bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of acidification parameter optimization method
Authors: Liu Qilun , Cao Jiefeng , Long Changjun , Zeng Zhiguo , Liu Wenge , Zhang Yingying , Su Dandan , Zhang Xu , Jia Jiangfen , Huang Bohua 
Published: March 2020

Abstract
The acidification technology is an important measure to increase the production and increase the injection of oil and water wells. However, due to the complicated working conditions of the acidification measures and the difficulty in determining the construction parameters, it is necessary to establish the acidification model of the injection wells and optimize the parameters. The paper uses the grey correlation analysis method to find the correlation between each construction parameter and the daily injection volume of the injection well, establishes the BP neural network program, trains it according to the existing data and predicts the artificial controllable parameters in turn to find the best construction parameter combination. Taking a single well as an example to predict the parameters and guide the on-site construction. The results show that combining the mathematical method with the acidification construction technology of the injection well and establishing the model prediction parameters can significantly improve the injection efficiency of the injection well.
Optimization calculation method and weighing test of static friction coefficient of RPC spherical joint based on half space contact model
Authors: Liang Jianjun , Lei Song , Li Kai 
Published: March 2020

Abstract
The application of new concrete materials in bridge engineering has always been a research direction of bridge scholars. Reactive powder concrete (RPC) has attracted many scholars’ attention in recent years due to its high strength, high toughness and high durability. But when it is applied to the spherical hinge in the bridge turning project, the result of static friction coefficient of RPC composite spherical hinge obtained by traditional calculation method is small. It may lead to the danger of overturning of the structure during the actual turning. For this reason, a more accurate method for calculating the static friction coefficient of this new type of spherical joint is needed. In this paper, we presented and verified a new stress distribution law and function expression of the friction surface of the spherical hinge, which was based on the contact model of half space body, combined with finite element analysis, weighing test and field measurement. This paper then proposes an optimized method for calculating the static friction coefficient of spherical joints. The results show that: The static friction coefficient of the spherical hinge obtained by the traditional calculation method is about 67% smaller than the actual static friction coefficient; The static friction coefficient of spherical hinge is 15.2% larger than that of the actual one, which is more accurate than that of the traditional method. If there is no test data, the static friction coefficient of this kind of RPC concrete composite spherical hinge is recommended to be between 0.03 and 0.06.
Discussion on harmless treatment technologies of drilling fluid waste in oil and gas fields
Authors: Wang Yandong , Wang Tengfei , Yan Xiangyang 
Published: March 2020

Abstract
Drilling fluid waste is the multiphase stable suspension composed of clay, drilling cuttings, weighting materials, chemical additives, inorganic salts and oil, containing a variety of substances harmful to the environment, such as oil, chemical additives, heavy metals and macromolecule organic compound. The effects of drilling fluid waste on the environment is mainly reflected in following aspects: pollution of surface water and groundwater resources; hardening of soil is harmful to plant growth or even unable to grow, resulting in the soil can not be replanted; various heavy metals and chemical additives affect the growth of animals and plants, and even are enriched in animals and plants, thus endangering human health. It is unfavourable to the implementation of the strategic objective of sustainable development of the environment and economy, so the drilling fluid should be treated innocuously after drilling.
Research and Application of Optimal Water Resources Allocation Based on Improved Multi-dimensional Dynamic Programming
Authors: Cheng Jianhua , Shi Hansheng , Zhang Yan , Zhang Muchuan 
Published: March 2020

Abstract
To solve the problem of the multi-dimensional dynamic programming model which including three state variables and three decision variables in each stage, we have been using discrete differential dynamic programming (DDDP) algorithm. In this paper, considering the particularity of each variable of the objective function is independent in the same stage and the variables of the constraint condition is increasing step by step, we propose a one-dimensional dynamic programming recursive optimization method to obtain the initial solution of the DDDP algorithm.
Study on vortex-induced vibration of non-uniform flow riser based on fluid-solid coupling
Authors: Lin Tiejun , Bao Xiaomin , Zhou Xu , Zuo Jinju , Mou Yisheng 
Published: March 2020

Abstract
Because marine riser is under complex ocean current environment, fatigue damage tends to happen due to vortex-induced vibration, which has a strong impact on the safety issue of deepwater drilling and completion. Vortex-induced vibration (VLV) induced by non-uniform flow loads on deep water riser coupling in complex Marine environments has been studied relatively infrequently at home and abroad. Therefore, CFD-FEM bidirectional fluid-solid coupling method was used to establish a vortex-induced vibration model of 1500m deep water riser and non-uniform flow in waves and currents. Vortex-induced vibration and mechanical behavior of riser in transverse and flow direction were studied from riser motion characteristics, tension factors and other aspects. The results show that the danger zone of vortex-induced vibration of riser under the action of non-uniform flow occurs in one third of the upper end. Increasing the tension can increase the riser’s natural frequency and reduce the amplitude of vortex-induced vibration, but may aggravate the riser’s high stress and low cycle fatigue damage.
Discussion on optimization design method for sidetracking wells in Bohai Oilfield
Authors: Wang Zhanling , Wang Xin , Liu Liming , Chen Liqiang , Tan Caiyuan , Guo Fang 
Published: March 2020

Abstract
Sidetracking of inefficient wells in Bohai Oilfield is one of the important means to stabilize production and increase production. Optimizing the sidetracking scheme to achieve cost reduction and efficiency enhancement is the research focus of refined sidetracking well design. In this paper, the theory of sidetracking technologies is introduced and optimization of sidetracking place is gived based on the location match of the low-efficient well and the sidetracking well and sidetracking plans in deep and shallow strata is identified. To aim at the shallow sidetracking scheme, The applicable conditions and difficulties are proposed in different cases for reentry technology of marine riser, sidetracking under insulator shoes, surface casing windowing sidetracking, sidetracking under surface casing shoes. Aiming at the deep sidetracking scheme, the optimal flow of the casing sidetracking scheme and sidetracking under production casing shoes is proposed. Taking two low-efficiency wells of A and B in Bohai as an example, the preferred slot and the sidetracking section are preferred, and the sidetracking point is preferred. Finally, the sidetracking location of the two wells is interchanged, and the footage is saved at 1428m. The on-site implementation results show that the two low-efficiency well sidetracking schemes are reasonable and can achieve the purpose of cost reduction and efficiency enhancement. The optimal method of low-efficiency well sidetracking proposed in this paper has certain guiding significance for the sidetracking design of low-efficiency wells in Bohai Oilfield.
Multi-scale Finite Element Method for Members for Pipe Frames
Authors: Hiu Haifeng , Wang Changzhi , Hu Xiaoguang 
Published: March 2020

Abstract
To consider the local buckling of the members in reticulated frames, based on the multi-scale simulation, the part of member may be collapsed were divided by the shell elements as a micro-model, and the other part of the member was simulated by beam elements as a macro-model. The incremental displacement constraint equations for the nodes on the section between the two models are established based on the plane section premise of classical beam theory. By constraint variational principle, the tangent stiffness matrixes and the nodal load vectors of the micro-model and the outside structure are combined, and then the equations are solved. The location of the collapsed part is predicted by the deflection function of the beam, and the length of the collapsed part is estimated. Two case studies about a single beam and a single-layer reticulated dome are presented to show the feasibility and the validity of this method.
Design and Realization of E-MWD Instrument in Coal Mine
Authors: Jie Lian 
Published: March 2020

Abstract
In order to ensure safe and efficient coal mining, it is usually necessary to construct a large number of gas drainage holes and water exploring and drainage holes in the coal mine. Directional construction drilling can improve the quality of such drilling construction, measure the main parameters such as drilling inclination angle, azimuth angle and tool orientation angle in real time, draw the drilling trajectory and adjust the drilling attitude according to the needs, realize the efficient utilization of gas drainage, and advance, regional, precise prevention and control of disasters. The measurement while drilling (MWD) system is the necessary support for drilling directional construction, which is applied to various directional drilling rigs in coal mines to measure the drilling trajectory in real time to guide the design and construction of drilling.
Analysis of waterflooding characteristics of the second class oil layer in the second area of the eastern Labei block
Authors: Di Yang 
Published: March 2020

Abstract
This paper makes use of the new drilling in the second area of the North East block to make statistics of the watered out state of the second type reservoir section, analyzes the watered out state of the reservoir under the conditions of different thickness level, different permeability water saturation level and different sedimentary micro equal level, basically finds out the basic watered out characteristics of the reservoir in the current development stage, and provides the necessary basis for the development and adjustment of the water accumulation and two drive in the next period Based on the data and the understanding of the regularity, the foundation is laid for the further exploitation of the potential of the water drive in the second type reservoir.
Numerical simulation of rock fracture with TBM cutter
Authors: Zhu Hangyun , Feng Lingbo 
Published: March 2020

Abstract
In order to study the process of rock fracture with TBM, the three-dimensional discrete element model of hard rock with joints is established based on the discrete element method. Uniaxial compression test and Brazilian disk splitting test were used to calibrate the relevant parameters. The joints have different strength, spacing and inclination. The dynamic cutting simulation of single cutter is completed. The fracture characteristics of the jointed rock and the load on the tool are obtained. The results show that the joint characteristics have a great influence on the rock breaking properties of the cutter. When the thickness of the joint is unchanged, the rock breaking loadof the cutter increases with the increase of the joinsstrength. When the strength of the joint is unchanged, the rock breaking load of the cutter increases with the increase of the thickness of the joint in a certain range. Moreover, under the conditions of different strength, different spacing and different inclination, the fracture characteristics of rocks are also different.
Optimization of Microemulsion Formulation of Fracture reservoirs
Authors: Jia Jiangfen , Cao Jiefeng , Zeng Zhiguo , Long Changjun , Ning Mengmeng , Xu Zhengdong , Zhang Bin , Wang Peng , Wang Xin , Liu Qilun 
Published: March 2020

Abstract
In order to screen out the optimal microemulsion oil drive system, the effect of micro emulsion performance on the residual oil of pore is selected, and the remarkable effect of improving recovery rate is proved from both macro and micro aspects by analyzing the fissure core oil drive experiment and the distribution law of the residual oil of the pore. The results showed that the best microemulsion system is made of positive octane 8mL, water 8mL, 4.5% mass fraction of the beetroot, 6% mass score of positive butanol, 5% quality score of NaCI. And that microemulsion system has a smaller particle size distribution range, higher viscosity, strong stability and a smaller proportion of pore residual oil.
Study on the method of energy evolution of rock under uniaxial compression test
Authors: Liu Zhixi 
Published: March 2020

Abstract
For investigation evolution of energy of rock during the unconfined compression, using same loading rate were carried out uniaxial cycle loading and unloading tests, uniaxial graded loading and unloading tests, and unconfined compression tests. Through the analysis of experimental phenomena shows that the number of cycles has little effect on elastic energy. It indicates that fatigue damage has no effect on elastic energy of rock. Further comparing the elastic energy of the uniaxial cyclic loading and unloading tests and the uniaxial cyclic graded loading and unloading tests, it can be found that their elasticity energy approximately when the loads are the same. Based on above elastic energy studying, can considered that the elastic energy of the rock does not change when the load is greater than or equal to the previous load. Therefore, their elastic energy are the same when the load of unconfined compression are equal to the load of unloading point of the uniaxial graded loading and unloading tests. Based on the above analysis results, the energy real-time evolution before the peak strength of unconfined compression is studied. The method provides a new idea for real-time evolution of energy before the peak strength of rock during the unconfined compression.
The detection and response characteristics of transient electromagnetic signals caused by the deformation and fracture of overlying strata affected by mining of a thick coal seam
Authors: Zhang Pingsong , Ou Yuanchao , Hu Xiongwu , Li Shenglin 
Published: March 2020

Abstract
The height at which overlying strata fail is an important parameter for the prevention and control of mine water damage. High overlying strata failures during mining of a thick coal seam make testing in mines challenging. Considering the mining conditions for the thick coal seam in Ordos City, Inner Mongolia, China, this work applies ground detection using transient electromagnetics. The response characteristics of transient electromagnetic signals during strata failure were investigated using numerical simulation, and the results of that investigation will provide guidance for on-site exploration. In addition, based on the conditions of the ground and mining face, test wires were distributed within the mining work face area to obtain electromagnetic detection data using large wireframes on the ground to further construct an electrical profile of the coal mining and non-mining areas and explain the characteristics of strata failure. This method succeeded in the practical application and is provided as guidance for strata failure detection for thick coal seam mining.
A root-cause analysis methodfor faultdiagnosisin condenser
Authors: Han Banglei , Zhang Chao , Xie Chu 
Published: March 2020

Abstract
Condenser is an important part of thermal power units. When the condenser fails, the quick determination of the root-cause fault can effectively avoid major safety accidents in thermal power units. Most existing methods are based on the assumption of stationary relationships among the variables. However, the relationships among the variables are non-stationary in the real industrial process. These methods are not suitable for real industries. According to the process knowledge, the condenser is a typical system of non-stationary. Aiming atthe non-stationary relationships, a root-cause analysis method based on multiple regression modelsis proposed in this paper.Firstly, the bottom-up piecewise linear representation method is applied to yield qualitative trends of historical data for each variable. Secondly, qualitative trend combinations of multiple variables are obtained based on amplitudes for each variable. Finally, the contributionsof the related variables in qualitative trend combinations to the main variableare calculatedbased on multiple regression models, and the root-cause variable can be determined according to the size of the contribution. Anindustrial example is provided to illustrate the effectiveness of the proposed method.
Experimental study on sand production characteristics in natural gas hydrate deposits
Authors: Yu Tianbo , Liu Yu , Song Yongchen 
Published: March 2020

Abstract
During the process of natural gas hydrate exploitation, the cementation state of the stratum changes due to the decomposition of skeleton hydrate. Fine sand in the reservoir will migrate to the wellbore with the fluid, which is the so-called sand production phenomenon. Sand production will bring great harm to hydrate exploitation. In this paper, a set of visualized sand production simulator was designed to obtain the factors influencing the sand production characteristics in different working conditions. It is found that fine sand will invade and block the gravel layer and it is accompanied by the subsidence of the sand layer. Fluid flow rate and initial hydrate saturation are important factors affecting the characteristics of sand production. In addition, it is of certain guiding significance to select the appropriate median diameter ratio of gravel to sand for sand control in the actual exploitation process.
Current Situation Detection and Performance Evaluation Analysis of Existing Double-curved arch bridge
Authors: Zhou Yongjun , Wang Gangqiang , Cao Xiaozhe , Tian Ruixin 
Published: March 2020

Abstract
The existing design load level of the existing double-curved arch bridge is generally low, the old-fashioned inferiority and the poor overall integrity, which are likely to cause structural damage and affect the normal use of such structures. Based on the appearance inspection and static and dynamic load test of a dangerous three span double-curved arch bridge without original design data, this paper discusses the methods of structural modeling, load test and structural performance evaluation of this kind of bridge, which provides reference to the current situation evaluation of similar bridges. Through the inspection of bridge appearance defects, component cracks, deformation displacement, steel protective layer thickness, concrete carbonization depth and material strength, combined with the load test results, the comprehensive technical status of the bridge is determined to be 4 types of bridges. The bearing capacity meets the requirements of load grade Automobile-10 class, but the safety reserve is insufficient.
Preparation of cyclodextrin-modified graphene oxide and its adsorption properties for Pb (II)
Authors: Li Lingcong , Chen Bing , Su Ziwen , Wu Jinmei , Pan Zhenxing , Fu Zhiping 
Published: March 2020

Abstract
In this paper, the improved Hummers method was used to prepare graphene oxide (GO) and modified by cyclodextrin to prepare cyclodextrin-modified graphene oxide (CDGO) composites. The composites were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The adsorption properties of GO and CDGO for Pb2+ were measured by atomic absorption spectrophotometer. The results showed that the number of functional groups of the modified material and the adsorption sites increased. The adsorption capacities of GO and CDGO for lead were respectively 86.47mg/g and 165.52mg/g, which were consistent with the quasi-secondary kinetic model and Langmuir isotherm adsorption model. CDGO showed better adsorption capacity.
DFT study of methane catalytic combustion on Pd-based diatomic catalysts
Authors: Pu Yunshuang , Mou Chuanlin , Yu Yang , Deng Qizheng , Wang Linyuan , Deng Hongbo , Zhang Lei 
Published: March 2020

Abstract
The processes of methane combustion on three Pd-based diatomic catalysts (Pd2, PdPt and PdNi) are investigated by using density functional theory (DFT) at the B3LYP/6-311++G(d,p)+SDD//B3LYP/6-311G(d,p)+LANL2DZ level. The optimized geometric structures, activation energy (Ea
), and reaction rate constant (k) of methane dehydrogenation and oxidation on Pd2, PdPt and PdNi are compared. The main reaction path for methane combustion on catalyst Pd2 is CH4→CH3→CH2→CHOH→CHO→CO→CO2. However, the main reaction paths on catalyst PdPt and PdNi are the same: CH4→CH3→CH2OH→CHOH→CHO→CO→CO2. The rate-determining steps (RDS) on catalyst Pd2 and PdPt are the same: CHOH→CHO, while the step of CH3→CH2OH is the RDS on PdNi. Further analysis shows that the catalytic activity followed the order of PdPt (k = 1.0639×104 s−1) > Pd2 (k = 1.7281×102 s−1) > PdNi (k = 1.9235×10 s−1). Thus, PdPt catalyst exhibits better performance than the other two catalysts in the methane catalytic combustion.
Numerical simulation analysis of cavitation of current limiting orifice plate
Authors: Ni Lingying , Li Bing , Geng Guangwei 
Published: March 2020

Abstract
In this paper, ANSYS-Fluent software is used to simulate the cavitation phenomenon that may occur in the current limiting orifice plate of the vertical oil inlet pipe with large drop in the underground water sealed oil depot. The influence of different orifice designs on the cavitation are calculated and summarized. The simulation results show that the shape of the orifice is an important factor affecting the cavitation intensity, the chamfering of the orifice can restrain the cavitation. The circular chamfer is better than the 45 ° chamfer to reduce the cavitation intensity, and the cavitation intensity will decrease with the increase of the thickness of the orifice chamfer.
Study on Dust Diffusion Law and Application of Wet Vibrating Wire Dust Removal Fan in Fully Mechanized Excavation Face
Authors: Ma Shengli , Zhang Kaiming , Zhang Heng , Zhang Qiang 
Published: March 2020

Abstract
Fully mechanized excavation face is the main place of dust generation in coal mines. Due to the huge dust production and long ventilation distance, the dust concentration is difficult to reach the safety standard. The purpose of this study is to improve the dust removal efficiency of 2410 roadway in Yuhua Coal Mine. Firstly, this paper carried out dust concentration and roadway wind speed measurement on the 2410 fully mechanized excavation face of Yuhua Coal Mine. According to the actual layout of fully mechanized excavation face, the geometric model is established. The distribution of wind field in fully mechanized excavation face is simulated and analyzed by Fluent software. The correctness and feasibility of the model and simulation method are verified by comparing the simulation results with the measured data. Then the paper studies the influence of the air duct outlet installation position on the airflow field and the dust distribution, and analyzes the dust removal effect of the existing wet vibrating wire dust collector dust removal system in Yuhua Coal Mine. The research conclusion is that the wet string vibration dedusting fan has remarkable dedusting effect, and the dedusting efficiency is the highest when the air duct is installed near 10 m from the working face.