scholarly journals Application of Multiphysics Coupling FEM on Open Wellbore Shrinkage and Casing Remaining Strength in an Incomplete Borehole in Deep Salt Formation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hua Tong ◽  
Daqiang Guo ◽  
Xiaohua Zhu
Keyword(s):  
Three Dimensional ◽  
Effect Of Temperature ◽  
Salt Rock ◽  
Salt Formation ◽  
Defect Level ◽  
Rock Creep ◽  
Multiphysics Coupling ◽  
Casing Strength ◽  
New Perspective ◽  
Harsh Condition

Drilling and completing wells in deep salt stratum are technically challenging and costing, as when serving in an incomplete borehole in deep salt formation, well casing runs a high risk of collapse. To quantitatively calculate casing remaining strength under this harsh condition, a three-dimensional mechanical model is developed; then a computational model coupled with interbed salt rock-defective cement-casing and HPHT (high pressure and high temperature) is established and analyzed using multiphysics coupling FEM (finite element method); furthermore, open wellbore shrinkage and casing remaining strength under varying differential conditions in deep salt formation are discussed. The result demonstrates that the most serious shrinkage occurs at the middle of salt rock, and the combination action of salt rock creep, cement defect, and HPHT substantially lessens casing remaining strength; meanwhile, cement defect level should be taken into consideration when designing casing strength in deep salt formation, and apart from the consideration of temperature on casing the effect of temperature on cement properties also cannot be ignored. This study not only provides a theoretical basis for revealing the failure mechanism of well casing in deep complicated salt formation, but also acts as a new perspective of novel engineering applications of the multiphysics coupling FEM.

scholarly journals Creep Properties and Constitutive Model of Salt Rock

2021 ◽  
Vol 2021 ◽  
pp. 1-29
Author(s):  
Qiang Zhang ◽  
Zhanping Song ◽  
Junbao Wang ◽  
Yuwei Zhang ◽  
Tong Wang
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Effect Of Temperature ◽  
Creep Process ◽  
Underground Storage ◽  
Self Healing ◽  
Salt Rock ◽  
Creep Properties ◽  
Term Operation ◽  
Rock Creep

Due to the advantages of low porosity, low permeability, high ductility, and excellent capacities for creep and damage self-healing, salt rock is internationally considered as the ideal medium for underground storage of energy and disposal of radioactive waste. As one of the most important mechanical properties of salt rock, creep properties are closely related to the long-term operation stability and safety of salt rock underground storage cavern. A comprehensive review on the creep properties and constitutive model of salt rock is put forward in this paper. The opinions and suggestions on the research priority and direction of salt rock's mechanical properties in the future are put forward: (1) permeability variation of salt rock under the coupling effect of temperature and stress; (2) damage mechanism and evolution process under the effect of creep-fatigue interaction and low frequency cyclic loading; (3) microdeformation mechanisms of salt rock and the relationship between microstructure variations and macrocreep behavior during creep process; (4) the establishment of the creep damage constitutive model with simple form, less parameters, easy application, and considering the damage self-healing ability of salt rock simultaneously.

scholarly journals Numerical Simulation on Open Wellbore Shrinkage and Casing Equivalent Stress in Bedded Salt Rock Stratum

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jianjun Liu ◽  
Linzhi Zhang ◽  
Jinzhou Zhao
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Finite Difference ◽  
Elasticity Modulus ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Salt Rock ◽  
Rock Stratum ◽  
Casing Strength

Most salt rock has interbed of mudstone in China. Owing to the enormous difference of mechanical properties between the mudstone interbed and salt rock, the stress-strain and creep behaviors of salt rock are significantly influenced by neighboring mudstone interbed. In order to identify the rules of wellbore shrinkage and casings equivalent stress in bedded salt rock stratum, three-dimensional finite difference models were established. The effects of thickness and elasticity modulus of mudstone interbed on the open wellbore shrinkage and equivalent stress of casing after cementing operation were studied, respectively. The results indicate that the shrinkage of open wellbore and equivalent stress of casings decreases with the increase of mudstone interbed thickness. The increasing of elasticity modulus will reduce the shrinkage of open wellbore and casing equivalent stress. Research results can provide the scientific basis for the design of mud density and casing strength.

scholarly journals Measuring the Feature of “The Global”: A Framework for Analyzing the Global City Ranking

2021 ◽  
Vol 13 (8) ◽  
pp. 4084
Author(s):  
Ka Lin ◽  
Aisha Ayaz ◽  
Lizheng Wang
Keyword(s):  
Urban Studies ◽  
Three Dimensional ◽  
Indicator System ◽  
Global City ◽  
Analysis Framework ◽  
City Development ◽  
Existing Problems ◽  
Urban Economic ◽  
Ranking Systems ◽  
New Perspective

This study discusses the measurement of the global city with the primary aim to uncover the logical grounds to measure the features of “the global” in the study of ranking and comparing the cities. The study sets up a three-dimensional analysis framework with infrastructure (economy), fluidity (openness), and reputation (influence) for the basic dimensions of measurement for the global cities. Using this framework, the studies of top-10 Chinese cities in the global city comparison have been conducted with the data of cities’ scores from various ranking systems. The resources used include the index of Globalization and World Cities, global urban economic competitiveness index, Economic daily and United Nations global urban sustainable competitiveness rankings. The study tests the effectiveness of this framework by illustrating the coherence and dissimilarity of this analysis with other city ranking systems, and further discloses the advantage of this indicator system. This study exposes the existing problems in the logic and rationale of the urban studies and establishes the basis of global city ranking, thus offering policymakers new perspective on the strategy of city development.

scholarly journals Temperature Compensation Method for Digital Cameras in 2D and 3D Measurement Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3685 ◽  
Author(s):  
Marcin Adamczyk ◽  
Paweł Liberadzki ◽  
Robert Sitnik
Keyword(s):  
Temperature Compensation ◽  
Three Dimensional ◽  
Compensation Method ◽  
Effect Of Temperature ◽  
Calibration Model ◽  
Digital Cameras ◽  
Compensation Model ◽  
Camera Design ◽  
Compensation Approach ◽  
2D And 3D

This paper presents the results of several studies concerning the effect of temperature on digital cameras. Experiments were performed using three different camera models. The presented results conclusively demonstrate that the typical camera design does not adequately take into account the effect of temperature variation on the device’s performance. In this regard, a modified camera design is proposed that exhibits a highly predictable behavior under varying ambient temperature and facilitates thermal compensation. A novel temperature compensation method is also proposed. This compensation model can be applied in almost every existing camera application, as it is compatible with every camera calibration model. A two-dimensional (2D) and three-dimensional (3D) application of the proposed compensation model is also described. The results of the application of the proposed compensation approach are presented herein.

Effect of Temperature Nonuniformity on Heat Transfer in an Unshrouded Transonic HP Turbine: An Experimental and Computational Investigation

2010 ◽  
Author(s):  
Imran Qureshi ◽  
Andy D. Smith ◽  
Kam S. Chana ◽  
Thomas Povey
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Test Facility ◽  
Effect Of Temperature ◽  
Inlet Temperature ◽  
Experimental Measurements ◽  
Turbine Stage ◽  
Cfd Simulations ◽  
Turbine Inlet

Detailed experimental measurements have been performed to understand the effects of turbine inlet temperature distortion (hot-streaks) on the heat transfer and aerodynamic characteristics of a full-scale unshrouded high pressure turbine stage at flow conditions that are representative of those found in a modern gas turbine engine. To investigate hot-streak migration, the experimental measurements are complemented by three-dimensional steady and unsteady CFD simulations of the turbine stage. This paper presents the time-averaged measurements and computational predictions of rotor blade surface and rotor casing heat transfer. Experimental measurements obtained with and without inlet temperature distortion are compared. Time-mean experimental measurements of rotor casing static pressure are also presented. CFD simulations have been conducted using the Rolls-Royce code Hydra, and are compared to the experimental results. The test turbine was the unshrouded MT1 turbine, installed in the Turbine Test Facility (previously called Isentropic Light Piston Facility) at QinetiQ, Farnborough UK. This is a short duration transonic facility, which simulates engine representative M, Re, Tu, N/T and Tg /Tw at the turbine inlet. The facility has recently been upgraded to incorporate an advanced second-generation temperature distortion generator, capable of simulating well-defined, aggressive temperature distortion both in the radial and circumferential directions, at the turbine inlet.

scholarly journals Hit the brakes – a new perspective on the loop extrusion mechanism of cohesin and other SMC complexes

2021 ◽  
Vol 134 (1) ◽  
pp. jcs247577
Author(s):  
Avi Matityahu ◽  
Itay Onn
Keyword(s):  
Present Model ◽  
Protein Complexes ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Order Structure ◽  
Chromatid Cohesion ◽  
Topologically Associated Domains ◽  
Extrusion Mechanism ◽  
New Perspective ◽  
Structural Maintenance Of Chromosome

ABSTRACTThe three-dimensional structure of chromatin is determined by the action of protein complexes of the structural maintenance of chromosome (SMC) family. Eukaryotic cells contain three SMC complexes, cohesin, condensin, and a complex of Smc5 and Smc6. Initially, cohesin was linked to sister chromatid cohesion, the process that ensures the fidelity of chromosome segregation in mitosis. In recent years, a second function in the organization of interphase chromatin into topologically associated domains has been determined, and loop extrusion has emerged as the leading mechanism of this process. Interestingly, fundamental mechanistic differences exist between mitotic tethering and loop extrusion. As distinct molecular switches that aim to suppress loop extrusion in different biological contexts have been identified, we hypothesize here that loop extrusion is the default biochemical activity of cohesin and that its suppression shifts cohesin into a tethering mode. With this model, we aim to provide an explanation for how loop extrusion and tethering can coexist in a single cohesin complex and also apply it to the other eukaryotic SMC complexes, describing both similarities and differences between them. Finally, we present model-derived molecular predictions that can be tested experimentally, thus offering a new perspective on the mechanisms by which SMC complexes shape the higher-order structure of chromatin.

scholarly journals Mathematical Modelling for Micropiles Embedded in Salt Rock

2016 ◽  
Vol 12 (1) ◽  
pp. 23-35
Author(s):  
Georgiana Rădan (Toader) ◽  
Nicoleta Rădulescu ◽  
Gheorghe Oancea
Keyword(s):  
Mathematical Modelling ◽  
3D Model ◽  
Three Dimensional ◽  
Salt Rock ◽  
In Situ Tests ◽  
Calibration And Validation ◽  
Plaxis 3D ◽  
2D Model ◽  
Computing Models

Abstract This study presents the results of the mathematical modelling for the micropiles foundation of an investement objective located in Slanic, Prahova county. Three computing models were created and analyzed with software, based on Finite Element Method. With Plaxis 2D model was analyzed the isolated micropile and the three-dimensional analysis was made with Plaxis 3D model, for group of micropiles. For the micropiles foundation was used Midas GTS-NX model. The mathematical models were calibrated based with the in-situ tests results for axially loaded micropiles, embedded in salt rock. The paper presents the results obtained with the three software, the calibration and validation models.

Fractal perspectives in pulmonary physiology

1991 ◽  
Vol 71 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. E. McNamee
Keyword(s):  
Three Dimensional ◽  
Geometric Dimension ◽  
Bronchial Tree ◽  
Pulmonary Vasculature ◽  
Two Dimensional ◽  
Mathematical Functions ◽  
Pulmonary Tissue ◽  
Pulmonary Physiology ◽  
New Perspective ◽  
Class Of Functions

Like other organs that exchange substantial quantities of material with blood, the lung accommodates a large two-dimensional surface in a component three-dimensional volume. The lung's structure shows a resemblance to certain one- and two-dimensional mathematical functions that possess plane- and space-filling properties. When viewed from a conventional geometric perspective, many of the familiar forms and functions of pulmonary tissue appear to possess unusual qualities that defy explanation. Mathematically, they behave as though they had a fractional geometric dimension. This property is shared by a class of functions known as fractals. Fractals are described, and practical techniques are presented to measure the properties of the edges and surfaces of the lung. The consequences of fractal structure are also considered for the bronchial tree, pulmonary vasculature, and microcirculation. Insights arising from viewing the lung in this new perspective are summarized.

The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor

1990 ◽  
Vol 41 (3) ◽  
pp. 479 ◽  
Author(s):  
PJ Ellison ◽  
BR Cullis ◽  
RW Bambach ◽  
PF Kable
Keyword(s):  
Germ Tube ◽  
Three Dimensional ◽  
Tube Growth ◽  
Effect Of Temperature ◽  
In Vitro Germination ◽  
Three Dimensional Models ◽  
C 30 ◽  
Tranzschelia Discolor ◽  
Germ Tube Growth

The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor was studied over time under constant temperature conditions. Studies were carried out on 1% water agar in the dark at 3�C, 5�C, 8�C, 10�C, 15�C, 20�C, 25�C, 28�C, 30�C and 32�C. Germination was observed at all temperatures between 5 and 30'C, and occurred rapidly over most of this range. At 2 h, germination exceeded 80% at temperatures between 10 and 28�C, and this level was reached at 3 h at 8�C. Germination at 5 and 30�C was much reduced and at 7 h reached only 44% and 38% respectively. Germ tube growth occurred most vigorously at 15 and 20�C, reaching lengths in excess of 500 8m at 9 h. The optimum range was narrower than that for germination, and growth was reduced or poor at 8�C, 10�C, 25�C and 28�C, which were favourable temperatures for germination. Average germ tube lengths at 9 h at these temperatures were 55, 245, 273 and 62 8m, respectively. Three-dimensional models were derived relating germination and germ tube growth to time and temperature.

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