Equations to Calculate Casing Collapse Strength Under Nonuniform Load Based on New ISO Model

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Kuanhai Deng ◽  
Yuanhua Lin ◽  
Wanying Liu ◽  
Dezhi Zeng ◽  
Yongxing Sun ◽  
...  
Keyword(s):  
Full Account ◽  
Manufacturing Defects ◽  
Iso Standards ◽  
Failure Data ◽  
Collapse Resistance ◽  
Collapse Model ◽  
Collapse Models ◽  
Nonuniform Load ◽  
Calculation Results ◽  
Casing Collapse

Many studies focused on casing collapse resistance under uniform load have been done, and API 5C3 and ISO standards have been formed. However, the collapse models presented by API 5C3 and ISO standards are not suitable for calculating and predicting the casing collapse resistance under nonuniform load (NUL), despite it is well known that the NUL has a significant impact on the casing collapse resistance. Hence, based on the elastic theory and new ISO collapse model, the conception of advance coefficient of plastic collapse of casing under NUL is put forward, and the new equations to compute casing collapse resistance under NUL are established, which takes into full account the effect of manufacturing defects (such as ovality and eccentricity) and residual stress on the casing collapse resistance. The influence rule of nonuniform coefficient of load (NCL) on casing collapse resistance has been analyzed. Numerical and experimental comparisons show that the calculation results (CR) of new equations are much closer to the real failure data than the current equations proposed by Han and EI-Sayed (1992, “Resistance of Cemented Concentric Casing Strings Under Nonuniform Loading,” SPE Drill. Eng., 7(1), pp. 59–64). Research results can provide an important theoretical reference for casing design in complicated stratum (such as plastic creep and dipping stratum).

On Some Factors Affecting Casing Collapse Resistance under External Pressure

2020 ◽  
Author(s):  
Bisen Lin ◽  
David Coe ◽  
Richard Harris ◽  
Timothy Thomas
Keyword(s):  
External Pressure ◽  
Factors Affecting ◽  
Collapse Resistance ◽  
Casing Collapse

Analysis on the Influence Factors of Casing Collapse Resistance Strength

2011 ◽  
Vol 415-417 ◽  
pp. 2121-2125 ◽  
Author(s):  
Qi Lou ◽  
Wei Du ◽  
Xin Li Han ◽  
Dong Feng Li ◽  
Guang Lu Zhang
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Material Properties ◽  
Influence Factors ◽  
Full Scale ◽  
Test Results ◽  
Resistance Property ◽  
Collapse Resistance ◽  
Strength Based ◽  
Casing Collapse

Casing collapse resistance strength is an important parameter for its properties in using. Specification, geometry accuracy, material properties, and many other reasons can influence casing collapse resistance property. Study each factors influence for casing collapse resistance strength based on full scale collapse test results of seventeen Φ177.80mm casings and there geometry and material properties test results. The results show that casing collapse resistance strength was influenced by geometry accuracy, yield strength and residual stress together. Ovality greater than 0.5% and fluctuated more than 0.5%, or eccentricity more than 10%, casing collapse resistance strength will be reduced obviously. Casing with excellent collapse resistance strength will be produced through making yield strength in appropriate level, controlling the geometry accuracy and reducing residual stress.

How Many Pipelines in North America Have Failed by Fatigue and Why?

2016 ◽  
Author(s):  
Andrew Cosham ◽  
Phil Hopkins
Keyword(s):  
United States ◽  
Historical Data ◽  
Mechanical Damage ◽  
The United States ◽  
Transportation Safety ◽  
Valuable Insight ◽  
Gas Pipelines ◽  
Manufacturing Defects ◽  
Failure Data ◽  
Incident Reports

Pipelines are aging: more than half of all pipelines in Europe and the United States are over 40 years old. Historically, only a small number of pipeline failures have been attributed to fatigue; however, as pipelines age, this might change. Indeed, two of the most serious pipelines failures in recent years in the United States were partly attributed to fatigue. The issue with fatigue is not so much how it should be addressed, but if or when, and where, it will become more of a problem. Historical failure data provides a valuable insight into the number and cause of failures that have been attributed to fatigue, and an indication of what might happen in the future. Historical failure data for onshore gas and liquid pipelines in the United States of America and Canada has been reviewed in order to estimate the number and cause of failures that can be attributed to fatigue; specifically, the OPS 30-day Incident Reports, the listing of pipeline rupture events compiled by the National Energy Board, and the findings of failure investigations conducted by the National Transportation Safety Board (NTSB) and the Transportation Safety Board of Canada (TSB). Failures that can (at least partly) be attributed to fatigue are not readily identifiable in the historical data, because fatigue is not listed as a secondary cause (as it is, strictly, only a growth mechanism). The narrative descriptions in historical data sets, as in the OPS 30-day Incident Reports, and the detail in the Pipeline Investigation Reports or Accident Briefs published by the NTSB, and the Pipeline Investigation Reports published by the TSB are essential for identifying the relevant failures and their causes. Failures in pipelines that can be attributed to fatigue are relatively rare, but fatigue failures have been reported in both onshore gas and liquid pipelines in both the United States and Canada, mostly originating from pre-existing mechanical damage or manufacturing defects. Corrosion-fatigue has been identified as a contributing factor in a minority of the failures. The number of failures in liquid pipelines is (as would be expected) higher than that in gas pipelines. The number of failures in onshore liquid pipelines in the United States that can be attributed to fatigue has increased, with over half of such failures having occurred in the last ten years. The increase is statistically significant. There has also been an increase, albeit smaller and not statistically significant, in the number in onshore gas pipelines. The increase in the number of failures is consistent with an ageing system.

KAJIAN EKSPERIMENTAL KERUNTUHAN TEKAN BENDA UJI BETON SELF COMPACTING CONCRETE

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Immanuel Panusunan Tua Panggabean ◽  
Charles Harry Siregar
Keyword(s):  
Test Object ◽  
Shear Failure ◽  
National Standard ◽  
Crack Model ◽  
Self Compacting Concrete ◽  
Concrete Mixtures ◽  
Collapse Model ◽  
Collapse Models ◽  
Concrete Type ◽  
Concrete Testing

Concrete test materials received in the field were treated and tested at the age of 28 (twenty eight) days, regulated in the Indonesian National Standard for concrete with the standard number SNI 2847: 2013. In addition, the equally important standard to be observed in concrete testing, especially in construction, is the observation of the shape of the collapse of the test object, which was written in the SNI 1974: 2011 concrete regulation. This collapse model needs to be considered because it can pay attention to the possibility of errors in testing. The test object used in this study was formed using Self Compacting Concrete type concrete. This type of concrete is an innovative concrete that does not require vibration for compaction. Because this concrete can flow by itself and actually fill the formwork until it reaches full compaction. These concrete collapse models must be considered because they are very interesting to see. Researchers conducted experiments on concrete collapse models made using several variations of concrete mixtures, ranging from variations in water content (standard, -5%, -10%, + 5%, + 10%), height variation of the test object (15 cm , 12.5 cm, 10 cm, 8.5 cm, 7.5 cm), and variation in age of the plan. From the research conducted by researchers, the number of specimens carried out shows the pattern of collapse of the crack model parallel to the upright axis, then there is the model of cone and shear failure and the least is the cone and split failure model.

HPHT Gas Well Cementing Complications and its Effect on Casing Collapse Resistance

2012 ◽  
Author(s):  
Zhaoguang Yuan ◽  
Jerome Schubert ◽  
Catalin Teodoriu ◽  
Paolo Gardoni
Keyword(s):  
Gas Well ◽  
Collapse Resistance ◽  
Casing Collapse

Effect of Nonuniform Loading on Conventional Casing Collapse Resistance

2004 ◽  
Vol 19 (03) ◽  
pp. 156-163 ◽  
Author(s):  
P.D. Pattillo ◽  
N.C. Last ◽  
W.T. Asbill
Keyword(s):  
Collapse Resistance ◽  
Nonuniform Loading ◽  
Casing Collapse

scholarly journals Non-Markovian wave-function collapse models are Bohmian-like theories in disguise

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 594
Author(s):  
Antoine Tilloy ◽  
Howard M. Wiseman
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Schrödinger Equation ◽  
Schrodinger Equation ◽  
Initial Conditions ◽  
Hidden Variables ◽  
Bohmian Mechanics ◽  
Primitive Ontology ◽  
Collapse Model ◽  
Collapse Models

Spontaneous collapse models and Bohmian mechanics are two different solutions to the measurement problem plaguing orthodox quantum mechanics. They have, a priori nothing in common. At a formal level, collapse models add a non-linear noise term to the Schrödinger equation, and extract definite measurement outcomes either from the wave function (e.g. mass density ontology) or the noise itself (flash ontology). Bohmian mechanics keeps the Schrödinger equation intact but uses the wave function to guide particles (or fields), which comprise the primitive ontology. Collapse models modify the predictions of orthodox quantum mechanics, whilst Bohmian mechanics can be argued to reproduce them. However, it turns out that collapse models and their primitive ontology can be exactly recast as Bohmian theories. More precisely, considering (i) a system described by a non-Markovian collapse model, and (ii) an extended system where a carefully tailored bath is added and described by Bohmian mechanics, the stochastic wave-function of the collapse model is exactly the wave-function of the original system conditioned on the Bohmian hidden variables of the bath. Further, the noise driving the collapse model is a linear functional of the Bohmian variables. The randomness that seems progressively revealed in the collapse models lies entirely in the initial conditions in the Bohmian-like theory. Our construction of the appropriate bath is not trivial and exploits an old result from the theory of open quantum systems. This reformulation of collapse models as Bohmian theories brings to the fore the question of whether there exists `unromantic' realist interpretations of quantum theory that cannot ultimately be rewritten this way, with some guiding law. It also points to important foundational differences between `true' (Markovian) collapse models and non-Markovian models.

scholarly journals SPECTROSCOPIC AND THERMOCHEMICAL PROPERTIES OF ACTINIDE-CONTAINING SPECIES FROM FIRST PRINCIPLES: THORIUM AND AMERICIUM MONOXIDE MOLECULES

2020 ◽  
Vol 63 (2) ◽  
pp. 4-13
Author(s):  
Alexander N. Smirnov ◽  
Victor G. N. Solomonik
Keyword(s):  
Ab Initio ◽  
Bond Length ◽  
Molecular Spectroscopy ◽  
High Accuracy ◽  
Ionization Potentials ◽  
Minor Actinide ◽  
Accuracy Evaluation ◽  
Molecular Constants ◽  
Full Account ◽  
Calculation Results

A relativistic version of a composite ab initio treatment of molecular spectroscopy and thermochemistry is developed, focusing on high-accuracy description of the properties of actinide (An) containing species. It is based on combining the calculation results at levels of theory with sufficiently full account of electron correlation, e.g., at the CCSDT(Q) level, but tackling only scalar relativity, with those obtained from more rigorous four-component relativistic calculations with the Dirac–Coulomb Hamiltonian. High accuracy achievable via this approach is revealed taking the examples of thorium and americium monoxide molecules. The errors in ab initio values for the bond length re, vibrational frequency ωe, and atomization energy D0 of the ThO molecule did not exceed 0.001 Å, 2.5 cm–1, and 0.5 kcal/mol, respectively. The composite numerical values for the first ionization potentials of the AmO molecule and the Am atom deviate from the experimental data just by 0.03 eV and 1 cm–1, respectively. For the first time, the proposed approach enabled high-accuracy evaluation of the molecular constants re, ωe and D0 for AmO and AmO+, as well as the second and third ionization potentials of the Am atom. The calculation results are indicative of a minor actinide contraction of the An–O bonds on going through the molecular series ThO → UO → AmO: the bond length in AmO is by 0.0073 Å shorter than that in ThO. The re(An–O) value is shown to be linearly dependent on the actinide atomic number in the periodic table. The results obtained may be used as benchmarks for parametrizing and calibrating the DFT functionals designed for treating An-containing molecules.

scholarly journals CSL Collapse Model Mapped with the Spontaneous Radiation

2017 ◽  
Author(s):  
Kristian Piscicchia ◽  
Angelo Bassi ◽  
Catalina Curceanu ◽  
Raffaele Del Grande ◽  
Sandro Donadi ◽  
...  
Keyword(s):  
Photon Emission ◽  
Model Parameters ◽  
Spontaneous Radiation ◽  
Emission Data ◽  
Upper Limits ◽  
Collapse Model ◽  
Collapse Models ◽  
Spontaneous Localization ◽  
Continuous Spontaneous Localization ◽  
Relevant Range

In this paper new upper limits on the parameters of the Continuous Spontaneous Localization (CSL) collapse model are extracted. To this end the X-ray emission data collected by the IGEX collaboration are analyzed and compared with the spectrum of the spontaneous photon emission process predicted by collapse models. This study allows to obtain the most stringent limits within a relevant range of the CSL model parameters, with respect to any other method. The collapse rate $\lambda$ and the correlation length $r_C$ are mapped, thus allowing to exclude a broad range of the parameter space.

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