Failure Analysis of Large-Diameter Coiled Tubing Based on Diameter Growth

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Le Zhao ◽  
Hong Zhang ◽  
Qingquan Duan ◽  
Guoping Tang
Keyword(s):  
Internal Pressure ◽  
Wall Thickness ◽  
High Pressures ◽  
Fatigue Behavior ◽  
Large Diameter ◽  
Fatigue Tests ◽  
Diameter Growth ◽  
Finite Element Software ◽  
Coiled Tubing ◽  
Bending Radius

Abstract Fatigue tests were conducted to analyze the fatigue behavior and diameter growth of large-diameter coiled tubing (CT) under the combined loads of bending and internal pressure. The experimental results reveal that mechanical limitations on the allowable diameter growth mean that the effective working life of CT at high pressures is only a fraction of the available fatigue life. The finite element software abaqus is used to further research the changes in diameter growth and to analyze the sensitivity of CT diameter growth to the main influencing factors, including internal pressure, tubing outside diameter (OD), wall thickness, yield strength, and bending radius. For CT with a diameter larger than 2 in., the diameter growth is sensitive to the above factors. As the bending and straightening cycles increase, the OD of the CT increases in association with obvious ovalization deformation, and the increase in the OD is closely related to the internal pressure load. The redistribution of material causes the wall thickness of the CT to become universally thinner. The ovality of the CT and the uneven decrease in wall thickness reduce the resistance to external extrusion. Therefore, it is becoming increasingly necessary to account for diameter growth as one of the key elements when predicting CT life or determining when to retire a string from service.

Effect of Expansion Ratio and Wall Thickness on Large-Diameter Solid Expandable Tubular after Expansion

2021 ◽  
Author(s):  
Changshuai Shi ◽  
Kailin Chen ◽  
Xiaohua Zhu ◽  
Feilong Cheng ◽  
Yuekui Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Performance Test ◽  
Large Diameter ◽  
Expansion Ratio ◽  
Fe Model ◽  
Laboratory Test Results ◽  
Low Efficiency ◽  
Pressure Resistance

Abstract The large-diameter solid expandable tubular with a smaller wall thickness faces the risk of internal pressure burst and external squeeze collapse in repairing damaged casing well. The internal pressure and external squeezing resistance calculation of the tubes using the analytical method require many expansion experiments and post-expansion tensile experiments, resulting in high costs and low efficiency. This paper gives a set of laboratory expansion and post-expansion performance test, which is based on the laboratory experiment and mechanical properties of material expansion. Two materials are studied: 316L and 20G. Then it analyses the error and causes of the error in the traditional analytical algorithm. Besides, it establishes an accurate finite element (FE) model to study the quantitative influence of expansion ratio and wall thickness on the burst strengths and collapse strengths of the tube. The results show that the toughness and hardening ratio of 316L is better than 20G at the same expansion ratio. The numerical simulation results of the model can effectively simulate the expansion process and the mechanical properties of SET in good agreement with the laboratory test results. The expansion ratio and wall thickness affect the mechanical properties after expansion. Thus the quantitative laws of the expansion driving force, internal pressure resistance, and external squeezing resistance under different variables are summarized. To ensure the integrity of the reinforced wellbore, the expansion ratio should not exceed 12.7%. In the current study lays a theoretical basis and technical support for optimizing SET and preventing downhole accidents.

scholarly journals Multiaxial fatigue behavior of 2618 aluminum alloy

2019 ◽  
Vol 300 ◽  
pp. 09003
Author(s):  
Benaïssa Malek ◽  
Catherine Mabru ◽  
Michel Chaussumier
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Internal Pressure ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Mean Stress ◽  
Research Project ◽  
Pressure Tests

The purpose of the present research project is to study multiaxial fatigue behavior of 2618 alloy. The influence of mean stress on the fatigue behavior under tension and torsion is particularly investigated. Fatigue tests under combined tensile-torsion, in or out of phase, as well as combined tensile-torsion-internal pressure tests have also been conducted. Multiaxial fatigue results are analyzed according to Fatemi-Socie criterion to predict the fatigue life.

LCF Life Prediction Model of Coiled Tubing Based on Fatigue Damage Accumulation

2013 ◽  
Vol 699 ◽  
pp. 426-431
Author(s):  
Zong Yue Bi ◽  
Lin Yun Xian
Keyword(s):  
Fatigue Behavior ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Coiled Tubing ◽  
Fatigue Damage Accumulation ◽  
Theoretical Predictions ◽  
Plastic Strain Energy ◽  
Cyclic Plastic Strain ◽  
Damage Rule ◽  
Life Prediction Model

This paper establishes a model to predict the fatigue behavior of coiled tubing subjected to variable total strain conditions. The approach based on nonlinear fatigue cumulative damage rule of effective hysteresis energy dissipation, but requires additional experimental results from fatigue tests that were performed under constant strain amplitude. Cyclic plastic strain energy is measured curve area of cyclic stress-strain curves. it is proved to be quite consistent between theoretical predictions and experimentl datas.

Mechanism Study on the Coiled Tubing Deformation under a Combination Loading

2011 ◽  
Vol 328-330 ◽  
pp. 1528-1532 ◽  
Author(s):  
Lei Li ◽  
Zhao Xi Shen ◽  
Peng Wang
Keyword(s):  
Internal Pressure ◽  
Deformation Behavior ◽  
Fatigue Tests ◽  
Deformation Mechanisms ◽  
Pressure Loading ◽  
Mechanism Study ◽  
Cyclic Bending ◽  
Coiled Tubing ◽  
Combination Loading

The tendency for coiled tubing to grow in diameter and thin in wall under a combination loading of internal pressure and cyclic bending. This can occur in spite of the fact that nominal stresses due to internal pressure loading are well within elastic limits in both hoop and radial directions. The deformation mechanisms are described. Fatigue tests of 10 coiled tubing specimens are finished. The results show that the trends in coiled tubing deformation behavior are according with the context of theory.

scholarly journals Steel–Concrete Composite Pressure Vessels for Hydrogen Storage at High Pressures

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Maan Jawad ◽  
Yanli Wang ◽  
Zhili Feng
Keyword(s):  
Internal Pressure ◽  
High Pressures ◽  
Solid Wall ◽  
National Laboratory ◽  
Large Diameter ◽  
Pressure Vessels ◽  
Steel Shell ◽  
Theoretical Formulation ◽  
Oak Ridge ◽  
Concrete Shell

Abstract The need to store large quantities of hydrogen in large diameter steel vessels under high pressures results in shell thicknesses that are too large to produce by most steel mills and not practical to fabricate. Accordingly, a research program was undertaken by Oak Ridge National Laboratory to develop a new concept of combining steel with concrete to construct such vessels economically and practically. The concept is to fabricate vessels where the steel shell thickness is approximately one half that required to resist the hoop forces due to internal pressure. As such, the steel shell is designed to carry the full amount of the longitudinal forces in the vessel but only one half of the hoop loads due to internal pressure. The other half of the hoop loads is carried by a prestressed and reinforced concrete shell. In large diameter vessels, the cost of the shell can further be reduced by using layered steel shell construction rather than solid-wall construction. Such shell construction has also the added advantage of easily venting the hydrogen that permeates through the steel shell directly to the atmosphere through vent holes. This mechanism prevents the hydrogen from damaging the steel shell. The theoretical formulation of the steel concrete shell design is presented in this paper. In addition, details of a full-scale mock up vessel designed, fabricated, and tested to prove the proposed methodology are given.

Photoelastic Study and Fatigue Tests of a Contoured, Integrally Reinforced Branch Connection

1971 ◽  
Vol 93 (4) ◽  
pp. 1021-1029
Author(s):  
R. W. Schneider ◽  
W. M. Jackson ◽  
W. R. Nicolls
Keyword(s):  
Stress Concentration ◽  
Internal Pressure ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Bending Moment ◽  
Fatigue Tests ◽  
Extensive Study ◽  
Cylindrical Pressure Vessel ◽  
Concentration Factors ◽  
Stress Concentration Factors

The paper describes the results of an extensive study of a contoured, integrally reinforced branch connection in a cylindrical pressure vessel (or run pipe). Three epoxy models were tested by means of three-dimensional photoelasticity using the stress-freezing and slicing technique. Loads applied were internal pressure, a longitudinal moment on the branch, and a transverse bending moment on the branch; one model was required for each mode of loading. Stress distribution curves are given. In addition, thirteen geometrically similar steel headers were fatigue tested by longitudinal and transverse forces cyclically applied to the branch pipes. Tests were conducted over a range of nominal stress in the branch. Stress concentration factors or stress indices from the photoelastic tests for bending and stress intensification factors from the bending fatigue tests are compared. Stress concentration factors for internal pressure loading, as derived from the photoelastic tests, are presented. Since stress intensification factors are not used to describe fatigue behavior under pulsating pressure, a similar comparison is not possible. Owing to the amount of data accumulated, only the most pertinent are presented; in every instance this includes the area of maximum stress.

scholarly journals Influence of Shot Peening on the Isothermal Fatigue Behavior of the Gamma Titanium Aluminide Ti-48Al-2Cr-2Nb at 750 °C

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1083
Author(s):  
Christoph Breuner ◽  
Stefan Guth ◽  
Elias Gall ◽  
Radosław Swadźba ◽  
Jens Gibmeier ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Elevated Temperatures ◽  
Stress Amplitude ◽  
Negative Impact ◽  
Fatigue Behavior ◽  
Surface Hardness ◽  
Fatigue Tests ◽  
Positive Effects ◽  
Isothermal Fatigue

One possibility to improve the fatigue life and strength of metallic materials is shot peening. However, at elevated temperatures, the induced residual stresses may relax. To investigate the influence of shot peening on high-temperature fatigue behavior, isothermal fatigue tests were conducted on shot-peened and untreated samples of gamma TiAl 48-2-2 at 750 °C in air. The shot-peened material was characterized using EBSD, microhardness, and residual stress analyses. Shot peening leads to a significant increase in surface hardness and high compressive residual stresses near the surface. Both effects may have a positive influence on lifetime. However, it also leads to surface notches and tensile residual stresses in the bulk material with a negative impact on cyclic lifetime. During fully reversed uniaxial tension-compression fatigue tests (R = −1) at a stress amplitude of 260 MPa, the positive effects dominate, and the fatigue lifetime increases. At a lower stress amplitude of 230 MPa, the negative effect of internal tensile residual stresses dominates, and the lifetime decreases. Shot peening leads to a transition from surface to volume crack initiation if the surface is not damaged by the shots.

Fatigue behavior of precipitation strengthened Cu–Ni–Si alloy modified by Cr and Zr addition

2020 ◽  
Vol 11 (6) ◽  
pp. 861-873
Author(s):  
Ş. Hakan Atapek ◽  
Spiros Pantelakis ◽  
Şeyda Polat ◽  
Apostolos Chamos ◽  
Gülşah Aktaş Çelik
Keyword(s):  
Design Methodology ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Lower Stress ◽  
Content Type ◽  
Hardened Alloy ◽  
Zr Addition ◽  
Nucleation Sites ◽  
The Matrix ◽  
Lower Stress Level

Purpose The purpose of this paper is to investigate the fatigue behavior of precipitation-strengthened Cu‒2.55Ni‒0.55Si alloy, modified by the addition of 0.25 Cr and 0.25 Zr (wt%), using mechanical and fractographical studies to reveal the effect of microstructural features on the fracture. Design/methodology/approach For strengthening, cast and hot forged alloy was subjected to solution annealing at 900°C for 60 min, followed by quenching in water and then aging at 490°C for 180 min. Precipitation-hardened alloy was exposed to fatigue tests at R=−1 and different stress levels. All fracture surfaces were examined within the frame of fractographical analysis. Findings Fine Ni-rich silicides responsible for the precipitation strengthening were observed within the matrix and their interactions with the dislocations at lower stress level resulted in localized shearing and fine striations. Although, by the addition of Cr and Zr, the matrix consisted of hard Ni, Zr-rich and Cr-rich silicides, these precipitates adversely affected the fatigue behavior acting as nucleation sites for cracks. Originality/value These findings contribute to the present knowledge by revealing the effect of microstructural features on the mechanical behavior of precipitation-hardened Cu‒Ni‒Si alloy modified by Cr and Zr addition.

Rotation and Diameter Growth of Coiled Tubing

2018 ◽  
Author(s):  
P. E. Ken Newman ◽  
Patrick Kelleher ◽  
David Rain ◽  
Charlie Cai
Keyword(s):  
Diameter Growth ◽  
Coiled Tubing

Circumferential Creep Strain of Cylinders Subjected to Internal Pressure: A Comparison of the Theories of Johnson and Bailey

1966 ◽  
Vol 8 (1) ◽  
pp. 22-26 ◽  
Author(s):  
E. C. Larke ◽  
R. J. Parker
Keyword(s):  
Internal Pressure ◽  
Creep Strain ◽  
Wall Thickness ◽  
Circumferential Strain ◽  
Axial Stress ◽  
Integration Procedure ◽  
Graphical Integration ◽  
Simple Equations

When considering the creep of cylinders subjected to internal pressure, the theory of Johnson et al. takes into account progressive changes of radial, circumferential and axial stress at any point in the wall thickness. This approach differs from that put forward by Bailey, who assumed that these stresses remained constant with time. The present paper summarizes an examination of both theories, with particular reference to outside and bore diameters, and presents simple equations which enable circumferential strain to be calculated without using the complex graphical integration procedure suggested by Johnson. Furthermore, it is demonstrated that these equations are mathematically identical with those derived by Bailey.

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