Evaluating Volcanic Hazard Risk Through Numerical Simulations

2019 ◽  
Vol 14 (4) ◽  
pp. 604-615 ◽  
Author(s):  
Eisuke Fujita ◽  
Yu Iriyama ◽  
Toshiki Shimbori ◽  
Eiichi Sato ◽  
Kensuke Ishii ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Evaluation System ◽  
Volcanic Hazard ◽  
Input Parameter ◽  
Volcanic Hazards ◽  
Hazard Evaluation ◽  
Solid Materials ◽  
Analysis And Evaluation ◽  
Precise Evaluation ◽  
Multi Phase

As volcanic hazards induce damage with their flows of gases, liquids, and solid materials, a numerical simulation using multi-phase formulation is applicable to the analysis and evaluation of the risks from these volcanic hazards in both normal and emergent periods. A numerical simulation can also be useful for crisis management. Quick and precise evaluation is needed for upcoming and ongoing hazards, and we present here a concept for the development of a volcanic hazard evaluation system for these hazards, a system in which an input parameter database is compiled and countermeasure information is provided by considering the exposure and vulnerability database.

A Similarity Solution for Imbibition Process and its Adaptation in Finite Difference Simulation of Fractured Reservoirs

2021 ◽  
Author(s):  
Song Du ◽  
Seong Lee ◽  
Xian-Huan Wen ◽  
Yalchin Efendiev
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Similarity Solution ◽  
Capillary Force ◽  
Fractured Reservoirs ◽  
Phase Flow ◽  
Scale Modeling ◽  
Fracture Models ◽  
Multi Phase Flow ◽  
Multi Phase

Abstract The imbibition process due to capillary force is an important mechanism that controls fluid flow between the two domains, matrix and fracture, in naturally or hydraulically fractured reservoirs. Many simulation studies have been done in the past decades to understand the multi-phase flow in the tight and shale formation. Although significant advances have been made in large-scale modeling for both unconventional and conventional fields, the imbibition processes in the fractured reservoirs remains underestimated in numerical simulation, that limits confidence in long-term field production predictions. In the meanwhile, to simulate the near-fracture imbibition process, traditionally very-fine simulation grids have to be applied so that the physical phenomena of small-length scale could be captured. However, this leads to expensive computation cost to simulate full-field models with a large number of fractures. To improve numerical efficiency in field-scale modeling, we propose a similarity solution for the imbibition process that can be incorporated into the traditional finite difference formulation with coarse grid cells. The semi-analytical similarity solutions are validated by comparing with numerical simulation results with fine-scale grids. The comparison clearly indicates that the proposed algorithm accurately represents the flow behaviors in complex fracture models. Furthermore, we adopt the semi-analytical study to hydraulic fracture models using Embedded Discrete Fracture Model (Lee et al., 2001) in our numerical studies at different scales to represent hydraulic fractures that are interconnected. We demonstrate: 1) the imbibition is critical in determining flow behavior in a capillary force dominant model, 2) conventional EDFM has its limitation in capturing sub-cell flow behaviors near fractures, 3) combining the proposed similarity solution and EDFM, we can accurately represent the multi-phase flow near fractures with coarser grids, and 4) it is straightforward to adapt the similarity solution concept in finite-difference simulations for fractured reservoirs

scholarly journals AN OVERVIEW OF SUPPLY CHAIN EVALUATION SYSTEM

2014 ◽  
Vol 17 (3) ◽  
pp. 88-100
Author(s):  
Thanh Van Vo ◽  
Trung Quoc Pham
Keyword(s):  
Supply Chain ◽  
Evaluation System ◽  
Design Management ◽  
Analysis And Evaluation ◽  
Management Evaluation ◽  
Capacity Evaluation ◽  
Practical Research ◽  
Evaluation Models ◽  
Two Factors ◽  
Customer Services

Design, analysis and evaluation of supply chain play an important role in the operation and establishment of of business competiveness. The design and analysis of supply chain generally solves issues concerning costs and customer services. Indicators of the two factors are often used in supply chain capacity evaluation models. In addition, there have been many supply chain evaluation models using indicators ranging from strategy to operation in the last decades. This study aims to summarize some supply chain capacity evaluation models and emphasize the importance of supply chain evaluation for the improvement of operation in the present competitive market, thereby creating a foundation for practical research on design, management, evaluation and operation of supply chains.

scholarly journals Optimization of development mode of asphalt profile control based on numerical simulation and study of its mechanism

2020 ◽  
Vol 75 ◽  
pp. 30
Author(s):  
Fulin Wang ◽  
Tao Yang ◽  
Yunfei Zhao ◽  
Yanjun Fang ◽  
Fuli Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Evaluation System ◽  
Injection Rate ◽  
Injection System ◽  
Injection Timing ◽  
High Concentration ◽  
Development Mode ◽  
Displacement Effect ◽  
Profile Control

Asphalt profile control is an effective method, which can further improve oil recovery of reservoir polymer flooded, it has a lot of advantages including high strength profile control, seal strata formation efficiency, low cost and no pollution, but there has not a perfect evaluation system for its development mode. The effect of different concentration, injection rate, radius of profile control, the timing of profile and segment combination way on the oil displacement effect of the asphalt profile control were researched using numerical simulation method on actual typical well area in Daqing oilfield, and the mechanism of asphalt profile control was studied in detail. According to the results of laboratory test, the largest Enhanced Oil Recovery (EOR) of asphalt was obtained at injection concentration 4000 mg/L, and the best combination was “high–low–high” concentration slug mode. According to the results of numerical simulation, the best concentration, injection rate, radius of profile control and injection timing were 4000 mg/L, 0.15 PV/a (Pore Volume [PV], m3), 1/2 of well spacing and 96% water cut in single slug of asphalt injection system, when the injection condition was multiple slug, the “high–low–high” slug combination mode was the best injection mode. These results could provide effective development basis for asphalt profile control after polymer flooding in thick oil layers.

Numerical Simulation of Multi-Phase Flow Distribution in Parallel Pipelines System of Oil Transfer Station

2019 ◽  
Author(s):  
Yingying Wang ◽  
Chunsheng Wang ◽  
Qiji Sun ◽  
Yuling Lv
Keyword(s):  
Numerical Simulation ◽  
Branch Pipe ◽  
Flow Distribution ◽  
Simulation Models ◽  
Phase Flow ◽  
Gas Oil ◽  
Inlet Flow ◽  
Multi Phase Flow ◽  
Oil Water ◽  
Multi Phase

Abstract The mal-distribution of gas-oil-water multi-phase flow in parallel petroleum processing pipelines can directly affect the working condition of the separators. In this paper, the influence of different factors on the flow distribution and the characteristics of gas-oil-water distribution in parallel pipelines was investigated by three-dimensional CFD numerical simulation. Firstly, four different simulation models are established based on different arrangement types of parallel pipelines. The simulation results show that the distribution of gas-oil-water flow in the radial entry symmetrical two-stage pipe-laying simulation model was the most uniform among the four simulation models. Then, four radial entry symmetrical two-stage pipe-laying simulation models with different distance between branch pipes were establish. From the simulated results, it can be found that the distance has no effect on the distribution of gas-oil-water flow in each branch pipe, but great influence on distribution of flow rate in each branch pipe. Finally, the influence of the inlet flow characters on the flow distribution is investigated. It can be found that the “bias flow” phenomenon of the parallel pipelines decreasing with the increase of the inlet flow velocity, the gas content of inlet flow and the water content of inlet liquid.

An Analysis of the Evaluation Methods for Thermal Transmittance of Curtain Wall System Based on Simulators

2017 ◽  
Vol 865 ◽  
pp. 383-389 ◽  
Author(s):  
Min Jung Bae ◽  
Yu Min Kim ◽  
Gyeong Seok Choi ◽  
Jae Sik Kang ◽  
Hyun Jung Choi
Keyword(s):  
Numerical Simulation ◽  
Evaluation System ◽  
Evaluation Methods ◽  
Experimental Results ◽  
Curtain Wall ◽  
Performance Evaluation System ◽  
Thermal Transmittance ◽  
Simulation Results ◽  
Primary Evaluation ◽  
Wall System

With the window rating system being enforced, window companies are required to assign window ratings to their products. As the window ratings is based on the experimental results of fenestration, they are required to spend a lot of time and money conducting laboratory tests in order to assign window ratings to all their products. Through the window performance evaluation system using simulation, the thermal transmittance of products calculated based on numerical simulation can be used in place of experimental results to obtain the window rating. To ensure the credibility of simulation results, it is necessary to use the correct evaluation methods and primary information derived from in use practice should be available for the numerical simulation. The purpose of this paper is to investigate the evaluation methods that the simulator actually uses for the thermal performance of fenestration in WINDOW/THERM. The evaluation methods used by twenty-one simulators were investigated using primary evaluation methods for numerical simulation as the criteria. This study found that most of the simulation results were not trustworthy even though they were similar to experimental results because the evaluation methods used by simulators are incorrect. Furthermore, to enhance the credibility of simulation results, the simulator should be provided with the detailed information used in practice related to the evaluation performance of numerical simulation.

Using Fuzzy Inference System to the Analysis of Debris Flow Hazard

2009 ◽  
Author(s):  
Pao H. Lin ◽  
K. H. Chen
Keyword(s):  
Debris Flow ◽  
Interface Design ◽  
Debris Flows ◽  
Evaluation System ◽  
Fuzzy Inference ◽  
Hazard Evaluation ◽  
Graphic User Interface ◽  
Design Environment ◽  
Inference System ◽  
Debris Flow Hazard

In this study 11 factors influential to the evolvement of debris flows are identified via literature review and a thorough comparison among previous studies. Aided by MATLAB software and the concept of property in Fuzzy logic theory, an evaluation system for debris flow hazard is developed. Also, the proposed inference system is facilitated with Graphic User Interface Design Environment, so that observers or researchers may easily become familiar with system operation and utilize the system’s estimation as references for hazard judgment. Validation results with simulated cases of three different degrees of hazard severity evidenced that the present evaluation system on debris flows was effective with debris flows of high, low, and median hazards, as well as acceptable feasibility. Further, based on data gathered from rivers subject to debris flow and several actual cases in Taiwan, this proposed system was proved to achieve acceptable precision on the hazard evaluation of debris flow.

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