Effect of Wear and Bending on Casing Collapse Strength

1992 ◽  
Author(s):  
Yukihisa Kuriyama ◽  
Yasushi Tsukano ◽  
Toshitaro Mimaki ◽  
Tetsuo Yonezawa
Keyword(s):  
Collapse Strength ◽  
Casing Collapse

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.

scholarly journals Casing Collapse Strength Analysis under Nonuniform Loading Using Experimental and Numerical Approach

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Dongfeng Li ◽  
Fu Yu ◽  
Heng Fan ◽  
Rui Wang ◽  
Shangyu Yang ◽  
...  
Keyword(s):  
Shale Gas ◽  
In Situ Stress ◽  
Strength Analysis ◽  
Collapse Strength ◽  
Diameter Variation ◽  
Nonuniform Loading ◽  
Variation Rate ◽  
Casing Deformation ◽  
Casing Collapse

Multistage fracturing is the main means of shale gas development, and casing deformation frequently occurs during fracturing of shale gas horizontal wells. Fracturing fluid entering the formation will change in situ stress nearby the wellbore. The changes of in situ stress are mainly reflected in the following two aspects: one is the increase of in situ stress and the other is the nonuniformity of in situ stress along the wellbore. And it is for this reason that the production casing is more likely to collapse under the nonuniform in situ stress load. According to the service conditions of production casing in shale gas reservoir, this paper studied the casing deformation and the collapsing strength subjected to the nonuniform loading by the experimental and numerical simulation method. The results show that under the condition of nonuniform loading, (1) the diameter variation rate of the casing reduces with the increase in the ratio of sample to tooling length. When the ratio is less than 3, the casing collapse strength will be significantly reduced. And when the ratio is greater than 6, the impact of sample length on casing collapse strength can be ignored. (2) The increase in the applied loading angle will decrease the diameter variation rate. When the loading angle increases from 0° to 90°, the critical load value increases from 1600 kN to 4000 kN. (3) The increase in load unevenness coefficient will rapidly decrease the casing collapse strength. When the load unevenness coefficient n is 0.8, the casing collapse strength reduces to 60%, and when the load unevenness coefficient n is 0, the casing collapse strength reduces to 28%. The findings of this study can help for better understanding of casing damage mechanism in volume fracturing of shale gas horizontal well and guide the selection of multistage fracturing casing type and fracturing interval design.

scholarly journals Influence of Volume Fracturing on Casing Stress in Horizontal Wells

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2057
Author(s):  
Jingpeng Wang ◽  
Youming Xiong ◽  
Zongyu Lu ◽  
Jiangang Shi ◽  
Jiwei Wu
Keyword(s):  
Temperature Effect ◽  
Temperature Change ◽  
Temperature Stress ◽  
Horizontal Wells ◽  
Wellhead Pressure ◽  
Collapse Strength ◽  
Fracturing Process ◽  
Casing Strength ◽  
Volume Fracturing ◽  
Casing Collapse

In horizontal wells, the casing string is affected by the gravity effect, temperature effect, swelling effect, bending effect, friction effect and other mechanical effects. In view of this situation, the mathematical models of casing swelling effect and temperature effect caused by volume fracturing are established. The case analysis shows that the length of the unsealed section in the vertical section has a great influence on the axial shortening of the casing during fracturing. With the increase of the unsealed section length, the axial shortening of the casing increases gradually under the same wellhead pressure. In the process of fracturing, repeated squeezing and pressurization lead to periodic changes of the wellhead pressure, casing deformation and load, which leads to fatigue damage and even fracture of casing. At the same time, a large amount of fracturing fluid is continuously injected through the casing during the fracturing process, which makes the wellbore temperature change greatly. The additional stress caused by the temperature change reduces the casing strength, which has an important impact on the wellbore integrity. The mathematical model of temperature stress and its effect on the casing strength during volume fracturing is established. With the increase of the temperature stress acting on the casing, the casing collapse strength decreases gradually. When the temperature stress reaches 200 MPa, the casing collapse strength decreases to 84% of the original. The research results can provide a reference for the casing integrity design and control in the horizontal well fracturing process.

scholarly journals Influence of expansion rate on circumferential residual stress distribution of expandable casing

2021 ◽  
Vol 245 ◽  
pp. 03090
Author(s):  
Zhang Jianbing ◽  
Kong Detao ◽  
Wang Qian ◽  
Wang Haobo ◽  
Wang Haiying
Keyword(s):  
Residual Stress ◽  
Elastic Recovery ◽  
Circumferential Stress ◽  
Expansion Rate ◽  
Residual Tensile Stress ◽  
Thickness Direction ◽  
Expansion Process ◽  
Distribution Law ◽  
Collapse Strength ◽  
Casing Collapse

To study the distribution law of circumferential residual stress after casing expansion, using the finite element explicit dynamic analysis method analyzed the expansion process of expandable casings under different expansion rates. The analysis obtained key technical parameters of circumferential residual stress, average circumferential residual stress and elastic recovery along the wall thickness direction after casing expansion. It is recognized that the maximum residual tensile stress after casing expansion locates in the middle part of the casing thickness direction. The maximum residual compressive stress locates in the outer wall of the casing. When the expansion rate exceeds 18%, the increase in expansion rate will not lead to an increase in circumferential residual stress after casing expansion. The elastic recovery after casing expansion will reduce the circumferential stress during the expansion process. Considering collapse strength and the influence of elastic recovery on casing patch sealing performance after casing expansion, 23% is the most suitable expansion rate, which can effectively reduce the circumferential residual stress and improve the casing collapse strength. The analysis in this paper can provide bases for the calculation of casing collapse strength after expansion.

Collapse Strength Study for the Solid Expandable Tubular

2013 ◽  
Author(s):  
Qiang Chen ◽  
Shan Gao ◽  
Yiliang Li ◽  
Tao Li ◽  
Xiuling Bi ◽  
...  
Keyword(s):  
Collapse Strength

Theoretical analysis of casing collapse in locally expansive mudstone

2021 ◽  
pp. 108643
Author(s):  
Zhan-feng Chen ◽  
Xu-yao Li ◽  
Wen Wang ◽  
Ke-qing Lu ◽  
Wei-ping Zhu
Keyword(s):  
Theoretical Analysis ◽  
Casing Collapse

scholarly journals DISCUSSION. THE COLLAPSE STRENGTH OF TUBULAR STEEL SCAFFOLD ASSEMBLIES.

1978 ◽  
Vol 65 (1) ◽  
pp. 217-218
Author(s):  
E LIGHTFOOT ◽  
G OLIVETO ◽  
BGR HOLLOWAY
Keyword(s):  
Collapse Strength
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