scholarly journals Hydraulic Fracture Extending into Network in Shale: Reviewing Influence Factors and Their Mechanism

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Lan Ren ◽  
Jinzhou Zhao ◽  
Yongquan Hu
Keyword(s):  
Hydraulic Fracture ◽  
Influence Factors ◽  
Horizontal Stress ◽  
Practical Significance ◽  
Propagation Mechanism ◽  
Fluid Viscosity ◽  
Essential Difference ◽  
Research Results ◽  
Network Propagation ◽  
Shale Reservoir

Hydraulic fracture in shale reservoir presents complex network propagation, which has essential difference with traditional plane biwing fracture at forming mechanism. Based on the research results of experiments, field fracturing practice, theory analysis, and numerical simulation, the influence factors and their mechanism of hydraulic fracture extending into network in shale have been systematically analyzed and discussed. Research results show that the fracture propagation in shale reservoir is influenced by the geological and the engineering factors, which includes rock mineral composition, rock mechanical properties, horizontal stress field, natural fractures, treating net pressure, fracturing fluid viscosity, and fracturing scale. This study has important theoretical value and practical significance to understand fracture network propagation mechanism in shale reservoir and contributes to improving the science and efficiency of shale reservoir fracturing design.

scholarly journals Clusters as an innovative organizational and economic form of efficient agricultural production in the system of sustainable development

Ekonomika APK ◽  
2020 ◽  
Vol 311 (9) ◽  
pp. 86-94
Author(s):  
Yurii Kernasiuk
Keyword(s):  
Sustainable Development ◽  
Agricultural Production ◽  
Cluster Model ◽  
Agricultural Development ◽  
Agricultural Sector ◽  
Scientific Basis ◽  
Practical Significance ◽  
Development Economic ◽  
Industrial Complex ◽  
Research Results

The purpose of the article is to highlight the conceptual understanding of the cluster as an innovative organizational and economic form of production in the system of sustainable development on the example of the agricultural sector and substantiate the scientific basis for ensuring its implementation at the regional level. Research methods. When carrying out the research, a set of general scientific methods and techniques was used; monographic - in the study of domestic and foreign publications and the above-mentioned problems; a systematic approach based on the principles of systems analysis and synthesis - to substantiate the relationship between sustainable development, the efficiency of agricultural production and the cluster model; abstract-logical - for the theoretical generalization of research results and determination of measures to ensure the implementation of the cluster model of agricultural development; economic analysis - to study the efficiency of agricultural production. Research results. The essence of the cluster in modern economic theory in the context of the concept of sustainable development has been studied and analyzed. Globalization, climate change and the aggravation of socio-economic and environmental problems in many countries of the world necessitate the search for new models of economic development. It has been established that one of the most optimal organizational and economic forms of effective agricultural production in the system of sustainable development is clusters. On the example of the Kirovograd region, a scientifically grounded regional model of the development of agro-clusters in the agro-industrial complex. Scientific novelty. Based on the synthesis of scientific theories of cluster and sustainable development, further study of theoretical and methodological approaches to the definition of the essence of clusters as a promising organizational and economic form of effective agricultural production in the system of sustainable development was obtained. Practical significance. The research results will find practical use in substantiating regional strategies for the development of agro-industrial production. They can be used in educational and educational programs, when providing consulting services for the creation of projects of agricultural clusters and in further scientific research.

scholarly journals Blockchain Network Propagation Mechanism Based on P4P Architecture

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Junjie Huang ◽  
Liang Tan ◽  
Sun Mao ◽  
Keping Yu
Keyword(s):  
Propagation Speed ◽  
Propagation Delay ◽  
Propagation Path ◽  
Propagation Mechanism ◽  
Internet Service ◽  
Network Provider ◽  
Network Propagation ◽  
System Overhead ◽  
Message Propagation

Blockchain is a mainstream technology in which many untrustworthy nodes work together to maintain a distributed ledger with advantages such as decentralization, traceability, and tamper-proof. The network layer communication mechanism in its architecture is the core of the networking method, message propagation, and data verification among blockchain nodes, which is the basis to ensure blockchain’s performance and key features. When blocks are propagated in peer-to-peer (P2P) networks with gossip protocol, the high propagation delay of the protocol itself reduces the propagation speed of the blocks, which is prone to the chain forking phenomenon and causes double payment attacks. To accelerate the propagation speed and reduce the fork probability, this paper proposes a blockchain network propagation mechanism based on proactive network provider participation for P2P (P4P) architecture. This mechanism first obtains the information of network topology and link status in a region based on the internet service provider (ISP), then it calculates the shortest path and link overhead of peer nodes using P4P technology, prioritizes the nodes with good local bandwidth conditions for transmission, realizes the optimization of node connections, improves the quality of service (QoS) and quality of experience (QoE) of blockchain networks, and enables blockchain nodes to exchange blocks and transactions through the secure propagation path. Simulation experiments show that the proposed propagation mechanism outperforms the original propagation mechanism of the blockchain network in terms of system overhead, rate of data success transmission, routing hops, and propagation delay.

Information Dissemination Mechanism Based on Cloud Computing Cross-Media Public Opinion Network Environment

2021 ◽  
Vol 14 (2) ◽  
pp. 70-83
Author(s):  
Ping Liu
Keyword(s):  
Cloud Computing ◽  
Public Opinion ◽  
Computer Technology ◽  
Information Dissemination ◽  
Transmission Mechanism ◽  
Practical Significance ◽  
Propagation Mechanism ◽  
Cross Media ◽  
User Density ◽  
Network Public Opinion

As an important expression of social public opinion, network public opinion develops rapidly with the popularization of the internet and then affects the real society. Therefore, the use of computer technology to study the network public opinion information transmission mechanism has strong practical significance. The purpose of this paper is to use cloud computing to realize the research of information dissemination mechanism in the context of cross-media public opinion network. Researched from three aspects of operator supervision, number of media, and user density, the hotspot propagation mechanism of Storm platform given in this paper can solve the efficiency problems of traditional algorithms while ensuring accuracy, improve efficiency, and lay the foundation for the research on the monitoring of Internet public opinion propagation.

scholarly journals Modeling and Analysis of Rumor Spreading with Social Reinforcement Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yuan Xu ◽  
Renjie Mei ◽  
Yujie Yang ◽  
Zhengmin Kong
Keyword(s):  
Social Networks ◽  
Online Social Networks ◽  
Diffusion Mechanism ◽  
Practical Significance ◽  
Propagation Mechanism ◽  
Spreading Process ◽  
Rumor Spreading ◽  
Modeling And Analysis ◽  
Reinforcement Mechanism ◽  
Theoretical Results

It is of great practical significance to figure out the propagation mechanism and outbreak condition of rumor spreading on online social networks. In our paper, we propose a multi-state reinforcement diffusion model for rumor spreading, in which the reinforcement mechanism is introduced to depict individual willingness towards rumor spreading. Multiple intermediate states are introduced to characterize the process that an individual's diffusion willingness is enhanced step by step. We study the rumor spreading process with the proposed reinforcement diffusion mechanism on two typical networks. The outbreak thresholds of rumor spreading on both two networks are obtained. Numerical simulations and Monte Carlo simulations are conducted to illustrate the spreading process and verify the correctness of theoretical results. We believe that our work will shed some light on understanding how human sociality affects the rumor spreading on online social networks.

A homogenization approach for modeling a propagating hydraulic fracture in a layered material

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. MR153-MR162 ◽  
Author(s):  
Egor V. Dontsov
Keyword(s):  
Elastic Properties ◽  
Hydraulic Fracture ◽  
Local Stress ◽  
Transversely Isotropic ◽  
Horizontal Stress ◽  
Layered Material ◽  
Elastic Response ◽  
Effective Parameters ◽  
Fine Mesh ◽  
Minimum Horizontal Stress

Shales are known to have a finely layered structure, which greatly influences the overall material’s response. Incorporating the effect of all these layers explicitly in a hydraulic fracture simulator would require a prohibitively fine mesh. To avoid such a scenario, a suitable homogenization, which would represent the effect of multiple layers in an average sense, should be performed. We consider a sample variation of elastic properties and minimum horizontal stress versus depth that has more than a hundred layers. We evaluate methodologies to homogenize the stress and the elastic properties. The elastic response of a layered material is found to be equivalent to that of a transversely isotropic material, and the explicit relations for the effective parameters are obtained. To illustrate the relevance of the homogenization procedure for hydraulic fracturing, the propagation of a plane strain hydraulic fracture in a finely layered shale is studied. To reduce the complexity of the numerical model, elastic layering is neglected and only the effect of the stress layers is analyzed. The results demonstrate the ability of the homogenized stress model to accurately capture the hydraulic fracture behavior using a relatively coarse mesh. This result is obtained by using a special asymptotic solution at the tip element that accounts for the local stress variation near the tip, which effectively treats the material at the tip element as nonhomogenized.

Influence of injection parameters on the dynamics of Hydraulic Fracturing monitored by Acoustic Emission

2020 ◽  
Author(s):  
Maria Bobrova ◽  
Egor Filev ◽  
Anna Shevtsova ◽  
Sergey Stanchits ◽  
Vladimir Stukachev ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Hydraulic Fracturing ◽  
Hydraulic Fracture ◽  
Fracture Plane ◽  
Fluid Viscosity ◽  
Breakdown Pressure ◽  
X Ray ◽  
3D Shape ◽  
Injection Parameters ◽  
Maximal Stress

<p>Understanding the processes of Hydraulic Fracturing (HF) initiation and propagation in different types of rocks is important for the design and optimization of HF during the exploitation of underground resources. The main goals were to study the dynamics of the process of hydraulic fracture growth and possible optimization of HF technology for both homogeneous and heterogeneous rocks. Laboratory experiments on HF with different injection parameters were carried out on natural limestone, dolomite and shale specimens. The dynamics of HF process was monitored by Acoustic Emission (AE) technique, on the analogy of induced microseismicity monitoring of HF in the field conditions. The shape of created HF and the size of leak-off zone were analyzed by X-Ray CT scanning technique after the testing.</p><p>Experiments on dolomite were conducted using fluids with different viscosities (1000-10000 cP) injected into the rock with a rate of 0.5 ml/min. In case of low viscosity, we observed low AE activity. After the test, the sample was cut in several pieces transverse to the expected fracture plane. We have found that HF has initiated, but did not reach the sample boundaries and leak-off was significant. The ten times increase of fluid viscosity resulted in significantly increased AE activity, smaller size of leak-off zone and higher breakdown pressure (21.8 against 18.7 MPa). The post-test 3D shape of HF surface obtained by X-Ray CT closely correlates with 3D shape of localized AE events, confirming that the fracture propagated in the direction of maximal stress, as expected. It means that viscosity of fracturing fluid had a significant effect on fracturing breakdown pressure and fracture behavior.</p><p>The influence of different rock types on hydraulic fracturing was studied with dolomite, limestone and shale samples. In case of dolomite and shale, sufficient number of Acoustic Emission events were recorded, which allowed tracing the direction and dynamics of fracture propagation. However, for the limestone, a very small number of AE events were localized with the same parameters of injected fluid. Comparison of dolomite and shale HFs shows that the crack in the shale had a more complex shape, deviating from the maximal stress direction, which was explained by rock heterogeneity, by the presence of natural cracks and inclined planes of weakness. It led us to conclusion that the rock fabric plays an important role in the behavior of hydraulic fracture in heterogeneous rock.</p>

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