bluuebunny/crossref_metadata_2025 huggingface dataset:
Power Bidirectional Flow Converter Based on Linear Phase Shift Transformer
Authors: Wu Mei , Zhao Jinghong , Yuan Zhifang
Published: February 2021

This article points out that the bidirectional power converter based on a linear phase-shifting transformer can be modularized, designed to improve equipment utilization. The analysis of the working status of the bidirectional power flow converter under inverter and rectifier conditions is introduced. The working conditions of the converter in the inverter and rectification state are simulated, and the output voltage and harmonics are analysed. The simulation results show that the system can meet the output index requirements under both inverter and rectification conditions, can be modularized, can reduce the number of components used in the device, and provide strong support for the optimization of subsequent prototypes.
Analysis on burning failure of main transformer in 220kV substation
Authors: Zhang Dewen , Lin Xianfeng , Su Geng , Liu Yang , Li Zhibin
Published: February 2021

Neutral point ungrounded three-phase system is widely used in 10kV and 35kV low-voltage systems because of its higher power supply reliability. When the single-phase grounding short-circuit fault occurs in the system, the other two phases can continue to operate for a period of time to ensure the reliability of power supply. However, when the system operates under single-phase grounding fault, arc grounding overvoltage is easy to occur, which may damage electrical equipment or develop into phase-to-phase short circuit. This paper analyses a burning accident of main transformer caused by arc grounding overvoltage in 220kV substation, obtains fault recording information, points out fault causes and puts forward corresponding preventive measures.
Causes and treatments of foaming and overflow of calcium-based wet desulphurization slurry
Authors: Shao Yuan , Li Hong , Xue Fang Ming , Zhang Yulong
Published: February 2021

During the operation of the calcium-based wet desulfurization system, slurry foaming and overflow are prone to occur, which is not conducive to the safe and stable operation of the desulfurization system. In order to solve the problem of slurry foaming, the main properties of the slurry were tested by taking the wet flue gas desulfurization device of a sintering machine of a steel company as an example. The foaming ability of the liquid is characterized by its foaming height and defoaming time, and the influence of surface active substances, particles and metal ions in the slurry on its foaming ability has been studied through multiple experiments. Combining the foaming mechanism and the desulfurization process, the cause of the slurry foaming is analyzed, and measures are given to prevent and treat the slurry foaming overflow to ensure the normal operation of the absorption tower.
Experimental study on load capacity of thermal generator unit in heating season
Authors: Lao Jinxu , Zheng Wei , Guo Junshan , Shang Panfeng , Zhang Yanpeng
Published: February 2021

With the development of renewable energy and the rapid growth of thermal load, due to the influence of the mode of “determining power by heat”, the power grid dispatching in heating season can not accurately adjust the unit load, and the peak load regulation capacity of power grid is limited. Through the load capacity test of cogeneration units in heating season, the adjustment range and limiting factors of different types of units are obtained, which can be used as reference for power generation enterprises and power grid dispatching operation.
Synthesis, Characterization of Two Novel Diphenylpyranylidene Molecules and their Application in Organic Solar Cells
Authors: Fan Hongzhi , Zhang Xiaoying , Bolag Altan , Yun Wu , Bao Tana , Ning Jun , Alata Hexig , Ojiyed Tegus
Published: February 2021

Two novel D-A and A-D-A structural small molecule based on diphenyl pyran donor and dicyanovinylene acceptor unit have been designed, prepared, and studied for the application of organic solar cells. The UV-vis absorption spectra showed that D-A structural molecule has more extended light-harvesting ability than the A-D-A molecule and can complement with P3HT in the wavelength of 300-500 nm and 600-800 nm.
Effect of Temperature on Tribological Properties of Tial Based Self-Lubricating Composites
Authors: Sun Zheng , Yang Liying , Wang Shouren
Published: February 2021

A kind of TiAl based alloy with high temperature self-lubricating property was prepared by vacuum hot pressing sintering technology, and its mechanical and physical properties were tested. The friction and wear experiments were carried out at different temperatures, and the high-temperature tribological properties of the new TiAl based alloy were studied. The results show that the new TiAl based self-lubricating material with TiC, TiB2 and CaF2 can effectively improve the mechanical and physical properties of the matrix, and make it have good mechanical and physical properties as well as good tribological properties above 500 °C.
Design of An Integrated Solar Panel Monitoring and Cleaning System Based on Pixy Cmucam5
Authors: Zhu Yuxi
Published: February 2021

In recent years solar power has become the main source of clean energy in China. At the same time, the country has also introduced relevant policies to support it, and against this background, the solar photovoltaic industry has also flourished. However, solar photovoltaic power generation still has many problems, such as the huge amount of light energy and water loss caused by contamination of the solar panel surface and the high labour costs of dealing with the contamination, so it is necessary to carry out research on solar panel crack detection and cleaning.
High-Efficiency Ship Propeller Based on Electric Direct Drive Without Shaft Rim
Authors: Yang Yefan
Published: February 2021

The ship propeller is a key component of a ship, a device for energy conversion, and a device for converting the energy emitted by the main engine into ship power. The most popular types of shaft-driven propellers derived from propeller propellers are currently on the market, including ducted propellers, pod propellers, and flat-rotating propellers. This type of propeller has many disadvantages of the shaft-driven propeller (system). These shortcomings have caused most of the existing small and medium-sized ships to have problems such as low transportation efficiency, high operation and maintenance costs, noise pollution, and lubricant leakage pollution. Therefore, the shaftless rim electric direct drive has gradually become an important development direction in the field of high-end marine propulsion equipment.
Research on Security Protection Strategy for Intelligent power terminals
Authors: Xu Bin , Zhai Feng , Wang Nan
Published: February 2021

In the context of Smart Grid 2.0, intelligent power terminals are an important part of the smart grid, but their weak security protection can easily become the main target and springboard for criminals to attack the grid. Therefore, ensuring the security of intelligent power terminals is the key to protect the security of smart grids. In this context, this paper through the analysis of intelligent power terminal security threats, proposes a three-layer intelligent power terminal protection framework including “physical layer”, “operating system layer” and “communication layer”, and thus proposed a security protection strategy for intelligent power terminal devices, which aims to comprehensively improve the security of power system comprehensively.
Research and analysis of constrained generalized predictive identification algorithm based on the control field of hydropower industry
Authors: Gou Xiaoping , Zhang Wan Jun , Zhang Feng , Zhang Jingxuan , Zhang Jingyi , Zhang Jingyan
Published: February 2021

For GPC with constraints, these shortcomings are made up on the basis of nonlinear programming algorithm. Because of the strong local search ability of nonlinear programming and the strong global search ability of the algorithm, combined with the advantages of the algorithm and introduced into the rolling optimization process of GPC, the optimal control law is obtained. In this paper, a constrained generalized predictive identification algorithm based on the control field of hydropower industry is proposed, and a model of the constrained generalized predictive identification algorithm based on the control field of hydropower industry is established. The simulation results verify the applicability and effectiveness of the combined algorithm in the study of GPC, improve the accuracy and speed of the optimization results, and obtain satisfactory control effect.
Research status of the external insulation pollution flashover of high voltage transmission line
Authors: Guo Kai , Jiang Bo , Liu Bingrui , Kong Kang , Wu Yaping , Tian Shuang , Gao Zhiyue , Zong Lijun , Yao Shuo , Zhao Mingzhe , Mi Chunxu
Published: February 2021

In recent years, China’s electric power industry has made great progress, especially the achievements of ultra high voltage and ultra high voltage power transmission and transformation technology have attracted worldwide attention. At present, China has put into operation power transmission projects such as ±660kV yin-East DC extra-high voltage, ±800kV upward, Yunnan-Guangzhou DC extra-high voltage and 1000kV Dongnan Jindong-Jingmen AC extra-high voltage. These long-distance and large-capacity power transmission projects provide strong technical support for the realization of the national strategic goal of “west power transmission to the east and North power transmission to the south”.With the rapid industrialization and environmental deterioration, various industrial and natural pollutions deposited on the insulators of high-voltage transmission lines are becoming increasingly serious. In severe weather, such as fog, dew, drizzle and snowmelt, the external insulation strength will be greatly reduced. Therefore, it is very important and necessary to thoroughly study the pollution flasking of uHV and UHV insulators and comprehensively consider the influence of China’s complex geographical environment on their external insulation characteristics, which is one of the key issues related to the safe and stable operation of power grid.
Study on the progress of piezoelectric microcantilever beam micromass sensor
Authors: Guo Kai , Jiang Bo , Liu Bingrui , Li Xingeng , Wu Yaping , Tian Shuang , Gao Zhiyue , Zong Lijun , Yao Shuo , Zhao Mingzhe , Mi Chunxu , Zhu Gengzeng
Published: February 2021

A variety of excitation modes and signal readout modes of the microcantilever beam are all derived from the deformation characteristics of the cantilever beam, while in the detection of environmental pollutants, deformation of non-quality factors such as environmental vibration, wind, rain and snow will inevitably occur. If we only start from the deformation quantity, the consistency between the obtained results and the actual fouling micro-mass value is more prominent. Therefore, the structure, size, working mode and material properties of the microcantilever beam should be fully considered in simulation and design. The resonant frequency of the microcantilever beam must be large enough to prevent external vibration interference measurement and improve the SNR.
Effect of Graphene Addition on Microstructure and Properties of Graphene/Copper Composite
Authors: Gu Ye , Hu Linli
Published: February 2021

Graphene/copper composites were prepared by wet milling and hot-press sintering process. The effect of graphene addition (0.2, 0.6, 1.0, 1.5wt.%) on the microstructure and properties of graphene/copper composites were investigated. The results reveal that graphene (addition of 0.2 and 0.6wt.%) was uniformly distributed in Cu matrix and plays a role in refining grain and enhance the properties. For the 0.6wt.% graphene/copper composite, the relative density, hardness and tensile strength reached largest (respectively 99.4%, 78.5HV and 290.47MPa), its electrical conductivity decreased slightly to 97.5% IACS. While addition reached/beyond 1.0wt.%, graphene agglomerated, the relative density, electrical conductivity and hardness decreased.
Quantitative analysis of the influence of pore structure parameters on remaining oil after polymer flooding based on digital network model
Authors: Xia Huifen , Zhang Siqi , Wang Lihui , Jiang Lili , Yang Tingyuan
Published: February 2021

There is still a large amount of remaining oil in formation after polymer flooding. Therefore, it is of great significance to clarify the factors affecting the distribution of remaining oil to further improve the oil recovery. By constructing a digital pore network model, this paper considers pore structure factors and simulatetes oil displacement efficiency after water flooding and polymer flooding. It simultaneously analyzes their influence of pore structure parameters on remaining oil and quantitatively characterizes the coordination number, shape factor, pore-throat ratio affected on pore-throat oil content ratio and oil saturation ratio. Evaluate the influence of the above factors on the remaining oil distribution after polymer flooding. The research results show that: the more coordination number, the larger the shape factor. However, other structural parameters, such as pore-throat ratio, the number of pore-throat oil content, the pore-throat oil saturation ratio and the probability of forming remaining oil, is smaller at the same time.
Analysis on the Causes of the third party destruction of City Gas Pipelines and Research on Countermeasures
Authors: Han Yiliang
Published: February 2021

While the universal application and rapid development of natural gas have improved people’s living standards, it has also improved the traditional energy structure and contributed to environmental protection. However, with the increasing speed and scale of urban gas engineering construction, the safety maintenance and prevention of gas pipelines that follow are particularly important for gas companies. In particular, the third-party construction unit does not pay enough attention to the gas pipeline network, and it is easy to cause damage to the pipeline network during construction and cause gas pipeline leakage accidents. This paper uses big data technology to find the key elements of third-party construction and construction damage risks in massive data, builds a high-prone construction area model and construction damage risk model, provides countermeasures against damage risks, and improves the effectiveness and prevention of external damage risks. Targeted, reduce the frequency and extent of damage to gas pipelines and facilities, and ensure the safe operation of the gas pipeline network.
Optimization of Identification Condition of Thin Layer Chromatography for Alpinia Katsumadai Hayata
Authors: Lv Lijuan , Wang Xiangpei , Wu Hongmei , Li Xiangmin , Zhong Ke
Published: February 2021

objective: To optimize the TLC identification conditions ofAlpinia katsumadaiHayata. Methods: Qualitative identification ofAlpinia katsumadai Hayatawas carried out by TLC, toluene: ethyl acetate: methanol (15: 4: 1) and toluene: ethyl acetate: methanol (14.5: 4.5: 1) were used as developing solvent, then observed under 365nm ultraviolet lamp. Results: The optimized conditions were better than those of TLC in 2020 edition of Chinese Pharmacopoeia. The optimized spots were more clear, the separating capacity was better, and the stability of the conditions was better. After optimization, there were 9 spots in TLC. Conclusion: The method is simple, specific and reproducible, which can provide reference for the quality control ofAlpinia katsumadaiHayata.
Asphalt Deck Pavement Design for Concrete Bridge under Frost Climate in the North Sea Region
Authors: Fu Jiancun , Wang Lin , Gai Guohui , Yang Fei
Published: February 2021

A prefered waterproofing system and bearing course mixtures for asphalt pavement deck were designed to determine a suitable waterproofing system and material/structure combination optimize proposal for Qingdao Bay Bridge, which was built under the frost climate of Shandong province, through a general analysis on the disease type and the damage mechanism of asphalt deck pavement. Based on the laboratory test results, the test section construction and long-term pavement performance observation, a comprehensive comparison and analysis about five types of waterproofing system(Synchronous Seal coat+ Asphalt Sand, Polymer Modified Bituminous Waterproofing Sheets, Priming Coat+Asphalt Rubber Membrance+Protection Board, Polymer Modified Emulsified Asphalt Waterproof coating, Gussasphalt)were made in terms of waterproof effect, workability, quality reliability and long-term performance. Furthermore, the asphalt deck pavement were proposed to be designed on the basis of the layer performance-related concept, and regarded as the system engineering. The construction effect indicates that both the multi-purpose layer (waterproofing high modulus asphalt sand) and the deck pavement structure are adapted to the evidence temperature difference and windy characteristics during the construction. It also shows the excellent workability and quality reliability.
Groundwater dynamic analysis of a typical small watershed in the Loess Plateau
Authors: Dong Qiguang , Li Na , He Jing , Zhang Panpan , Liu Zhe , Chang Min
Published: February 2021

After the implementation of the project of returning farmland to forest and ditching and rebuilding land in Yan’an area, the hydrological process in the basin has changed. In order to clarify the dynamic characteristics of groundwater, a typical Nanniwan basin was selected, and groundwater monitoring equipment was installed in the upstream, middle and downstream respectively. The dynamic changes of groundwater in the basin. The results show that among the annual precipitation in the small watershed of the Loess Plateau, June-August (summer) is the wet season, with the most concentrated precipitation, with a total precipitation of 451.8 mm, of which August has the largest precipitation; the groundwater depth gradually increases before September. After September, the upstream and downstream water levels begin to stabilize or rise; the upstream groundwater level fluctuates slightly; the shallow groundwater areas in the middle reaches have large fluctuations due to the large water users; the groundwater depths in the downstream areas are generally between the upstream and Between the middle reaches, the depth of burial showed a slight increase overall.
Study on Optimization of Compound Flocculant’s Purification Process of Sugarcane Juice
Authors: Wang Xiaoming , Li Dacheng , Wu Juxian , Shi Xiaoyan , Zhou Shaoji , Luo Xingxie
Published: February 2021

Sugarcane juice contains a lot of non-sugar organic impurities, and most of the non-sugar organic impurities are suspended in the sugarcane juice in the form of colloidal particles, making the juice turbid. Flocculant is an indispensable clarification aid in the cane juice cleaning process, and its use effect will directly affect the production cost of sugar cane sugar and the quality of white granulated sugar products. This paper is based on the sulfite process of sugar production. After the sulfur smoked juice is heated, the composite flocculant is mixed with the sugarcane juice and then settled. The clear juice is taken to determine the physical and chemical indicators, and the clarification effect of the composite flocculant is investigated. The response surface method is optimized to obtain the composite The best material ratio of the flocculant is PAM 1.70ppm, CTS 1.90ppm, diatomaceous earth 2.10ppm, and the compound flocculant with the best material ratio is used for the cane juice cleaning process experiment. The orthogonal test method optimizes the cane juice cleaning process as The cleaning effect is best when the added amount of phosphoric acid is 160 ul/L, the pre-ash pH value is 6.4, and the neutralization pH value is 7.4, the obtained clear juice is clear and bright, and the color value is low.
Analysis on Application of fracturing stimulation technology in Oilfield
Authors: Yu Junxiong , Xu Hongzhi , Liu Xiaopan
Published: February 2021

with the continuous progress of modern science and technology, in the process of oilfield production and operation, the traditional fracturing technology has been unable to adapt to the fracturing construction technology of modern oilfield. There are some problems in the construction safety, fracturing technology and environmental protection production in the construction process. Therefore, we should continue to explore the fracturing technology and develop new technology Technology is imperative, so as to meet the actual requirements of oilfield in different development stages.
Impact of the excavation and dewatering of the foundation pit on the stability of the plug-in steel cylinder
Authors: Liu Wenbin
Published: February 2021

The plug-in steel cylinders performance well in forming the bulkhead of the man-made island. In the late stage of the man-made island constructure period, the excavation and dewatering treatment will be conducted in the island, and these treatments may influence the stabilities of the steel cylinders. This paper analyzed the impact of the excavation and dewatering treatment on the steel cylinder based on an engineering case with numerical simulation method. And corresponding engineering treatments for preventing the local instability of the cylinders are proposed.
Description and Understanding of Complex Fault Block Reservoir Geology
Authors: Li Qiang
Published: February 2021

Reservoir description is an important step in oilfield development. Before mining, using various technical means to analyze and study oilfield structure can achieve the purpose of fully understanding the reservoir and provide theoretical basis for reservoir development. In this exploration, the background of description of complex fault block reservoir geology is analyzed, and X35 reservoir is selected as the research object to study the regional geological reservoir. By analyzing the fault distribution characteristics of X35 reservoir, the reservoir strata are divided. The three-dimensional (3D) geological model of the reservoir is established by using the method of facies-controlled modeling and numerical simulation. Finally, the 3D geological model is tested. The results show that the model has high accuracy and reflects the distribution of X35 reservoir, which has a certain guiding significance for the exploration and effective development of the remaining oil in the reservoirs distributed in this area.
Study on the prediction method of drilling tool deflection ability
Authors: Huan Huang
Published: February 2021

The build rate of the tools is a key point in trajectory control and prediction of horizontal well, which is based on the mechanical analysis and geometry analysis of tools. But if the tools have initial bending, the application of “beam-column theory” is limited. With a method of equivalent loading, this problem can be solved. Through the analysis of tools, the side force of bit can be calculated, and then a method, named “method of modified three-point fix Round” is used to determine the build rate of tools at the basis of VB program.
Safety classification and application of coal-rock gas compound dynamic disaster in coal mine
Authors: Dai Linchao
Published: February 2021

Coal and gas outburst, rockburst are the most serious dynamic disaster in the coal mine production. Based on the current situation of frequent occurrence of coal and gas outbursts and rock burst disasters in deep mines, the characteristic regularity and influencing factors of coal and gas outburst and rockburst disaster are analyzed. The safety grading evaluation system of coal-rock gas compound dynamic disaster is established. And the safety grading evaluation is carried out on the impact-outburst dynamic disaster of 32 production mines. The research results show that the influencing factors of the coal and gas outburst, rockburst disaster can be divided into natural factors, technical factors and management factors. Meanwhile, the safety classification of 32 production mines coal-rock gas compound dynamic disaster are mostly II level, in line with the actual situation.
Method for Potential Evaluation and Parameter Optimization for CO2-WAG in Low Permeability Reservoirs based on Machine Learning
Authors: Lv Wenfeng , Tian Weidong , Yang Yongzhi , Yang Jinghui , Dong Zhenzhen , Zhou Yongyi , Li Weirong
Published: February 2021

The CO2 water-alternating-gas flooding (CO2-WAG) is a key technology to improve the oil recovery of low permeability reservoirs. The effect of CO2 flooding to enhance the oil recovery is affected by geological conditions and production systems. The effect of CO2 flooding parameters on the enhanced recovery factor should be clarified to optimize the production system. In this paper, the machine learning algorithms are used to carry out the study and establish a set of procedures for optimizing CO2 flooding parameters based on the artificial neural network (ANN) and the particle swarm optimization (PSO) algorithm. Firstly, large amounts of basic data are generated by the Monte Carlo sampling method. Then, the recovery factor by the water flooding and the CO2-WAG and the enhanced recovery factor by CO2-WAG in different models are calculated in the reservoir numerical simulator. Moreover, the machine learning method is used to establish a neural network model, and analysis of the sensitivity of parameters of the enhanced oil recovery (EOR) is carried out by combining with the Sobol method. Finally, the neural network model and the particle swarm algorithm are combined to optimize the parameters of CO2-WAG flooding. The results show that the established model has a good prediction accuracy (97.6%), thus it could be used to predict the enhanced recovery factor by CO2-WAG, and it is applicable in potential evaluation of enhancing the oil recovery and optimization for parameters in the CO2-WAG well group.
Research Progress of Advanced Cementitious Composites
Authors: Zhang Wei
Published: February 2021

This paper mainly introduces the definitions, properties, manufacturing methods of macro-defect-free cementitious composites, densitified system containing homogeneously arranged ultra-fine particles, reactive power concrete, engineered cementitious composites, self-compacting concrete, their research situations at home and abroad as well as existing problems and solutions.
An Experimental Research on Crack Propagation Regularity During Fracture Grouting
Authors: Cheng Shaozhen , Yang Fa , Dai Yuchen , Yang Zili , Shi Ye
Published: February 2021

A new grouting model test device has been developed to model the fracture grouting process and improve understanding of the crack propagation regularity during grouting. It was concluded that the propagation process of crack is not one-time formed but undergoes the sequential mode of “expansion, stagnation, re-expansion, re-stagnation” after fracture initiation. The smaller the grouting pressure is, the longer the stagnation time is, and the smaller the crack propagation velocity is. The crack width increases rapidly when the crack tip stagnates or the expansion speed is small. Research results can help achieve better grouting aims and realize grouting safety in practice
Experimental and numerical simulation investigation on tubular expansion process
Authors: Li Xiucheng , Ren Shuai , Li Dejun , Wang Jingliang , Li Xiao , Wang Zhixing , Shang Chengjia
Published: February 2021

Solid expansion technology has brought a revolution for oil and gas drilling and production. The performance of the expandable tubular is determined by the strength of material and the dimensional accuracy of the tube. In this study, the expansion pressures of two expandable tubulars at an expansion ratio of 15.0% were measured by full-scale tests. A 3D finite-element-method model was developed using Abaqus to dynamically simulate the expansion process of solid expandable tubulars. The simulated expansion pressures are in good agreement with experimental results, which proves the validity of the model. Based on the FEM model, the relationship between wall thickness uniformity after expansion and the strain hardening exponent of tubular material was investigated. The results show that the expandable tubular with a high strain hardening exponent can obtain more uniform wall thickness after expansion. The FEM model may be applied for design of expansion process and development of expandable tubulars in the future.
Research on Comprehensive Treatment Method of Low-Production and Low-efficiency Well
Authors: An Xu
Published: February 2021

In recent years, low-yield and low-efficiency wells are increasing year by year, which seriously affects the overall development effect of the development zone. On the basis of field investigation, combined with the actual situation, this paper deeply analyzes the causes of low-yield and low-efficiency wells, studies the treatment methods of different types of low-yield and low-efficiency wells, and summarizes the treatment method of “focusing on adjusting water injection wells and using pressure to supplement and plug production wells”. At the same time, combined with a series of supporting measures to tap the potential, the method of tapping the potential is continuously optimized, and the treatment scheme of single well measures is formulated one by one.
Post-Evaluation Feedback Mechanism of Geological Oil Reservoir Engineering
Authors: Fan Hailin
Published: February 2021

Post evaluation of oilfield productivity construction project is a comprehensive work. Reservoir engineering project, as the hardcore of entire post evaluation, is the basis of oil production and surface engineering project post evaluations. The feedback effect of post evaluation on reservoir engineering project has two points: later adjusting on block evaluated and guidance for reservoir engineering project design. It has important significance to oilfield development adjusting that accomplishing feedbacks well of post evaluation work and information.
Application of Fine Management in Polymer Injection Quality in Oilfield
Authors: Li Hui
Published: February 2021

The implementation of polymer injection in oilfield has a very important impact on oilfield exploitation, which is related to oilfield exploitation efficiency and oil quality to a certain extent. In this paper, the refined management method in oilfield polymer injection work is analyzed and studied, and the important role of refined management concept and its application in oilfield polymer injection process is briefly expounded. Taking SL oilfield as an example, the specific application of refined management concept in oilfield polymer injection work is expounded.
Discussion on Reasonable Well Spacing of Polymer Flooding in the Second Class Reservoir of Lamadian Oilfield
Authors: Dai Xin
Published: February 2021

Lamadian Oilfield entered the development stage of polymer flooding in the second-class reservoir in 2006. At present, 8 blocks of well distribution schemes have been compiled and 6 blocks have been put into production by perforation. From the well spacing adopted in the polymer flooding development block of Class II reservoir and the polymer flooding test area of Sa iii 4-10 reservoir in La’nan Area 1, the injection-production well spacing is mainly 106 m ~ 212 m. According to the current development effect of each block, the well spacing of each set has certain inadaptability. Therefore, this paper, on the premise of guiding the preparation of well distribution plan in Area 2 of Middle East Block of La’nan, discusses the reasonable well spacing of polymer flooding in the second class reservoir from the aspects of control degree of polymer flooding, well pattern density, single well controlled reserves and so on. Combined with the actual situation of the implemented polymer flooding block, it is concluded that when the injection-production well spacing is 150m, it has about 80% polymer flooding control degree for the second-class reservoir, which can ensure reasonable well pattern density and single well controlled reserves, and obtain higher recovery ratio and economic benefits.
Research on the Causes and Treatment Measures of the Test Instruments for Water Injection Wells
Authors: Sun Bing
Published: February 2021

Based on the development demand of comprehensive treatment of water injection wells in oil fields, in the process of carrying out maintenance operations, comprehensive analysis is carried out from the angles of water injection well test resistance, tracking description, etc., so as to improve the practical application effect of water injection well test instruments, and play a positive role in improving the treatment effect of water injection well test instruments. Combined with the actual application of water injection well testing instruments, this paper analyzes the reasons for the resistance of water injection well testing instruments, and optimizes the maintenance of water injection well testing instruments and the treatment of pipe corrosion and scaling, so as to improve the treatment effect of water injection well testing instruments.
Experimental Study on Improving Oil Displacement Efficiency by Air Foam Flooding in Tight Oil Layer
Authors: Shang Linlin
Published: February 2021

The tight oil layer is poor in physical property, small pore throat radius, serious heterogeneity of reservoir, low flooding efficiency, poor water flooding efficiency and final recovery is lower than 10%. In order to further improve the oil displacement yield and simulate the conditions of oil layer, we have carried out the experiment of air foam liquid system to flooding oil, and studied the rule of improving the displacement efficiency of air tight foam reservoir. The experimental results show that the density of Gaotaizi water flooding ultimate oil displacement efficiency is 48.95% on average, after water flooding to air - foam flooding alternating final displacement efficiency is high up 79.63%, the oil displacement efficiency can be increased by 26.92%; a short alternately displacement than the big slug is better, the gas-liquid ratio is too high, the breakthrough time of change in short, flooding effect, direct air - foam liquid slug can achieve good flooding effect. That air foam flooding can improve the oil displacement efficiency of dense oil after water flooding by air - foam liquid slug, gas-liquid ratio, cycle injection parameter optimization, to further improve the dense oil displacement effect, the results of air foam flooding field test has the reference and guiding significance for the tight reservoir.
Effect Analysis of Cross-layer Fracturing in Horizontal Wells
Authors: Chen Xiaoyan , Wang Ning , He Lei , Pan Hongbo , Zhao Hui
Published: February 2021

This paper mainly analyzes the fracturing effect of horizontal wells in the development process of horizontal wells in low permeability A reservoir. On the basis of tracer monitoring, microseismic monitoring and production performance data, it is considered that fracturing breakthrough can be basically realized with the current fracturing scale of horizontal wells, but the actual breakthrough effect of communication layer depends on synchronous water injection to maintain formation energy. At the same time, the large-scale fracturing of horizontal wells can form a network fracture body in the formation, which is conducive to the production of oil layers near the well. Based on this conclusion, the next step is to formulate water injection policy for horizontal well development, so as to provide basis for future development research and water injection adjustment of horizontal wells in the same type of oilfield.
Study on potential and distribution of remaining oil after polymer flooding in XX Oilfield
Authors: Chen Zhao
Published: February 2021

XX oilfield has been put into polymer flooding development for 24 years, with cumulative oil production reaching XX million tons. Since 2005, the first-class reservoirs of early polymer flooding have been transferred to subsequent water flooding. After long-term water flooding, polymer flooding and subsequent water flooding, these reservoirs are in the development stage of “double extra high”, with high reservoir production degree, serious ineffective circulation and highly dispersed remaining oil, which makes it difficult to further tap potential. Therefore, the remaining oil potential and distribution law are studied in the first class oil layer in XX area of oilfield, which provides geological basis for further development and adjustment of EOR.
Study on the standard of well and layer selection for infill wells in L13 well area of medium and low permeability L Oilfield
Authors: Xu Xiaoming , Xu Guoqing , Gong Liwei , Zhang Qiaoming , Hao Ming
Published: February 2021

L oilfield entered the stage of high water cut development, because the high water flooded zone in infill wells was not used in the early stage, the relationship between subsurface injection and production in some horizons was imperfect, and the remaining oil showed a distribution pattern of “overall dispersion and local relative enrichment”, which affected the oilfield development effect. By filling holes in infill wells in time and perfecting the local injection-production relationship, the remaining oil in the imperfect injection-production parts can be effectively used and the oilfield development effect can be improved. In this paper, through the comprehensive analysis of previous hole-patching effects, the original well-selecting and layer-selecting standards are re-evaluated, the hole-patching and layer-selecting standards are further improved, and the oilfield hole-patching potential is implemented, which is of great significance for guiding the oilfield to tap the potential remaining oil.
Study and application of geology-engineering integration technology in tight thin heterogeneous carbonate reservoir
Authors: Yan Jun , Cui Mingyue , He Anle , Liang Chong , Wang Sukai , Zhang Hewen , Wen Xiaohong
Published: February 2021

The marginal block Zana oil field is a typical hard-to-produce carbonate reservoir, thin net pay, poor reservoir physical properties, low pressure, strong heterogeneity, bottom water and gas cap risks coexist, and it is difficult to obtain profitable production in conventional development model. In order to realize its high-efficiency development, research on integrated geological and engineering technology was carried out. First, the static and dynamic data analysis combined with pilot well technology was used to accurately determine the target layer, confirm the material basis and guide the horizontal well orientation optimization; Second, after comprehensive consideration of production, cost, performance feasibility, and management after putting into production, an integrated solution of completion and stimulation was recommended; Third, optimized well trajectory control and cementing quality control, improved the drilling rate of the horizontal section and the cementing quality, created wellbore conditions for subsequent stimulation; Fourth, optimized the stimulation method, the treatment scale and parameters, maximized the stimulated reservoir under the premise of avoiding water and avoiding gas; Fifth, Optimize the formula of acid system and liquid combination system, adopt the gas lift flowing and lift integrated pipe column and assisted technique using coiled tubing and nitrogen, realized rapid backflow in low-pressure wells and reduced the secondary damage of reacted acid. Based on the above research, integrated technology of geological and engineering considered geological, reservoir, completion, and stimulation has been applied 14 wells with a success rate of 100%. The average single well production is 10.7 times that of adjacent wells, the cumulative production exceeded 20 × 104t, achieved significant production and economic benefits, and that all provide a technical reference for the development of similar reservoirs.
Application of EH4 Electromagnetic Imaging System in Goaf detection
Authors: Xu Jiangtao , Yang Zhenwei , Zhang Yaohui
Published: February 2021

During the site selection process of a proposed wind farm, it was found that there was a coal field nearby and there might be a goaf. In order to avoid the goaf of coal mine and eliminate the hidden safety risks brought by the goaf to the construction, geological exploration was needed. After comprehensive consideration, the author chooses EH4 electromagnetic system to probe the research area. Through the practice of wind farm site selection project, it is proved that the detection results are accurate and the method is reliable, which provides reliable reference and effective Suggestions for the later construction of fan station.
Research and Application of Precision Characterization Technology for Numerical Simulation of Side Bottom Water Reservoir
Authors: Li Shujing , Ma Lijie
Published: February 2021

In this paper, according to the technical requirements of accurate characterization of middle and bottom water reservoir model in reservoir numerical simulation, three technical means have been used to solve the difficult problem that puzzles the technicians. The first is to establish a mixture of analytical and numerical water bodies to accurately characterize the side water energy and at the same time to reduce the effective grid to improve the operation speed of the model; the second is to solve the problem of oil reservoir simulation in long time and stratified injection wells. The application of these characteristic technologies has played a good technical support role in the high water cut development period.
Analysis of water Plugging Mechanism of new gel plugging agent
Authors: Nie Xu , Guo Hao , Yan Xu , Du Changpeng , Guo Liqiang , Jin Haibo
Published: February 2021

In this paper, the selective blocking ability of double crosslinking gel plugging agent was tested. The parallel core experiment was conducted by using the fractures with different permeability sizes in the chamber. We investigated the injection of gel in simulated fractures, the liquid distribution ratio, the breakthrough of pressure gradient, water plugging rate, oil plugging rate and erosion resistance with different size fractures. The selective plugging mechanism of double crosslinking gel plugging agent was analyzed.
Discussion on Water Dew Point and Hydrocarbon Dew Point of Natural Gas
Authors: Zou Xiaomei , Huang Fengxia , Zhang Liming , Gele Tumeng
Published: February 2021

During natural gas processing and gathering and transportation, water dew point and hydrocarbon dew point as two of control parameters in natural gas because of safety, economy and efficiency etc. In the field chilled mirror manual visual method always be taken to measure water and hydrocarbon dew point due to online instrument test under a differential condition from the pipeline. For hydrocarbon dew point, there’re some assays have implied that heavier components in natural gas have an important effect on hydrocarbon dew point, at the same time hydrocarbon dew point gained under the pressure between 2MPa~4MPa is equal to the max condensation temperature which has a practical meaning. On the other hand, the retrograde condensation cannot be ignored; for water dew point, application of molecular sieve would make dew point measurement easier, while application of dehydrating agents such as methanol; glycols and glycerol could cause interference, instruments &operators differences are exist, but the changing process is consistent when chilled down temperature. In this case, Attention should be given to a white fog which might appear on the center of the surface of the chilled mirror one or more times while temperature dropping down. At last some suggestions are given from two aspects of processing and measurement of water and hydrocarbon dew point.
Research on Laboratory Experiment of Acidification and Blockage Removal of Coalbed Methane Gas Well in Block M
Authors: Feng Kun , Wang Fenglin
Published: February 2021

The coal reservoir in Block M is the low-permeability coal reservoir, in the process of coalbed gas production, since different degrees of blockage occurs in the fracture and pore of the coal reservoir; as a result, the production of coalbed methane is low or shut down. In this paper, the coal rock reservoir in Block M as the research object, and the acidification and blockage removal acid system was selected, and the acidification and blockage removal effect of the optimal acid liquid was evaluated. The coal core soaking experiment was carried out to test the permeability and porosity of the coal core before and after acidification, the experiment showed that the permeability of the coal core was increased to 1.9 to 15.3 times, and the porosity was increased by 0.25% to 3.56%.
Study on the Impact of Farmland Transfer on the Welfare of Transferring-out Farmers Under the Background of Rural Revitalization in Shanxi
Authors: Zhang Zhenyu , Tian Minghua , Li Jianjun , Wang Fang , Ma Shuang , Wang Jun
Published: February 2021

Under the background of rural revitalization, farmland transfer has become an important way to promote agricultural scale and modern management. While the farmland transfer promotes the concentration of farmland and the transformation of agricultural production methods, what is the impact of farmland transfer on farmers’ welfare? Based on the rural survey data of Xinzhou in Shanxi, this paper used the grey fuzzy comprehensive evaluation method to measure the changes of farmers’ welfare before and after farmland transfer. The study found that the overall welfare level of farmers in three counties of Xinzhou was improved after farmland transfer. The welfare level of farmers was increased by 7.63%, from 0.367 to 0.395. However, the changes in various welfare elements were quite different, and some welfare levels were even declined. After farmland transfer, the welfare distribution gap of farmers transferred out farmland has a tendency to expand.
Experimental Measurement of Oil Shale Permeability and its Influence on In-situ Upgrading
Authors: Chen Xudong , Wang Yiwei , Meng Xianglong , Chen Kankan , Su Jianzheng
Published: February 2021

Oil shale permeability is one of the important parameters for in-situ oil shale production. Increasing oil shale permeability is an important means to improve oil and gas recovery. In the experiment, the oil shale samples were heated to a certain tempera ture, and then its permeability is measured the experimental results showed that the per meability in Maoming area increases first, then decreases, and then increases again. W e established the following oil shale in-situ upgrading model. Based on the measured p ermeability and pyrolysis parameters of oil shale, a mathematical model of in-situ ther mal recovery of oil shale is established. The heating methods include isothermal interm ittent heating and equal heat flow rate heating. The oil and gas seepage migration is ch aracterized by Darcy’s law, in which the permeability is described It is a function of te mperature; increasing the permeability between wells will reduce the heat transfer effi ciency between fluid and rock, increase the heat loss and decrease the production rate.
Effect of Particle Size on Mechanical Properties of Coarse-grained Soil
Authors: Gong Chaofan , Cao Zhixiang , Song Xinwei , Zhang Lingjie , Yuan Shifang
Published: February 2021

In order to explore the effcet of particle size on the mechanical properties of coarse-grained soil, 40 groups of direct shear tests were conducted on 3 kinds of coarse-grained soil with the same dry density by DHJ50-2 shear test machine. The results show that the cohesive forces decreases with the increase of particle size, and the internal friction angle increases with the increase of particle size. Under low density and low vertical load, the peak shear stress of coarse-grained soil decreases with the increase of particle size. The threshold porosity of 3 kinds of coarse-grained soil was calculated. When the porosity of soil sample is lower than the corresponding threshold porosity, the peak shear stress increases with the increase of particle size. The research results have certain significance for the follow-up study of mechanical properties of complex graded soil.