Research Article
Experimental Study on Sealing Failure Mechanism of Injection-Production String in Underground Gas Storage under Cyclic Loading
Table 3
Operation load of the injection-production tubular string.
| Annulus pressure change (MPa) | Operating condition | Calculation condition | Maximum load during injection (kN) | Maximum load during production (kN) |
| | Initial gas injection | Effective axial force (formula (1)) | 733.13 | — | Consider stress relaxation (formula (2)) | 393.31 | — | Consider pressure drop (formula (3)) | 984.74 | — | Consider stress relaxation and pressure drop (formula (5)) | 670.63 | — | 0 | Gas production operation | Effective axial force (formula (1)) | — | −371.68 | Consider stress relaxation (formula (2)) | — | −634.19 | Consider pressure drop (formula (3)) | — | −522.63 | Consider stress relaxation and pressure drop (formula (5)) | — | −743.08 | | Gas injection operation | Effective axial force (formula (1)) | 665.12 | — | Consider stress relaxation (formula (2)) | 316.17 | — | Consider pressure drop (formula (3)) | 792.01 | — | Consider stress relaxation and pressure drop (formula (5)) | 468.93 | — |
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