Effect of Nonuniform Loading on Conventional Casing Collapse Resistance

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.

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

10.2118/153986-ms ◽

2012 ◽

Cited By ~ 5

Author(s):

Zhaoguang Yuan ◽

Jerome Schubert ◽

Catalin Teodoriu ◽

Paolo Gardoni

Keyword(s):

Gas Well ◽

Collapse Resistance ◽

Casing Collapse

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

Mathematical Problems in Engineering ◽

10.1155/2021/5577250 ◽

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.

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

Journal of Pressure Vessel Technology ◽

10.1115/1.4033154 ◽

2016 ◽

Vol 138 (5) ◽

Cited By ~ 1

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).

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A novel kinked rebar configuration for simultaneously improving the seismic performance and progressive collapse resistance of RC frame structures

Engineering Structures ◽

10.1016/j.engstruct.2017.06.042 ◽

2017 ◽

Vol 147 ◽

pp. 752-767 ◽

Cited By ~ 17

Author(s):

Peng Feng ◽

Hanlin Qiang ◽

Weihong Qin ◽

Meng Gao

Keyword(s):

Seismic Performance ◽

Progressive Collapse ◽

Frame Structures ◽

Rc Frame ◽

Collapse Resistance ◽

Rc Frame Structures

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Comparison of steel frames with RWS and WFP beam-to-column connections through seismic fragility analysis

Advances in Structural Engineering ◽

10.1177/1369433220977284 ◽

2020 ◽

pp. 136943322097728

Author(s):

Haoran Yu ◽

Weibin Li

Keyword(s):

Limit State ◽

Pushover Analysis ◽

Steel Frames ◽

Fragility Analysis ◽

Structural Safety ◽

Seismic Fragility ◽

Fe Modelling ◽

Collapse Resistance ◽

Seismic Collapse ◽

Probabilistic Seismic Demand

Reduced web section (RWS) connections and welded flange plate (WFP) connections can both effectively improve the seismic performance of a structure by moving plastic hinges to a predetermined location away from the column face. In this paper, two kinds of steel frames—with RWS connections and WFP connections—as well as different frames with welded unreinforced flange connections were studied through seismic fragility analysis. The numerical simulation was conducted by using multiscale FE modelling. Based on the incremental dynamic analysis and pushover analysis methods, probabilistic seismic demand analysis and seismic capability analysis were carried out, respectively. Finally, combined with the above analysis results, probabilistic seismic fragility analysis was conducted on the frame models. The results showed that the RWS connection and WFP connection (without double plates) have little influence on reducing the maximum inter-storey drift ratio under earthquake action. RWS connections slightly reduce the seismic capability in non-collapse stages and improve the seismic collapse resistance of a structure, which exhibits good structural ductility. WFP connections can comprehensively improve the seismic capability of a structure, but the seismic collapse resistance is worse than that of RWS connections when the structure has a large number of storeys. The frame with WFP connections has a lower failure probability at every seismic limit state, while the frame with RWS connections sacrifices some of its structural safety in non-collapse stages to reduce the collapse probability.

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