Research Article
Experimental Study on Sealing Failure Mechanism of Injection-Production String in Underground Gas Storage under Cyclic Loading
| The sample number | Times | Yield strength (MPa) | Tensile strength (MPa) | Elongation rate (%) |
| Tubing body after the test | 1 | 702 | 881 | 23 | 2 | 739 | 903 | 23 | 3 | 722 | 897 | 24 |
| Tubing body before the test | 1 | 820 | 891 | 26 | 2 | 824 | 882 | 24 | 3 | 822 | 877 | 25 |
| Regulations in API Spec 5C | 758∼965 | ≥862 | ≥13 |
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