Elasto-plastic Collapse Strength Calculation of Casing under Pure External Pressure

2011 ◽  
Author(s):  
Jiandong Wang ◽  
Xinhu Wang
Keyword(s):  
External Pressure ◽  
Strength Calculation ◽  
Plastic Collapse ◽  
Collapse Strength

Examination of Commercial Casing Collapse Strength Under Axial Loading

1982 ◽  
Vol 104 (4) ◽  
pp. 343-348 ◽  
Author(s):  
T. Tamano ◽  
Y. Inoue ◽  
H. Mimura ◽  
S. Yanagimoto
Keyword(s):  
Axial Load ◽  
Axial Stress ◽  
Axial Loading ◽  
External Pressure ◽  
Plastic Collapse ◽  
Slight Effect ◽  
Collapse Pressure ◽  
Minimum Value ◽  
Collapse Strength ◽  
Casing Collapse

Collapse testing of commercial API grade 7-in. casing was conducted under combined external pressure and axial load. The measured collapse pressure was considerably higher than the API minimum value, especially for the large D/t ratio, as expected. For the casings of large D/t ratio, the measured collapse pressure was a little smaller than the theoretical value for ideal pipe and the axial stress had a slight effect on the collapse pressure. In the range of plastic collapse, the measured collapse pressure was not less than the yield pressure for ideal pipe except near the boundary of the elastic and plastic collapse ranges.

Experimental Study on the Effect of Axial Tension Load on the Collapse Strength of Oilwell Casing

1982 ◽  
Vol 22 (05) ◽  
pp. 609-615 ◽  
Author(s):  
T. Kyogoku ◽  
K. Tokimasa ◽  
H. Nakanishi ◽  
T. Okazawa
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Testing Machine ◽  
External Pressure ◽  
Tension Stress ◽  
Plastic Collapse ◽  
Collapse Pressure ◽  
Axial Tension ◽  
Collapse Strength ◽  
Tension Load

Abstract This paper discusses a newly developed collapse testing machine that permits investigation of practical performances of oilwell casings. Although a theoretical performances of oilwell casings. Although a theoretical analysis has shown that "axial tension stress has no effect on collapse pressure in the elastic case," this theory is not applied to the design of casing string because of lack of useful experimental data or authorized recommendation. To investigate the effect of axial tension load, full-size commercial casings have been tested under combined loading of axial tension load and external pressure. From the experimental results, the theory mentioned was proved in the case of so-called high-collapse casing, which has been used widely in recent years. Also shown is the applicable d/h range, which is wider than API's elastic collapse range. If the results of this experiment were applied to the design of a casing program, an economical and safe one could be obtained. program, an economical and safe one could be obtained. Introduction Recently, improved drilling techniques have permitted deeper and deeper oil and gas wells. As well depth increases, steel pipes for well casings receive greater external pressure and axial tension load because of the weight of the casing string. High-collapse casing, which has higher collapse strength per unit weight, has become easily available. To select and to design casing for such wells properly and economically, estimating collapse strength of the casing under axial tension load is very important. Much research and many experiments concerning collapse problems on casing, drillpipe, and tubing has been conducted by 1939. A theoretical analysis showed that axial tension stress lowers the collapse pressure in the case of plastic collapse and that axial tension stress has no effect on collapse pressure in the elastic case. Although collapse tests under axial tension load simulating oilwell casing in service were conducted on 2-in.-OD tubings, the theory for the effect of axial tension stress in the elastic collapse had not been proved sufficiently. There are few published experimental proved sufficiently. There are few published experimental data on collapse strength under axial tension load. In 1968, API summarized the collapse data and showed the formulas for collapse pressure and for collapse pressure under axial tension stress in the case of plastic collapse. The purpose of our study is to show how the collapse strength of commercial casings with large OD's behaves under the axial tension load, especially in the case of elastic collapse. To test the large-size casings, a multipurpose collapse testing machine that can simulate the service condition of oilwell casing has been developed. Statement of the Problem The collapse strength of casings under combined external pressure and axial tension load may be calculated from pressure and axial tension load may be calculated from Ref. 6's Formula 1.1.5.1: ....................(1) SPEJ p. 609

Plastic Collapse Behaviors of Tubulars With Recess Patterns

2015 ◽  
Author(s):  
Haifeng Zhao ◽  
David Iblings ◽  
Aleksey Barykin ◽  
Mohamed Mehdi
Keyword(s):  
Empirical Relationship ◽  
External Pressure ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Plastic Collapse ◽  
Strength Reduction Factor ◽  
Periodic Distribution ◽  
Collapse Strength ◽  
Post Buckling ◽  
Collapse Behavior

The collapse strength of tubulars with recess patterns machined into their walls is an important topic for oilfield downhole tools as it applies to perforating guns, prepacked sand screens, and perforated and slotted liners. This paper presents a study of the plastic collapse behavior of thick-walled tubulars (those with an outside diameter to thickness ratio of approximately 10) having different patterns of circular recesses (blind holes partially machined into the tubing wall) that are subjected to external pressure. An empirical relationship between the reduction in collapse strength and the periodic distribution of recesses was constructed to account for the weakening effects of recess diameter, recess depth, axial spacing, angular phasing, etc. This strength reduction factor was introduced into the Tamano formula to predict collapse strength of recessed tubulars. Applicability of this empirical formula was validated with the aid of nonlinear, post-buckling Finite Element Analyses (FEA). The modeling approach was verified by full-scale physical tests. However, results of the physical testing are not presented in this paper. The strength reduction factor in combination with the Tamano formula provides a simple way of parametrically predicting the collapse strength of tubulars having circular recess patterns.

Plastic Collapse Behaviors of Tubulars with Recess Patterns—Application in Hollow Carrier Perforating Guns

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Haifeng Zhao ◽  
David Iblings ◽  
Aleksey Barykin ◽  
Mohamed Mehdi
Keyword(s):  
Empirical Relationship ◽  
External Pressure ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Oil Field ◽  
Plastic Collapse ◽  
Strength Reduction Factor ◽  
Periodic Distribution ◽  
Collapse Strength ◽  
Collapse Behavior

The collapse strength of tubulars with recess patterns machined into their walls is an important topic for oil field downhole tools, especially in hollow carrier perforating gun systems. This paper presents a study of the plastic collapse behavior of thick-walled tubulars (those with an outside diameter to thickness ratio of approximately ten) having different patterns of circular recesses (blind holes partially machined into the tubing wall) that are subjected to external pressure. An empirical relationship between the reduction in collapse strength and the periodic distribution of recesses was constructed to account for the weakening effects of recess diameter, recess depth, axial spacing, angular phasing, etc. This strength reduction factor was introduced into the Tamano formula to predict collapse strength of recessed tubulars. Applicability of this empirical formula was validated with the aid of nonlinear, postbuckling finite element analyses (FEA). The strength reduction factor in combination with the Tamano formula provides a simple way of parametrically predicting the collapse strength of tubulars having circular recess patterns.

Uncertainty in Collapse Strength Prediction of Sandwich Pipelines

2021 ◽  
Author(s):  
U. Bhardwaj ◽  
A. P. Teixeira ◽  
C. Guedes Soares
Keyword(s):  
Probabilistic Models ◽  
Uncertainty Propagation ◽  
Simulation Method ◽  
External Pressure ◽  
Design Parameters ◽  
Collapse Strength ◽  
Parameters Uncertainty ◽  
Wide Range ◽  
Model Predictions ◽  
Strength Models

Abstract This paper assesses the uncertainty in the collapse strength of sandwich pipelines under external pressure predicted by various strength models in three categories based on interlayer adhesion conditions. First, the validity of the strength models is verified by comparing their predictions with sandwich pipeline collapse test data and the corresponding model uncertainty factors are derived. Then, a parametric analysis of deterministic collapse strength predictions by models is conducted, illustrating insights of models’ behaviour for a wide range of design configurations. Furthermore, the uncertainty among different model predictions is perceived at different configurations of outer and inner pipes and core thicknesses. A case study of a realistic sandwich pipeline is developed, and probabilistic models are defined to basic design parameters. Uncertainty propagation of models’ predictions is assessed by the Monte Carlo simulation method. Finally, the strength model predictions of sandwich pipelines are compared to that of an equivalent single walled pipe.

scholarly journals OS0820 Plastic collapse strength and maximum load evaluation method of flawed stainless piping subjected to axial tension and bending

2012 ◽  
Vol 2012 (0) ◽  
pp. _OS0820-1_-_OS0820-2_
Author(s):  
Seiji YANAGIHARA ◽  
Masaaki MATSUBARA ◽  
Ryousuke SUZUKI ◽  
Masato SUZUKI ◽  
Taisuke SHIRAISHI ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Maximum Load ◽  
Plastic Collapse ◽  
Axial Tension ◽  
Collapse Strength ◽  
Load Evaluation

Elastic-plastic collapse of 3-D damaged cylindrical shells subjected to uniform external pressure

2004 ◽  
Vol 10 (4) ◽  
pp. 343-349 ◽  
Author(s):  
X. W. Zhao ◽  
J. H. Luo ◽  
M. Zheng ◽  
H. L. Li ◽  
M. X. Lu
Keyword(s):  
Cylindrical Shells ◽  
External Pressure ◽  
Plastic Collapse ◽  
Uniform External Pressure ◽  
Elastic Plastic
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