring parts.

Addressing the lack of clarity regarding spontaneous imbibition displacement mechanisms and production management strategies for shale oil in the Cangdong Sag, a model was established that considered the “synergy of imbibition, flowback, and productivity”. The model was designed to dynamically reflect the mutual constraints and synergies between spontaneous imbibition displacement and engineering parameters such as flowback rates and soaking durations. Through comprehensive numerical simulations integrating geology and engineering across the entire lifecycle, the spontaneous imbibition displacement patterns and optimal flowback regimes for the C1 and C3 sweet spots in the Kong-2 Member, which served as the main development interval in the Cangdong Sag, were elucidated. The results indicate that spontaneous imbibition displacement continues to occur during the flowback process. The optimal soaking durations for the C1 and C3 sweet spots are determined to be between 37 and 42 days, with a reasonable flowback rate ranging from 20 to 40 tons per day. The research findings provide a theoretical foundation for studies on spontaneous imbibition mechanisms and reasonable production management strategies for deep shale oil and gas reservoirs.

Due to factors such as temperature, pressure, and production rate, integrity issues like annular leakage in gas well tubing frequently occur frequently. In order to study the influence of working conditions on the process of downhole oil pipe leakage, a high temperature and high pressure oil pipe leakage simulation model was established based on field parameters and compared with the existing mathematical model of small hole leakage. Based on the simulation model, the influence of flow field change, leakage aperture, casing pressure difference and leakage environment on the leakage process was analyzed. The results show that the changes of flow field mainly focus on the inside of the leak hole and the inlet and outlet of the leak hole. With the increase of the leak aperture, the leakage quantity, leakage velocity, pressure and density inside the leak hole increase. The greater the pressure difference between tubing and oil jacket annulus, the greater the leakage amount and leakage velocity, and the more drastic the change of pressure and density. The gas velocity and pressure in the upper part of the annular protective fluid are greater than that in the annular protective fluid section.

To mitigate the risk of annular pressure buildup caused by solid-phase deposition in the B and C annuli of deep-water wells, experimental tests were conducted on sedimentation behavior using common deep-water drilling fluid systems. The sedimentation height and post-settling solid-phase permeability of various drilling fluids were measured. Based on the parameters of solid phase percolation characteristics, and considering the impact of annular fluid solid deposition, a predictive analytical method was established for annular pressure under percolation conditions. Case analysis was conducted to validate the approach. Results show that the sedimentation height follows the order: oil-based drilling fluid > EZFLOW drilling fluid > HEM drilling fluid. In contrast, the post-settling solid-phase permeability is ranked as EZFLOW drilling fluid > HEM drilling fluid > oil-based drilling fluid, with a maximum permeability of 2.216 μm². Under annular fluid solid-phase deposition conditions, reductions in annular fluid viscosity, increases in formation permeability, and longer open-hole cement sheath sections reduce fluid viscous resistance, enlarge the seepage contact area with the formation, and enhance fluid flow. Therefore, reducing drilling fluid viscosity and extending the open-hole cement sheath length can improve the pressure release capacity in the B and C annuli of deep-water wells. However, the presence of solid-phase deposition significantly restricts seepage flow rates compared to conditions without deposition, leading to a potential risk of incomplete pressure relief following solid-phase sedimentation.

With the development of global oil and gas exploration and development to deep and ultra-deep wells, the problems such as underground high temperature environment and unreasonable selection of drilling parameters in field operation make the bit wear increasingly serious. In order to prolong the bit life and improve the rock breaking efficiency, a 3D simulation model of polycrystalline diamond compact(PDC) cutters marble was established, and the effects of different cutting depth, cutting speed and bit caster on the PDC cutters surface temperature and rock breaking efficiency were analyzed. The results show that the temperature rise of the cutting gear can be divided into three stages: ascending period, transitional period and stable period, and the crushing form of the rock changes from plastic to brittle when the cutting depth increases to a certain extent. With the increase of cutting speed, both temperature and crushing work ratio increase. With the increase of cutting depth and bit caster, the crushing work ratio increases and the temperature increases first and then decreases. The response surface method was used to optimize the cutting speed, cutting depth and bit caster, and the optimal parameter combination was given. The research results can provide guidance for efficient rock breaking of PDC bit in field.

To enhance heat transfer efficiency and improve thermal exchange performance, a composite enhanced thermal exchange technology was explored that combined annular internal fins with protruding units, aiming to create an innovative thermal exchange structure. Through numerical simulation methods, the flow and heat transfer characteristics of this structure were studied within the Reynolds number Re range is 8 000~20 000. The analysis results indicate that the layout of the protruding units and four parameters (depth, radius, spacing, and quantity) have a significant impact on thermal performance. The mechanism of enhanced heat transfer was explained using field synergy theory. Under optimal parameters, with a depth of 2 mm, a radius of a specific value, a spacing of 20 mm, and six protruding units, the best thermal exchange performance is achieved, with an overall heat transfer performance improvement of 4.71%~23.59% compared to internal finned tubes. Increasing depth, radius, and quantity, while decreasing spacing, enhances heat transfer but also increases resistance, limiting the growth of overall thermal performance. Field synergy analysis shows that the structure promotes strong secondary vortices, significantly enhancing the synergy effect between the velocity field and the temperature field.