bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of a digital intelligent evaluation platform for energy consumption of large oilfield water injection systems
Authors: Ruan Yan , Zhang Xuliang , Ning Junfeng
Published: May 2021

With the development of oilfield water injection systems becoming more and more complex, relying on artificial experience to judge the efficiency of energy consumption and the status of the system more difficult. Based on hydraulic theory and matrix theory, establish the characteristic equations of the node unit, pipeline unit and auxiliary unit of the water injection system, and use the flow balance to form the overall matrix equation of the water injection system. Established a theoretical model of water injection system simulation, based on this, build a digital intelligent evaluation platform for water injection system energy consumption. In this way, it simulates the production operation status of the water injection system under theoretical conditions and compares it with the actual production operation data, so as to accurately analyze and evaluate the current status of the water injection system’s pipe network energy consumption and the operating efficiency of the branch pipe network energy consumption of each water injection station. The intelligent analysis and evaluation of energy consumption of the water injection pipe network system has been realized, and the optimization and transformation goals have been defined. It has played a significant role in promoting the realization of digital and intelligent oilfield water injection systems.
An Novel Method for Object Tracking in Sensor Network Combination with Trilateration and UT Transform
Authors: Kang Zhang , Xuan-zhi Zhao , Wen Zhang
Published: May 2021

Positioning and tracking are the key technologies of wireless sensor networks. Trilateration is an important method for the localization of wireless sensor network nodes. This method uses three anchor nodes to determine the location of the target. In this paper, UT transform and trilateral measurement method are combined to obtain the statistics of target position, and then use it as the virtual observation of Kalman filter to realize dynamic target tracking. The simulation results verify the performance of the method proposed in this paper.
Passive Ranging Based on Accurate Prediction of Target Radiation Temperature
Authors: Xiaoning Fu , Shiwen Xu
Published: May 2021

In this paper, a passive ranging method based on accurate prediction of target radiation temperature is proposed. Firstly, different wave bands are intercepted and the corresponding light radiation energy on two different wave bands are obtained; secondly, the temperature of target is estimated according to the linear relationship of the corresponding light radiation energy in two different wave bands; and the target can be equivalent to a blackbody of different temperature categories; thus, the range information of the target can be obtained, and the passive ranging error of air target can be realized. In this way, the target can be divided into different categories according to its own temperature, and the subspace of passive ranging can be effectively divided, which can provide a rule to avoid blindness for the subsequent target distance estimation. In the end of this paper, the accuracy of the method is verified by experiments, and the error of ranging accuracy is analyzed, which proves the feasibility of this method, and lays a foundation for future engineering applications.
Flat Film Structure Wireless Passive Pressure Sensor based on SiCN materials
Authors: Wang Caishun , Zhang Jiajia , Zhang Xin , Li Huan
Published: May 2021

In order to solve the measurement of air pressure in harsh environment, a new kind of wireless passive pressure sensor based on the amorphous SiCN material with high heat resistance was proposed. Ansoft HFSS software was used to study the relationship between the size of the rectangular resonator with the resonant frequency and quality factors. By optimizing the position and size of the sloped antenna, a wireless passive pressure sensor with high performance was designed. The sensitivity is 0.25mpa/GHZ and the bandwidth is 0.85GHZ of the pressure sensor at the working frequency of 6.8GHZ. This indicates its potential application in the harsh environment with high temperature.
Research and evaluation of the measurement uncertainty with the pipeline robot
Authors: Hu Chang’an , Luo Shutong , Li Wanze , Lv Fei , Cai Dongyan , Kong Linghui
Published: May 2021

The pipeline robot used to detect and maintain the pipeline is a novel technical means, which changes the single traditional mode of excavation sampling inspection of pipeline. This detection technology not only improved the accuracy of pipeline detection but also is easy to analyze the causes of pipeline defects for pipeline engineering management maintenance staff. It is possible to carry out a review of defect and develop pipeline maintenance solutions. Using this method can eliminate the security hidden danger before repairing or replacing section. Thus, the use of a pipeline can save a lot of maintenance costs and reduce pipeline maintenance cost, which can also ensure the safety of people’s life and property. In addition, this method can also reduce the toxic gas or liquid leakage to protect environmental pollution. Therefore, the research of a pipeline detection robot has an important scientific significance and social value. In this paper, our group has a base of the long-term research with the geometric measurement technology, so the measurement uncertainty of the common pipeline robot is studied. The measurement uncertainty of error about positioning is defined as U=0.59mm+9×10−2L, k=2 (L unit is m), and the uncertainty evaluation of angle errors measured, including the forward and backward pitching angle, left-right tilt angle, is U=0.10°+4.6×10−3
θ(θ unit is °).
Development of Intelligent Planning & Integrated Office Management System for Drilling Operations in South Azadagan
Authors: Liu Zhikun , Li Aixi , Li Jihui , Bai Mingna
Published: May 2021

Due to the distance limitation between the drilling department in Iran and the head office in China, it is necessary to improve the management level of the south Azadagan drilling department in the south of Iran. According to the drilling operation characteristics of Iran south Azadagan department, we design and develop an Intelligent Planning & Integrated Office Management System (IPIOMS) including design management, work report, planning and cost control, operation management, statistical query and logistics support.
Acoustic emission monitoring and phased array ultrasonic testing for the steel bifurcated pipe of 800MPa grade strength in hydraulic test
Authors: Wu Weiping , Fan Qinhong
Published: May 2021

The paper analyzes and studies the acoustic emission monitoring and phased array ultrasonic testing of steel bifurcated pipe of 800MPa grade strength in hydraulic test. The comprehensive grade of AE location source is assessed, and the structure health is evaluated, the AE characteristic parameters of an important hazardous area corresponding to the load elevated stage and load holding stages are analyzed and compared, and Kaiser effect is verified. PAUT is used to examine the area of great activity located by AE, and the position of welding defects found by PAUT is basically consistent with the AE location map, then the location error of AE is illustrated in the region of irregular shape. The AE and PAUT are of great advantage in hydraulic test of the steel bifurcated pipe.
Research of Active Disturbance Rejection Controller Design for PMSM Servo System
Authors: Hongliang Yan , Jiapeng Li , Leiming Li , Juju Ma
Published: May 2021

In the permanent magnet synchronous motor (PMSM) speed control system, an improved active disturbance rejection control strategy with higher tracking accuracy for time-varying input is proposed. The traditional active disturbance rejection controller is mainly used for fast and static-free tracking of step signals, but there is a large tracking error for time-varying signals, which limits the application of active disturbance rejection controller. In this paper, the theoretical analysis of the existence of steady-state error is carried out, and then an improved speed active disturbance rejection controller (ADRC) with derivative feedforward and parallel linear extended state observer(P-LESO) is designed to reduce the tracking error of the system. In order to observe and compensate the reverse electromotive force in real time and reduce the current following error, a current loop linear active disturbance rejection controller is designed. By constructing Simulink simulation model for verification, the control system not only improves the tracking accuracy of PMSM for time-varying input, but also has a good dynamic performance for step input.
An intelligent dynamic analysis system for oil and gas reservoirs based on custom components
Authors: Haoyu Zhang , Zhigao Mao , Ying Ning
Published: May 2021

This paper introduces an intelligent dynamic analysis system of reservoir with components. The system has 6 modules: production early warning, report analysis, single well dynamic analysis, injection-production well group dynamic analysis, reservoir dynamic analysis, and intelligent knowledge base. The system data comes from the production data lake, monitors the production status of the reservoir in real time, and USES the conventional production warning and big data analysis warning to report the warning to users. Researchers can use the system’s three-stage dynamic analysis module to process and resolve the corresponding warning information to maintain the normal production of the field. The system adopts component development, divides the commonly used algorithms and drawings for reservoir dynamic analysis into three categories of components. Each component can be independently applied to a specific scenario by connecting to the database. Through the configuration of free page XML, each component can quickly form different analysis scenarios in an adaptive way, so as to meet the complex and changeable requirements of reservoir geology and production, and better help oil field enterprises to reduce cost and increase efficiency.
The Research and Implementation Transmission Line Tower Rod and Monitoring System Using Reverse Network RTK Technology
Authors: Jin Yi , Wang Wei , Pei Ling , Chen Xin , Song Bao
Published: May 2021

In order to solve the problems of low monitoring accuracy, high false alarm rate, untimely pre-warning and high equipment failure rate of the transmission line tower rod oblique posture monitoring system, a transmission line tower rod oblique monitoring system based on reverse network RTK was developed. The system integrated the Beidou multi-source sensor, network communication and prediction and forewarning, used the height and millimeter level position information of the transmission line tower to measure and calculate oblique posture information of the tower pole, and made risk assessments, so as to realize the control of these information. The actual tests results showed that the monitoring system could accurately obtain the oblique posture information of the transmission line tower pole, and the pre-alarming monitoring results met the requirements of intelligent, accurate and digital management of transmission line tower pole.
Study on oil and suspension solid removal from oil field wasted water by sedimentation
Authors: Wang Yan , Cao Baihan , Reifsnyder Sam , Gao Sheng , Rosso Diego
Published: May 2021

In order to remove oil and suspended solid in oilfield wastewater, Takacs model was improved and applied to the simulation of oil floating, the parameters of oil coagulation velocity were added. By this model, the accurate oil floating model and sludge sedimentation model were established. On the basis of this model, the experimental verification was carried out by the sample from the wasted water station. By the response surface method, the influence of flow rate, treatment fluid concentration and settling time and their interaction on oil removal rate and suspension removal rate were studied, and the important influence of time factor was determined. According to the pollution degree of oil field wasted water, based on the theory and experimental method of this paper, the treatment capacity and settling time of oil field wasted water could be optimized, which provides theoretical guidance for the improvement of settlement device and the industrial application in the oilfield.
A Study of the Lyapunov Stability of an Self-Excited Induction Generator
Authors: Li Haitao , Peng Xuehu , Zhang Meiyan , Chen Lili
Published: May 2021

The self-excited induction generators (SEIGs) can provide attractive renewable energy sources. Since it can be used in an open-loop fashion which includes no control closed-loop, its inherent stability can be counted on to allow operation over a wide range of operating conditions. Unlike classical arguments based on transient and steady-state analysis, it is proposed rigorous holistic analytical stability arguments based on the full nonlinear transient state-space model of a SEIG under two-phase stationary reference frame using dynamical systems theory. The conditions for critical transient stability of the unloaded SEIG are obtained in the sense of Lyapunov. Analytic formulas from the limit cycle conditions give the values of the range of capacitance, the range of rotor speed and the stator frequency for self-excitation. Analytic formulas from steady-state conditions give all the steady-state parameter and state values. Thus, the analytical results yield a set of simple and universal analytic formulas that can predict and evaluate the transient and steady-state stability characteristics of the SEIG. Good agreement between the experimental results and computed results validates the analytical results.
Eccentric array-based borehole transient electromagnetic system for NDT of multipipe strings in sidetrack well
Authors: Ling Yang , Ruirong Dang , Bo Dang , Rui Guo
Published: May 2021

In the middle and late stage of oilfield development, the sidetracking technology is widely used for restoring the production of stripper well, damaged well and abandoned well. In this paper, we present an eccentric array-based borehole transient electromagnetic (TEM) system for nondestructive testing (NDT) of multipipe strings in sidetrack well. Using the borehole TEM signal model, the response of eccentric sensor is analyzed, which contains more information in the direction of eccentricity. On this basis, multiple eccentric sensors with different depths and different angles are utilized to form an eccentric array, which can be used to determine the direction of sidetracking and to detect the multiple pipes in hanging casing strings. The performance of the proposed system was verified by applying it to sidetrack wells in Shengli oilfield. In addition, field experiments were conducted, and the results demonstrated the effectiveness of the proposed method.
Inversion method of horizontal well boundary detection based on geo-steering electromagnetic wave measuring instrument
Authors: Xie XiCao , Wu Jie
Published: May 2021

Based on the adaptive damping Gauss-Newton Inversion Algorithm, this paper studies the inversion method of the horizontal well boundary detection by the geo-potential electromagnetic wave measuring instrument. Based on the drilling trajectory and logging data of a real horizontal well, the simulation inversion is used to detect the position of formation boundary, and the validity of the inversion method is verified.
Optimization Method of Output Power Quality of Z-Source Inverter Based on SVPWM
Authors: Hailong Liu , Aiqing Huo , Qizhi Zhang , Hongliang Yan
Published: May 2021

A linear modulation of SVPWM control strategy employed in Z-source inverter is proposed in this paper. The DC bus voltage is regulated by adjusting the shoot through duty based on load. The reference voltage vectors are limited in the inscribed circle of hexagon of basic voltage vectors. Overmodulation is avoided. The linear relationship between the peak value of the output voltage and the DC bus voltage is kept in all regions. The change of system load is responded by this control strategy. The system control algorithm is simplified and the output capability of the system is enhanced. To validate its advantages, analytical, simulation, and experimental results are also presented.
Application Research on Corrosion Scanning of Coated Pressure Vessel with Ultrasonic Phased Array Inspection Technology
Authors: Daoxiang Wei , Daorui Wei , Jun Si
Published: May 2021

Ultrasonic testing is a commonly nondestructive testing method used in the periodic inspection of pressure vessels. The coating on the surface of the vessel should be polished before testing. In order to solve this problem, in this paper, ultrasonic phased array detection is used to detect the coating without removing the coating, and the experimental study is carried out on the painted test plate, the test results are basically the same as the actual size of defects. The results show that the application of ultrasonic phased array detection technology in the corrosion scanning of pressure vessels is feasible. It lays a foundation for the application of ultrasonic phased array detection technology in the corrosion sweep of pressure vessel insulation coating.
Experimental study on the choice of transducer resonance frequency in downhole flow measurement
Authors: Huiqin Jia , Bai Yongxin , Ruirong Dang , Liu Jingjing , Wang Chengyun
Published: May 2021

In the process of downhole layered oil recovery, it is necessary to measure the liquid production of each layer in real time, so as to control the oil production plan of each layer in real time according to the oil production plan. Need to use ultrasonic time difference flowmeter to measure the flow in the process of injection and production. Due to the complex and changeable downhole environment, impurities such as sand and bubbles often appear in the process of downhole flow measurement. How to choose a suitable ultrasonic transducer frequency is of great significance to the flow measurement results. At present, common transducer resonance frequencies on the market mainly include 1MHz, 500KHz, 180KHz, and 40KHz. In this paper, the attenuation characteristics of the resonant signal of the transducer in the medium containing impurities are studied through simulation and experiment. The experimental data shows that in the stratified oil recovery system, the receiving effect of the system is best when the transducer frequency is 1MHz.
Data Mining on the Influence of Capillary Force on the Productivity of CBM Wells
Authors: Bin Liu , Hongli Wang , Suian Zhang , Xiao Zhang , Qiguang Liu
Published: May 2021

To explore the influence of the capillary force in the coal matrix on the productivity, based on the dynamic capillary force of the gas and water phase, the high-pressure Hg injection method, the porous plate method, and the centrifuge method were used to analyze the No.3 coal seam of the Zhengzhuang block in the southern Qinshui Basin. Through the experimental analysis of 97 samples, 3 different capillary force models are proposed. Through data mining, it is found that when the displacement pressure is 1.247 MPa, the average residual water saturation of the sample is 89.21%; when the displacement pressure is 4.0 MPa, the residual saturation of 82.5% of the samples exceeds 80%. This means that the desorption process of adsorbed coalbed methane is subject to greater capillary force. If the capillary force cannot be overcome, the gas production of coalbed methane wells will be at a low level.
Prediction of narrow channel sand body by dynamic and static data
Authors: Libo Sun
Published: May 2021

At present, a description method has been formed for prediction of the sand body in narrow underwater distributary channel in delta inner front intrafacies. Usually, static data, such as core data and well logging data, are used to predict the sand body distribution in narrow channel. However, dynamic data are inconsistent with static data during dynamic analysis based on the description results. In this paper, a narrow channel was predicted and depicted by combining dynamic and static data, resulting in not only theoretical deduction and genetic interpretation based on static data, but also improvement and verification based on dynamic data. Thus, the geological prediction results are more compliant with the underground conditions. A method for prediction of narrow channel sand body based on dynamic and static data is formed.
Processing of the Passive Drilling-bit Ranging Signal Based on Wavelet Packet
Authors: Yang Quanzhi , Zhang Xiaobin , Yu Xiaolong , Yang Xianlun , Li Weifeng , Hou Yunyi
Published: May 2021

Recent technological advances have increased interest to acoustic ranging especially the passive acoustic ranging which is easier to operate in the oilfield. For analyzing the non-stationary drilling-bit signal, the conventional discrete Fourier Transform (DFT) has been known to be less efficient. A new extraction method based on wavelet packet (WP) is presented. In the signal processing, WP is used to decompose the original drilling-bit signal into the sub-frequency bands (SFBs). By analyzing energy spectrum of the SFBs, the first four SFBs are found that contain the characteristic of the drilling-bit, and the specific frequency band of the drilling-bit signal is determined after power spectrum analyzing. The field test shows that when the bit is near to the casing of the adjacent well, the reconstruction drilling-bit signal changes significantly which can give warning accurately.
Research on Weld Defect Identification with X-ray Based on Convolutional Neural Network
Authors: Zhang Long-fei , Gao Wei-xin , Wang Zheng , Wu Xiao-meng
Published: May 2021

In the process of X-ray weld defect detection, a deep learning network structure based on the principle of simulated visual perception is constructed. The size and number of layers of convolutional neural network template, and the influence of different activation functions, are analyzed with an improved method proposed, which may avoid the characteristic steps for the extraction of defect images, and can be used to directly determine the presence of any defect. Experiments on 200 images show that the proposed method for SDR images has an identification rate of more than 98%, which is better than other methods, and has highly practically in pipeline defect detection.
Time-varying Numerical Simulation Of Reservoir Physical Properties Based On Surface Flux
Authors: Jie Jiang , Zijun Huang , Ruxiang Gong , Jibo Ren , Gaoming Yu , Yu Zhang
Published: May 2021

Most of the domestic oilfields are developed by water flooding. The long-term erosion of injected water will transform the reservoir and change the physical properties of the reservoir. These changes continue to progress slowly, but the cumulative change range cannot be ignored. The reservoir physical property changes will affect the oil-water movement ability, and have a great impact on the oilfield development influence and the distribution of remaining oil in the later period. However, the mainstream commercial numerical simulation software at present fails to fully consider the time-varying phenomenon of reservoir physical property. According to the literature review, the numerical simulation methods considering the time-varying reservoir physical properties have some defects in continuity representation, directional representation and stability of calculation results. To solve this problem, it is necessary to establish a numerical simulation method based on the time-varying reservoir parameters. In this paper, a useful attempt is made to solve this problem, and an Eclipse-based time-varying simulation program is developed. Through the verification of various examples, all functions meet the design requirements and can realize time-varying simulation under different conditions.
Research on the parameter analysis of combined focusing of right Angle cone and projectile
Authors: Li Zhou Li , Shi Kai Kai , Qian Cai Ling , Zhang Qing Bin
Published: May 2021

In a sound wave measurement engineer, a combination focusing device of right angle cone and parabola was designed to increase the emission sound pressure, and by exploring and simulating the relationship between the position and size of the spherical focus area and the height of the right-angled cone, the position of the apex of the right-angled cone, the focal length of the parabolic and other parameters. The analytical relationship between each parameter and the sound pressure level of the spherical area focused at a certain position from the vertex of the right-angled cone is obtained.
Diagnosis strategy design method based on ant colony algorithm
Authors: Yun Lin , Lu Han
Published: May 2021

Diagnosis strategy design is an important step in testability design. In order to be close to the reality, the optimization design of diagnosis strategy is carried out under the condition of unreliable test. Firstly, the changes caused by unreliable test conditions are analyzed, and test cost and error cost are established as optimization objectives. Then the mathematical model of the problem is established. Ant colony algorithm is used to solve the problem, and a new heuristic evaluation function is established. the objective function is redefined. Finally, the effectiveness of the proposed method is verified by an example and compared with other algorithms.
A Brief Overview of Deep Learning and Memristor
Authors: Cheng Guojian , An Xiaoxin
Published: May 2021

At present, the deep learning has become a main topic in academic and engineering domain. It has been considered to be the general solutions to solve various of classification, clustering, regression and generate tasks in all fields, but it needs higher computing power at the same time. In other words, it needs the new equipment possessing lower power consumption and higher efficiency, which further triggers the development of new hardware and computing technology. A kind of promising solution is an emerging equipment known as memristor, which can be naturally mixed into a feasible computing device to realize neural computing to extend computing power of existing hardware. In this paper, more convenience and practically of using memristor to realize deep neural networks are obtained by summarizing mechanism of deep learning and structure of memristor.
Research on the distortion effect of Ultra-wide-band radar antenna
Authors: Nan Chengfeng , Sun Yong
Published: May 2021

In this paper, the distortion effect of Ultra-wide-band radar antenna was designed and measured. The equal-part low-pass prototype was used as the model. The model can minimize the insertion-loss while providing the need stop-band attenuation. On the base of the low-pass prototype model, the network model was built using the theory of coupled cavity resonator, and coupling coefficients between resonators and external Q factors at two terminal resonators were used as basic parameters in designing narrow-band filters. The λ/4 inductive coupled TEM-mode coaxial resonators were used in microwave realization. The designed filter is compact, stable, easily made and cheap.
Simulation and Experimental Research on Magnetic Flux Leakage Detection Method of Long-distance Pipeline Local Dents Stress
Authors: Kang Xiao-wei , Xiong Zhi-kun , Zhang Lin , He Ren-bi , Meng Xiang-ji , Chen Jin-zhong , Zhang Xue-wei
Published: May 2021

The mechanical damage of the pipeline will cause local dents of the pipe wall, accompanied by different levels of localized stresses. In this paper, the magnetic flux leakage detection technology is used to simulate and test the local dents of pipeline mechanical damage. The magnetic field distribution of the magnetic leakage detection is observed in the local stress loading state of the pipeline mechanical damage. Meanwhile, it is modeled and analyzed the equivalent change and detection effect of the magnetic flux density in the leakage magnetic field in the state that the pipeline mechanical damage is at different degree stress loading. Then the experiment is conducted with reference to the simulation results. Simulated artificial injuries with different deformation degrees of local dents are processed on the Φ323.9 steel pipe. It conducted magnetic flux leakage detection on local dents of pipeline mechanical damage by parameters of different DC magnetization strength. It showed that the leakage magnetic field effect of 5% OD pipeline mechanical damage local dents is better than 0.5% OD and 1% OD.
Realization of shock accelerometer sequence-to-sequence calibration based on deep learning
Authors: Zhen Huang , Wu Yahui
Published: May 2021

The sensitivity parameters or mathematical model of sensor are obtained through traditional shock accelerometer under calibration test, and then the measurement signal is restored through compensation and correction. As the shock signal with complex components is used in a harsh environment, it is very difficult to accurately restore the measured signals. In the meantime, the deconvolution process of signal recovery is an inverse problem in mathematical physics, which has ubiquitously ill-posed problems, thereby bringing great challenges to the accuracy and precision of the solution. Thus, we propose a depth calibration network based LSTM, which can be used to learn the mapping relationship between the calibrated sensor signal and the standard signal. The measured signal can be restored through a data-driven sequence-to-sequence calibration network, which is trained and verified through the exclusive open-source data set of shock signals. The test results proved the superior performance of the network in shock signal calibration.
Study on Processing Method of Acoustic Emission Signal for Hydraulic Fracture Measurement
Authors: Fu Haifeng , Zheng Xinquan , Cai Bo , Liang Tiancheng , Qiu Jinping , Chen Feng , Liu Yunzhi , Rong Jiaojun
Published: May 2021

Hydraulic fracturing has become a key technology for the unconventional oil and gas development. Due to the complexity of geological conditions and the limitation of monitoring technology, it is still very difficult to accurately understand the three-dimensional distribution characteristics of hydraulic fractures. Based on the acoustic emission monitoring and three-dimensional laser scanning for large scale (762 mm * 762 mm * 914 mm) hydraulic fracturing test, hydraulic fracture morphology characterization is measured. The control method of acoustic emission signal quality based on amplitude, root-mean-square phase and multi-channel contrast signal recognition was explored. A multi-parameter constrained grid search and location method was established, which significantly improved the location accuracy and realized the dynamic and static real-time characterization of hydraulic fracture space expansion under indoor conditions. The results show that: based on laser scanning technology, the detailed characterization method of hydraulic fracture morphology is established, and the fracture morphology in laboratory experiment can be improved from two-dimensional observation to three-dimensional display. Due to mutual influence of natural fracture and in situ stress field, the hydraulic fracture appears complex geometry such as turning and bifurcation. The accuracy of acoustic emission location is improved by 10%, and the consistency with the actual fracture scale reaches 95%. The processing method of acoustic emission signal in this paper can be directly used in the optimization of field microseismic monitoring to guide the evaluation of unconventional reservoir stimulation, which shows a broad application prospect.
Realization of Accurate Modeling and Simulation of Oilfield Water Mixing Gathering and Transportation System
Authors: Wang Yan , Li Jie , Ruijie Zhang , Gao Sheng , Ren Yongliang
Published: May 2021

In order to solve the shortcomings that the simulation accuracy of oilfield water mixing gathering and transportation system is not high, the dual-process of mixing water and returning to the station cannot be realized at the same time, the system is accurately modeled, and the data structure and computer model suitable for calculation are established by reading static data. The design modeling software realizes the logical and data interface and realizes the display of the physical model on the computer. Based on the quasi-Newton loop iteration method, an online algorithm is proposed. Using the flow rate of each node of the system as the constraint condition, the water mixing process node and pipeline parameters are calculated. According to the calculation results and the oil well produced fluid parameters, the principle of mixed calorimetry is applied to construct the initial value and iterative formula of the return flow simulation. The temperature at the return station is consistent with the inlet temperature of the heating furnace at the joint station. It can dynamically reflect the production and operation status of the water mixing system, and provide a scientific basis for the control and operation of the water mixing system.
Research and Development of Drilling Operation Data Benchmarking Management System
Authors: He Jingbin , Chen Weilin , Chen Lin , Shi Chongdong
Published: May 2021

Benchmarking management, as a measure for the continuous improvement of scientific management of enterprises, provides advanced ideas for enterprises to analyze the problem of insufficient production capacity, and through data modeling can provide solutions for the improvement of deficiencies, which is conducive to the improvement of the overall management level and competitiveness of enterprises. Changqing Drilling Corporation has a large difference in the speed of drilling among the drilling crew, and has not formed an overall drilling speed-up plan. This paper uses an integrated data platform to establish a drilling operation benchmarking management system model, through the comparative analysis in different regions, different operation conditions of ROP and drilling cycle. Using machine learning to establish a benchmark optimization model for ROP and drilling cycle, in order to lay a foundation for drilling operations to improve operating efficiency and reduce operating costs.
Automatic Trend Tracking Model for Coalbed Methane Production Forecast
Authors: Qingzhong Zhu , Haiwei Du , Qiujia Hu , Bin Fan , Jigang Wang , Jiasheng Yu , Hongli Wang
Published: May 2021

Nowadays, huge quantities of coalbed methane (CMB) well production data have been saved in the fields’ database, which declares that the industry of CBM enters the age of Big Data. The traditional gas production data analysis methods, such as the decline curve and type curve, are not effective for complex production conditions. So, we proposed an automatic segmentation trend tracking Model for the CBM production forecast, which is based on the production data and is more robust for the complex production condition.
Calculation and Simulation of Eddy Current Magnetic Field of Ellipsoid in Changing Magnetic Field
Authors: Wen Haodong , Liu Shengdao , Ouyang Jianfeng
Published: May 2021

The eddy current magnetic field generated by the ellipsoid in the changing magnetic field is theoretically deduced and calculated and simulated. The theoretical calculation and the value obtained by the simulation are compared and verified and the error is analyzed. It can be seen from the fitting results that the theoretical calculation method used in this paper and the simulation result have reached a 93% degree of fit, indicating that this method has a certain reference value for the study of the spatial distribution of the eddy current magnetic field.
Material identification in nuclear waste drums using muon scattering tomography and multivariate analysis
Authors: Weekes M.J. , Alrheli A.F. , Barker D. , Kikoła D. , Kopp A.K. , Mhaidra M. , Stowell J.P. , Thompson L.F. , Velthuis J.J.
Published: May 2021

The use of muon scattering tomography for the non-invasive
characterisation of nuclear waste is well established. We report
here on the application of a combination of feature discriminators
and multivariate analysis techniques to locate and identify
materials in nuclear waste drums. After successful training and
optimisation of the algorithms they are then tested on a range of
material configurations to assess the system's performance and
limitations. The system is able to correctly identify uranium, iron
and lead objects on a few cm scale. The system's sensitivity
to small uranium objects is also established as
0.90+0.07
-0.12, with a false positive rate of
0.12+0.12
-0.07.
Flash drought in Australia and its relationship to evaporative demand
Authors: Parker Tess , Gallant Ailie , Hobbins Mike , Hoffmann David
Published: May 2021

Flash droughts can be distinguished by rapid intensification from near-normal soil moisture to drought conditions in a matter of weeks. Here, we provide the first characterisation of a climatology of flash drought across Australia using a suite of indices. The experiment is designed to capture a range of conditions related to drought: evaporative demand describes the atmospheric demand for moisture from the surface; precipitation, the supply of moisture from the atmosphere to the surface; and evaporative stress, the supply of moisture from the surface relative to the demand from the atmosphere. We show that regardless of the definition, flash droughts occur in all seasons. They can terminate as rapidly as they start, but in some cases can last many months, resulting in a seasonal-scale drought. We show that flash-drought variability and its prevalence can be related to phases of the El Niño–Southern Oscillation, highlighting scope for seasonal-scale prediction. Using a case study in southeast Australia, we show that monitoring precipitation is less useful for capturing the onset of flash drought as it occurs. Instead, indices like the Evaporative Demand Drought Index and Evaporative Stress Index are more useful for monitoring flash-drought development.
The 11 year solar cycle UV irradiance effect and its dependency on the Pacific Decadal Oscillation
Authors: Guttu Sigmund , Orsolini Yvan , Stordal Frode , Otterå Odd Helge , Omrani Nour-Eddine
Published: May 2021

The stratospheric, tropospheric and surface impacts from the 11 year ultraviolet solar spectral irradiance (SSI) variability have been extensively studied using climate models and observations. Here, we demonstrate using idealized model simulations that the Pacific Decadal Oscillation (PDO), which has been shown to impact the tropospheric and stratospheric circulation from sub-decadal to multi-decadal timescales, strongly modulates the solar-induced atmospheric response. To this end, we use a high-top version of the coupled ocean–atmosphere Norwegian Climate Prediction Model forced by the SSI dataset recommended for Coupled Model Intercomparison Project 6. We perform a 24-member ensemble experiment over the solar cycle 23 in an idealized framework. To assess the PDO modulation of the solar signal, we divide the model data into the two PDO phases, PDO+ and PDO−, for each solar (maximum or minimum) phase. By compositing and combining the four categories, we hence determine the component of the solar signal that is independent of the PDO and the modulation of the solar signal by the PDO, along with the solar signal in each PDO phase. Reciprocally, we determine the PDO effect in each solar phase. Our results show that the intensification of the polar vortex under solar maximum is much stronger in the PDO− phase. This signal is transferred into the troposphere, where we find a correspondingly stronger polar jet and weaker Aleutian Low. We further show that the amplification of the solar signal by the PDO− phase is driven by anomalous meridional advection of solar-induced temperature anomalies over northern North America and the North Pacific, which contributes to a decreased meridional eddy heat flux and hence to a decreased vertical planetary wave flux into the stratosphere.
Improving the snowpack monitoring in the mountainous areas of Sweden from space: a machine learning approach
Authors: Zhang Jie , Pohjola Veijo A , Pettersson Rickard , Norell Björn , Marchand Wolf-Dietrich , Clemenzi Ilaria , Gustafsson David
Published: May 2021

Under a warming climate, an improved understanding of the water stored in snowpacks is becoming increasingly important for hydropower planning, flood risk assessment and water resource management. Due to inaccessibility and a lack of ground measurement networks, accurate quantification of snow water storage in mountainous terrains still remains a major challenge. Remote sensing can provide dynamic observations with extensive spatial coverage, and has proved a useful means to characterize snow water equivalent (SWE) at a large scale. However, current SWE products show very low quality in the mountainous areas due to very coarse spatial resolution, complex terrain, large spatial heterogeneity and deep snow. With more high-quality satellite data becoming available from the development of satellite sensors and platforms, it provides more opportunities for better estimation of snow conditions. Meanwhile, machine learning provides an important technique for handling the big data offered from remote sensing. Using the Överuman Catchment in Northern Sweden as a case study, this paper explores the potentials of machine learning for improving the estimation of mountain snow water storage using satellite observations, topographic factors, land cover information and ground SWE measurements from the spatially distributed snow survey. The results show that significantly improved SWE estimation close to the peak of snow accumulation can be achieved in the catchment using the random forest regression. This study demonstrates the potentials of machine learning for better understanding the snow water storage in mountainous areas.
Linear stability analysis of double rows of point vortices for an inviscid generalized two-dimensional fluid system
Authors: Iwayama Takahiro , Watanabe Takeshi
Published: May 2021

The linear stability of double rows of equidistant point vortices for an inviscid generalized two-dimensional (2D) fluid system is studied. This system is characterized by the relation q = −(Δ)
α/2
ψ between the active scalar q and the stream function ψ. Here, α is a positive real number not exceeding 3, and q is referred to as the generalized vorticity. The stability of double rows of equidistant point vortices for a 2D Euler system (α = 2) is a well-known classical problem and was originally investigated by Kármán approximately 100 years ago. Two types of vortex rows, i.e., symmetrical and staggered arrangements of vortex rows, are considered in this study. Special attention is paid to the effect of the parameter α on the stability of vortex rows. As is well-known, the symmetrical vortex rows for the Euler system are unstable, whereas the staggered vortex rows are neutrally stable only when the transverse-to-longitudinal spacing ratio k is

k
=

π

−
1

cosh

−
1

2

. Irrespective of α, the symmetrical vortex rows for the generalized 2D fluid system are unstable, whereas the staggered vortex rows are neutrally stable. The stable spacing ratio of the staggered vortex rows is a decreasing function of α for 0.63 ≲ α and approaches zero as α → 3. In contrast, a finite stable region of the spacing ratio is found when α ≲ 0.63. It turns out that the deformation and usual vorticity induced by the point vortices and their coupling play important roles on the stability of the staggered vortex rows.
Retraction: Assessment of Ecological Risk of Soil in Rapid Urbanization Area by Risk Regionalization (IOP Conf. Ser.: Earth Environ. Sci.
687 012169)
Authors: Zhao Run , Li Ning
Published: May 2021

This article has been retracted at the request of the authors, who admit a similar paper has already been published based on the same project [1] . IOP Publishing confirms significant overlap between the two articles and agrees to retract on the basis of redundant publication. IOP Publishing expresses additional concern regarding the authorship of the article, which differs between the two articles. The authors state that all authors of the two papers are members of the same research group, and research achievements are the joint property of the group. This conflicts with the IOP Publishing ethical policy, which states all those who have made a significant contribution are cited as co-authors. Any other individuals who have contributed to the study in a lesser capacity should be acknowledged.

[1] Xiaoying Ye and Chaofeng Shao 2018, Ecological Risk Assessment of Soil in Rapid Urbanization Area by Risk Regionalization, International Conference on Advanced Chemical Engineering and Environmental Sustainability (ICACEES 2018) http://www.dpi-proceedings.com/index.php/dtetr/article/view/25496/24910

Retraction published: 06 May 2021
The Analysis Research on the Scheme of Moving Functions in the NC Lathe Turning the Free Surface
Authors: Xu Qiang , jian Hai , Wan Jun , Baker Vernon
Published: May 2021

In order to solve the design problem of the scheme of moving functions in the NC lathe turning the free surface, the work piece is cut into n equal parts along the height h, set up the continuous and smooth Centre line of the n equal parts, each equal part is compared of a generatrix and a guide line. Using the generative design principle, the mathematical describing matrixes of the generating line and the cutting point of turning tool are first established. Thus, determine the positional and gesture matrixes of the turning tool. Since the positional and gesture matrixes are achieved through the cascade matrixes, the possible motion schemes of the tandem machine tools for turning free-form surface is decided, a solid foundation is laid for optimizing the design of the CNC lathes and compound machine tools.
Development and testing of a hydraulic-driven cutting saw system applied for 7,000m JIAOLONG Human Occupied Vehicle
Authors: Shi Xianpeng , Ren Chong , Liu Baohua
Published: May 2021

In this paper, a hydraulic-driven cutting saw system applied for 7,000m JIAOLONG Human Occupied Vehicle was researched and designed according to real applications including underwater cutting engineering, underwater salvage, marine scientific research and others. Firstly, based on the spatial arrangement of JIAOLONG manned submersible’s sampling basket and the actual operation requirement of JIAOLONG’s manipulator, the preliminary design for the cutting saw system is carried out using Solidworks software. Then, the detailed design of the system was conducted in accordance with the selected motor, and the the torque provided by the motor, the tangential force of the saw disk, the linear velocity of the saw disk, and the flow and power for this motor can be calculated successively. Based on the design and calculation, this system was assembled and the pressure-resistant test for this system was smoothly conducted in a pressure testing tank. Finally, the cutting experiment was carried out successfully, which had verified the feasibility of the system design.