Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network

As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.

Local events-based fast RTM surface-offset gathers via dip-guided interpolation

Reverse Time Migration(RTM)Surface Ofset Gathers(SOGs)are demonstrated to deliver more superior residual dip information than ray-based approaches.It appears more powerful in complex geological settings,such as salt areas.Still,the computational cost of constructing RTM SOGs is a big challenge in applying it to 3D feld data.To tackle this challenge,we propose a novel method using dips of local events as a guide for RTM gather interpolation.The residual-dip information of the SOGs is created by connecting local events from depth-domain to time-domain via ray tracing.The proposed method is validated by a synthetic experiment and a feld example.It mitigates the computational cost by an order of magnitude while producing comparable results as fully computed RTM SOGs.

An optimization method for shale gas gathering system-Consideration of reliability enhancement under earthquake-related uncertainties

Shale gas gathering systems are of great importance in gas fields for the efficient and reliable transportation of gas.In traditional design methods,pipeline layouts are optimized only from an economic point of view,where reliability is evaluated after optimization.However,reliability can be enhanced by spare pipelines so that both economic and reliable aspects are evaluated simultaneously.Based on the idea of enhancing reliability,this research proposes a methodology for optimizing the pipeline layout problem including well clustering,stations site selecting,and piping.Different topology arrangements and spare pipelines are investigated to enhance the production efficiency and reliability of the pipeline network under earthquake-related uncertainties.Reliability evaluation is converted into an economic one so that the objective of this work is to minimize the total annual cost.To solve such a complex problem,genetic algorithm,K-means algorithm,Geo Steiner algorithm,Kruskal algorithm,linear programming and Monte Carlo simulations are combined.A real-world case study illustrates the effectiveness of the proposed methodology and shows a 36.53%reduction in the total annual cost compared with the initial scheme.

Extraction of amplitude-preserving angle gathers based on vector wavefield reverse-time migration

Angle-domain common-image gathers （ADCIGs） transformed from the shot- domain common-offset gathers are input to migration velocity analysis （MVA） and prestack inversion. ADCIGs are non-illusion prestack inversion gathers, and thus, accurate. We studied the extraction of elastic-wave ADCIGs based on amplitude-preserving elastic-wave reverse- time migration for calculating the incidence angle of P- and S-waves at each image point and for different source locations. The P- and S-waves share the same incident angle, namely the incident angle of the source P-waves. The angle of incidence of the source P-wavefield was the difference between the source P-wave propagation angle and the reflector dips. The propagation angle of the source P-waves was obtained from the polarization vector of the decomposed P-waves. The reflectors＇ normal direction angle was obtained using the complex wavenumber of the stacked reverse-time migration （RTM） images. The ADCIGs of P- and S-waves were obtained by rearranging the common-shot migration gathers based on the incident angle. We used a horizontally layered model, the graben medium model, and part of the Marmousi-II elastic model and field data to test the proposed algorithm. The results suggested that the proposed method can efficiently extract the P- and S-wave ADCIGs of the elastic-wave reverse-time migration, the P- and S-wave incident angle, and the angle-gather amplitude fidelity, and improve the MVA and prestack inversion.

Method for extracting angle-domain common image gathers in Kirchhoff beam migration

Kirchhoff beam migration is a simplified Gaussian beam migration,which omits the dynamic information and can calculate multi-arrival traveltime,so it is a high-precision and fast seismic imaging method.In the imaging process,extracting common image gathers can be used for velocity analysis,improving the accuracy of modeling and imaging quality.Compared with the conventional common image gathers extracting methods,the angle-domain common image gathers extracting method can avoid the artifacts caused by multi-arrival seismic waves.The authors present a new method of extracting common image gathers in angle-domain from Kirchhoff beam migration and verify the method by numerical calculations.

Extracting angle-domain common-image gathers in VTI media using ansiotropic-Helmholtz P/S wave-mode decomposition

Common-image gathers are extensively used in amplitude versus angle(AVA)and migration velocity analysis(MVA).The current state of methods for anisotropic angle gathers extraction use slant-stack,local Fourier transform or low-rank approximation,which requires much computation.Based on an anisotropic-Helmholtz P/S wave-mode decomposition method,we propose a novel and efficient approach to produce angle-domain common-image gathers(ADCIGs)in the elastic reverse time migration(ERTM)of VTI media.To start with,we derive an anisotropic-Helmholtz decomposition operator from the Christoffel equation in VTI media,and use this operator to derive the decomposed formulations for anisotropic P/S waves.Second,we employ the first-order Taylor expansion to calculate the normalized term of decomposed formulations and obtain the anisotropic-Helmholtz decomposition method,which generates the separated P/S wavefields with correct amplitudes and phases.Third,we develop a novel way that uses the anisotropic-Helmholtz decomposition operator to define the polari-zation angles for anisotropic P/S waves and substitute these angles to decomposing formulations.The polarization angles are then calculated directly from the separated vector P-and S-wavefields and converted to the phase angles.The ADCIGs are thusly produced by applying the phase angles to VTI ERTM.In addition,we develop a concise approximate expression of residual moveout(RMO)for PP-reflections of flat reflectors in VTI media,which avoids the complex transformations between the group angles and the phase angles.The approximate RMO curves show a good agreement with the exact solution and can be used as a tool to assess the migration velocity errors.As demonstrated by two selected examples,our ADCIGs not only produce the correct kinematic responses with regards to different velocity pertubatation,but also generate the reliable amplitude responses versus different angle.The final stacking images of ADCIGs data exhibit the identical imaging effect as that of VTI ERTM.

A computational method for wide-azimuth 3D dip-angle gathers using Gaussian beam migration

The dip-angle-domain common-image gather(DDCIG)is a key tool to separate the diffraction and reflection imaging results.Reflectors with different spatial geometries produce different responses in DDCIGs.Compared with Kirchhoff migration,Gaussian beam migration(GBM)is more effective and robust to overcome the multipathing problem.As a ray-based method,it has explicit angle information naturally during the propagation.We have developed a 3D DDCIG computational method using GBM,which obtain both the imaging result and angle-domain gathers with only one pass of calculation.The angle-gather computation is based on geometrical optics,and multiple angle conversions are implemented under the rules of space geometry,which helps to avoid rounding errors and improve accuracy.Additionally,the multi-azimuth joint presentation strategy is proposed to describe the characteristic of omnidirectional dip angles using a finite number of gathers.After using a 2D model to illustrate application advantages of DDCIG,we apply the proposed method to two 3D models to test its feasibility and accuracy.A field data example further demonstrates the adaptability of our method to seismic imaging for a land survey.

Prestack gathers feature enhancement method based on BEMD and CTKEO

The hydrocarbon detection method based on pre-stack gather data has higher accuracy and reliability than those methods based on post-stack data.This kind of method requires that pre-stack gather data have high SNR(Signal Noise Ratio)and obvious AVO(amplitude variation with offset)characteristics.Therefore,it is important to optimize the pre-stack gathers and enhance their AVO(Amplitude variation with offset)effect.This abstract proposes a gather optimization and AVO feature enhanced method for hydrocarbon detection.The gather optimization method based on the improved BEMD(bidimensional empirical mode decomposition).It starts from the original signal directly,and can be optimized as pre-stack gather steadily and quickly.Then,the characters of CTKEO(Corss Teager-Kaiser energy)algorithm which is strong sensitivity to interaction of two signals is fully utilized to enhance AVO features.The method proposed in this abstract provides a good data base for pre-stack inversion from gather optimization to AVO feature enhancement.

基于多模态双协同Gather Transformer网络的虚假信息检测方法

社交媒体网站是人们在日常生活中分享信息、表达和交换意见的便捷平台。随着用户数量的不断增加,社交媒体网站上出现了大量的信息数据。然而,由于用户没有检查共享信息的可靠性,这些信息的真实性难以保证,从而导致大量虚假信息在社交媒体上广泛传播。然而,现有方法大多存在以下局限性:1)大多数方法通过简单提取文本与视觉特征,将其拼接后得到多模态特征来进行虚假信息判断,忽略了模态间和模态内细粒度内在联系,缺乏对关键信息的检索和筛选;2)多模态信息间缺乏指导性的特征提取,文本和视觉等特征之间缺乏交互增强,对多模态信息的理解不足。为了应对这些挑战,提出了一种新颖的基于多模态双协同Gather Transformer网络(Multimodal Dual-Collaborative Gather Transformer Network,MDCGTN)的虚假信息检测方法。在MDCGTN模型中,通过文本-视觉编码网络对文本和视觉信息的特征表示进行提取,将获得的视觉和文本特征表示输入多模态Gather Transformer网络进行多模态信息融合,使用Gather机制提取关键信息,充分捕捉和融合模态内和模态间细粒度关系。此外,设计了一个双协同机制对社交媒体帖子的多模态信息进行整合,以实现模态之间信息的交互和增强。在两个公开可用的基准数据集上进行了大量实验,结果表明,与现有的先进基准方法相比,所提方法准确率明显提升,证明了其对于虚假信息检测的优越性能。

The 10th China Obesity Science Conference Held in Beijing

The 10th China Obesity Science Conference was held in Beijing from May 10th to 11th, 2024. Experts from authoritative institutions such as the National Health Commission, the Chinese Center for Disease Control and Prevention, and the China Institute of Sports Science gathered to discuss on the topics including obesity prevalence trends.

Leveraging Quantum Computing for the Ising Model to Simulate Two Real Systems: Magnetic Materials and Biological Neural Networks (BNNs)

Quantum computing is a field with increasing relevance as quantum hardware improves and more applications of quantum computing are discovered. In this paper, we demonstrate the feasibility of modeling Ising Model Hamiltonians on the IBM quantum computer. We developed quantum circuits to simulate these systems more efficiently for both closed and open boundary Ising models, with and without perturbations. We tested these various geometries of systems in both 1-D and 2-D space to mimic two real systems: magnetic materials and biological neural networks (BNNs). Our quantum model is more efficient than classical computers, which can struggle to simulate large, complex systems of particles.

Countermeasures to reduce the risk of infections at the 2024 Olympic and Paralympic Games—A balancing act

The Olympic and Paralympic Games are a global celebration of athletic dedication and achievement,bringing together athletes and spectators from around the world.However,such large gatherings present public health challenges for the Organizing Committees and local governments.As highlighted by the coronavirus disease 2019(COVID-19)pandemic,these events are associated with an increased risk of transmission of infections,which can significantly impact the health and well-being of athletes and attendees.Prioritizing the health and safety of athletes,officials and spectators is fundamental to ensure the successful hosting of the Games.Therefore,it is essential to design and implement comprehensive countermeasures to mitigate the risk of an infectious disease outbreak among participants but also to the residents of the host city.

Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field

During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.

Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline

During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.

Advancing the Modernization Drive of the Global South and Working Together to Build a Community with a Shared Future for Mankind

The 13th Meeting of the China-Africa Think Tanks Forum took place in Dar es Salaam,Tanzania,on March 8,2024.Under the theme of“China-African Practice:Building a Community with a Shared Future”,the forum delved into the major concerns and strategic cooperation between China and Africa in the new era.It aimed to advance the implementation of various initiatives and accomplishments in China-Africa cooperation while also gathering insights for the upcoming session of the Forum on China-Africa Cooperation(FOCAC).

The Miracle of Hefei:From Small to Smart

The tale of an inconspicuous inland city gathering a thriving cluster of dynamic tech-intensive industries.MODERNIZING the industrial system and developing new quality productive forces at a faster pace-this is one of China’s major tasks for 2024 as laid down in the Report on the Work of the Government.

Quantum circuit-based proxy blind signatures:A novel approach and experimental evaluation on the IBM quantum cloud platform

This paper presents a novel approach to proxy blind signatures in the realm of quantum circuits,aiming to enhance security while safeguarding sensitive information.The main objective of this research is to introduce a quantum proxy blind signature(QPBS)protocol that utilizes quantum logical gates and quantum measurement techniques.The QPBS protocol is constructed by the initial phase,proximal blinding message phase,remote authorization and signature phase,remote validation,and de-blinding phase.This innovative design ensures a secure mechanism for signing documents without revealing the content to the proxy signer,providing practical security authentication in a quantum environment under the assumption that the CNOT gates are securely implemented.Unlike existing approaches,our proposed QPBS protocol eliminates the need for quantum entanglement preparation,thus simplifying the implementation process.To assess the effectiveness and robustness of the QPBS protocol,we conduct comprehensive simulation studies in both ideal and noisy quantum environments on the IBM quantum cloud platform.The results demonstrate the superior performance of the QPBS algorithm,highlighting its resilience against repudiation and forgeability,which are key security concerns in the realm of proxy blind signatures.Furthermore,we have established authentic security thresholds(82.102%)in the presence of real noise,thereby emphasizing the practicality of our proposed solution.

A Democracy That Works Western democracies have failed to address people’s livelihood concerns while the Chinese practice has made notable achievements

More than 200 scholars,researchers,former government o!cials and party leaders from over 50 countries gathered in the sprawling building of the Chinese Academy of History in Beijing on 20 March for the third International Forum on Democracy:The Shared Human Values.The forum debated the concept of democracy,its trajectories and prospects,and,more importantly,how it can be made to work and deliver tangible results for di"erent countries.

Global exhibitors from across textile spectrum gather at upcoming Intertextile Apparel

Shanghai,2 August 2024.Including everything from organic buttons and floral prints,to temperature-regulating and weather-resistant fibres,the apparel value chain is as diverse as it is extensive.Buyers at trade fairs with thousands of exhibitors can be hard pressed finding the fabrics they need,which is a key reason numerous suppliers at autumn's lntertextile Apparel will gather under the banners of specialised zones and pavilions.Taking place from 27-29 August at the National Exhibition and Convention Center (Shanghai),the fair will featu re eight product zones,including Accessories Vision,Functional Lab,and Verve for Design.Meanwhile,suppliers in eight country and region pavilions will showcase various innovations and high-quality textiles.Altogether the platform is set to welcome around 4,000 exhibitors from 25countries and regions.