Geological characteristics and main controlling factors of Permian lacustrine tight oil in the eastern part of the Junggar Basin

Junwei Zhao,Huaimin Xu,Cui He,Lin Li,Zhen Yi,Huijing Fang,Zhicheng Lei 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.2

The Junggar basin is rich in oil and gas resources, and recently, unconventional oil and gas reservoirs have become important targets. Significant amounts of oil and gas are located in Permian formations in the Shazhang–Dajing area, however, fewer studies have focused on unconventional oil and gas reservoirs, particularly on the factors controlling the distribution of unconventional reservoirs. In this study, a sequence stratigraphic framework of the study area was developed based on cores, well logs and seismic data. Source rock samples were analyzed, including tests of kerogen, vitrinite reflectance, chloroform bitumen, organic carbon and group composition. The physical properties and pore characteristics of reservoir samples were also analyzed using scanning electron microscope and high resolution electron microscope. The Permian Pingdiquan Formation comprises three thirdorder sequences in which individual sequence can be divided into a low-stand system tract (LST), a transgression system tract (TST), an early high-stand system tract (E-HST), and a late high-stand system tract (L-HST). Several source rock lithologies have high total organic carbon (TOC), and are matured, having excellent hydrocarbon generation potential. Clastic and dolomitic rocks are the main reservoirs, and nanometer-scale pores are the main reservoir space in the tight reservoirs. The distribution of tight oil is controlled by the sequence stratigraphy, palaeogeomorphic units, and sedimentary facies. The fine sediments, which were generally deposited near the initial flooding surface (FFS) and the maximum flooding surface (MFS), are favorable zones for tight oil. The distributions of the hydrocarbon source rocks are controlled by the depositional environment, depending on the palaeogeomorphic units; the deep depression in the Huoshaoshan area and the moderately-deep depression in the Shishugou area are two distinct hydrocarbon generating centers. The distribution of tight oil is clearly controlled by the sedimentary facies; the tight oil is mainly located in the fan delta front and lacustrine depositional environments. The distribution of tight oil in this area is summarized, and favorable areas of tight oil are proposed.

Preparation of an Early Strengthening Agent for Concrete under Low-Temperature Conditions and Evaluation of Its Reaction Mechanism

Bao, Junwei,Ren, Qifang,Sun, Lei,Ding, Yi,Oh, Won-Chun Materials Research Society of Korea 2021 한국재료학회지 Vol.31 No.4

To solve the common problems of concrete preparation in low-temperature environments, calcium formate (C₂H₂O₄Ca), anhydrous sodium sulfate (Na₂SO₄), triethanolamine (C₆H₁₅O₃N), calcium bromide (CaBr₂), and triisopropanolamine (C₉H₂₁NO₃) are selected as early strength agents and mixed with C40 concrete in different dosages under low-temperature environments of 5 ℃ and 10 ℃ to develop a high-efficiency low-temperature compound early strength agent based on the effect of single-doped early strength agents. The effects of the compound early strength agent on the early strength of the concrete, the cement paste setting time, and cement fluidity at 5 ℃ and 10 ℃ are investigated, and the corresponding reaction mechanism is discussed from the perspective of micro-products. The best compound early strength agent ratio is found to be 2 % of calcium formate + 0.08 % of TEA (C₆H₁₅O₃N). The compound early strength agent effectively promotes the formation of hydration products, such as Ca(OH)₂ and C-S-H gel. In comparison with the control group, the strength of the concrete cured for 18 h, 1 d, 3 d, and 7 d under simulated natural conditions at 5 ℃ increases by 700 %, 540 %, 11.4 % and 10 %, respectively, whereas at 10 ℃, the corresponding values are 991 %, 400 %, 19.6 % and 11 %, respectively. The strength of the concrete at each age is close to the normal temperature standard of the curing strength. The addition of the compound early strength agent causes a reduction in cement fluidity and initial and final setting times, and also yields a good effect on the porosity of the early concrete.

Application and Research of Monte Carlo Sampling Algorithm in Music Generation

Jun MIN,Lei WANG,Junwei PANG,Huihui HAN,Dongyang Li,Maoqing ZHANG,Yantai HUANG 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.10

Composing music is an inspired yet challenging task, in that the process involves many considerations such as assigning pitches, determining rhythm, and arranging accompaniment. Algorithmic composition aims to develop algorithms for music composition. Recently, algorithmic composition using artificial intelligence technologies received considerable attention. In particular, computational intelligence is widely used and achieves promising results in the creation of music. This paper attempts to provide a survey on the music generation based on the Monte Carlo (MC) algorithm. First, transform the MIDI music format files to digital data. Among these data, use the logistic fitting method to fit the time series, obtain the time distribution regular pattern. Except for time series, the converted data also includes duration, pitch, and velocity. Second, using MC simulation to deal with them summed up their distribution law respectively. The two main control parameters are the value of discrete sampling and standard deviation. Processing the above parameters and converting the data to MIDI file, then compared with the output generated by LSTM neural network, evaluate the music comprehensively.

Weather Forecasting Using Ensemble of Spatial-Temporal Attention Network and Multi-Layer Perceptron

Yuanpeng Li,Junwei Lang,Lei Ji,Jiqin Zhong,Zaiwen Wang,Yang Guo,Sailing He 한국기상학회 2021 Asia-Pacific Journal of Atmospheric Sciences Vol.57 No.3

Weather forecasting is a challenging task, which is especially suited for artificial intelligence due to the large amount of data involved. This paper proposed an end-to-end hybrid regression model, called Ensemble of Spatial-Temporal Attention Network and Multi-Layer Perceptron (E-STAN-MLP), to forecast surface temperature, humidity, wind speed, and wind direction at 24 automatic weather stations in Beijing. Combining the data from historical observations with the data from the numerical weather prediction (NWP) system, our proposed model give better results than the NWP system or previously reported algorithms. Our E-STAN-MLP model consists of two parts. One is to use the spatial-temporal attention based recurrent neural network to model the time series of meteorological elements. The other is a simple but efficient multilayer perceptron architecture forecasts the regression value while ignoring time dependence. Results at each time stamp are integrated together using a step-wise fusion strategy. Moreover, we use a joint loss step integrating both the regression loss function and the classification loss function to simultaneously forecast the wind speed and direction. Experiments demonstrate that our proposed E-STAN-MLP model achieves state-of-the-art results in weather forecasting.

Research on Adaptive Sliding Mode Control of Simplified Supersonic Missile System with Three Kinds of Uncertain Parameters

Jinyong Yu,Junwei Lei,Di Liu,Zexue Li 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.11

A new kind of adaptive sliding mode control method is proposed for simplified missile model of pitch channel with time varying and uncertain parameters. Sliding mode control is an effective method for coping with system uncertainties. Adaptive method is integrated with sliding mode method and a Lyapunov function is constructed to guarantee the whole system is stable. Through the theoretical analysis and numericala simulation, comparison between PID control and sliding mode control shows that the adaptive sliding mode control of the uncertain missile system has a better control effect. And with consideration of three kind of parameter uncertainties in simulation, sliding mode control has better robustness.

Research on Two Kinds of Adaptive Synchronization Method for Uncertain Fourth Order Chaotic Systems based on Sigmoid Function and Soft Function Method

Zhanlei Shang,Jing Cheng,Junwei Lei,Ruiqi Wang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.6

Synchronization of chaotic systems can be used in the secure communication so it greatly attracted interests of many researchers. The bounded characteristics of chaotic system was used and an uniformed adaptive law was designed to solve system uncertainties which make the whole design very simple. And two kinds of functions was used to take place of traditional sign function, then the chattering problem was greatly improved. A Lyapunov function was chosen to guarantee the stability of the whole design. At last, detailed simulation was done to show the rightness and effectiveness of the proposed method.

Research on Three Kinds of Lane Keeping Method based on Anti-saturation and Adaptive Method

Jie Yang,Junbo Zhao,Junwei Lei 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12

The lane keeping problem of automatic driving for vehicles was studied based on the simplified linear lateral dynamic model. Three kinds of sliding mode methods were proposed by adopting integral sliding mode, anti-saturation and adaptive method. The stability of each method was proved by constructing Lyapunov method. What is worthy pointing out is that the anti-saturation method can not only reduce the oscillations by using soft function and sigmoid function, but also it can solve the saturation problem of front wheels by using the bounded characteristics of above two functions. And this method is also very simple and it has a reasonable physical meaning which makes the chosen of control parameter very easy. At last, detailed numerical simulations were done for proposed three methods and simulation results were compared with other three methods in the past references to testify the rightness of the proposed method.

Adaptive Prescribed Performance Output Regulation of Nonlinear Systems with Nonlinear Exosystems

Fujin Jia,Cui Lei,Junwei Lu,Yuming Chu 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.8

The paper studies the prescribed performance output regulation problem for a class of nonlinear uncertain strict-feedback systems which are driven by nonlinear exosystems. Fuzzy logic systems (FLSs) are used to approximate the unknown functions. A fuzzy adaptive observer is designed to estimate the system state. A fuzzy internal model is designed to reject disturbance. Simultaneously, a parameter-type Lyapunov function and L function are designed to ensure the prescribed performance of the system. As illustrated by example, the proposed prescribed performance fuzzy adaptive output feedback control scheme is shown to guarantee semi-globally uniformly ultimately bounded, and the dynamic performance and steady-state performance of the tracking error are dependent on the prescribed performance functions.

Robust Adaptive and Sliding Mode Synchronization of Uncertain Chaotic Systems

Cheng Gan,Zhaorui Ma,Junwei Lei,Ruiqi Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.1

Parameter uncertainty of chaotic systems brings the complexity to the design of control law in many past research papers. In order to simplify the design of adaptive PID composite synchronous rule further and use the robust control method to deal with uncertainty conveniently, two kind of robust adaptive and nonlinear sliding mode synchronization algorithms are proposed for uncertain chaotic systems in this paper. The design strategy of the algorithm lies in using the boundedness of chaotic systems. The unknown information of driven system and response system is limited to be a given uncertainty range described by a bounded function. The robust adaptive controller is designed to complete synchronization. At last, it can be seen from the simulation that chaotic systems can achieve synchronization and eliminate the vibration phenomenon at the same time. The only disadvantage is that the precision of synchronization is limited by the control gain.

Adaptive Synchronization of Chaotic Systems with known Response System Parameters

Cheng Gan,Yuan Cheng,Ruiqi Wang,Junwei Lei 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.5

A kind of adaptive synchronous control method was proposed to solve a special synchronization problem between two chaotic systems, where the response system is totally known without uncertainty but the driven system contains both unknown parameters and uncertain nonlinear functions. An update law of estimation of unknown parameters of driven system by constructing a proper Lyapunov energy function and the stability of the whole system was guaranteed by Lyapunov stability theorem. What is worthy pointing out is that the chaotic systems are not required to satisfy the Lipscitz condition. At last, detailed numerical situation was done to show the rightness and effectiveness of the proposed method.